Resolution No. 93901
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RESOLUTION NO. 9390
A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF
VERNON DECLARING THE RESULTS OF AN IRON AND
MANGANESE TREATMENT ALTERNATIVE SURVEY AND
AUTHORIZING THE CITY TO DO ALL ACTIONS DEEMED
NECESSARY OR ADVISABLE CONCERNING THE WATER
TREATMENT PROCESS
WHEREAS, the City of Vernon ("City") needs to address iron
and manganese concentrations in a number of wells in the City in
accordance with the requirement of the State Department of Public
Health ("DHS") in order to comply with regulations for iron and
manganese levels in the City's drinking water in accordance with Title
22 of the California Code of Regulations; and
WHEREAS, Title 22 of the California Code of Regulations
establishes Secondary Containment Levels for drinking water and
several of the City's wells exceed the secondary levels for iron and
manganese which have no adverse effects on human health; and
WHEREAS, the concerns with the excess levels of iron and
manganese in City wells are related specifically to aesthetic issues
including the remote possibility of objectionable tastes and water
that has a slightly reddish tint that has the potential to stain
clothes; and
WHEREAS, the DHS advised the City that treatment for removal
of iron and manganese must be undertaken unless a waiver is obtained
through a customer survey and vote; and
WHEREAS, the basis for DHS granting waivers is the degree of
consumer acceptance of existing water quality and the customer's
willingness or unwillingness to pay the cost of meeting these quality
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(standards; and
WHEREAS, on February 20, 2007, the City Council of the City
adopted Resolution No. 9243 approving an agreement with Carollo
Engineers to perform a study to evaluate treatment alternatives and
develop detailed planning level costs for iron and manganese treatment
Ifor a customer survey that will meet the requirements of the
California Code of Regulations; and
WHEREAS, Carollo Engineers prepared a Final DHS Engineering
Report on Iron and Manganese Treatment, Treatment Alternatives and
Cost Estimates and Survey form, dated July 2007 ("the Engineer's
Report"), which is attached hereto as Exhibit A and incorporated by
reference, addressing the elevated levels if iron and manganese in the
City's water supply including the treatment removal alternatives
available and the costs associated with those alternatives in
compliance with DHS requirements and the requirements of Title 22 of
the California Code of Regulations; and
WHEREAS, the results of the survey will determine if the
City will be granted a waiver; and
WHEREAS, in order for the survey to be valid, more than 500
of the billed customers must have filled out and returned the Survey
Vote Form and if no vote is received from a customer, it will count as
a vote for full treatment; and
WHEREAS, a Survey Vote Form -City of Vernon was hand
delivered to 642 customers who pay the water bill for pickup prior to
August 1, 2007, and mailed to 221 customers who pay the water bill
with a self addressed, stamped envelope for return to the City by
July 30, 2007; and
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WHEREAS, the Survey Vote Form requested the customer to vote
for Alternative 1 (no change, no treatment), or Alternative 2
(conditioning system, sequestration), or Alternative 3 (oxidation and
filtration treatment system) and advised of a public hearing to be
held to present the results of the survey; and
WHEREAS, the Director of Community Services & Water
Department canvassed the returns of the survey; and
WHEREAS, the City Council of the City held a noticed public
hearing on August 27, 2007, at which time all interested persons were
given an opportunity to be heard; and
WHEREAS, the City Council has heard and considered all
evidence, both written and oral, presented respecting the water
treatment alternatives for removal if iron and manganese based on the
customer survey results.
NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE
CITY OF VERNON AS FOLLOWS:
SECTION 1: The City Council of the City of Vernon hereby
finds and determines that the recitals contained hereinabove are true
and correct.
SECTION 2: The City Council further finds and determines
that all persons have had the opportunity to be heard or to file
written comments to the proposed survey and alternative water
treatments and after due consideration of all the evidence submitted at
the public hearing determines that there are compelling reasons to
justify the following actions, and that the City is in conformance with
all applicable requirements of Title 22 of the California Code of
Regulations:
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A. The City of Vernon hereby adopts the Final DHS
Engineering Report on Iron and Manganese Treatment, Treatment
Alternatives and Cost Estimates and Survey form, dated July 2007
attached hereto as Exhibit A.
B. The City of Vernon hereby adopts the Iron Manganese
Compliance Survey Returns, a copy of which is attached hereto as
Exhibit B and incorporated by reference, which reveals that 75.660 of
the customers responded rendering the survey valid.
C. The City of Vernon hereby declares and determines that
the final tally is as follows:
542 votes for no change, no treatment (Alternative 1);
64 votes for conditioning system or sequestration
(Alternative 2); and
257 votes for oxidation and filtration treatment system
(Alternative 3).
D. The City of Vernon determines that it is now eligible
to request a nine-year waiver from the DHS allowing the City to operate
without providing any means of treatment to remove iron and manganese
from affected water production facilities.
SECTION 3: The City Council of the City of Vernon hereby
directs the City Administrator, or his designee, to send to the DHS a
certified copy of this Resolution together with such documents and to
take such actions as are deemed necessary to comply with all Federal
and State regulations and statutes.
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SECTION 4: The City Clerk of the City of Vernon shall
certify to the passage of this resolution, and thereupon and
thereafter the same shall be in full force and effect.
APPROVED AND ADOPTED this 27th day of August, 2007.
ATTEST:
FRISTEN ENbMOTo, beP`"-1-y City Clem
Name: I-EoNIS C. MAL9VRG,
Title : Mayor /T— �-T
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1 STATE OF CALIFORNIA )
2 ) ss
COUNTY OF LOS ANGELES )
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4 I, KRISTEN ENOMOTO, Deputy City Clerk of the City of Vernon, do
5 hereby certify that the foregoing Resolution, being Resolution No.
6 9390, was duly adopted by the City Council of the City of Vernon at a
7 special meeting of the City Council duly held on Monday, August 27,
8 2007, and thereafter was duly signed by the Mayor or Mayor Pro-Tem of
9 the City of Vernon.
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KRISTEN ENOMOTO, Deputy City Clerk
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EXHIBIT
0
Signed: July 5, 2007 Signed: July 5, 2007
City of Vernon
DHS ENGINEERING REPORT ON IRON
AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
FINAL
July 2007
10540 TALBERT AVENUE, SUITE 200 EAST • FOUNTAIN VALLEY, CALIFORNIA 92708 • (714) 593-5100 • FAX (714) 593-5101
H:1ClienAVemon SAOWV708A001TRATMO1 RNALdoc
City of Vernon
DHS ENGINEERING REPORT ON IRON AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
TECHNICAL MEMORANDUM
NO. 1
TABLE OF CONTENTS
Page No.
1.0 BACKGROUND....................................................................................................1-1
2.0 EXISTING WATER SYSTEM................................................................................1-1
2.1 Water Supply...............................................................................................1-2
2.2 Storage and Distribution System.................................................................1-2
3.0 WATER QUALITY.................................................................................................1-4
4.0
DRINKING WATER REGULATIONS....................................................................1-6
4.1
Iron..............................................................................................................1-6
4.2
Manganese.................................................................................................1-6
5.0
IRON AND MANGANESE ALTERNATIVE TREATMENT METHODS ..................1-6
5.1
Oxidation and Filtration...............................................................................1-6
5.2
Sequestration..............................................................................................1-7
5.3
Ion Exchange..............................................................................................1-8
5.4
GAC............................................................................................................1-8
5.5
Membranes.................................................................................................1-9
5.6
Biological Filtration......................................................................................1-9
5.7
Fe/Mn Summary and Recommendation......................................................1-9
6.0
RECOMMENDED
TREATMENT TRAINS.............................................................1-9
6.1
Summary of Recommended Processes......................................................1-9
6.2
Oxidation/Filtration Treatment System.......................................................1-11
6.3
Sequestration Using Polyphosphate..........................................................1-15
7.0
PRELIMINARY
CAPITAL AND O&M COSTS FOR SELECTED TREATMENT
SYSTEMS...........................................................................................................1-16
7.1
Assumptions Used to Develop Preliminary Cost Estimates .......................1-17
7.2
Equipment Capital Cost Estimates............................................................1-18
7.3
Cost Estimates for the Iron and Manganese Oxidation and Filtration
TreatmentSystem...............................................................................................1-19
7.4
Cost Estimates for the Iron and Manganese Sequestration System ..........1-24
8.0 SUMMARY AND RECOMMENDATION..............................................................1-26
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LIST OF TABLES
Table 1.1
City of Vernon Water Service Connections..................................................1-1
Table 1.2
Information About Existing Potable Water Wells..........................................1-2
Table 1.3
Historical Water Qualities of Well Nos. 12, 14, 17, and 20 ...........................1-4
Table 1.4
Advantages and Disadvantages of Fe/Mn Treatment Technologies ..........
1-10
Table 1.5
Summary of Available Oxidation Alternatives for Fe/Mn Removal .............1-10
Table 1.6
Summary of Available Filter Media for Fe/Mn Removal.............................1-11
Table 1.7
Oxidation and Filtration Systems for Fe and Mn........................................1-11
Table 1.8
Recommended Dosage for Sequestration Chemical from SPER Chemical1-16
Table 1.9
Chemical Usages for Sequestration Chemical from SPER Chemical ........1-16
Table 1.10
Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals ....1-17
Table 1.11
Treatment Cost Estimate Factors..............................................................1-18
Table 1.12
Iron/Manganese Equipment Cost -Alternative 1 Loprest System................1-19
Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System..............1-20
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System..............1-20
Table 1.15
Iron/Manganese System Capital Cost Estimate.........................................1-21
Table 1.16
Oxidation and Filtration O&M Requirements..............................................1-22
Table 1.17
Iron/Manganese System Annual O&M Cost Estimate................................1-23
Table 1.18
Total Annualized Costs for Oxidation and Filtration System ......................1-23
Table 1.19
Estimated Capital Cost for Sequestration System.....................................1-24
Table 1.20
Estimated O&M Cost for Sequestration System (for High Concentration)..1-25
Table 1.21
Total Annualized Costs for Sequestration System.....................................1-26
Table 1.22
Pros and Cons of Alternatives for Fe and Mn............................................1-28
Table 1.23
Summary of Cost Estimates - in 2010 Dollars...........................................1-28
LIST OF FIGURES
Figure 1.1 City of Vernon Service Area........................................................................1-3
Figure 1.2 Water System Schematic............................................................................1-5
Figure 1.3 Schematic of an Oxidation/Filtration System ................ ...........................1-12
Figure 1.4 Schematic of a Sequestering System........................................................1-13
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Technical Memorandum No. 1
TREATMENT ALTERNATIVES AND COST ESTIMATES
1.0 BACKGROUND
The City of Vernon (City) is located near the geographic center of metropolitan Los Angeles
County, situated within 2 miles of four major freeways and near the site of Hobart Yard,
which is a major rail terminal for Los Angeles. Elevated levels of iron (Fe) and manganese
(Mn), both classified by the Environmental Protection Agency (EPA) as non -hazardous
contaminants, have been found in four of the City wells. Levels in the wells exceeded the
California Safe Drinking Water Act of 1986 (SDWA) secondary maximum contaminant level
(MCLs). Although these are secondary MCLs, the City is required either to comply with the
MCLs or to obtain a waiver in accordance with Title 22, Section 64449 of the California
Code of Regulations (CCR).
In order for the City to obtain a waiver on treatment and to comply with the CCR
requirement, the City needs to conduct a study to evaluate treatment alternatives and
develop costs for Fe and Mn treatment.
This report constitutes the requirements for the study. The cost information will be used as
a basis for developing rate increases to be included in the mailer survey to the residents to
vote whether or not the treatment option should be implemented.
2.0 EXISTING WATER SYSTEM
The City Water Department serves water to the majority of the City. A small portion of the
northeast corner of the City is served by California Water Service and a small area in the
southeast area of the City is served by Maywood Mutual No. 3. Figure 1.1 shows the City's
service area.
The City has approximately 45,000 daytime residents and 93 permanent residents. Based
on the City's 2006 Annual Report to the Drinking Water program, only 21 of the 1,760 active
connections were residential, and the remaining were mainly commercial and industrial.
The approximate annual water demand was estimated to be 11,000 acre-feet or 3.9 billion
gallons (2006 data). Table 1.1 summarizes the number and types of connections the City
currently has.
Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered
General and Residential 16
Commercial 1,343
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Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered
Industrial 404
Irrigation (Ag and Residential) 0
Total Active Connections 1,763
2.1 Water Supply
The primary water supply for the City is groundwater. In addition, the City has a direct
connection to the Metropolitan Water District of Southern California (MWD). The MWD
connection provides both a supplemental water source and an emergency supply in the
event of a major power outage. The City's groundwater system is made up of eight active
wells and one inactive well. There is no treatment of the water other than chlorination.
Table 1.2 provides a summary of selected information about the nine wells.
Table 1.2
Information About Existing Potable Water Wells
DHS Engineering
Report on Iron and Manganese Treatment
City of Vernon
Date
Total
Ground
Capacity,
Well No.
Drilled
Perforated Intervals, ft
Depth, ft
Elevation, ft
gpm
11
5/23/1952
741-776, 816-826,
1,343
197.22
1,143
863-871, 983-997,
1,105-1,142, 1,163-1,186
12
11/20/1953
996-1,015, 1,067-1,169,
1,588
183.29
700
1,260-1,580
14
3/23/1962
360-1,251
1,302
203.75
1,351
15
10/27/1966
510-1,502
1,550
177.76
1,953
16
8/18/1970
510-1,460
1,520
197.22
1,450
17
11/1/1970
510-1,500
1,550
183.29
1,750
18
11 /30/1958
510-1,361
1,443
184.57
1,450
(inactive)
19
9/19/1988
510-1,550
1,660
180.45
1,380
20
9/23/1988
510-1,550
1,620
159.47
1,460
2.2 Storage and Distribution System
The City's water distribution system consists of 250,000 linear feet of pipe, six ground level
reservoirs, one elevated tank, and one belowground reservoir. The total storage capacity in
these facilities is 16 million gallons (MG). The average pressure in the distribution system is
about 75 psi.
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Figure 1.2 shows the City's overall distribution system. It is made up of three main booster
pump stations/plants. Booster Plant 1 is fed by Well Nos. 11 and 16, has a 10-MG
reservoir, and has five distribution pumps. A 24-inch MWD connection is also available at
this location. Booster Plant 2 is supplied by Well Nos. 12 and 17, has three 1-MG storage
tanks, and has six distribution pumps. Booster Plant 3 is supplied by Well Nos. 15 and 19,
has three 1-MG storage tanks, and has five distribution pumps. Well No. 19 can discharge
either directly to the distribution system or to the three storage tanks. The remaining three
wells, Well Nos. 14, 18, and 20, discharge directly to the distribution system without going
through any storage. In addition, the City also owns a 0.6-MG elevated storage tank.
3.0 WATER QUALITY
Overall, the groundwater quality of the City's wells is good. However, the groundwater
sources have a history of exceeding the secondary MCLs for Fe (300 ug/L) and Mn
(50 pg/L). Both of these secondary limits are regularly exceeded in water pumped from
Wells Nos. 12 and 14, while the Mn MCL is exceeded regularly in water pumped from Wells
Nos. 17 and 20. These findings have been noted in the Consumer Confidence Reports that
the City distributes to its customers annually.
Table 1.3 summarizes the water quality of the four wells for selected parameters.
Table 1.3
Historical Water Qualities of Well Nos. 12, 14, 17, and 20
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Secondary
Well
Well
Well
Well
Parameter
Units MCL
No. 12
No. 14
No. 17
No. 20
Manganese
pg/L 50
54-180
40-1200
30-120
30-111
Iron
pg/L 300
ND-2,000
ND- 5,400
ND-144
ND-740
Sulfate
mg/L 250
79-82.
75-110
62-67
50-79
TDS
mg/L 500
370-380
450-520
350-390
350-420
Alkalinity
mg/L -
190-210
180-240
180-200
170-210
Hardness
mg/L --
212-220
240-300
200-217
190-200
Bicarbonate
mg/L --
230-250
229-284
220-250
210-250
pH
--
7.8-7.9
7.4-8.2
7.6-7.9
7.7-8.0
Flow rate
gpm --
700
1,350
1750
1460
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4.0 DRINKING WATER REGULATIONS
4.1 Iron
The California Department of Health Services (DHS) has set a secondary MCL for Fe of
300 pg/L. Exceeding the suggested level usually results in discolored water, laundry, and
plumbing fixtures. This, in turn, results in consumer complaints and potential dissatisfaction
with the water utility.
4.2 Manganese
Based on the health effects, the California DHS has set a notification level for Mn, which is
currently at 500 pg/L. However, at concentrations exceeding 100 pg/L, Mn imparts an
undesirable taste and stains plumbing fixtures and laundry. These considerations lead the
EPA to set a secondary MCL of 50 pg/L for Mn in drinking water (Federal Register, 1979).
5.0 IRON AND MANGANESE ALTERNATIVE TREATMENT
METHODS
As mentioned earlier, the City can apply for a compliance waiver to meet the secondary
standards for Fe and Mn. However, the City is still required to evaluate the treatment
alternatives and report the findings to the DHS, under this option.
There are several treatment alternatives available for Fe and Mn control in a water
treatment plant. The most basic methods are chemical oxidation followed by clarification
and filtration. Other treatment alternatives are described in the following paragraphs and
include ion exchange, sequestering processes, biological removal, GAC, and membranes.
5.1 Oxidation and Filtration
Oxidation followed by filtration is the most popular process in the United States (U.S.) for Fe
and Mn removal. Under reducing conditions, Fe and Mn are stable as soluble forms
(ferrous [Fe 21 and manganous [Mn21 ions). When they are oxidized, they become insoluble
ferric (Fe 31) and manganic hydroxide (Mn31) species, and these can be physically removed
with a filtration process.
Chlorine and potassium permanganate are common oxidants applied in commercial
packaged systems. It has been reported that soluble Mn (II) was rapidly oxidized by
potassium permanganate, chlorine dioxide, and ozone in low dissolved organic carbon
(DOC) waters. When chlorine is used as an oxidant, it may react with natural organic matter
in the raw water to form trihalomethanes (THMs) and haloacetic acids (HAAs), which are
regulated contaminants under the Stage 2 Disinfectants/Disinfection By-products (DBPs)
Rule (D/DBPR). Therefore, if halogenated DBPs are an issue, other oxidants may offer
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benefits compared to chlorine, such as potassium permanganate, ozone, and chlorine
dioxide. In the City's case, it is not an issue since the water organic content is expected to
be low.
Optimal Mn oxidation occurs in the pH range of 8.0 to 8.5. Chlorine dosages as high as
five times the theoretical stoichiometric requirements may be necessary to oxidize Fe and
Mn within reasonable detention times. Potassium permanganate is a stronger oxidant than
chlorine and chlorine dioxide and can be effective with regard to dissolved Mn oxidation at
pH values above 7.5. The rates of reactions of Fe and Mn with permanganate are very fast
and could minimize the space requirement by eliminating the reaction vessel sometimes
needed with chlorine oxidation. However, the chemical is more expensive than chlorine.
Once oxidized and precipitated, particulate Fe and Mn must be removed from the water.
Several technologies are available and have been applied to accomplish this solids
separation step. Dual -media filters with anthracite and sand are commonly used for solids
separation in the water treatment and can be applied for the removal of Fe and Mn. Fe and
Mn can also be removed with a catalytic filter media that uses oxygen in the water to
convert metal ions from a soluble form to an insoluble form. This insoluble precipitate is
then filtered out onto the surface of the media.
Most of the commercial systems use Mn greensand medium, which is a term used for
naturally rich Mn dioxide minerals, which promote adsorption of dissolved Mn or other
proprietary media. Greensand medium can also serve for physical removal of ferric
hydroxide and ferric oxide precipitates.
5.2 Sequestration
Sequestration means preventing the formation of objectionable color and turbidity without
actually removing the Fe and Mn. It is the addition of chemicals to groundwater aimed at
controlling problems caused by Fe and Mn. These chemicals are usually added to
groundwater at the wellhead or at the pump intake before the water has a chance to come
in contact with air or chlorine. This ensures that the Fe and Mn stay in the soluble form.
Polyphosphate is one of the sequestering agents that can bond with Fe and Mn and thus
prevent them from precipitating in water. Although this approach requires only minor
modifications to any existing system, it does not provide a permanent solution (removal) for
high Fe and Mn concentrations. Furthermore, depending on the type of polyphosphate
used, the Fe -polyphosphate complex may break down when heated. The Fe and Mn
released may then cause a problem such as precipitation or staining. Thus,
high -temperature processes or laundries using hot water may experience potential
problems when sequestering agents are used. Furthermore, sequestration of Fe and Mn
may pose negative effects on some of the City's customers' internal processes. If a
customer is using some type of oxidation and filtration processes to remove Fe and Mn
from the tap water, this process may not operate as designed because the sequestered Fe
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and Mn are complexed (bound) with the polyphosphate. That is, Fe and Mn would not be
removed from the water. Another process that may be affected by the sequestration
process is reverse osmosis (RO) filtration. The polyphosphate agent and sequestered
compounds could increase the fouling potential on the RO membranes. Additional
pretreatment processes could be required for removal of these compounds to prevent
membrane fouling. In addition, there may be other potential interferences from
polyphosphate on different types of water treatment and manufacturing processes, but it is
difficult to ascertain exact impacts without detailed information about these processes.
In terms of chemical dose, theoretically, there is no limit to the amount of soluble Fe and Mn
that would make sequestration an effective mitigation method. However, various studies
have reported some upper limits for chemical sequestration of Fe and Mn. The National
Drinking Water Clearing House states that sequestration followed by chlorination can be
effective for water containing less than 1,000 pg/L Fe and 300 lag/L Mn. According to the
California Department of Health Services Policy Memo 2001-1 Secondary Standards,
various levels of Fe and. Mn up to 5,000 lag/L have been cited as the economical and
technical limit for effectivemitigation method. The policy also states that levels above
2,000 pg/L are less likely to be successfully mitigated with polyphosphates based on their
experience. If sequestration is selected, bench- or pilot -scale testing is highly
recommended to evaluate the feasibility and effects of using this method to address the Fe
and Mn issues in the groundwater.
Sequestering agents are injected via a chemical metering pump at the wellhead before
other chemical additives (chlorine, fluoride, caustic soda, etc.). If permissible, these agents
are injected down the well casing to mix with groundwater at the pump intake.
5.3 Ion Exchange
The ion exchange process involves exchange of soluble ionic species. Application of
softening in water treatment for Fe and Mn removal is limited since it can only be used
where Fe and Mn exist completely in the soluble forms. In addition, the system should be
airtight; otherwise, oxidation of Fe and Mn with oxygen could result in breakthrough from
the ion exchange resin bed. The potential of fouling in ion exchange resins may increase as
Fe and Mn concentrations increase. This alternative is not considered to be a practical
application in this case.
5.4 GAC
Bituminous -based GACs can remove Fe. However, these systems are not capable of
removing Mn unless the pH is greater than 8.5. Therefore, GAC is not considered as a
suitable alternative.
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5.5 Membranes
Both reverse osmosis (RO) and nanofiltration (NF) can remove the soluble forms of Fe and
Mn. The true benefit of the high-pressure membrane treatment processes is their ability to
also remove other dissolved contaminants at the same time. However, because of their
high capital and operating costs and concentrate stream disposal issues, it is not
economically feasible to apply these technologies for Fe and Mn removal alone.
Low-pressure membranes such as ultrafiltration (UF) and microfiltration (MF) can be used
downstream of pre -oxidation of Fe and Mn, as a filtration step to remove the insoluble
precipitates. For treating Fe and Mn removal, membrane systems will be more costly than
granular media pressure filter -based systems.
5.6 Biological Filtration
.Biological filtration uses indigenous microorganisms that are able to metabolize Fe and Mn
to reduce their levels in source water. It offers lower operating and capital costs than
comparable physical/chemical processes. It also produces less waste product that allows
easier dewatering and disposal of residual. However, biological treatment requires specific
raw water qualities and conditions, and not all groundwater or surface water can be treated
economically using this technique. Success of this treatment process depends on several
factors such as nutrient availability, oxidation/reduction conditions, temperature, and filter
operation strategy. When both Fe and Mn are present in the water, a two -stage process is
required. Cost and practicality of a two -stage process are considerations that make this
alternative less attractive. Biological filtration also requires equalization to ambient pressure
for operation and needs permitting by DHS for implementation for drinking water
application. Therefore, biological filtration is not considered a practical alternative in this
case.
5.7 Fe/Mn Summary and Recommendation
A summary of the advantages and disadvantages for each of the alternative for treatment of
Fe and Mn is presented in Table 1.4.
6.0 RECOMMENDED TREATMENT TRAINS
6.1 Summary of Recommended Processes
Based on the water quality of the wells and the above discussion on the various unit
processes, the oxidation/filtration process is the recommended approach for the Fe and Mn
removal. Figure 1.3 depicts the possible treatment train at each of the well sites. Even
though the sequestration approach is not a removal process (Fe and Mn still remain in the
water in dissolved forms), it was evaluated for comparison purposes per City's request to
apply for a waiver. Figure 1.4 shows the typical setup of a sequestration system.
FINAL - July 5, 2007 1-9
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5.5 Membranes
Both reverse osmosis (RO) and nanofiltration (NF) can remove the soluble forms of Fe and
Mn. The true benefit of the high-pressure membrane treatment processes is their ability to
also remove other dissolved contaminants at the same time. However, because of their
high capital and operating costs and concentrate stream disposal issues, it is not
economically feasible to apply these technologies for Fe and Mn removal alone.
Low-pressure membranes such as ultrafiltration (UF) and microfiltration (MF) can be used
downstream of pre -oxidation of Fe and Mn, as a filtration step to remove the insoluble
precipitates. For treating Fe and Mn removal, membrane systems will be more costly than
granular media pressure filter -based systems.
5.6 Biological Filtration
Biological filtration uses indigenous microorganisms that are able to metabolize Fe and Mn
to reduce their levels in source water. It offers lower operating and capital costs than
comparable physical/chemical processes. It also produces less waste product that allows
easier dewatering and disposal of residual. However, biological treatment requires specific
raw water qualities and conditions, and not all groundwater or surface water can be treated
economically using this technique. Success of this treatment process depends on several
factors such as nutrient availability, oxidation/reduction conditions, temperature, and filter
operation strategy. When both Fe and Mn are present in the water, a two -stage process is
required. Cost and practicality of a two -stage process are considerations that make this
alternative less attractive. Biological filtration also requires equalization to ambient pressure
for operation and needs permitting by DHS for implementation for drinking water
application. Therefore, biological filtration is not considered a practical alternative in this
case.
5.7 Fe/Mn Summary and Recommendation
A summary of the advantages and disadvantages for each of the alternative for treatment of
Fe and Mn is presented in Table 1.4.
6.0 RECOMMENDED TREATMENT TRAINS
6.1 Summary of Recommended Processes
Based on the water quality of the wells and the above discussion on the various unit
processes, the oxidation/filtration process is the recommended approach for the Fe and Mn
removal. Figure 1.3 depicts the possible treatment train at each of the well sites. Even
though the sequestration approach is not a removal process (Fe and Mn still remain in the
water in dissolved forms), it was evaluated for comparison purposes per City's request to
apply for a waiver. Figure 1.4 shows the typical setup of a sequestration system.
FINAL - July 5, 2007 1-11
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When greensand is used in other packaged systems, reaction tanks are generally not
required unless the Fe and Mn concentrations are very high (greater than 5,000 lag/L). Most
systems can operate on pressurized lines such that no additional backwash pumps are
required. These systems typically have multiple -vessel designs and can backwash one
vessel using the treated water from the other vessels. Backwash water is typically directed
to a wastewater decant tank. Approximately 80 to 90 percent of the backwash wastewater
can be reclaimed in most cases. The backwash water is stored in a backwash tank, where
solids such as precipitated Fe and Mn settle to the bottom of the tank. Sewer disposal for
the sludge would be desired, but this option depends on other contaminants in the raw
water, the proximity of a sewer, and the local sewer discharge regulations. The cost of
discharge to the sewer is expected to be low if a nearby sewer pipe exists already.
However, if there is no existing sewer connection in close proximity, trucking may be more
cost effective than building a sewer line. Local trucking companies have been contacted to
gather pricing information for the off -site disposal alternative, which is listed with the other
O&M costs below.
The filter run time varies from system to system. Typically, every system provides a
pressure sensor to initiate a backwash cycle at a selected filter head loss. The head loss
cannot exceed 10 psig since higher headloss accumulation may damage the filter media.
Backwashing after a set operating time is a common practice for most of the systems. For
systems treating Fe and Mn at concentrations occurring in the four wells, backwash is
typically set once per day in the early morning when water demand is low. Backwash time
is estimated to be 5 to 30 minutes with backwash loading rates at 12 to 14 gpm/ft2,
depending on the systems.
6.2.1 Alternative 1 - Loprest - Greensand Filtration (with Chlorine Oxidation)
For Wells 12 and 17 sites, Loprest recommends a treatment process that consists of two
horizontal pressure filter tanks (8 feet in diameter and 16 feet long) based on the 1,750-gpm
flow rate (Well 17) and the existing background concentrations. The filter media consists of
manganese greensand (24-inch) and anthracite (12-inch). Chlorine dosage of 2.2 mg/L for
Well 12 and 0.9 mg/L for Well 17 mg/L would be used for oxidation of Fe and Mn at the
design concentrations for these contaminants.
For the Well 14 site, the treatment system is similar, but will only require one horizontal
pressure filter tank (8 feet in diameter and 32 feet long) based on the 1,350-gpm flow rate
and concentrations. The recommended chlorine dosage is 2.2 mg/L.
Finally, for the Well 20 site, a similar set up would be used, with one horizontal pressure
filter tank (8 feet in diameter and 24 feet long) at a flow rate of 1,460 gpm. The
recommended chlorine dose is 1.5 mg/L.
FINAL- July 5, 2007 1-14
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6.2.2 Alternative 2 - Filtronics - Chlorine and Sodium Bisulfite with Electromedia
Filtration
The Fe and Mn removal systems designed and manufactured by Filtronics require an
additional step compared to the system offered by Loprest and Pureflow. The Filtronics
system consists of two in -series reactor vessels (5-foot diameter with an 11-foot straight
side shell) and one filter vessel (ranging from 84-inch diameter with a 161-inch straight side
shell (at Well 14 or Well 20), to 7-foot diameter with a 21-foot straight side shell (at
Well Nos. 12 and 17)). In the lead reaction vessel, Mn is oxidized by addition of an oxidizing
chemical (sodium hypochlorite). The second vessel is used to quench the remaining
concentration of oxidizer (chlorine) by reaction with sodium bisulfite. The filter vessels
contain proprietary Electromedia I, which is granulated, naturally occurring sand -like filtering
media. Atypical design feed loading rate is 15 gpm/ft2.
6.2.3 Alternative 3 - Pureflow
The Pureflow treatment process is a proprietary process. Well waters containing Fe and Mn
along with other dissolved contaminants, such as organic carbon, are first treated with
chlorine prior to filtration. This step oxidizes these contaminants to a form that can be
processed and provides free chlorine residual to the water distribution system.
The oxidation step is then followed by filtration, in which the Fe and Mn precipitates are
removed by a NSF -approved proprietary media that has an adsorptive attraction for partially
oxidized Fe and Mn. The contaminants are held in the filter bed allowing the total oxidizing
reaction to occur in the filter. The filter media is cleaned by reversing the flow using
processed water. The filter effluent is continuously monitored with a chlorine residual
analyzer to ensure complete oxidation of contaminants and disinfection of the treated water.
For all three well sites, Pureflow recommends their C-3000 filter system, with a filter vessel
of 7-foot diameter and 21-foot straight side shell. The filtration -loading rate averages
between 9 to 11 gpm/ft2. The backwash rate is 20 gpm/ft2 for 4 minutes.
6.3 Sequestration Using Polyphosphate
A few vendors were contacted for the sequestration option, but only one company provided
information for evaluation of this treatment option. SPIER Chemical recommends their
Sequest-All Potable Water System for all three (or four) wells. The system simply consists
of an injection pump (LMI model AA 151-490HI) that injects the chemical into discharge
pipe from the well. Sequest-All is a blend of granular or liquid polyphosphates, each having
different properties that enhance the overall ability and function of the product. Sequest-All
will inactivate minerals including iron, calcium, and manganese preventing scale buildup
and "red water". According to SPIER Chemical, it can also slowly soften and remove
existing scale present within the water distribution system and it suppresses both anodic
and cathodic electrochemical reactions along with depositing a protective coating effectively
reducing corrosion rates. The chemical also comes in liquid form, in which case a
FINAL - July 5, 2007 1-15
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200-gallon tank and mixing system would be required. The system is designed to be stable
under otherwise extreme conditions of temperature and time. As mentioned previously, it
should be noted that polyphosphate sequestration does not remove Fe and Mn but rather
stabilizes them in water to attenuate the effects of Fe and Mn.
Sequestration is only needed at the wells with high Fe and Mn levels, and a system -wide
application of polyphosphate injection is not necessary, as blending of sequestered and
non -sequestered water does not pose any water quality degradation issues.
However, enough time should be allowed for Fe and Mn to completely react with
polyphosphate (at least 15 to 30 seconds) before chlorine is injected. If chlorine or another
oxidant is injected too soon after polyphosphate injection, Fe and Mn may not be
completely sequestered and may precipitate out in the distribution system. Thus, the actual
time required between polyphosphate injection and chlorine injection to allow effective
sequestration must be tested prior to system installation.
The recommended dosage and usages for each well are listed in Tables 1.8 and 1.9.
Table 1.8 Recommended Dosage for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well No. Dosage (mg/L as PO4)
12 1.5 - 2.75
14 2-4
17 1.5 - 1.75
20 1.75 - 2.25
Table 1.9 Chemical Usages for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well Granular Form Liquid Form
12 (700 gpm) 0.53 Ibs - 0.96 lbs. per well hour 0.13 gal - 0.24 gal. per well hour
14 (1,350 gpm) 1.35 lbs - 2.71 lbs. per well hour 0.33 gal - 0.68 gal. per well hour
17 (1,750 gpm) 1.30 lbs; - 1.55 lbs. per well hour 0.33 gal - 0.39 gal. per well hour
20 (1,460 gpm) 1.28 lbs - 1.65 lbs. per well hour 0.32 gal - 0.41 gal. per well hour
7.0 PRELIMINARY CAPITAL AND O&M COSTS FOR SELECTED
TREATMENT SYSTEMS
Preliminary cost estimates are provided below for planning purposes. Cost estimates are
based on information provided by the vendors and other similar projects completed
FINAL - July 5, 2007 1-16
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recently. It should be noted that these are planning level costs with an estimated accuracy
of +30 percent to -20 percent. These estimates reflect professional opinion of accurate
costs at this time and are subject to change depending on the final design. Engineers have
no control over variances in the cost of labor, materials, equipment, services provided by
others, contractor's methods of determining prices, competitive bidding or market
conditions, practices, or bidding strategies.
7.1 Assumptions Used to Develop Preliminary Cost Estimates
The following is a list of assumptions used in preparing the budget level capital and O&M
costs:
1. One system will be installed for Wells 12 and 17, as only one of these wells will be in
operation at any given time.
2. The wells operate 24 hours per day, 6 days per week (Monday through Saturday).
3. Water Quality: Table 1.1, presented earlier, shows the historical data of the Fe and
Mn concentrations in the wells. The median concentration of Fe in the wells ranges
from 88 to 94 lag/L; while the median Mn concentration ranges from 120 lag/L to
480 lag/L. However, for the purpose of establishing a cost estimate, the historical
maximum data was used. The design values for the contaminants are listed in
Table 1.10.
Table 1.10 Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well
Well
Well
Well Finished
Parameters No. 12
No. 14
No. 17
No. 20 Water Goal
Manganese, lag/L 180
430
120
110 40
Iron, lag/L 1,300
2,200(')
140
740 240
pH 7.8-7.9
7.4-8.2
7.6-7.9
7.7-8.0 -
Hardness, mg/L as CaCO3 212-220
240-300
200-217
190-200 -
Alkalinity, mg/L as CaCO3 190-210
180-240
180-200
170-210 -
Flow Rate, gpm 700
1,350
1,750
1,460 -
Notes:
(1) The historical maximum iron concentration of 5,400 lag/L for Well 14 was not used, as
this data may be erroneous.
4. The treatment goal is set to the 80 percent of the respective contaminant MCLs.
Table 1.9 presents the finished water goal for each contaminant to be used as a basis
for the treatment system.
5. The chlorine -dosing requirement is calculated based on Fe and Mn concentrations
only.
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6. The calculation of pounds per year of sodium hypochlorite needed was based on the
typical stoichiometric (chlorine to Fe and Mn ratio) without major chlorine demand and
does not take into account any organic or other constituents in the water that may
affect chlorine demand.
7. Power costs are based on the unit cost of $0.09/kWhr provided by the City.
8. Mid -point of construction is January 2010. This is based on DHS' requirement of the
City to construct and build the system in three years once the waiver survey is
completed. Since the waiver survey has to be signed and completed by
August 29, 2007, the City would need to start construction of the system by summer
of 2009, assuming one-year construction time. This would put January 2010 as the
mid -point of construction for cost estimate purposes.
9. Estimated project costs (2007 dollars) will be escalated with an annual rate of
8 percent to determine mid -point construction dollars (2010 dollars).
10. Amortized capital cost is based on 20 years and 6-percent interest rate.
11. O&M Costs will also be escalated to January 2010 using a standard inflation rate of
3 percent.
7.2 Equipment Capital Cost Estimates
The capital cost estimates of the treatment systems are based on various sources,
including quotes from commercial system providers, recent projects, and other standard
cost estimating tools available. Equipment costs from various vendors may not be
comparable since the equipment supplied from each vendor is configured differently, such
as chemical feed set-up, the number of vessels, etc.
Table 1.11 lists items included and excluded in the cost estimates.
Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
1. Items Included in the Cost Estimates:
• Equipment Purchase (vessels, valves, etc).
• Media.
• Delivery and Setup.
• Installation and Start-up Equipment.
• System Hook-up.
• Yard Piping.
• Electrical.
• Instrumentation.
• Engineering, Legal, and Administration.
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Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
2. Items Not Included in the Cost Estimates:
• Building.
• New Sewer Connection.
• Permitting.
• Disinfection System.
7.3 Cost Estimates for the Iron and Manganese Oxidation and Filtration
Treatment System
7.3.1 Capital Cost Estimate of Iron and Manganese Treatment System
The unit equipment cost estimates for the oxidation and filtration systems offered by the
three vendors for each of the three sites are summarized in Tables 1.12 to 1.14.
Table 1.12 Iron/Manganese Equipment Cost -Alternative 1 Loprest System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Water Source Process Description and Items
Equipment Costs
Wells 12 and 17 Greensand and anthracite filter vessel (two
$400,000
horizontal pressure tank 8 ft by 16 ft); Chemical
feed system.
Well 14 Greensand and anthracite filter vessel (One
$290,000
horizontal pressure tank 8 ft by 32 ft); Chemical
feed system.
Well 20 Greensand and anthracite filter vessel (one
$260,000
horizontal pressure tank 8 ft by 24 ft); Chemical
feed system.
Total
$950,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Equipment
Supplier
Process Description and Items
Costs
Well Nos. 12
Reaction Vessel No. 1 with sodium hypochlorite
$420,000
and 17
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 21-foot straight side shell, working pressure
of 60 psi) with chemical feed systems, plus reclaim
system (without the reclaim tank).
Well No. 14
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-foot straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Well No. 20
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-fo6t straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Total
$1,110,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Supplier
Process Description and Items
Equipment Costs
Well Nos. 12
One filter vessel (7-foot diameter with a 21-foot
$500,000
and 17
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 14
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 20
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Total
$1,500,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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The total capital cost estimate for the oxidation and filtration systems from the three
vendors are presented in Table 1.15.On an annualized basis, (amortized over 20 years at
6-percent interest rate) the capital cost varies between $440,000 and $600,000 per year.
Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and
Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Equipment Cost:
$950,000
$1,110,000
$1,500,000
• Vessels.
• Valves and Gauges.
• Flow Meters.
• Media.
• Chlorine Analyzer.
• Filter Control Panel
• Start-up and Training Services.
• Backwash Reclaim Pump.
$30,000
Included
Included
• Sales Tax.
$76,000
$86,000
$116,000
• Freight Charge.
$20,000
$20,000
Included
• Subtotal (Oxidation/Filtration plus Backwash
$1,080,000
$1,220,000
$1,620,00
Reclaim Pump.
• Backwash Reclaim Tank.
$410,000
$410,000
$410,00
SUBTOTAL (EQUIPMENT COST)
$1,480,000
$1,620,000
$2,020,00
Contractor Markup Cost (15%)
$223,000
$244,000
$304,00
Installation Cost:
• Installation including Yard Piping and site
$670,000
$730,000
$910,00
work (45%).
SUBTOTAL (INSTALLED COST)
$2,370,000
$2,598,000
$3,239,00
Construction Cost:
• Electrical (15% of installed cost).
$360,000
$390,000
$486,000
• Instrumentation (10% of installed cost).
$237,000
$260,000
$324,000
SUBTOTAL (CONSTRUCTION COST)
$2,970,000
$3,250,000
$4,050,00
FINAL - July 5, 2007 1-21
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Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Project Cost:
• Engineering, Legal, and Administrative (25%).
$742,000
$812,000
$1,012,00
• Construction Management (10 %).
$297,000
$325,000
$405,000
• Contingency (35%).
$1,039,000
$1,137,000
$1,417,00
TOTAL PROJECTED CAPITAL COST
$5,050,000
$5,520,000
$6,880,00
AMORTIZED CAPITAL COST (20 years,
$440,000
$480,000
$600,000
6% interest rate)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
7.3.2 O&M Costs for the Fe/Mn Treatment System
O&M requirements by each treatment system are listed in Table 1.16. Orders of magnitude
O&M costs for commercially available oxidation/filtration processes are presented in
Table 1.17. O&M costs include the use of oxidant, media replacement, and electrical costs,
sludge hauling and disposal costs, and labor. The annual O&M cost is estimated to be
between $260,000 to $320,000.
Table 1.16 Oxidation and Filtration O&M Requirements
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
O&M Items Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Oxidant Usage - Chlorine
(12.5%)
• Well Nos. 12 and 17 Well 12 - 2.2 mg/L NA 1.25 mg/L
• Well No. 14
• Well No. 20
Sludge Disposal Volume (gal)
Electricity
Media Replacement
(20 lbs/day)
(26 Ibs/day)
Well 17 - 0.9 mg/L
(20 Ibs/day)
3.6 mg/L
NA
2.95 mg/L
(60 lbs/day)
(48 lbs/day)
1.5 mg/L
NA
1.61 mg/L
(27 lbs/day)
(28 lbs/day)
71,000
NA
NA
NA
NA
268 kWh/day
$60/ft3
NA
NA
1,150 ft3 (lasts for
10 years)
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H:\Client\Vemon SAO\M7708A00\TM\TM01 FINAL.doo
Table 1.17 Iron/Manganese System Annual O&M Cost Estimate
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alt 1 - Alt 2 - Alt 3 -
Category Loprest Filtronics Pureflow
Oxidant Use (e.g., chlorine)(') $50,000 $12,000 $49,00
Media Replacement(2) $8,500 $1,500 N
Electrical Costs (3) $10,000 $4,000 $6,50
Sludge Hauling Cost(4) $15,000 $15,000 $15,00
Sludge Disposal(5) $5,000 $5,000 $5,00
Replacement Parts and Valves (allowance - 5% $74,000 $76,000 $95,00
equipment cost)
Labor (8 hours per day, $60/hr)(6) $150,000 $150,000 $150,00
Total Annual O&M Cost $310,000 $264,000 $320,00
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%). Escalate at 3% to 2010.
(1) Assume $2.1/gallon for Sodium hypochlorite (12.5% assume 1.3 SG, Cost was
provided by the City.
(2) Media cost for Loprest was based on $60/ft3, media has shelf life of 10 years, for
Pureflow media, minimal media loss per year and no requirement of media change out.
(3) Assume control panel and chemical pump operating 24 hours/day, 6 days a week,
reclaim pump works 6 hours/day.
(4) Assume $0.25/gallon for sludge hauling.
(5) Estimated based on past projects. The final cost will depend on feed water quality,
which will affect chemical dosing and sludge volume. It will also depend on final
disposal site location.
(6) Assume about 8 hours per day of labor needed for these systems.
7.3.3 Total Annualized Cost for Oxidation and Filtration
Table 1.18 shows the total annualized costs of each oxidation and filtration system, capital
cost plus annual O&M cost in 2007 dollars and mid -point construction dollars (January
2010).
Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $440,000 $480,000 $600,000
Annual O&M Costs ($) (Year 2007) $310,000 $260,000 $320,000
Total Annualized Cost ($) 2007 $750,000 $740,000 $920,000
FINAL - July 5, 2007 1-23
H3Client\Vemon SAOVN7708A00\TM\TM01 FINAL.doc
Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs ($) $6,200,000 $6,700,000 $8,400,000
Annualized Project Costs ($) $540,000 $590,000 $730,000
Annual O&M Costs ($) (Year 2010) $330,000 $280,000 $350,000
Total Annualized Cost ($) 2010 $870,000 $870,000 $1,100,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
Based on the total annualized costs listed above, Alternatives 1 and 2 have the lowest cost.
7.4 Cost Estimates for the Iron and Manganese Sequestration System
The sequestration system (same for all wells) consists only of an injection pump and cost of
installing an injection tap at the well site if using the liquid chemical. Additional equipment is
required as mentioned earlier if the granular form of the chemical is used. Table 1.19 lists
the estimated capital costs.
Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and Manganese
Treatment
City of Vernon
Items
Liquid
Granular
Equipment Costs:
• Injection Pumps.
$5,800
$5,800
• Injection Tap.
$800
$800
• Tank Assembly (200-gallon tank and mixing
NA
$17,000
system).
• Disinfection Control System Upgrade.
$40,000
$40,000
• Sales Tax (7,75%).
$3,600
$5,000
TOTAL EQUIPMENT COST
$50,000
$69,000
Contractor markup cost (15%).
$7,500
$10,00
Installation Costs:
$23,000
$31,000
• Installation Including Yard Piping and Site
Work (45%).
TOTAL INSTALLED COSTS
$80,000
$110,000
FINAL - July 5, 2007 1-24
H:%ClienflVemon SA01M7708A00\TM\TM01 FINAL.doc
Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and
Manganese Treatment
City of Vernon
Items
Liquid
Granular
Construction Cost:
• Electrical (15% of installed cost).
$12,000
$17,000
• Instrumentation (10% of installed cost).
$8,000
$11,000
TOTAL CONSTRUCTION COSTS
$100,000
$138,000
Project Cost:
• Engineering, Legal, and Administrative (25%).
$25,000
$34,000
• Construction Management (10%).
$10,000
$14,000
• Contingency (35%).
$35,000
$48,000
TOTAL PROJECTED CAPITAL COST
$170,000
$230,000
AMORTIZED CAPITAL COST (20 years,
$15,000
$20,000
6% interest)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
The estimated O&M costs based on the recommended chemical usage rate are shown in
Table 1.20.
Table 1.20 Estimated O&M Cost for Sequestration System (for High Concentration)
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Liquid Granular
Sequestering Chemical(') $104,000 $95,000
Freight Charges(2) $38,000 $20,300
Replacement Parts and Valves (Allowance - 5% $2,500 $3,500
equipment cost)
Labor (4 hours per day, $60/hr)(3) $74,900 $74,900
Total Annual O&M Costs $219,000 $194,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on vendor quotes, for liquid media $513 per 55-gal drum (625-Ibs poly drum), for
granular media $647 per 323 Ibs (30-gal steel drum), based on 24 hr/day, 6 days per
week.
(2) Freight charge - Granular: $190/drum, $521 per four drums, $878 per eight drums;
Liquid: $292 per drum, $836 per four drums, and $1,250 per eight drums. -
(3) Assumed a maximum of 4 hours per day of labor at $60/hr rate.
FINAL - July 5, 2007 1-25
H:\Client\Vemon SAOW\7708A00\TM\TM01 FINAL.doc
The total annualized costs for sequestration treatment system in June 2007 dollars and
January 2010 dollars (mid -point construction) are summarized in Table 1.21.
Table 1.21 Total Annualized Costs for Sequestration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Liquid
Granular
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $15,000
$20,000
Annual O&M Costs ($) (Year 2007) $219,000
$194,000
Total Annualized Cost ($) 2007 $234,000
$214,000
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs $207,000
$281,000
Annualized Project Costs ($) $18,000
$24,000
Annual O&M Costs ($) (Year 2010) $236,000
$209,000
Total Annualized Cost ($) 2010 $254,000
$233,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
8.0 SUMMARY AND RECOMMENDATION
Based on the findings from the feasibility study, the following key points are presented in
this report:
• The iron level ranges from 140 to 2,200 pg/L and manganese level ranges from 110
to 430 pg/L. These were the historical maximum data and were used as the basis for
estimating the cost of treatment.
• The total design flow rate for all four wells averages about 4,560 gpm. Based on the
production data provided by the City for the last three years, the total average
production from these wells is estimated to be 3,200 AFY.
• An oxidation/filtration system is recommended to treat Fe and Mn from the well water.
Chlorine or potassium permanganate is recommended as the chemical to be used for
oxidation. Proprietary media or greensand media can be used for filtration.
• Based on DHS's requirement of 3 years to construct from the completion of the
waiver process, the mid -point of construction is estimated to be January 2010.
FINAL - July 5, 2007 1-26
H:\Client\Vemon SAOW\7708A00\TM\TMOt FINAL.doc
Three major equipment suppliers have been contacted and three estimates have
been obtained for oxidation and filtration. Filtronics, Loprest, and Pureflow have
provided costs.
The total projected capital costs (2010 dollars) for the treatment plants
(oxidation/filtration system) are estimated to be in the range of $6,200,000 to
$8,400,000 and the amortized capital cost is expected to be between $540,000 and
$730,000. The capital costs include equipment, media, delivery and setup, installation
and start-up, instrumentation, engineering, legal, and administration, with a
35-percent contingency.
• The projected annual O&M costs (2010 dollars) are estimated to be approximately
$280,000 to $350,000. These O&M costs cover oxidant use, media replacement,
labor costs, and electrical costs. Sludge hauling and disposal cost allowances were
included, but refined costs are needed once the disposal facility is identified for this
project.
• The total annualized costs in 2010 (mid -point construction) dollars range from
$870,000 to $1,100,000.
• An oxidant demand test can be done at the bench scale to better estimate the
chemical dose requirement and the cost for such tests can be provided once the
scope of the test is defined if needed.
• Although sequestration is not a removal process and not considered as a compliance
alternative, the costs are included in the evaluation for comparison purposes per
City's request.
• The total projected capital costs (2010 dollars) for the sequestration system ranges
from $210,000 for a liquid phosphate system to $280,000 for a granular
polyphosphate system. The annual O&M costs (2010 dollars) are estimated to be
about $236,000 for liquid phosphate or $210,000 for granular polyphosphate.
Table 1.22 summarizes the pros and cons of doing nothing, using an oxidation filtration
treatment system, and using sequestration to treat/mitigate the Fe and Mn in the City water
supply.
FINAL - July 5, 2007 1-27
H:\Client\Vemon SAOw17708A00\TM\TM01 FINAL.doc
Table 1.22 Pros and Cons of Alternatives for Fe and Mn
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change .
Does not cost anything. •
Does not address iron and
•
Does not change the
manganese issue.
current condition of water. •
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning 0
Removes the impact of 0
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost 0
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for iron
temperature.
and manganese.
May have negative impacts
on customers' internal
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and o
Full removal of iron and
Costs more than other
Filtration Treatment
manganese.
alternatives.
System (using
chlorine solution)
Proven process for iron •
Rate increase is expected.
and manganese.
Table 1.23 summarizes the cost estimates of each system for the recommended oxidation
and filtration treatment system and the sequestration treatment system in 2010 dollars. In
order to put these numbers into perspective, the unit costs of the product water are
calculated and presented in Table 1.23. The costs of the most expensive system for each
treatment method are used for the comparison. This is to provide the most conservative
estimates for the unit costs of the product water.
Table 1.23 Summary of Cost Estimates - in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/
System
Filtration System
(Sequestration
Cost (Pureflow)
- Liquid)
Project Capital Cost $8,400,000
$210,000
Amortized Capital Cost (20 years, 6% interest $730,000
$18,000
FINAL - July 5, 2007 1-28
H:\Client\Vemon SAO M770BA00\TM\TM01 MAU=
Table 1.23 Summary of Cost Estimates - in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/
System
Filtration System
(Sequestration
Cost (Pureflow)
- Liquid)
rate)
Annual O&M Cost $350,000
$236,000
Total Annualized Cost $1,100,000
$254,000
Additional Annual Water Treatment Cost ($/AF)(1) $343.8
$79.4
Additional Annual Water Treatment Cost $1.05
$0.24
($/1,000 gal)(')
Additional Annual Water Treatment Cost $0.79
$0.18
($/100 ft)(1)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) The Total water production is based on the last three years production data.
Based on the estimated project costs shown in Table 1.23, the City estimates that up to a
21 percent City-wide increase in the user rate would be required to undertake treatment of
the well water to remove Fe and Mn. The additional annual water treatment costs shown in
Table 1.23 are for the wells that require either treatment or conditioning, and the increase in
these costs for the subject wells was used by the City to calculate the City-wide increase in
the commodity cost of water. This will increase the current user rates from $1.16/100 ft3 to
$1.41/100 ft3. If sequestration were used, the City estimates that up to a 5 percent increase
in the user rate would be required, from the current $1.16/100 ft3 to $1.22/100 ft3.
FINAL - July 5, 2007 1-29
H:lCiient\Vemon SAOw\7708A00\TM\TM01 MAU=
SURVEY VOTE FORM - CITY OF VERNON
IRON AND MANGANESE COMPLIANCE
Subject: Water Quality Compliance for Iron and Manganese
Please select one alternative. Not casting a vote will count as a vote for full treatment (Alt 3).
Iron and Manganese Compliance Vote - Select Only One Alternative
Increase in the
Commodity Cost
Check Only One
Alternative Processes
of Water
Box
Alt 1 - No Change (No Treatment)
• 0%
Alt 2 - Conditioning System
0 Up to 5%
(Sequestration)
Alt 3 - Oxidation and Filtration
. Up to 21%
Treatment System
• Alt 1 - Existing water quality is acceptable in terms of iron and manganese. I VOTE
NO CHANGE.
• Alt 2 - Existing water quality is NOT acceptable. I WANT THE WATER
CONDITIONED WITH CHEMICALS (SEQUESTERATION), AND I ACCEPT AN
INCREASE IN THE WATER COMMODITY COST OF UP TO 5%. 1 understand that
this is a temporary measure (9 years) allowed by the State and that this option may
result in iron and manganese settling in water when it is heated and may otherwise
affect internal water treatment processes at my home or business.
• Alt 3 - Existing water quality is NOT acceptable. I WANT THE WATER TREATED
TO REMOVE IRON AND MANGANESE WITH OXIDATION AND FILTRATION,
AND I ACCEPT AN INCREASE IN WATER COMMODITY COST OF UP TO 21 %.
Site Address
Print Name
Signature
Date
PLEASE RETURN THIS SURVEY USING THE SELF ADDRESSED STAMPED ENVELOPE BY
JULY 30, 2007.
A PUBLIC HEARING WILL BE HELD ON AUGUST 20, 2007 AT 10 AM. TO PRESENT THE
RESULTS OF THE SURVEY.
If you have any concerns or comments you may contact Scott B. Rigg at (323) 583-8811
extension 279 or forward to his attention at 4305 Santa Fe Ave, Vernon, CA 90058.
•
July 2, 2007
Subject: Iron and Manganese Compliance Survey Vote
Dear Customer:
INTRODUCTION
The State Department of Public Health (DHS) has ordered the City of Vernon to comply with the
regulations for iron and manganese levels in the City's drinking water. These regulations have
been established to improve the aesthetics of your drinking water. The median concentration of
iron in the City's wells ranges from 88 to 94 micrograms per liter (,ug/L) while. the median for
manganese concentration ranges from 120 to 480 pg/L. The limits in terms of the regulations are
50,ug/L for iron and 300 pg/L for manganese. Currently, the levels of iron and manganese DO
NOT cause health issues but can cause aesthetic concerns such as taste, staining of cloths and
plumbing fixtures, and brown water events under certain conditions.
The DHS advised the City that treatment for removal of iron and manganese must be undertaken
unless a waiver is obtained through a customer survey and vote.
The basis for granting waivers is the degree of consumer acceptance of existing water quality and
the CUSTOMER'S WILLINGNESS (OR UNWILLINGNESS) TO PAY THE COST of meeting these
water quality standards.
PLEASE REMEMBER THAT IF YOU DO NOT VOTE, YOU WILL BE CONSIDERED TO BE IN
FAVOR OF FULL TREATMENT AND YOU WILL BE WILLING TO BEAR THE ADDITIONAL
COST. In other words, if a majority of customers do not respond to this surveyor vote for
treatment, DHS will require compliance with the regulations through treatment. You are strongly
encouraged to evaluate this matter and vote by completing the attached "Survey Vote Form". The
survey form shall be picked up by the City staff no later than August 1, 2007.
BACKGROUND
The City retained Carollo Engineers to prepare an engineering report to comply with DHS
requirements. The report was completed by Carollo Engineers and reviewed by the City staff and
DHS. Copies of the full report are available for review at the City of Vernon located at 4305 Santa
Fe Avenue or at the City web -site www.cityofvernon.org.
The report indicates that either chemical conditioning to prevent iron and manganese from settling
in the water, or treatment of the water to remove iron and manganese using oxidation and
filtration are the most feasible methods to improve the water quality and comply with DHS
requirements. The advantages and disadvantages of three final alternatives are shown in Tablet.
Table 1 Pros and Cons of Alternatives for Iron and Manganese Compliance
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change 9
Does not cost anything.
&
Does not address iron and
•
Does not change the
manganese issue.
current condition of water.
•
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning .
Removes the impact of
0
Does not remove iron and
System
(Sequestration)
iron and manganese at a
manganese from water.
substantially lower cost
•
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for
temperature.
addressing elevated
•
May have negative impacts
levels of iron and
on customers' internal
manganese.
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and .
Full removal of iron and
0
Costs more than other
Filtration Treatment
System (using
manganese.
alternatives.
chlorine solution) 0
Proven process for iron
9
Rate increase is expected.
and manganese removal.
The estimated project cost including loan fees and contingencies is estimated to be up to $8.4
million for the oxidation and filtration treatment system (Alt 3). The conditioning system (Alt 2)
using a polyphosphate chemical to help prevent iron and manganese precipitation is estimated to
cost up to $210,000.
The City staff has reviewed financing options and has found that THE LEAST EXPENSIVE
OPTION IS TO USE CONDITIONING CHEMICALS (Alt 2 - SEQUESTRATION) TO HELP
PREVENT IRON AND MANGANESE PRECIPITATION. Up to a 5 percent increase in the
commodity cost of water beyond the present minimum payment is expected. It should be noted,
however, that the performance of sequestration chemicals is sensitive to temperature, and iron
and manganese may settle out under certain conditions where water is heated for use. Water
conditioning may also have negative impacts on some customers' internal processes, such as
water filtration equipment.
y <
c
r
• t
FULL TREATMENT TO REMOVE IRON AND MANGANESE (Alt 3) WILL INCREASE THE
WATER COST BY UP TO 21 PERCENT. Since iron and manganese are removed from the water,
this option is NOT sensitive to temperature and iron and manganese WILL NOT settle out.
Chemical conditioning and full treatment both have proven track records. The DHS will review and
approve any treatment system to ensure it meets all drinking water standards.
ESTIMATED COMPLIANCE COSTS
The decision as to which course of action the City will pursue must be made by the City's
customers. The choices and cost associated with each alternative are shown in Table 2.
Table 2 Cost Estimates for Iron and Manganese Compliance
Alternative Processes
Commodity Cost of Water Expected Rate Increase
Alt 1. No Change (current rate) .
$1.159 per 100 ft3 0 0%
Alt 2. Conditioning System 0
(Sequestration)
Up to $1.216 per 100 ft3 0 5%
Alt 3. Oxidation and Filtration 0
Treatment System
Up to $1.406 per 100 ft3 21 %
In making the decision, each customer will be entitled to a single vote. If a majority of customers
vote in favor of Alternative 1, it will be construed as acceptance of existing water quality (in terms
of iron and manganese) and a waiver from the regulations will be sought from DHS. It is critical
that you cast the vote you are entitled to.
A public meeting to discuss the survey results will be held at the City offices at 10 a.m. on
August 20, 2007.
Sincerely,
City of Vernon
EXHIBIT
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SUPPORTING
DOCUMENTS
�n
COMMUNITY SERVICES & WATER DEPARTMENT
Samuel Kevin Wilson, Director of Community Services & Water
4305 Santa Fe Avenue, Vernon, California 90058
Telephone (323) 583-8811 Fax (323) 826-1435
August 14, 2007
Honorable City Council
City of Vernon
4305 Santa Fe Avenue
Vernon, CA 90058
Dear Honorable Mayor and City Councilmen:
APPROVED AUG 27 '07 CITY COUNCIL
Res. g390
The City of Vernon has recorded low levels of iron and manganese in its water supply for the past
several years. These minerals have no adverse effects on human health and concerns are based solely on
aesthetic issues. The California Department of Health Services (CDHS) requested that the City of Vernon
prepare an engineer's report and conduct a customer survey to determine if Vernon water customers are
experiencing water quality problems and if they are willing to increase water rates in order to finance water
treatment plants to remove the iron and manganese from the water supply.
The Community Services and Water Department has completed the requirements stipulated by the
CDHS and hereby advise you that the results of the iron and manganese survey indicate that the City's
customers have opted for Alternative No. 1 of the survey which is a vote for no treatment. The Community
Services Department delivered a total of 863 surveys to City customers who pay the water bill and received
back 653 or 75.66 percent. A 50-perecent response rate was required in order for this survey to be valid.
According to the CDHS the 210 no responses must be calculated as votes for full treatment. The final official
tally is then 64 votes for sequestration, 257 votes for full treatment and 542 votes for no treatment. The City is
now eligible to request a 9-year waiver from the CDHS permitting the distribution of water from effected water
production facilities.
E Ccfusivefy IndustfiaC
In order to receive an official waiver from the CDHS, the City must provide a final hard copy of the
engineering report and survey form along with the results of the survey and a brief report of the Public Hearing
and minutes. A Public Hearing to advise the community of the survey results has been scheduled for the
August 20, 2007 City Council meeting. Thank you. i7
Levin Wilson, P.E.
of Community Services and Water
SKW/sr
Enclosures
c: Eric Fresch, City Administrator
Jeff Harrison, City Attorney
Signed: July 5, 2007 Signed: July 5, 2007
City of Vernon
DHS ENGINEERING REPORT ON IRON
AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
DRAFT
June 2007
occ7cplw�b
10540 TALBERT AVENUE, SUITE 200 EAST • FOUNTAIN VALLEY, CALIFORNIA 92708 • (714) 593-5100 • FAX (714) 593-5101
H:\CIientlVemon_SAOM770BAOO\TAATM01 FINALdx
P.
City of Vernon
DHS ENGINEERING REPORT ON IRON AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
TECHNICAL MEMORANDUM
NO. 1
TABLE OF CONTENTS
Page No.
1.0 BACKGROUND....................................................................................................1-1
2.0 EXISTING WATER SYSTEM................................................................................1-1
2.1 Water Supply...............................................................................................1-2
2.2 Storage and Distribution System.................................................................1-2
3.0 WATER QUALITY.................................................................................................1-4
4.0 DRINKING WATER REGULATIONS....................................................................1-6
4.1
Iron..............................................................................................................1-6
4.2
Manganese.................................................................................................1-6
5.0 IRON AND MANGANESE ALTERNATIVE TREATMENT METHODS ..................1-6
5.1
Oxidation and Filtration...............................................................................1-6
5.2
Sequestration..............................................................................................1-7
5.3
Ion Exchange..............................................................................................1-8
5.4
GAC............................................................................................................1-8
5.5
Membranes.................................................................................................1-9
5.6
Biological Filtration......................................................................................1-9
5.7
Fe/Mn Summary and Recommendation......................................................1-9
6.0 RECOMMENDED
TREATMENT TRAINS .............................................................
1-9
6.1
Summary of Recommended Processes......................................................1-9
6.2
Oxidation/Filtration Treatment System.......................................................1-11
6.3
Sequestration Using Polyphosphate..........................................................1-15
7.0 PRELIMINARY
CAPITAL AND O&M COSTS FOR SELECTED TREATMENT
SYSTEMS...........................................................................................................1-16
7.1
Assumptions Used to Develop Preliminary Cost Estimates .......................1-17
7.2
Equipment Capital Cost Estimates............................................................1-18
7.3
Cost Estimates for the Iron and Manganese Oxidation and Filtration
TreatmentSystem
...............................................................................................1-19
7.4
Cost Estimates for the Iron and Manganese Sequestration System ..........1-24
8.0 SUMMARY AND RECOMMENDATION..............................................................1-26
DRAFT - July 9, 2007
H:\Client\Vemon_SAO M7708A00\TM\TM01 FINAL.doc
LIST OF TABLES
Table 1.1
City of Vernon Water Service Connections..................................................1-1
Table 1.2
Information About Existing Potable Water Wells..........................................1-2
Table 1.3
Historical Water Qualities of Well Nos. 12, 14, 17, and 20 ...........................1-4
Table 1.4
Advantages and Disadvantages of Fe/Mn Treatment Technologies ..........
1-10
Table 1.5
Summary of Available Oxidation Alternatives for Fe/Mn Removal .............1-10
Table 1.6
Summary of Available Filter Media for Fe/Mn Removal.............................1-11
Table 1.7
Oxidation and Filtration Systems for Fe and Mn........................................1-11
Table 1.8
Recommended Dosage for Sequestration Chemical from SPER Chemical1-16
Table 1.9
Chemical Usages for Sequestration Chemical from SPER Chemical ........1-16
Table 1.10
Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals ....1-17
Table 1.11
Treatment Cost Estimate Factors..............................................................1-18
Table 1.12
Iron/Manganese Equipment Cost -Alternative 1 Loprest System................1-19
Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System..............1-20
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System..............1-20
Table 1.15
Iron/Manganese System Capital Cost Estimate.........................................1-21
Table 1.16
Oxidation and Filtration O&M Requirements..............................................1-22
Table 1.17
Iron/Manganese System Annual O&M Cost Estimate................................1-23
Table 1.18
Total Annualized Costs for Oxidation and Filtration System ......................1-23
Table 1.19
Estimated Capital Cost for Sequestration System.....................................1-24
Table 1.20
Estimated O&M Cost for Sequestration System (for High Concentration)..1-25
Table 1.21
Total Annualized Costs for Sequestration System.....................................1-26
Table 1.22
Pros and Cons of Alternatives for Fe and Mn............................................1-28
Table 1.23
Summary of Cost Estimates - in 2010 Dollars...........................................1-28
LIST OF FIGURES
Figure 1.1 City of Vernon Service Area........................................................................1-3
Figure 1.2 Water System Schematic............................................................................1-5
Figure 1.3 Schematic of an Oxidation/Filtration System.............................................1-12
Figure 1.4 Schematic of a Sequestering System........................................................1-13
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Technical Memorandum No. 1
TREATMENT ALTERNATIVES AND COST ESTIMATES
1.0 BACKGROUND
The City of Vernon (City) is located near the geographic center of metropolitan Los Angeles
County, situated within 2 miles of four major freeways and near the site of Hobart Yard,
which is a major rail terminal for Los Angeles. Elevated levels of iron (Fe) and manganese
(Mn), both classified by the Environmental Protection Agency (EPA) as non -hazardous
contaminants, have been found in four of the City wells. Levels in the wells exceeded the
California Safe Drinking Water Act of 1986 (SDWA) secondary maximum contaminant level
(MCLs). Although these are secondary MCLs, the City is required either to comply with the
MCLs or to obtain a waiver in accordance with Title 22, Section 64449 of the California
Code of Regulations (CCR).
In order for the City to obtain a waiver on treatment and to comply with the CCR
requirement, the City needs to conduct a study to evaluate treatment alternatives and
develop costs for Fe and Mn treatment.
This report constitutes the requirements for the study. The cost information will be used as
a basis for developing rate increases to be included in the mailer survey to the residents to
vote whether or not the treatment option should be implemented.
2.0 EXISTING WATER SYSTEM
The City Water Department serves water to the majority of the City. A small portion of the
northeast corner of the City is served by California Water Service and a small area in the
southeast area of the City is served by Maywood Mutual No. 3. Figure 1.1 shows the City's
service area.
The City has approximately 45,000 daytime residents and 93 permanent residents. Based
on the City's 2006 Annual Report to the Drinking Water program, only 21 of the 1,760 active
connections were residential, and the remaining were mainly commercial and industrial.
The approximate annual water demand was estimated to be 11,000 acre-feet or 3.9 billion
gallons (2006 data). Table 1.1 summarizes the number and types of connections the City
currently has.
Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered
General and Residential 16
Commercial 1,343
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Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered
Industrial
Irrigation (Ag and Residential)
Total Active Connections
2.1 Water Supply
404
0
1,763
The primary water supply for the City is groundwater. In addition, the City has a direct
connection to the Metropolitan Water District of Southern California (MWD). The MWD
connection provides both a supplemental water source and an emergency supply in the
event of a major power outage. The City's ground water system is made up of eight active
wells and one inactive well. There is no treatment of the water other than chlorination.
Table 1.2 provides a summary of selected information about the nine wells.
Table 1.2
Information About Existing Potable Water Wells
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Date
Total
Ground
Capacity,
Well No.
Drilled
Perforated Intervals, ft
Depth, ft
Elevation, ft
gpm
11
5/23/1952
741-776, 816-826,
1,343
197.22
1,143
863-871, 983-997,
1,105-1,142, 1,163-1,186
12
11 /20/1953
996-1,015, 1,067-1,169,
1,588
183.29
700
1,260-1,580
14
3/23/1962
360-1,251
1,302
203.75
1,351
15
10/27/1966
510-1,502
1,550
177.76
1,953
16
8/18/1970
510-1,460
1,520
197.22
1,450
17
11/1/1970
510-1,500
1,550
183.29
1,750
18
11 /30/1958
510-1,361
1,443
184.57
1,450
(inactive)
19
9/19/1988
510-1,550
1,660
180.45
1,380
20
9/23/1988
510-1,550
1,620
159.47
1,460
2.2 Storage and Distribution System
The City's water distribution system consists of 250,000 linear feet of pipe, six ground level
reservoirs, one elevated tank, and one belowground reservoir. The total storage capacity in
these facilities is 16 million gallons (MG). The average pressure in the distribution system is
about 75 psi.
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Figure 1.2 shows the City's overall distribution system. It is made up of three main booster
pump stations/plants. Booster Plant 1 is fed by Well Nos. 11 and 16, has a 10-MG
reservoir, and has five distribution pumps. A 24-inch MWD connection is also available at
this location. Booster Plant 2 is supplied by Well Nos. 12 and 17, has three 1-MG storage
tanks, and has six distribution pumps. Booster Plant 3 is supplied by Well Nos. 15 and 19,
has three 1-MG storage tanks, and has five distribution pumps. Well No. 19 can discharge
either directly to the distribution system or to the three storage tanks. The remaining three
wells, Well Nos. 14, 18, and 20, discharge directly to the distribution system without going
through any storage. In addition, the City also owns a 0.6-MG elevated storage tank.
3.0 WATER QUALITY
Overall, the groundwater quality of the City's wells is good. However, the groundwater
sources have a history of exceeding the secondary MCLs for Fe (300 lag/L) and Mn
(50 pg/L). Both of these secondary limits are regularly exceeded in water pumped from
Wells Nos. 12 and 14, while the Mn MCL is exceeded regularly in water pumped from Wells
Nos. 17 and 20. These findings have been noted in the Consumer Confidence Reports that
the City distributes to its customers annually.
Table 1.3 summarizes the water quality of the four wells for selected parameters.
Table 1.3
Historical Water Qualities of Well Nos. 12, 14, 17, and 20
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Secondary
Well
Well
Well
Well
Parameter
Units MCL
No. 12
No. 14
No. 17
No. 20
Manganese
lag/L 50
54-180
40-1200
30-120
30-111
Iron
lag/L 300
ND-2,000
ND- 5,400
ND-144
ND-740
Sulfate
mg/L 250
79-82
75-110
62-67
50-79
TDS
mg/L 500
370-380
450-520
350-390
350-420
Alkalinity
mg/L --
190-210
180-240
180-200
170-210
Hardness
mg/L --
212-220
240-300
200-217
190-200
Bicarbonate
mg/L --
230-250
229-284
220-250
210-250
pH
--
7.8-7.9
7.4-8.2
7.6-7.9
7.7-8.0
Flow rate
gpm --
700
1,350
1750
1460
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4.0 DRINKING WATER REGULATIONS
4.1 Iron
The California Department of Health Services (DHS) has set a secondary MCL for Fe of
300 lag/L. Exceeding the suggested level usually results in discolored water, laundry, and
plumbing fixtures. This, in turn, results in consumer complaints and potential dissatisfaction
with the water utility.
4.2 Manganese
Based on the health effects, the California DHS has set a notification level for Mn, which is
currently at 500 pg/L. However, at concentrations exceeding 100 pg/L, Mn imparts an
undesirable taste and stains plumbing fixtures and laundry. These considerations lead the
EPA to set a secondary MCL of 50 lag/L for Mn in drinking water (Federal Register, 1979).
5.0 IRON AND MANGANESE ALTERNATIVE TREATMENT
METHODS
As mentioned earlier, the City can apply for a compliance waiver to meet the secondary
standards for Fe and Mn. However, the City is still required to evaluate the treatment
alternatives and report the findings to the DHS, under this option.
There are several treatment alternatives available for Fe and Mn control in a water
treatment plant. The most basic methods are chemical oxidation followed by clarification
and filtration. Other treatment alternatives are described in the following paragraphs and
include ion exchange, sequestering processes, biological removal, GAC, and membranes.
5.1 Oxidation and Filtration
Oxidation followed by filtration is the most popular process in the United States (U.S.) for Fe
and Mn removal. Under reducing conditions, Fe and Mn are stable as soluble forms
(ferrous [Fe2+] and manganous [Mn21 ions). When they are oxidized, they become insoluble
ferric (Fe3+) and manganic hydroxide (Mn3+) species, and these can be physically removed
with a filtration process.
Chlorine and potassium permanganate are common oxidants applied in commercial
packaged systems. It has been reported that soluble Mn (11) was rapidly oxidized by
potassium permanganate, chlorine dioxide, and ozone in low dissolved organic carbon
(DOC) waters. When chlorine is used as an oxidant, it may react with natural organic matter
in the raw water to form trihalomethanes (THMs) and haloacetic acids (HAAs), which are
regulated contaminants under the Stage 2 Disinfectants/Disinfection By-products (DBPs)
Rule (D/DBPR). Therefore, if halogenated DBPs are an issue, other oxidants may offer
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benefits compared to chlorine, such as potassium permanganate, ozone, and chlorine
dioxide. In the City's case, it is not an issue since the water organic content is expected to
be low.
Optimal Mn oxidation occurs in the pH range of 8.0 to 8.5. Chlorine dosages as high as
five times the theoretical stoichiometric requirements may be necessary to oxidize Fe and
Mn within reasonable detention times. Potassium permanganate is a stronger oxidant than
chlorine and chlorine dioxide and can be effective with regard to dissolved Mn oxidation at
pH values above 7.5. The rates of reactions of Fe and Mn with permanganate are very fast
and could minimize the space requirement by eliminating the reaction vessel sometimes
needed with chlorine oxidation. However, the chemical is more expensive than chlorine.
Once oxidized and precipitated, particulate Fe and Mn must be removed from the water.
Several technologies are available and have been applied to accomplish this solids
separation step. Dual -media filters with anthracite and sand are commonly used for solids
separation in the water treatment and can be applied for the removal of Fe and Mn. Fe and
Mn can also be removed with a catalytic filter media that uses oxygen in the water to
convert metal ions from a soluble form to an insoluble form. This insoluble precipitate is
then filtered out onto the surface of the media.
Most of the commercial systems use Mn greensand medium, which is a term used for
naturally rich Mn dioxide minerals, which promote adsorption of dissolved Mn or other
proprietary media. Greensand medium can also serve for physical removal of ferric
hydroxide and ferric oxide precipitates.
5.2 Sequestration
Sequestration means preventing the formation of objectionable color and turbidity without
actually removing the Fe and Mn. It is the addition of chemicals to groundwater aimed at
controlling problems caused by Fe and Mn. These chemicals are usually added to
groundwater at the wellhead or at the pump intake before the water has a chance to come
in contact with air or chlorine. This ensures that the Fe and Mn stay in the soluble form.
Polyphosphate is one of the sequestering agents that can bond with Fe and Mn and thus
prevent them from precipitating in water. Although this approach requires only minor
modifications to any existing system, it does not provide a permanent solution (removal) for
high Fe and Mn concentrations. Furthermore, depending on the type of polyphosphate
used, the Fe -polyphosphate complex may break down when heated. The Fe and Mn
released may then cause a problem such as precipitation or staining. Thus,
high -temperature processes or laundries using hot water may experience potential
problems when sequestering agents are used. Furthermore, sequestration of Fe and Mn
may pose negative effects on some of the City's customers' internal processes. If a
customer is using some type of oxidation and filtration processes to remove Fe and Mn
from the tap water, this process may not operate as designed because the sequestered Fe
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and Mn are complexed (bound) with the polyphosphate. That is, Fe and Mn would not be
removed from the water. Another process that may be affected by the sequestration
process is reverse osmosis (RO) filtration. The polyphosphate agent and sequestered
compounds could increase the fouling potential on the RO membranes. Additional
pretreatment processes could be required for removal of these compounds to prevent
membrane fouling. In addition, there may be other potential interferences from
polyphosphate on different types of water treatment and manufacturing processes, but it is
difficult to ascertain exact impacts without detailed information about these processes.
In terms of chemical dose, theoretically, there is no limit to the amount of soluble Fe and Mn
that would make sequestration an effective mitigation method. However, various studies
have reported some upper limits for chemical sequestration of Fe and Mn. The National
Drinking Water Clearing House states that sequestration followed by chlorination can be
effective for water containing less than 1,000 pg/L Fe and 300 pg/L Mn. According to the
California Department of Health Services Policy Memo 2001-1 Secondary Standards,
various levels of Fe and Mn up to 5,000 lag/L have been cited as the economical and
technical limit for effective mitigation method. The policy also states that levels above
2,000 pg/L are less likely to be successfully mitigated with polyphosphates based on their
experience. If sequestration is selected, bench- or pilot -scale testing is highly
recommended to evaluate the feasibility and effects of using this method to address the Fe
and Mn issues in the groundwater.
Sequestering agents are injected via a chemical metering pump at the wellhead before
other chemical additives (chlorine, fluoride, caustic soda, etc.). If permissible, these agents
are injected down the well casing to mix with groundwater at the pump intake.
5.3 Ion Exchange
The ion exchange process involves exchange of soluble ionic species. Application of
softening in water treatment for Fe and Mn removal is limited since it can only be used
where Fe and Mn exist completely in the soluble forms. In addition, the system should be
airtight; otherwise, oxidation of Fe and Mn with oxygen could result in breakthrough from
the ion exchange resin bed. The potential of fouling in ion exchange resins may increase as
Fe and Mn concentrations increase. This alternative is not considered to be a practical
application in this case.
5.4 GAC
Bituminous -based GACs can remove Fe. However, these systems are not capable of
removing Mn unless the pH is greater than 8.5. Therefore, GAC is not considered as a
suitable alternative.
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5.5 Membranes
Both reverse osmosis (RO) and nanofiltration (NF) can remove the soluble forms of Fe and
Mn. The true benefit of the high-pressure membrane treatment processes is their ability to
also remove other dissolved contaminants at the same time. However, because of their
high capital and operating costs and concentrate stream disposal issues, it is not
economically feasible to apply these technologies for Fe and Mn removal alone.
Low-pressure membranes such as ultrafiltration (UF) and microfiltration (MF) can be used
downstream of pre -oxidation of Fe and Mn, as a filtration step to remove the insoluble
precipitates. For treating Fe and Mn removal, membrane systems will be more costly than
granular media pressure filter -based systems.
5.6 Biological Filtration
Biological filtration uses indigenous microorganisms that are able to metabolize Fe and Mn
to reduce their levels in source water. It offers lower operating and capital costs than
comparable physical/chemical processes. It also produces less waste product that allows
easier dewatering and disposal of residual. However, biological treatment requires specific
raw water qualities and conditions, and not all groundwater or surface water can be treated
economically using this technique. Success of this treatment process depends on several
factors such as nutrient availability, oxidation/reduction conditions, temperature, and filter
operation strategy. When both Fe and Mn are present in the water, a two -stage process is
required. Cost and practicality of a two -stage process are considerations that make this
alternative less attractive. Biological filtration also requires equalization to ambient pressure
for operation and needs permitting by DHS for implementation for drinking water
application. Therefore, biological filtration is not considered a practical alternative in this
case.
5.7 Fe/Mn Summary and Recommendation
A summary of the advantages and disadvantages for each of the alternative for treatment of
Fe and Mn is presented in Table 1.4.
6.0 RECOMMENDED TREATMENT TRAINS
6.1 Summary of Recommended Processes
Based on the water quality of the wells and the above discussion on the various unit
processes, the oxidation/filtration process is the recommended approach for the Fe and Mn
removal. Figure 1.3 depicts the possible treatment train at each of the well sites. Even
though the sequestration approach is not a removal process (Fe and Mn still remain in the
water in dissolved forms), it was evaluated for comparison purposes per City's request to
apply for a waiver. Figure 1.4 shows the typical setup of a sequestration system.
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H:\Client\Vemon—SAOV\1\7708AOO\TM\TMO1 FINAL.doc
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6.2 Oxidation/Filtration Treatment System
Oxidation with chlorine or potassium permanganate, followed by media filtration and
greensand filtration with chemical feed for regeneration are the best alternatives for treating
the Fe and Mn. This conclusion is based on an evaluation of available oxidation and
filtration alternatives, as shown in Tables 1.5 and 1.6.
Table 1.6 Summary of Available Filter Media for Fe/Mn Removal
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Catalytic Media (Greensand Greensand with
Dual Media without Regeneration) Regeneration
In -situ (in -vessel) No Partial Yes
Oxidation
Media Regeneration
No
No
Yes, with KMn04
Media Cost
Low
High
High
Pre Reaction Vessel
Yes
No
No
Requirements
Oxidant Compatibility
No specific
No specific requirement
Must use KMn04
requirement
Several Fe and Mn oxidation and filtration systems are available as supplied by the
manufactures listed in Table 1.7.
Table 1.7 Oxidation and Filtration Systems for Fe and Mn
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alt 1 - Loprest Water Company 0 Greensand and anthracite filter vessel.
Alt 2 - Filtronics, Inc. 0 Reaction vessel with sodium hypochlorite.
• Reaction vessel with sodium bisulfite.
• Filter vessel with Electromedia I.
Alt 3 - Pureflow
• Proprietary treatment process.
All of the above systems have proven capability for treating water with elevated levels of Fe
and Mn. These packaged systems have vertical or horizontal vessels depending on the
system size. Due to the difference in the type and depth of the media, the filtration rate
ranges from 2 to 10 gpm/ft2. Some of the packaged systems (e.g., Filtronics) require
additional reaction tanks to oxidize Fe and Mn to the insoluble forms upstream of the filters
in order to provide enough time to ensure sufficient oxidation of Fe and Mn. Non-greensand
medium is used in the filter to remove the insoluble particles produced from the reaction
tanks.
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When greensand is used in other packaged systems, reaction tanks are generally not
required unless the Fe and Mn concentrations are very high (greater than 5,000 pg/L). Most
systems can operate on pressurized lines such that no additional backwash pumps are
required. These systems typically have multiple -vessel designs and can backwash one
vessel using the treated water from the other vessels. Backwash water is typically directed
to a wastewater decant tank. Approximately 80 to 90 percent of the backwash wastewater
can be reclaimed in most cases. The backwash water is stored in a backwash tank, where
solids such as precipitated Fe and Mn settle to the bottom of the tank. Sewer disposal for
the sludge would be desired, but this option depends on other contaminants in the raw
water, the proximity of a sewer, and the local sewer discharge regulations. The cost of
discharge to the sewer is expected to be low if a nearby sewer pipe exists already.
However, if there is no existing sewer connection in close proximity, trucking may be more
cost effective than building a sewer line. Local trucking companies have been contacted to
gather pricing information for the off -site disposal alternative, which is listed with the other
O&M costs below.
The filter run time varies from system to system. Typically, every system provides a
pressure sensor to initiate a backwash cycle at a selected filter head loss. The head loss
cannot exceed 10 psig since higher headloss accumulation may damage the filter media.
Backwashing after a set operating time is a common practice for most of the systems. For
systems treating Fe and Mn at concentrations occurring in the four wells, backwash is
typically set once per day in the early morning when water demand is low. Backwash time
is estimated to be 5 to 30 minutes with backwash loading rates at 12 to 14 gpm/ft2,
depending on the systems.
6.2.1 Alternative 1 - Loprest - Greensand Filtration (with Chlorine Oxidation)
For Wells 12 and 17 sites, Loprest recommends a treatment process that consists of two
horizontal pressure filter tanks (8 feet in diameter and 16 feet long) based on the 1,750-gpm
flow rate (Well 17) and the existing background concentrations. The filter media consists of
manganese greensand (24-inch) and anthracite (12-inch). Chlorine dosage of 2.2 mg/L for
Well 12 and 0.9 mg/L for Well 17 mg/L would be used for oxidation of Fe and Mn at the
design concentrations for these contaminants.
For the Well 14 site, the treatment system is similar, but will only require one horizontal
pressure filter tank (8 feet in diameter and 32 feet long) based on the 1,350-gpm flow rate
and concentrations. The recommended chlorine dosage is 2.2 mg/L.
Finally, for the Well 20 site, a similar set up would be used, with one horizontal pressure
filter tank (8 feet in diameter and 24 feet long) at a flow rate of 1,460 gpm. The
recommended chlorine dose is 1.5 mg/L.
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6.2.2 Alternative 2 Filtronics - Chlorine and Sodium Bisulfate with Electromedia
Filtration
The Fe and Mn removal systems designed and manufactured by Filtronics require an
additional step compared to the system offered by Loprest and Pureflow. The Filtronics
system consists of two in -series reactor vessels (5-foot diameter with an 11-foot straight
side shell) and one filter vessel (ranging from 84-inch diameter with a 161-inch straight side
shell (at Well 14 or Well 20), to 7-foot diameter with a 21-foot straight side shell (at
Well Nos. 12 and 17)). In the lead reaction vessel, Mn is oxidized by addition of an oxidizing
chemical (sodium hypochlorite). The second vessel is used to quench the remaining
concentration of oxidizer (chlorine) by reaction with sodium bisulfite. The filter vessels
contain proprietary Electromedia I, which is granulated, naturally occurring sand -like filtering
media. A typical design feed loading rate is 15 gpm/ft2.
6.2.3 Alternative 3 - Pureflow
The Pureflow treatment process is a proprietary process. Well waters containing Fe and Mn
along with other dissolved contaminants, such as organic carbon, are first treated with
chlorine prior to filtration. This step oxidizes these contaminants to a form that can be
processed and provides free chlorine residual to the water distribution system.
The oxidation step is then followed by filtration, in which the Fe and Mn precipitates are
removed by a NSF -approved proprietary media that has an adsorptive attraction for partially
oxidized Fe and Mn. The contaminants are held in the filter bed allowing the total oxidizing
reaction to occur in the filter. The filter media is cleaned by reversing the flow using
processed water. The filter effluent is continuously monitored with a chlorine residual
analyzer to ensure complete oxidation of contaminants and disinfection of the treated water.
For all three well sites, Pureflow recommends their C-3000 filter system, with a filter vessel
of 7-foot diameter and 21-foot straight side shell. The filtration -loading rate averages
between 9 to 11 gpm/ft2. The backwash rate is 20 gpm/ft2 for 4 minutes.
6.3 Sequestration Using Polyphosphate
A few vendors were contacted for the sequestration option, but only one company provided
information for evaluation of this treatment option. SPER Chemical recommends their
Sequest-All Potable Water System for all three (or four) wells. The system simply consists
of an injection pump (LMI model AA 151-490H1) that injects the chemical into discharge
pipe from the well. Sequest-All is a blend of granular or liquid polyphosphates, each having
different properties that enhance the overall ability and function of the product. Sequest-All
will inactivate minerals including iron, calcium, and manganese preventing scale buildup
and "red water'. According to SPER Chemical, it can also slowly soften and remove
existing scale present within the water distribution system and it suppresses both anodic
and cathodic electrochemical reactions along with depositing a protective coating effectively
reducing corrosion rates. The chemical also comes in liquid form, in which case a
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200-gallon tank and mixing system would be required. The system is designed to be stable
under otherwise extreme conditions of temperature and time. As mentioned previously, it
should be noted that polyphosphate sequestration does not remove Fe and Mn but rather
stabilizes them in water to attenuate the effects of Fe and Mn.
Sequestration is only needed at the wells with high Fe and Mn levels, and a system -wide
application of polyphosphate injection is not necessary, as blending of sequestered and
non -sequestered water does not pose any water quality degradation issues.
However, enough time should be allowed for Fe and Mn to completely react with
polyphosphate (at least 15 to 30 seconds) before chlorine is injected. If chlorine or another
oxidant is injected too soon after polyphosphate injection, Fe and Mn may not be
completely sequestered and may precipitate out in the distribution system. Thus, the actual
time required between polyphosphate injection and chlorine injection to allow effective
sequestration must be tested prior to system installation.
The recommended dosage and usages for each well are listed in Tables 1.8 and 1.9.
Table 1.8 Recommended Dosage for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well No. Dosage (mg/L as PO4)
12 1.5 - 2.75
14 2 4
17 1.5 - 1.75
20 1.75 - 2.25
Table 1.9 Chemical Usages for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well Granular Form Liquid Form
12 (700 gpm) 0.53 Ibs - 0.96 lbs. per well hour 0.13 gal - 0.24 gal. per well hour
14 (1,350 gpm)
1.35 lbs - 2.71 lbs. per well hour
0.33 gal - 0.68 gal. per well hour
17 (1,750 gpm)
1.30 lbs- 1.55 lbs. per well hour
0.33 gal - 0.39 gal. per well hour
20 (1,460 gpm)
1.28 lbs - 1.65 lbs. per well hour
0.32 gal -'0.41 gal. per well hour
7.0 PRELIMINARY CAPITAL AND O&M COSTS FOR SELECTED
TREATMENT SYSTEMS
Preliminary cost estimates are provided below for planning purposes. Cost estimates are
based on information provided by the vendors and other similar projects completed
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recently. It should be noted that these are planning level costs with an estimated accuracy
of +30 percent to -20 percent. These estimates reflect professional opinion of accurate
costs at this time and are subject to change depending on the final design. Engineers have
no control over variances in the cost of labor, materials, equipment, services provided by
others, contractor's methods of determining prices, competitive bidding or market
conditions, practices, or bidding strategies.
7.1 Assumptions Used to Develop Preliminary Cost Estimates
The following is a list of assumptions used in preparing the budget level capital and O&M
costs:
1. One system will be installed for Wells 12 and 17, as only one of these wells will be in
operation at any given time.
2. The wells operate 24 hours per day, 6 days per week (Monday through Saturday).
3. Water Quality: Table 1.1, presented earlier, shows the historical data of the Fe and
Mn concentrations in the wells. The median concentration of Fe in the wells ranges
from 88 to 94 lag/L; while the median Mn concentration ranges from 120 pg/L to
480 lag/L. However, for the purpose of establishing a cost estimate, the historical
maximum data was used. The design values for the contaminants are listed in
Table 1.10.
Table 1.10 Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well
Well
Well
Well Finished
Parameters No. 12
No. 14
No. 17
No. 20 Water Goal
Manganese, lag/L 180
430
120
110 40
Iron, fag/L 1,300
2,200(')
140
740 240
pH 7.8-7.9
7.4-8.2
7.6-7.9
7.7-8.0 -
Hardness, mg/L as CaCO3 212-220
240-300
200-217
190-200 -
Alkalinity, mg/L as CaCO3 190-210
180-240
180-200
170-210 -
Flow Rate, gpm 700
1,350
1,750
1,460 -
Notes:
(1) The historical maximum iron concentration of 5,400 lag/L for Well 14 was not used, as
this data may be erroneous.
4. The treatment goal is set to the 80 percent of the respective contaminant MCLs.
Table 1.9 presents the finished water goal for each contaminant to be used as a basis
for the treatment system.
5. The chlorine -dosing requirement is calculated based on Fe and Mn concentrations
only.
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6. The calculation of pounds per year of sodium hypochlorite needed was based on the
typical stoichiometric (chlorine to Fe and Mn ratio) without major chlorine demand and
does not take into account any organic or other constituents in the water that may
affect chlorine demand.
7. Power costs are based on the unit cost of $0.09/kWhr provided by the City.
8. Mid -point of construction is January 2010. This is based on DHS' requirement of the
City to construct and build the system in three years once the waiver survey is
completed. Since the waiver survey has to be signed and completed by
August 29, 2007, the City would need to start construction of the system by summer
of 2009, assuming one-year construction time. This would put January 2010 as the
mid -point of construction for cost estimate purposes.
9. Estimated project costs (2007 dollars) will be escalated with an annual rate of
8 percent to determine mid -point construction dollars (2010 dollars).
10. Amortized capital cost is based on 20 years and 6-percent interest rate.
11. O&M Costs will also be escalated to January 2010 using a standard inflation rate of
3 percent.
7.2 Equipment Capital Cost Estimates
The capital cost estimates of the treatment systems are based on various sources,
including quotes from commercial system providers, recent projects, and other standard
cost estimating tools available. Equipment costs from various vendors may not be
comparable since the equipment supplied from each vendor is configured differently, such
as chemical feed set-up, the number of vessels, etc.
Table 1.11 lists items included and excluded in the cost estimates.
Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
1. Items Included in the Cost Estimates:
• Equipment Purchase (vessels, valves, etc).
• Media.
• Delivery and Setup.
• Installation and Start-up Equipment.
• System Hook-up.
• Yard Piping.
• Electrical.
• Instrumentation.
• Engineering, Legal, and Administration.
• Contingency.
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Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
2. Items Not Included in the Cost Estimates:
• Building.
• New Sewer Connection.
• Permitting.
• Disinfection System.
7.3 Cost Estimates for the Iron and Manganese Oxidation and Filtration
Treatment System
7.3.1 Capital Cost Estimate of Iron and Manganese Treatment System
The unit equipment cost estimates for the oxidation and filtration systems offered by the
three vendors for each of the three sites are summarized in Tables 1.12 to 1.14.
Table 1.12 Iron/Manganese Equipment Cost -Alternative 1 Loprest System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Water Source Process Description and Items Equipment Costs
Wells 12 and 17 Greensand and anthracite filter vessel (two $400,000
horizontal pressure tank 8 ft by 16 ft); Chemical
feed system.
Well 14 Greensand and anthracite filter vessel (One $290,000
horizontal pressure tank 8 ft by 32 ft); Chemical
feed system.
Well 20 Greensand and anthracite filter vessel (one $260,000
horizontal pressure tank 8 ft by 24 ft); Chemical
feed system.
Total $950,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Equipment
Supplier
Process Description and Items
Costs
Well Nos. 12
Reaction Vessel No. 1 with sodium hypochlorite
$420,000
and 17
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 21-foot straight side shell, working pressure
of 60 psi) with chemical feed systems, plus reclaim
system (without the reclaim tank).
Well No. 14
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-foot straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Well No. 20
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-foot straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Total
$1,110,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Supplier
Process Description and Items
Equipment Costs
Well Nos. 12
One filter vessel (7-foot diameter with a 21-foot
$500,000
and 17
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 14
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 20
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Total
$1,500,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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The total capital cost estimate for the oxidation and filtration systems from the three
vendors are presented in Table 1.15. On an annualized basis, (amortized over 20 years at
6-percent interest rate) the capital cost varies between $440,000 and $600,000 per year.
Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and
Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Equipment Cost:
$950,000
$1,110,000
$1,500,000
• Vessels.
• Valves and Gauges.
• Flow Meters.
• Media.
• Chlorine Analyzer.
• Filter Control Panel.
• Start-up and Training Services.
• Backwash Reclaim Pump.
$30,000
Included
Included
• Sales Tax.
$76,000
$86,000
$116,00
• Freight Charge.
$20,000
$20,000
Included
• Subtotal (Oxidation/Filtration plus Backwash
$1,080,000
$1,220,000
$1,620,00
Reclaim Pump.
• Backwash Reclaim Tank.
$410,000
$410,000
$410,000
SUBTOTAL (EQUIPMENT COST)
$1,480,000
$1,620,000
$2,020,000
Contractor Markup Cost (15%)
$223,000
$244,000
$304,00
Installation Cost:
• Installation including Yard Piping and site
$670,000
$730,000
$910,00
work (45%).
SUBTOTAL (INSTALLED COST)
$2,370,000
$2,598,000
$3,239,00
Construction Cost:
• Electrical (15% of installed cost).
$360,000
$390,000
$486,000
• Instrumentation (10% of installed cost).
$237,000
$260,000
$324,000
SUBTOTAL (CONSTRUCTION COST)
$2,970,000
$3,250,000
$4,050,00
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Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and
Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Project Cost:
• Engineering, Legal, and Administrative (25%).
$742,000
$812,000
$1,012,00
• Construction Management (10 %).
$297,000
$325,000
$405,00
Contingency (35%).
$1,039,000
$1,137,000
$1,417,00
TOTAL PROJECTED CAPITAL COST
$5,050,000
$5,520,000
$6,880,00
AMORTIZED CAPITAL COST (20 years,
$440,000
$480,000
$600,00
6% interest rate)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
7.3.2 O&M Costs for the Fe/Mn Treatment System
O&M requirements by each treatment system are listed in Table 1.16. Orders of magnitude
O&M costs for commercially available oxidation/filtration processes are presented in
Table 1.17. O&M costs include the use of oxidant, media replacement, and electrical costs,
sludge hauling and disposal costs, and labor. The annual O&M cost is estimated to be
between $260,000 to $320,000.
Table 1.16 Oxidation and Filtration O&M Requirements
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
O&M Items Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Oxidant Usage - Chlorine
(12.5%)
• Well Nos. 12 and 17 Well 12 - 2.2 mg/L NA 1.25 mg/L
(20 Ibs/day)
(26 Ibs/day)
Well 17 - 0.9 mg/L
(20 Ibs/day)
• Well No. 14
3.6 mg/L
NA
2.95 mg/L
(60 Ibs/day)
(48 Ibs/day)
• Well No. 20
1.5 mg/L
NA
1.61 mg/L
(27 Ibs/day)
(28 Ibs/day)
Sludge Disposal Volume (gal)
71,000
NA
NA
Electricity
NA
NA
268 kWh/day
Media Replacement
$60/ft3
NA
NA
1,150 ft3 (lasts for
10 years)
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1-22
Table 1.17 Iron/Manganese System Annual O&M Cost Estimate
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alt 1 - Alt 2 - Alt 3 -
Category Loprest Filtronics Pureflow
Oxidant Use (e.g., chlorine)(') $50,000 $12,000 $49,00
Media Replacement(2) $8,500 $1,500 N
Electrical Costs(3) $10,000 $4,000 $6,50
Sludge Hauling Cost(') $15,000 $15,000 $15,00
Sludge Disposal(5) $5,000 $5,000 $5,00
Replacement Parts and Valves (allowance - 5% $74,000 $76,000 $95,00
equipment cost)
Labor (8 hours per day, $60/hr)(6) $150,000 $150,000 $150,00
Total Annual O&M Cost $310,000 $264,000 $320,00
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%). Escalate at 3% to 2010.
(1) Assume $2.1/gallon for Sodium hypochlorite (12.5% assume 1.3 SG, Cost was
provided by the City.
(2) Media cost for Loprest was based on $60/ft3, media has shelf life of 10 years, for
Pureflow media, minimal media loss per year and no requirement of media change out.
(3) Assume control panel and chemical pump operating 24 hours/day, 6 days a week,
reclaim pump works 6 hours/day.
(4) Assume $0.25/gallon for sludge hauling.
(5) Estimated based on past projects. The final cost will depend on feed water quality,
which will affect chemical dosing and sludge volume. It will also depend on final
disposal site location.
(6) Assume about 8 hours per day of labor needed for these systems.
7.3.3 Total Annualized Cost for Oxidation and Filtration
Table 1.18 shows the total annualized costs of each oxidation and filtration system, capital
cost plus annual O&M cost in 2007 dollars and mid -point construction dollars (January
2010).
Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $440,000 $480,000 $600,000
Annual O&M Costs ($) (Year 2007) $310,000 $260,000 $320,000
Total Annualized Cost ($) 2007 $750,000 $740,000 $920,000
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Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs ($) $6,200,000 $6,700,000 $8,400,000
Annualized Project Costs ($) $540,000 $590,000 $730,000
Annual O&M Costs ($) (Year 2010) $330,000 $280,000 $350,000
Total Annualized Cost ($) 2010 $870,000 $870,000 $1,100,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
Based on the total annualized costs listed above, Alternatives 1 and 2 have the lowest cost.
7.4 Cost Estimates for the Iron and Manganese Sequestration System
The sequestration system (same for all wells) consists only of an injection pump and cost of
installing an injection tap at the well site if using the liquid chemical. Additional equipment is
required as mentioned earlier if the granular form of the chemical is used. Table 1.19 lists
the estimated capital costs.
Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Items
Liquid
Granular
Equipment Costs:
• Injection Pumps.
$5,800
$5,800
• Injection Tap.
$800
$800
• Tank Assembly (200-gallon tank and mixing
NA
$17,000
system).
• Disinfection Control System Upgrade.
$40,000
$40,000
• Sales Tax (7.75%).
$3,600
$5,000
TOTAL EQUIPMENT COST
$50,000
$69,000
Contractor markup cost (15%).
$7,500
$10,00
Installation Costs:
$23,000
$31,000
• Installation Including Yard Piping and Site
Work (45%).
TOTAL INSTALLED COSTS
$80,000
$110,000
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Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and
Manganese Treatment
City of Vernon
Items
Liquid
Granular
Construction Cost:
• Electrical (15% of installed cost).
$12,000
$17,000
• Instrumentation (10% of installed cost).
$8,000
$11,000
TOTAL CONSTRUCTION COSTS
$100,000
$138,000
Project Cost:
• Engineering, Legal, and Administrative (25%).
$25,000
$34,000
• Construction Management (10%).
$10,000
$14,000
• Contingency (35%).
$35,000
$48,000
TOTAL PROJECTED CAPITAL COST
$170,000
$230,000
AMORTIZED CAPITAL COST (20 years,
$15,000
$20,000
6% interest)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
The estimated O&M costs based on the recommended chemical usage rate are shown in
Table 1.20.
Table 1.20 Estimated O&M Cost for Sequestration System (for High Concentration)
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Liquid Granular
Sequestering Chemical(') $104,000 $95,000
Freight Charges(2) $38,000 $20,300
Replacement Parts and Valves (Allowance - 5% $2,500 $3,500
equipment cost)
Labor (4 hours per day, $60/hr)(3) $74,900 $74,900
Total Annual O&M Costs $219,000 $194,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on vendor quotes, for liquid media $513 per 55-gal drum (625-Ibs poly drum), for
granular media $647 per 323 Ibs (30-gal steel drum), based on 24 hr/day, 6 days per
week.
(2) Freight charge - Granular: $190/drum, $521 per four drums, $878 per eight drums;
Liquid: $292 per drum, $836 per four drums, and $1,250 per eight drums.
(3) Assumed a maximum of 4 hours per day of labor at $60/hr rate.
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The total annualized costs for sequestration treatment system in June 2007 dollars and
January 2010 dollars (mid -point construction) are summarized in Table 1.21.
Table 1.21 Total Annualized Costs for Sequestration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Liquid
Granular
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $15,000
$20,000
Annual O&M Costs ($) (Year 2007) $219,000
$194,000
Total Annualized Cost ($) 2007 $234,000
$214,000
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs $207,000
$281,000
Annualized Project Costs ($) $18,000
$24,000
Annual O&M Costs ($) (Year 2010) $236,000
$209,000
Total Annualized Cost ($) 2010 $254,000
$233,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
8.0 SUMMARY AND RECOMMENDATION
Based on the findings from the feasibility study, the following key points are presented in
this report:
• The iron level ranges from 140 to 2,200 lag/L and manganese level ranges from 110
to 430 lag/L. These were the historical maximum data and were used as the basis for
estimating the cost of treatment.
• The total design flow rate for all four wells averages about 4,560 gpm. Based on the
production data provided by the City for the last three years, the total average
production from these wells is estimated to be 3,200 AFY.
• An oxidation/filtration system is recommended to treat Fe and Mn from the well water.
Chlorine or potassium permanganate is recommended as the chemical to be used for
oxidation. Proprietary media or greensand media can be used for filtration.
• Based on DHS's requirement of 3 years to construct from the completion of the
waiver process, the mid -point of construction is estimated to be January 2010.
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Three major equipment suppliers have been contacted and three estimates have
been obtained for oxidation and filtration. Filtronics, Loprest, and Pureflow have
provided costs.
The total projected capital costs (2010 dollars) for the treatment plants
(oxidation/filtration system) are estimated to be in the range of $6,200,000 to
$8,400,000 and the amortized capital cost is expected to be between $540,000 and
$730,000. The capital costs include equipment, media, delivery and setup, installation
and start-up, instrumentation, engineering, legal, and administration, with a
35-percent contingency.
The projected annual O&M costs (2010 dollars) are estimated to be approximately
$280,000 to $350,000. These O&M costs cover oxidant use, media replacement,
labor costs, and electrical costs. Sludge hauling and disposal cost allowances were
included, but refined costs are needed once the disposal facility is identified for this
project.
• The total annualized costs in 2010 (mid -point construction) dollars range from
$870,000 to $1,100,000.
• An oxidant demand test can be done at the bench scale to better estimate the
chemical dose requirement and the cost for such tests can be provided once the
scope of the test is defined if needed.
• Although sequestration is not a removal process and not considered as a compliance
alternative, the costs are included in the evaluation for comparison purposes per
City's request.
• The total projected capital costs (2010 dollars) for the sequestration system ranges
from $210,000 for a liquid phosphate system to $280,000 for a granular
polyphosphate system. The annual O&M costs (2010 dollars) are estimated to be
about $236,000 for liquid phosphate or $210,000 for granular polyphosphate.
Table 1.22 summarizes the pros and cons of doing nothing, using an oxidation filtration
treatment system, and using sequestration to treat/mitigate the Fe and Mn in the City water
supply.
DRAFT - July 9, 2007 1-27
H:\Client\Vemon_SAOW\7708A00\TM\TM01 FINAL.doc
Table 1.22 Pros and Cons of Alternatives for Fe and Mn
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change 0
Does not cost anything. &
Does not address iron and
•
Does not change the
manganese issue.
current condition of water. •
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning &
Removes the impact of
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost •
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for iron
temperature.
and manganese.
May have negative impacts
on customers' internal
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and •
Full removal of iron and 0
Costs more than other
Filtration Treatment
manganese.
alternatives.
System (using
•
chlorine solution)
Proven process for iron 0
Rate increase is expected.
and manganese.
Table 1.23 summarizes the cost estimates of each system for the recommended oxidation
and filtration treatment system and the sequestration treatment system in 2010 dollars. In
order to put these numbers into perspective, the unit costs of the product water are
calculated and presented in Table 1.23. The costs of the most expensive system for each
treatment method are used for the comparison. This is to provide the most conservative
estimates for the unit costs of the product water.
Table 1.23 Summary of Cost Estimates - in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/ System
Filtration System (Sequestration
Cost (Pureflow) - Liquid)
Project Capital Cost $8,400,000 $210,000
Amortized Capital Cost (20 years, 6% interest $730,000 $18,000
DRAFT - July 9, 2007 1-28
H:\Client\Vemon_SAOW\7708A00\TM\TM01 FINAL.doc
Table 1.23 Summary of Cost Estimates- in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/
System
Filtration System
(Sequestration
Cost (Pureflow)
- Liquid)
rate)
Annual O&M Cost $350,000
$236,000
Total Annualized Cost $1,100,000
$254,000
Additional Annual Water Treatment Cost ($/AF)(') $343.8
$79.4
Additional Annual Water Treatment Cost $1.05
$0.24
($/1,000 gal)(')
Additional Annual Water Treatment Cost $0.79
$0.18
($/100 ft)(1)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to-20%).
(1) The Total water production is based on the last three years production data.
Based on the estimated project costs shown in Table 1.23, the City estimates that up to a
21 percent City-wide increase in the user rate would be required to undertake treatment of
the well water to remove Fe and Mn. The additional annual water treatment costs shown in
Table 1.23 are for the wells that require either treatment or conditioning, and the increase in
these costs for the subject wells was used by the City to calculate the City-wide increase in
the commodity cost of water. This will increase the current user rates from $1.16/100 ft3 to
$1.41/100 ft3. If sequestration were used, the City estimates that up to a 5 percent increase
in the user rate would be required, from the current $1.16/100 ft3 to $1.22/100 ft3.
DRAFT - July 9, 2007 1-29
H:\Client\Vemon_SA01M7708A00\TM\TM01 FINAL.doc
SURVEY VOTE FORM - CITY OF VERNON
IRON AND MANGANESE COMPLIANCE
Subject: Water Quality Compliance for Iron and Manganese
Please select one alternative. Not casting a vote will count as a vote for full treatment (Alt 3).
Iron and Manganese Compliance Vote - Select Only One Alternative
Alternative Processes
Increase in the
Commodity Cost
of Water
Check Only One
Box
Alt 1 - No Change (No Treatment)
0%
Alt 2 - Conditioning System
(Sequestration)
0 Up to 5%
Alt 3 - Oxidation and Filtration
Treatment System
0 Up to 21 %
1-1
• Alt 1 - Existing water quality is acceptable in terms of iron and manganese. I VOTE
NO CHANGE.
• Alt 2 - Existing water quality is NOT acceptable. I WANT THE WATER
CONDITIONED WITH CHEMICALS (SEQUESTERATION), AND I ACCEPT AN
INCREASE IN THE WATER COMMODITY COST OF UP TO 5%. 1 understand that
this is a temporary measure (9 years) allowed by the State and that this option may
result in iron and manganese settling in water when it is heated and may otherwise
affect internal water treatment processes at my home or business.
• Alt 3 - Existing water quality is NOT acceptable. I WANT THE WATER TREATED
TO REMOVE IRON AND MANGANESE WITH OXIDATION AND FILTRATION,
AND I ACCEPT AN INCREASE IN WATER COMMODITY COST OF UP TO 21 %.
Site Address
Print Name
Signature
Date
PLEASE RETURN THIS SURVEY USING THE SELF ADDRESSED STAMPED ENVELOPE BY
JULY 30, 2007.
A PUBLIC HEARING WILL BE HELD ON AUGUST 20, 2007 AT 10 AM. TO PRESENT THE
RESULTS OF THE SURVEY.
If you have any concerns or comments you may contact Scott B. Rigg at (323) 583-8811
extension 279 or forward to his attention at 4305 Santa Fe Ave, Vernon, CA 90058.
July 2, 2007
Subject: Iron and Manganese Compliance Survey Vote
Dear Customer:
INTRODUCTION
The State Department of Public Health (DHS) has ordered the City of Vernon to comply with the
regulations for iron and manganese levels in the City's drinking water. These regulations have
been established to improve the aesthetics of your drinking water. The median concentration of
iron in the City's wells ranges from 88 to 94 micrograms per liter (pg/L) while the median for
manganese concentration ranges from 120 to 480,ug/L. The limits in terms of the regulations are
50 pg/L for iron and 300,ug/L for manganese. Currently, the levels of iron and manganese DO
NOT cause health issues but can cause aesthetic concerns such as taste, staining of cloths and
plumbing fixtures, and brown water events under certain conditions.
The DHS advised the City that treatment for removal of iron and manganese must be undertaken
unless a waiver is obtained through a customer survey and vote.
The basis for granting waivers is the degree of consumer acceptance of existing water quality and
the CUSTOMER'S WILLINGNESS (OR UNWILLINGNESS) TO PAY THE COST of meeting these
water quality standards.
PLEASE REMEMBER THAT IF YOU DO NOT VOTE, YOU WILL BE CONSIDERED TO BE IN
FAVOR OF FULL TREATMENT AND YOU WILL BE WILLING TO BEAR THE ADDITIONAL
COST. In other words, if a majority of customers do not respond to this survey or vote for
treatment, DHS will require compliance with the regulations through treatment. You are strongly
encouraged to evaluate this matter and vote by completing the attached "Survey Vote form". The
survey form shall be picked up by the City staff no later than August 1, 2007.
BACKGROUND
The City retained Carollo Engineers to prepare an engineering report to comply with DHS
requirements. The report was completed by Carollo Engineers and reviewed by the City staff and
DHS. Copies of the full report are available for review at the City of Vernon located at 4305 Santa
Fe Avenue or at the City web -site www.cityofvernon.org.
The report indicates that either chemical conditioning to prevent iron and manganese from settling
in the water, or treatment of the water to remove iron and manganese using oxidation and
filtration are the most feasible methods to improve the water quality and comply with DHS
requirements. The advantages and disadvantages of three final alternatives are shown in Tablet.
Table 1 Pros and Cons of Alternatives for Iron and Manganese Compliance
Alternative
Processes Advantages Disadvantages
Alt 1. No Change 0
Does not cost anything. 0
Does not address iron and
•
Does not change the
manganese issue.
current condition of water. •
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning •
Removes the impact of •
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost •
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for
temperature.
addressing elevated
May have negative impacts
levels of iron and
on customers' internal
manganese.
processes that involve
treating or heating water.
• Waiver needs to be
reapplied every 9 years.
• Rate increase is expected.
Alt 3. Oxidation and . Full removal of iron and Costs more than other
Filtration Treatment manganese. alternatives.
System (using
chlorine solution) 0 Proven process for iron • Rate increase is expected.
and manganese removal.
The estimated project cost including loan fees and contingencies is estimated to be up to $8.4
million for the oxidation and filtration treatment system (Alt 3). The conditioning system (Alt 2)
using a polyphosphate chemical to help prevent iron and manganese precipitation is estimated to
cost up to $210,000.
The City staff has reviewed financing options and has found that THE LEAST EXPENSIVE
OPTION IS TO USE CONDITIONING CHEMICALS (Alt 2 - SEQUESTRATION) TO HELP
PREVENT IRON AND MANGANESE PRECIPITATION. Up to a 5 percent increase in the
commodity cost of water beyond the present minimum payment is expected. It should be noted,
however, that the performance of sequestration chemicals is sensitive to temperature, and iron
and manganese may settle out under certain conditions where water is heated for use. Water
conditioning may also have negative impacts on some customers' internal processes, such as
water filtration equipment.
FULL TREATMENT TO REMOVE IRON AND MANGANESE (Alt 3) WILL INCREASE THE
WATER COST BY UP TO 21 PERCENT. Since iron and manganese are removed from the water,
this option is NOT sensitive to temperature and iron and manganese WILL NOT settle out.
Chemical conditioning and full treatment both have proven track records. The DHS will review and
approve any treatment system to ensure it meets all drinking water standards.
ESTIMATED COMPLIANCE COSTS
The decision as to which course of action the City will pursue must be made by the City's
customers. The choices and cost associated with each alternative are shown in Table 2.
Table 2 Cost Estimates for Iron and Manganese Compliance
Alternative Processes
Commodity Cost of Water Expected Rate Increase
Alt 1. No Change (current rate)
. $1.159 per 100 ft3 0 0%
Alt 2. Conditioning System
(Sequestration)
0 Up to $1.216 per 100 ft3 0 5%
Alt 3. Oxidation and Filtration
Treatment System
. Up to $1.406 per 100 ft3 0 21 %
In making the decision, each customer will be entitled to a single vote. If a majority of customers
vote in favor of Alternative 1, it will be construed as acceptance of existing water quality (in terms
of iron and manganese) and a waiver from the regulations will be sought from DHS. It is critical
that you cast the vote you are entitled to.
A public meeting to discuss the survey results will be held at the City offices at 10 a.m. on
August 20, 2007.
Sincerely,
City of Vernon
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COMMUNITY SERVICES & WATER DEPARTMENT
OFFICE MEMORANDUM
TO: Eric Fresch, City Administrator
FROM: Samuel Kevin Wilson, irector of Community Services & Water
DATE: August 13, 2007
SUBJECT: Survey Results - Iron & Manganese Treatment Alternatives
As you are aware, the Water Department delivered survey forms to City customers that provided three
alternatives to select from relating to treatment options for the removal of iron and manganese from impacted
water production facilities. The three alternatives are outlined below:
• Alternative No. 1: No Change (No Treatment);
• Alternative No. 2: Conditioning System (Sequestration); and
• Alternative No. 3: Oxidation and Filtration Treatment System.
The City delivered a total of 863 surveys and received back 653. According to the California
Department of Health Services (CDHS), more than 50% of the billed customers must have filled out a survey
form for the study to be valid. A final review of the survey's revealed that 75.66% of the customers responded
rendering the survey valid. However, the 210 surveys not returned must be calculated as votes for full treatment
and must be added to Alternative No. 3. With this said, the final tally is then 64 votes for sequestration, 257
votes for full treatment and 542 votes for no treatment. The City, based on the survey results, is now eligible to
request a 9-year waiver from the CDHS allowing the City to operate without providing any means of treatment
to remove iron and manganese from affected water production facilities.
In order to receive an official waiver, the City must provide the CDHS with a final hard copy of the
engineering report and survey prepared by Carollo Engineering. In addition, the results of the survey and a brief
report of the Public Hearing and minutes must be included with the engineering report. A Public Hearing has
been scheduled for August 20, 2007 to advise the community of the survey results.
SKW/sr
Enclosure
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NOTICE OF PUBLIC HEARING TO REVIEW THE RESULTS OF THE
CUSTOMER SURVEY REGARDING IRON & MANGANESE TREATMENT
ALTERNATIVES
The City of Vernon will conduct a Public Hearing, which you may attend.
PLACE: Vernon City Hall
City Council Chambers
4305 Santa Fe Avenue
Vernon, CA 90058
DATE & Monday, August 20, 2007 at 10:00 a.m.
TIME: (or as soon thereafter as the matter can be heard)
PURPOSE: To consider water treatment alternatives for the removal of iron and manganese
based on the customer survey results.
The City of Vernon has experienced slightly elevated levels of iron and manganese in its
water supply for the past several years. These minerals have no adverse effects on human health
and concerns are based solely on aesthetic issues. The California Department of Health Services
has requested that the City of Vernon prepare and Engineers Report and conduct a customer
survey to determine if Vernon water customers are experiencing water quality problems and if
they are willing to increase water rates in order to finance water treatment plants to remove the
iron and manganese from the water supply.
A copy of the Engineers Report and Survey form will be available for public review
during normal business hours in the Vernon Community Services & Water Department, located
at 4305 Santa Fe Avenue, Vernon, California, from August 1, 2007 to August 20, 2007.
The public is also invited to submit written comments prior to the hearing. You may
submit written comments on Engineers Report until 10:00 a.m. on August 20, 2007. Comments
received after that date may not receive full consideration.
The hearing may be continued or adjourned to a stated time and place without further
notice of a public hearing.
Dated: rl 17� [o 7
anuela Giron
City Clerk
AFFIDAVIT OF POSTING
I, Gary Sawyer, Utilityman R of the City of Vernon, do hereby certify that I did, on the
26th day of July 2007, post three (3) copies of the following:
NOTICE OF PUBLIC HEARING, to be held on August 20, 2007 (see attached copy)
to consider water treatment alternatives for the removal of iron and manganese based on the
customer survey results.
One in each of the following places to wit: At the northwest corner of 38th Street and
Santa Fe Avenue; the northeast corner of Leonis Boulevard and Pacific Boulevard; and on the
bulletin board located outside on the wall near the second floor entrance to the City Hall of said
City, located at 4305 Santa Fe Avenue, all in the City of Vernon, County of Los Angeles, State of
California, there being no newspaper of general circulation printed and published in the City of
Vernon.
Sign:
Gary Sawy r, Utilityman I
STATE OF CALIFORNIA )
COUNTY OF LOS ANGELES) ss.
CITY OF VERNON )
Date: %'2-6-0)
On 2,4 m q before me, Manuela Giron, Notary Public, personally
appeared William Wilson, personally known to me (or- known to fae en the basis of satisfaete
evidexee) to be the person whose name is subscribed to the within instrument and acknowledged
to me that he executed the same in his authorized capacity, and that by his signature on the
instrument the person, or the entity upon behalf of which the person acted, executed the
instrument.
WITNESS my hand and official seal.
.� --A
~' LeMMUELA GIRON
Commission # 1611388
Notary PUbIic - Colifornio
Los Angeles County
MV Comm. Expires Nov 4,2004
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COMMUNITY SERVICES & WATER DEPARTMENT
OFFICE MEMORANDUM
TO: Manuela Giron, CityClerk
FROM: Samuel Kevin Wilson,,;'Director of Community Services & Water
DATE: July 24, 2007
SUBJECT: Public Hearing Notice
The California Department of Health Services has requested that the City of Vernon prepare an
Engineer's Report and conduct a customer survey to determine if Vernon water customers are experiencing
water quality problems and if they are willing to increase water rates in order to finance water treatment to
remove the iron and manganese from the water supply. The Community Services and Water Department had its
consultant, Carollo Engineering, prepare the Engineer's Report and Survey form addressing the elevated levels
of iron and manganese in the City's water supply including the treatment removal alternatives available and the
costs associated with the those alternatives. The results of the survey will determine if the City will be granted a
waiver.
The City is required to have a public hearing to advise its customers of the results of the Survey. It is
recommended that a Public Hearing be set for August 20, 2007. Please sign the enclosed Public Hearing
Notice. Thank you.
SKW/sr
Enclosures
COMMUNITY SERVICES & WATER DEPARTMENT
OFFICE MEMORANDUM
TO: Eric Fresch, City Administrator
4;.%
FROM: Samuel Kevin Wilson, Director of Community Services & Water
DATE: July 16, 2007
CD
SUBJECT: Iron & Manganese Treatment of City Water
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S"IBUTIOW
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Title 22 of the California Code of Regulations establishes Secondary Containment Levels for drinking
water. Several of the City of Vernon wells have exceeded the secondary levels for iron and manganese. These
minerals have no adverse effects on human health and concerns are related specifically to aesthetic issues
including the remote possibility of objectionable tastes and water that has a slight reddish tint that has the
potential to stain cloths.
The California Department of Health Services has requested that the City of Vernon prepare an
Engineers Report and conduct a customer survey to determine if Vernon water customers are experiencing
water quality problems and if they are willing to increase water rates in order to finance water treatment to
remove the iron and manganese from the water supply. The Community Services and Water Department had its
consultant, Carollo Engineering, prepare the Engineer's Report and Survey form addressing the elevated levels
of iron and manganese in the City's water supply including the treatment removal alternatives available and the
costs associated with the those alternatives, copies of which are enclosed herewith.
The results of the survey will determine if the City will be granted a waiver. In order for the survey to
be valid more than 50 percent of the billed customers must have filled out and returned the survey form. In
addition, if a vote of no is received from a customer it will count as a vote for full treatment.
Survey forms will be hand delivered and picked up prior to August 1, 2007 to City customers who pay
the water bill. The City is required to have a public hearing to advise its customers of the results of the Survey
and has scheduled the hearing for August 20, 2007. Please place this item on the August 20, 2007 City Council
agenda. Thank you.
SKW/sr
Enclosures
SURVEY VOTE FORM - CITY OF VERNON
IRON AND MANGANESE COMPLIANCE
Subject: Water Quality Compliance for Iron and Manganese
Please select one alternative. Not casting a vote will count as a vote for full treatment (Alt 3).
Iron and Manganese Compliance Vote - Select Only One Alternative
Increase in the
Commodity Cost
Check Only One
Alternative Processes
of Water
Box
Alt 1 - No Change (No Treatment)
0%
Alt 2 - Conditioning System
. Up to 5%
(Sequestration)
Alt 3 - Oxidation and Filtration
0 Up to 21 %
Treatment System
• Alt 1 - Existing water quality is acceptable in terms of iron and manganese. I VOTE
NO CHANGE.
• Alt 2 - Existing water quality is NOT acceptable. I WANT THE WATER
CONDITIONED WITH CHEMICALS (SEQUESTERATION), AND I ACCEPT AN
INCREASE IN THE WATER COMMODITY COST OF UP TO 5%. 1 understand that
this is a temporary measure (9 years) allowed by the State and that this option may
result in iron and manganese settling in water when it is heated and may otherwise
affect internal water treatment processes at my home or business.
Alt 3 - Existing water quality is NOT acceptable. I WANT THE WATER TREATED
TO REMOVE IRON AND MANGANESE WITH OXIDATION AND FILTRATION,
AND I ACCEPT AN INCREASE IN WATER COMMODITY COST OF UP TO 21%.
Site Address
Print Name
Signature
Date
THIS SURVEY SHEET MUST BE PICKED UP BY THE CITY STAFF BY AUGUST 1, 2007 TO
BE VALID.
A PUBLIC HEARING WILL BE HELD ON AUGUST 20, 2007 AT 10 AM. TO PRESENT THE
RESULTS OF THE SURVEY.
If you have any concerns or comments you may forward them to Scott B. Rigg at
4305 Santa Fe Ave, Vernon, CA 90058.
July 2, 2007
Subject: Iron and Manganese Compliance Survey Vote
Dear Customer:
INTRODUCTION
The State Department of Public Health (DHS) has ordered the City of Vernon to comply with the
regulations for iron and manganese levels in the City's drinking water. These regulations have
been established to improve the aesthetics of your drinking water. The median concentration of
iron in the City's wells ranges from 88 to 94 micrograms per liter (pg/L) while the median for
manganese concentration ranges from 120 to 480 pg/L. The limits in terms of the regulations are
50 Ng/L for iron and 300,ug/L for manganese. Currently, the levels of iron and manganese DO
NOT cause health issues but can cause aesthetic concerns such as taste, staining of cloths and
plumbing fixtures, and brown water events under certain conditions.
The DHS advised the City that treatment for removal of iron and manganese must be undertaken
unless a waiver is obtained through a customer survey and vote.
The basis for granting waivers is the degree of consumer acceptance of existing water quality and
the CUSTOMER'S WILLINGNESS (OR UNWILLINGNESS) TO PAY THE COST of meeting these
water quality standards.
PLEASE REMEMBER THAT IF YOU DO NOT VOTE, YOU WILL BE CONSIDERED TO BE IN
FAVOR OF FULL TREATMENT AND YOU WILL BE WILLING TO BEAR THE ADDITIONAL
COST. In other words, if a majority of customers do not respond to this survey or vote for
treatment, DHS will require compliance with the regulations through treatment. You are strongly
encouraged to evaluate this matter and vote by completing the attached "Survey Vote Form". The
survey form shall be picked up by the City staff no later than August 1, 2007.
BACKGROUND
The City retained Carollo Engineers to prepare an engineering report to comply with DHS
requirements. The report was completed by Carollo Engineers and reviewed by the City staff and
DHS. Copies of the full report are available for review at the City of Vernon located at 4305 Santa
Fe Avenue or at the City web -site www.citvofvernon.org.
The report indicates that either chemical conditioning to prevent iron and manganese from settling
in the water, or treatment of the water to remove iron and manganese using oxidation and
filtration are the most feasible methods to improve the water quality and comply with DHS
requirements. The advantages and disadvantages of three final alternatives are shown in Tablet.
Table 1 Pros and Cons of Alternatives for Iron and Manganese Compliance
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change .
Does not cost anything.
•
Does not address iron and
•
Does not change the
manganese issue.
current condition of water.
•
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning
Removes the impact of
•
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost
•
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for
temperature.
addressing elevated
.
May have negative impacts
levels of iron and
on customers' internal
manganese.
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and •
Full removal of iron and
0
Costs more than other
Filtration Treatment
manganese.
alternatives.
System (using
chlorine solution) •
Proven process for iron
0
Rate increase is expected.
and manganese removal.
The estimated project cost including loan fees and contingencies is estimated to be up to $8.4
million for the oxidation and filtration treatment system (Alt 3). The conditioning system (Alt 2)
using a polyphosphate chemical to help prevent iron and manganese precipitation is estimated to
cost up to $210,000.
The City staff has reviewed financing options and has found that THE LEAST EXPENSIVE
OPTION IS TO USE CONDITIONING CHEMICALS (Alt 2 - SEQUESTRATION) TO HELP
PREVENT IRON AND MANGANESE PRECIPITATION. Up to a 5 percent increase in the
Commodity cost of water beyond the present minimum payment is expected. It should be noted,
however, that the performance of sequestration chemicals is sensitive to temperature, and iron
and manganese may settle out under certain conditions where water is heated for use. Water
conditioning may also have negative impacts on some customers' internal processes, such as
water filtration equipment.
FULL TREATMENT TO REMOVE IRON AND MANGANESE (Alt 3) WILL INCREASE THE
WATER COST BY UP TO 21 PERCENT. Since iron and manganese are removed from the water,
this option is NOT sensitive to temperature and iron and manganese WILL NOT settle out.
Chemical conditioning and full treatment both have proven track records. The DHS will review and
approve any treatment system to ensure it meets all drinking water standards.
ESTIMATED COMPLIANCE COSTS
The decision as to which course of action the City will pursue must be made by the City's
customers. The choices and cost associated with each alternative are shown in Table 2.
Table 2 Cost Estimates for Iron and Manganese Compliance
Alternative Processes
Commodity Cost of Water Expected Rate Increase
Alt 1. No Change (current rate)
• $1.159 per 100 ft3 • 0%
Alt 2. Conditioning System
(Sequestration)
• Up to $1.216 per 100 ft3 • 5%
Alt 3. Oxidation and Filtration
Treatment System
• Up to $1.406 per 100 ft3 21 %
In making the decision, each customer will be entitled to a single vote. If a majority of customers
vote in favor of Alternative 1, it will be construed as acceptance of existing water quality (in terms
of iron and manganese) and a waiver from the regulations will be sought from DHS. It is critical
that you cast the vote you are entitled to.
A public meeting to discuss the survey results will be held at the City offices at 10 a.m. on
August 20, 2007.
Sincerely,
City of Vernon
13
Hl
Signed: July 5, 2007 Signed: July 5, 2007
City of Vernon
DHS ENGINEERING REPORT ON IRON
AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
DRAFT
June 2007
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10540 TALBERT AVENUE, SUITE 200 EAST • FOUNTAIN VALLEY, CALIFORNIA 92708 • (714) 593-5100 • FAX (714) 593-5101
H:1ClienflVernon SAOWV708A001TM\TM01 FINAL.doc
3
City of Vernon
DHS ENGINEERING REPORT ON IRON AND MANGANESE TREATMENT
TREATMENT ALTERNATIVES AND COST ESTIMATES
TECHNICAL MEMORANDUM
NO. 1
TABLE OF CONTENTS
Page No.
1.0 BACKGROUND....................................................................................................1-1
2.0 EXISTING WATER SYSTEM................................................................................1-1
2.1 Water Supply........................................................... ...........1-2
.........................
2.2 Storage and Distribution System.................................................................1-2
3.0 WATER QUALITY.................................._..............................................................1-4
4.0 DRINKING WATER REGULATIONS....................................................................1-6
4.1
Iron..............................................................................................................1-6
4.2
Manganese.................................................................................................1-6
5.0 IRON AND MANGANESE ALTERNATIVE TREATMENT METHODS ... ...............
1-6
5.1
Oxidation and Filtration...............................................................................1-6
5.2
Sequestration..............................................................................................1-7
5.3
Ion Exchange..............................................................................................1-8
5.4
GAC............................................................................................................1-8
5.5
Membranes.................................................................................................1-9
5.6
Biological Filtration......................................................................................1-9
5.7
Fe/Mn Summary and Recommendation......................................................1-9
6.0 RECOMMENDED
TREATMENT TRAINS.............................................................1-9
6.1
Summary of Recommended Processes......................................................1-9
6.2
Oxidation/Filtration Treatment System.......................................................1-11
6.3
Sequestration Using Polyphosphate..........................................................1-15
7.0 PRELIMINARY
CAPITAL AND O&M COSTS FOR SELECTED TREATMENT
SYSTEMS...........................................................................................................1-16
7.1
Assumptions Used to Develop Preliminary Cost Estimates .......................1-17
7.2
Equipment Capital Cost Estimates............................................................1-18
7.3
Cost Estimates for the Iron and Manganese Oxidation and Filtration
TreatmentSystem ........................................ .......................................................
1-19
7.4
Cost Estimates for the Iron and Manganese Sequestration System ..........1-24
8.0 SUMMARY AND RECOMMENDATION..............................................................1-26
DRAFT - July 9, 2007
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t .-
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LIST OF TABLES
Table 1.1
City of Vernon Water Service Connections..................................................1-1
Table 1.2
Information About Existing Potable Water Wells..........................................1-2
Table 1.3
Historical Water Qualities of Well Nos. 12, 14, 17, and 20 ...........................1-4
Table 1.4
Advantages and Disadvantages of Fe/Mn Treatment Technologies ..........
1-10
Table 1.5
Summary of Available Oxidation Alternatives for Fe/Mn Removal .............1-10
Table 1.6
Summary of Available Filter Media for Fe/Mn Removal.............................1-11
Table 1.7
Oxidation and Filtration Systems for Fe and Mn........................................1-11
Table 1.8
Recommended Dosage for Sequestration Chemical from SPER Chemical1-16
Table 1.9
Chemical Usages for Sequestration Chemical from SPER Chemical ........1-16
Table 1.10
Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals ....1-17
Table 1.11
Treatment Cost Estimate Factors..............................................................1-18
Table 1.12
Iron/Manganese Equipment Cost -Alternative 1 Loprest System................1-19
Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System..............1-20
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System..............1-20
Table 1.15
Iron/Manganese System Capital Cost Estimate.........................................1-21
Table 1.16
Oxidation and Filtration O&M Requirements..............................................1-22
Table 1.17
Iron/Manganese System Annual O&M Cost Estimate................................1-23
Table 1.18
Total Annualized Costs for Oxidation and Filtration System ......................1-23
Table 1.19
Estimated Capital Cost for Sequestration System.....................................1-24
Table 1.20
Estimated O&M Cost for Sequestration System (for High Concentration)-1-25
Table 1.21
Total Annualized Costs for Sequestration System.....................................1-26
Table 1.22
Pros and Cons of Alternatives for Fe and Mn............................................1-28
Table 1.23
Summary of Cost Estimates - in 2010 Dollars...........................................1-28
LIST OF FIGURES
Figure 1.1 City of Vernon Service Area........................................................................1-3
Figure 1.2 Water System Schematic............................................................................1-5
Figure 1.3 Schematic of an Oxidation/Filtration System.............................................1-12
Figure 1.4 Schematic of a Sequestering System........................................................1-13
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Technical Memorandum No. 1
TREATMENT ALTERNATIVES AND COST ESTIMATES
1.0 BACKGROUND
The City of Vernon (City) is located near the geographic center of metropolitan Los Angeles
County, situated within 2 miles of four major freeways and near the site of Hobart Yard,
which is a major rail terminal for Los Angeles. Elevated levels of iron (Fe) and manganese
(Mn), both classified by the Environmental Protection Agency (EPA) as non -hazardous
contaminants, have been found in four of the City wells. Levels in the wells exceeded the
California Safe Drinking Water Act of 1986 (SDWA) secondary maximum contaminant level
(MCLs). Although these are secondary MCLs, the City is required either to comply with the
MCLs or to obtain a waiver in accordance with Title 22, Section 64449 of the California
Code of Regulations (CCR).
In order for the City to obtain a waiver on treatment and to comply with the CCR
requirement, the City needs to conduct a study to evaluate treatment alternatives and
develop costs for Fe and Mn treatment.
This report constitutes the requirements for the study. The cost information will be used as
a basis for developing rate increases to be included in the mailer survey to the residents to
vote whether or not the treatment option should be implemented.
2.0 EXISTING WATER SYSTEM
The City Water Department serves water to the majority of the City. A small portion of the
northeast corner of the City is served by California Water Service and a small area in the
southeast area of the City is served by Maywood Mutual No. 3. Figure 1.1 shows the City's
service area.
The City has approximately 45,000 daytime residents and 93 permanent residents. Based
on the City's 2006 Annual Report to the Drinking Water program, only 21 of the 1,760 active
connections were residential, and the remaining were mainly commercial and industrial.
The approximate annual water demand was estimated to be 11,000 acre-feet or 3.9 billion
gallons (2006 data). Table 1.1 summarizes the number and types of connections the City
currently has.
Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered I
General and Residential 16
Commercial 1,343
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Table 1.1 City of Vernon Water Service Connections
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Type/Category Metered
Industrial
Irrigation (Ag and Residential)
Total Active Connections
2.1 Water Supply
404
0
1,763
The primary water supply for the City is groundwater. In addition, the City has a direct
connection to the Metropolitan Water District of Southern California (MWD). The MWD
connection provides both a supplemental water source and an emergency supply in the
event of a major power outage. The City's ground water system is made up of eight active
wells and one inactive well. There is no treatment of the water other than chlorination.
Table 1.2 provides a summary of selected information about the nine wells.
Table 1.2
Information About Existing Potable Water Wells
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Date
Total
Ground
Capacity,
Well No.
Drilled
Perforated Intervals, ft
Depth, ft
Elevation, ft
gpm
11
5/23/1952
741-776, 816-826,
1,343
197.22
1,143
863-871, 983-997,
1,105-1,142, 1,163-1,186
12
11 /20/1953
996-1, 015, 1,067-1,169,
1,588
183.29
700
1,260-1,580
14
3/23/1962
360-1,251
1,302
203.75
1,351
15
10/27/1966
510-1,502
1,550
177.76
1,953
16
8/18/1970
510-1,460
1,520
197.22
1,450
17
11 /1 /1970
510-1,500
1,550
183.29
1,750
18
11 /30/1958
510-1,361
1,443
184.57
1,450
(inactive)
19
9/19/1988
510-1,550
1,660
180.45
1,380
20
9/23/1988
510-1,550
1,620
159.47
1,460
2.2 Storage and Distribution System
The City's water distribution system consists of 250,000 linear feet of pipe, six ground level
reservoirs, one elevated tank, and one belowground reservoir. The total storage capacity in
these facilities is 16 million gallons (MG). The average pressure in the distribution system is
about 75 psi.
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1-2
Figure 1.2 shows the City's overall distribution system. It is made up of three main booster
pump stations/plants. Booster Plant 1 is fed by Well Nos. 11 and 16, has a 10-MG
reservoir, and has five distribution pumps. A 24-inch MWD connection is also available at
this location. Booster Plant 2 is supplied by Well Nos. 12 and 17, has three 1-MG storage
tanks, and has six distribution pumps. Booster Plant 3 is supplied by Well Nos. 15 and 19,
has three 1-MG storage tanks, and has five distribution pumps. Well No. 19 can discharge
either directly to the distribution system or to the three storage tanks. The remaining three
wells, Well Nos. 14, 18, and 20, discharge directly to the distribution system without going
through any storage. In addition, the City also owns a 0.6-MG elevated storage tank.
3.0 WATER QUALITY
Overall, the groundwater quality of the City's wells is good. However, the groundwater
sources have a history of exceeding the secondary MCLs for Fe (300 lag/L) and Mn
(50 lag/L). Both of these secondary limits are regularly exceeded in water pumped from
Wells Nos. 12 and 14, while the Mn MCL is exceeded regularly in water pumped from Wells
Nos. 17 and 20. These findings have been noted in the Consumer Confidence Reports that
the City distributes to its customers annually.
Table 1.3 summarizes the water quality of the four wells for selected parameters.
Table 1.3
Historical Water Qualities.of Well Nos. 12, 14, 17, and 20
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Secondary
Well
Well
Well
Well
Parameter
Units MCL
No. 12
No. 14
No. 17
No. 20
Manganese
lag/L 50
54-180
40-1200
30-120
30-111
Iron
lag/L 300
ND-2,000
ND- 5,400
ND-144
ND-740
Sulfate
mg/L 250
79-82
75-110
62-67
50-79
TDS
mg/L 500
370-380
450-520
350-390
350-420
Alkalinity
mg/L —
190-210
180-240
180-200
170-210
Hardness
mg/L --
212-220
240-300
200-217
190-200
Bicarbonate
mg/L --
230-250
229-284
220-250
210-250
pH
--
7.8-7.9
7.4-8.2
7.6-7.9
7.7-8.0
Flow rate
gpm --
700
1,350
1750
1460
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4.0 DRINKING WATER REGULATIONS
4.1 Iron
The California Department of Health Services (DHS) has set a secondary MCL for Fe of
300 ug/L. Exceeding the suggested level usually results in discolored water, laundry, and
plumbing fixtures. This, in turn, results in consumer complaints and potential dissatisfaction
with the water utility.
4.2 Manganese
Based on the health effects, the California DHS has set a notification level for Mn, which is
currently at 500 ug/L. However, at concentrations exceeding 100 pg/L, Mn imparts an
undesirable taste and stains plumbing fixtures and laundry. These considerations lead the
EPA to set a secondary MCL of 50 lag/L for Mn in drinking water (Federal Register, 1979).
5.0 IRON AND MANGANESE ALTERNATIVE TREATMENT
METHODS
As mentioned earlier, the City can apply for a compliance waiver to meet the secondary
standards for Fe and Mn. However, the City is still required to evaluate the treatment
alternatives and report the findings to the DHS, under this option.
There are several treatment alternatives available for Fe and Mn control in a water
treatment plant. The most basic methods are chemical oxidation followed by clarification
and filtration. Other treatment alternatives are described in the following paragraphs and
include ion exchange, sequestering processes, biological removal, GAC, and membranes.
5.1 Oxidation and Filtration
Oxidation followed by filtration is the most popular process in the United States (U.S.) for Fe
and Mn removal. Under reducing conditions, Fe and Mn are stable as soluble forms
(ferrous [Fe 21 and manganous [Mn2+] ions). When they are oxidized, they become insoluble
ferric (Fe 3) and manganic hydroxide (Mn3+) species, and these can be physically removed
with a filtration process.
Chlorine and potassium permanganate are common oxidants applied in commercial
packaged systems. It has been reported that soluble Mn (II) was rapidly oxidized by
potassium permanganate, chlorine dioxide, and ozone in low dissolved organic carbon
(DOC) waters. When chlorine is used as an oxidant, it may react with natural organic matter
in the raw water to form trihalomethanes (THMs) and haloacetic acids (HAAs), which are
regulated contaminants under the Stage 2 Disinfectants/Disinfection By-products (DBPs)
Rule (D/DBPR). Therefore, if halogenated DBPs are an issue, other oxidants may offer
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benefits compared to chlorine, such as potassium permanganate, ozone, and chlorine
dioxide. In the City's case, it is not an issue since the water organic content is expected to
be low.
Optimal Mn oxidation occurs in the pH range of 8.0 to 8.5. Chlorine dosages as high as
five times the theoretical stoichiometric requirements may be necessary to oxidize Fe and
Mn within reasonable detention times. Potassium permanganate is a stronger oxidant than
chlorine and chlorine dioxide and can be effective with regard to dissolved Mn oxidation at
pH values above 7.5. The rates of reactions of Fe and Mn with permanganate are very fast
and could minimize the space requirement by eliminating the reaction vessel sometimes
needed with chlorine oxidation. However, the chemical is more expensive than chlorine.
Once oxidized and precipitated, particulate Fe and Mn must be removed from the water.
Several technologies are available and have been applied to accomplish this solids
separation step. Dual -media filters with anthracite and sand are commonly used for solids
separation in the water treatment and can be applied for the removal of Fe and Mn. Fe and
Mn can also be removed with a catalytic filter media that uses oxygen in the water to
convert metal ions from a soluble form to an insoluble form. This insoluble precipitate is
then filtered out onto the surface of the media.
Most of the commercial systems use Mn greensand medium, which is a term used for
naturally rich Mn dioxide minerals, which promote adsorption of dissolved Mn or other
proprietary media. Greensand medium can also serve for physical removal of ferric
hydroxide and ferric oxide precipitates.
5.2 Sequestration
Sequestration means preventing the formation of objectionable color and turbidity without
actually removing the Fe and Mn. It is the addition of chemicals to groundwater aimed at
controlling problems caused by Fe and Mn. These chemicals are usually added to.
groundwater at the wellhead or at the pump intake before the water has a chance to come
in contact with air or chlorine. This ensures that the Fe and Mn stay in the soluble form.
Polyphosphate is one of the sequestering agents that can bond with Fe and Mn and thus
prevent them from precipitating in water. Although this approach requires only minor
modifications to any existing system, it does not provide a permanent solution (removal) for
high Fe and Mn concentrations. Furthermore, depending on the type of polyphosphate
used, the Fe -polyphosphate complex may break down when heated. The Fe and Mn
released may then cause a problem such as precipitation or staining. Thus,
high -temperature processes or laundries using hot water may experience potential
problems when sequestering agents are used. Furthermore, sequestration of Fe and Mn
may pose negative effects on some of the City's customers' internal processes. If a
customer is using some type of oxidation and filtration processes to remove Fe and Mn
from the tap water, this process may not operate as designed because the sequestered Fe
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and Mn are complexed (bound) with the polyphosphate. That is, Fe and Mn would not be
removed from the water. Another process that may be affected by the sequestration
process is reverse osmosis (RO) filtration. The polyphosphate agent and sequestered
compounds could increase the fouling potential on the RO membranes. Additional
pretreatment processes could be required for removal of these compounds to prevent
membrane fouling. In addition, there may be other potential interferences from
polyphosphate on different types of water treatment and manufacturing processes, but it is
difficult to ascertain exact impacts without detailed information about these processes.
In terms of chemical dose, theoretically, there is no limit to the amount of soluble Fe and Mn
that would make sequestration an effective mitigation method. However, various studies
have reported some upper limits for chemical sequestration of Fe and Mn. The National
Drinking Water Clearing House states that sequestration followed by chlorination can be
effective for water containing less than 1,000 pg/L Fe and 300 pg/L Mn. According to the
California Department of Health Services Policy Memo 2001-1 Secondary Standards,
various levels of Fe and Mn up to 5,000 pg/L have been cited as the economical and
technical limit for effective mitigation method. The policy also states that levels above
2,000 pg/L are less likely to be successfully mitigated with polyphosphates based on their
experience. If sequestration is selected, bench- or pilot -scale testing is highly
recommended to evaluate the feasibility and effects of using this method to address the Fe
and Mn issues in the groundwater.
Sequestering agents are injected via a chemical metering pump at the wellhead before
other chemical additives (chlorine, fluoride, caustic soda, etc.). If permissible, these agents
are injected down the well casing to mix with groundwater at the pump intake.
5.3 Ion Exchange
The ion exchange process involves exchange of soluble ionic species. Application of
softening in water treatment for Fe and Mn removal is limited since it can only be used
where Fe and Mn exist completely in the soluble forms. In addition, the.system should be
airtight; otherwise, oxidation of Fe and Mn with oxygen could result in breakthrough from
the ion exchange resin bed. The potential of fouling in ion exchange resins may increase as
Fe and Mn concentrations increase. This alternative is not considered to be a practical
application in this case.
5.4 GAC
Bituminous -based GACs can remove Fe. However, these systems are not capable of
removing Mn unless the pH is greater than 8.5. Therefore, GAC is not considered as a
suitable alternative.
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5.5 Membranes
Both reverse osmosis (RO) and nanofiltration (NF) can remove the soluble forms of Fe and
Mn. The true benefit of the high-pressure membrane treatment processes is their ability to
also remove other dissolved contaminants at the same time. However, because of their
high capital and operating costs and concentrate stream disposal issues, it is not
economically feasible to apply these technologies for Fe and Mn removal alone.
Low-pressure membranes such as ultrafiltration (UF) and microfiltration (MF) can be used
downstream of pre -oxidation of Fe and Mn, as a filtration step to remove the insoluble
precipitates. For treating Fe and Mn removal, membrane. systems will be more costly than
granular media pressure filter -based systems.
5.6 Biological Filtration
Biological filtration uses indigenous microorganisms that are able to metabolize Fe and Mn
to reduce their levels in source water. It offers lower operating and capital costs than
comparable physical/chemical processes. It also produces less waste product that allows
easier dewatering and disposal of residual. However, biological treatment requires specific
raw water qualities and conditions, and not all groundwater or surface water can be treated
economically using this technique. Success of this treatment process depends on several
factors such as nutrient availability, oxidation/reduction conditions, temperature, and filter
operation strategy. When both Fe and Mn are present in the water, a two -stage process is
required. Cost and practicality of a two -stage process are considerations that make this
alternative less attractive. Biological filtration also requires equalization to ambient pressure
for operation and needs permitting by DHS for implementation for drinking water
application. Therefore, biological filtration is not considered a practical alternative in this
case.
5.7 Fe/Mn Summary and Recommendation
A summary of the advantages and disadvantages for each of the alternative for treatment of
Fe and Mn is presented in Table 1.4.
6.0 RECOMMENDED TREATMENT TRAINS
6.1 Summary of Recommended Processes
Based on the water quality of the wells and the above discussion on the various unit
processes, the oxidation/filtration process is the recommended approach for the Fe and Mn
removal. Figure 1.3 depicts the possible treatment train at each of the well sites. Even
though the sequestration approach is not a removal process (Fe and Mn still remain in the
water in dissolved forms), it was evaluated for comparison purposes per City's request to
apply for a waiver. Figure 1.4 shows the typical setup of a sequestration system.
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6.2 Oxidation/Filtration Treatment System
Oxidation with chlorine or potassium permanganate, followed by media filtration and
greensand filtration with chemical feed for regeneration are the best alternatives for treating
the Fe and Mn. This conclusion is based on an evaluation of available oxidation and
filtration alternatives, as shown in Tables 1.5 and 1.6.
Table 1.6 Summary of Available Filter Media for Fe/Mn Removal
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Catalytic Media (Greensand Greensand with
Dual Media without Regeneration) Regeneration
In -situ (in -vessel) No Partial Yes
Oxidation
Media Regeneration No No Yes, with KMn04
Media Cost Low High High
Pre Reaction Vessel Yes No No
Requirements
Oxidant Compatibility No specific No specific requirement Must use KMn04
requirement
Several Fe and Mn oxidation and filtration systems are available as supplied by the
manufactures listed in Table 1.7.
Table 1.7 Oxidation and Filtration Systems for Fe and Mn
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alt 1 - Loprest Water Company Greensand and anthracite filter vessel.
Alt 2 - Filtronics, Inc. Reaction vessel with sodium hypochlorite.
• Reaction vessel with sodium bisulfite.
• Filter vessel with Electromedia I.
Alt 3 - Pureflow
• Proprietary treatment process.
All of the above systems have proven capability for treating water with elevated levels of Fe
and Mn. These packaged systems have vertical or horizontal vessels depending on the
system size. Due to the difference in the type and depth of the media, the filtration rate
ranges from 2 to 10 gpm/ft2. Some of the packaged systems (e.g., Filtronics) require
additional reaction tanks to oxidize Fe and Mn to the insoluble forms upstream of the filters
in order to provide enough time to ensure sufficient oxidation of Fe and Mn. Non-greensand
medium is used in the filter to remove the insoluble particles produced from the reaction
tanks.
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When greensand is used in other packaged systems, reaction tanks are generally not
required unless the Fe and Mn concentrations are very high (greater than 5,000 pg/L). Most
systems can operate on pressurized lines such that no additional backwash pumps are
required. These systems typically have multiple -vessel designs and can backwash one
vessel using the treated water from the other vessels. Backwash water is typically directed
to a wastewater decant tank. Approximately 80 to 90 percent of the backwash wastewater
can be reclaimed in most cases. The backwash water is stored in a backwash tank, where
solids such as precipitated Fe and Mn settle to the bottom of the tank. Sewer disposal for
the sludge would be desired, but this option depends on other contaminants in the raw
water, the proximity of a sewer, and the local sewer discharge regulations. The cost of
discharge to the sewer is expected to be low if a nearby sewer pipe exists already.
However, if there is no existing sewer connection in close proximity, trucking may be more
cost effective than building a sewer line. Local trucking companies have been contacted to
gather pricing information for the off -site disposal alternative, which is listed with the other
O&M costs below.
The filter run time varies from system to system. Typically, every system provides a
pressure sensor to initiate a backwash cycle at a selected filter head loss. The head loss
cannot exceed 10 psig since higher headloss accumulation may damage the filter media.
Backwashing after a set operating time is a common practice for most of the systems. For
systems treating Fe and Mn at concentrations occurring in the four wells, backwash is
typically set once per day in the early morning when water demand is low. Backwash time
is estimated to be 5 to 30 minutes with backwash loading rates at 12 to 14 gpm/ft2,
depending on the systems.
6.2.1 Alternative 1 - Logrest - Greensand Filtration (with Chlorine Oxidation
For Wells 12 and 17 sites, Loprest recommends a treatment process that consists of two
horizontal pressure filter tanks (8 feet in diameter and 16 feet long) based on the 1,750-gpm
flow rate (Well 17) and the existing background concentrations. The filter media consists of
manganese greensand (24-inch) and anthracite (12-inch). Chlorine dosage of 2.2 mg/L for
Well 12 and 0.9 mg/L for Well 17 mg/L would be used for oxidation of Fe and Mn at the
design concentrations for these contaminants.
For the Well 14 site, the treatment system is similar, but will only require one horizontal .
pressure filter tank (8 feet in diameter and 32 feet long) based on the 1,350-gpm flow rate
and concentrations. The recommended chlorine dosage is 2.2 mg/L.
Finally, for the Well 20 site, a similar set up would be used, with one horizontal pressure
filter tank (8 feet in diameter and 24 feet long) at a flow rate of 1,460 gpm. The
recommended chlorine dose is 1.5 mg/L.
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6.2.2 Alternative 2 - Filtronics - Chlorine and Sodium Bisulfite with Electromedia
Filtration
The Fe and Mn removal systems designed and manufactured by Filtronics require an
additional step compared to the system offered by Loprest and Pureflow. The Filtronics
system consists of two in -series reactor vessels (5-foot diameter with an 11-foot straight
side shell) and one filter vessel (ranging from 84-inch diameter with a 161-inch straight side
shell (at Well 14 or Well 20), to 7-foot diameter with a 21-foot straight side shell (at
Well Nos. 12 and 17)). In the lead reaction vessel, Mn is oxidized by addition of an oxidizing
chemical (sodium hypochlorite). The second vessel is used to quench the remaining
concentration of oxidizer (chlorine) by reaction with sodium bisulfite. The filter vessels
contain proprietary Electromedia I, which is granulated, naturally occurring sand -like filtering
media. A typical design feed loading rate is 15 gpm/ft2.
6.2.3 Alternative 3 - Pureflow
The Pureflow treatment process is a proprietary process. Well waters containing Fe and Mn
along with other dissolved contaminants, such as organic carbon, are first treated with
chlorine prior to filtration. This step oxidizes these contaminants to a form that can be
processed and provides free chlorine residual to the water distribution system.
The oxidation step is then followed by filtration, in which the Fe and Mn precipitates are
removed by a NSF -approved proprietary media that has an adsorptive attraction for partially
oxidized Fe and Mn. The contaminants are held in the filter bed allowing the total oxidizing
reaction to occur in the filter. The filter media is cleaned by reversing the flow using
processed water. The filter effluent is continuously monitored with a chlorine residual
analyzer to ensure complete oxidation of contaminants and disinfection of the treated water.
For all three well sites, Pureflow recommends their C-3000 filter system, with a filter vessel
of 7-foot diameter and 21-foot straight side shell. The filtration -loading rate averages
between 9 to 11 gpm/ft2. The backwash rate is 20 gpm/ft2 for 4 minutes.
6.3 Sequestration Using Polyphosphate
A few vendors were contacted for the sequestration option, but only one company provided
information for evaluation of this treatment option. SPER Chemical recommends their
Sequest-All Potable Water System for all three (or four) wells. The system simply consists
of an injection pump (LMI model AA 151-490H1) that injects the chemical into discharge
pipe from the well. Sequest-All is a blend of granular or liquid polyphosphates, each having
different properties that enhance the overall ability and function of the product. Sequest-All
will inactivate minerals including iron, calcium, and manganese preventing scale buildup
and 'red water". According to SPER Chemical, it can also slowly soften and remove
existing scale present within the water distribution system and it suppresses both anodic
and cathodic electrochemical reactions along with depositing a protective coating effectively
reducing corrosion rates. The chemical also comes in liquid form, in which case a
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200-gallon tank and mixing system would be required. The system is designed to be stable
under otherwise extreme conditions of temperature and time. As mentioned previously, it
should be noted that polyphosphate sequestration does not remove Fe and Mn but rather
stabilizes them in water to attenuate the effects of Fe and Mn.
Sequestration is only needed at the wells with high Fe and Mn levels, and a system -wide
application of polyphosphate injection is not necessary, as blending of sequestered and
non -sequestered water does not pose any water quality degradation issues.
However, enough time should be allowed for Fe and Mn to completely react with
polyphosphate (at least 15 to 30 seconds) before chlorine is injected. If chlorine or another
oxidant is injected too soon after polyphosphate injection, Fe and Mn may not be
completely sequestered and may precipitate out in the distribution system. Thus, the actual
time required between polyphosphate injection and chlorine injection to allow effective
sequestration must be tested prior to system installation.
The recommended dosage and usages for each well are listed in Tables 1.8 and 1.9.
Table 1.8 Recommended Dosage for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well No. Dosage (mg/L as PO4)
12 1.5 - 2.75
14 2-4
17 1.5 - 1.75
20 1.75 - 2.25
Table 1.9 Chemical Usages for Sequestration Chemical from SPER Chemical
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well Granular Form Liquid Form
12 (700 gpm) 0.53 Ibs - 0.96 lbs. per well hour 0.13 gal - 0.24 gal. per well hour
14 (1,350 gpm) 1.35 lbs - 2.71 lbs. per well hour 0.33 gal - 0.68 gal. per well hour
17 (1,750 gpm) 1.30 Ibs - 1.55 lbs. per well hour 0.33 gal - 0.39 gal. per well hour
20 (1,460 gpm) 1.28 lbs - 1.65 lbs. per well hour 0.32 gal - 0.41 gal. per well hour
7.0 PRELIMINARY CAPITAL AND O&M COSTS FOR SELECTED
TREATMENT SYSTEMS
Preliminary cost estimates are provided below for planning purposes. Cost estimates are
based on information provided by the vendors and other similar projects completed
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recently. It should be noted that these are planning level costs with an estimated accuracy
of +30 percent to -20 percent. These estimates reflect professional opinion of accurate
costs at this time and are subject to change depending on the final design. Engineers have
no control over variances in the cost of labor, materials, equipment, services provided by
others, contractor's methods of determining prices, competitive bidding or market
conditions, practices, or bidding strategies.
7.1 Assumptions Used to Develop Preliminary Cost Estimates
The following is a list of assumptions used in preparing the budget level capital and O&M
costs:
1. One system will be installed for Wells 12 and 17, as only one of these wells will be in
operation at any given time.
2. The wells operate 24 hours per day, 6 days per week (Monday through Saturday).
3. Water Quality: Table 1.1, presented earlier, shows the historical data of the Fe and
Mn concentrations in the wells. The median concentration of Fe in the wells ranges
from 88 to 94 pg/L; while the median Mn concentration ranges from 120 pg/L to
480 lag/L. However, for the purpose of establishing a cost estimate, the historical
maximum data was used. The design values for the contaminants are listed in
Table 1.10.
Table 1.10 Water Qualities of Wells Nos. 12, 14, 17, and 20 and Treatment Goals
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Well
Well Well Well Finished
Parameters No. 12
No. 14 No. 17 No. 20 Water Goal
Manganese, lag/L 180
430 120 110 40
Iron, lag/L 1,300
2,200(') 140 740 240
pH 7.8-7.9
7.4-8.2 7.6-7.9 7.7-8.0 -
Hardness, mg/L as CaCO3 212-220
240-300 200-217 190-200 -
Alkalinity, mg/L as CaCO3 190-210
180-240 180-200 170-210 -
Flow Rate, gpm 700
1,350 1,750 1,460 -
Notes:
(1) The historical maximum iron concentration of 5,400 lag/L for Well 14 was not used, as
this data may be erroneous.
4. The treatment goal is set to the 80 percent of the respective contaminant MCLs.
Table 1.9 presents the finished water goal for each contaminant to be used as a basis
for the treatment system.
5. The chlorine -dosing requirement is calculated based on Fe and Mn concentrations
only.
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6. The calculation of pounds per year of sodium hypochlorite needed was based on the
typical stoichiometric (chlorine to Fe and Mn ratio) without major chlorine demand and
does not take into account any organic or other constituents in the water that may
affect chlorine demand.
7. Power costs are based on the unit cost of $0.09/kWhr provided by the City.
8. Mid -point of construction is January 2010. This is based on DHS' requirement of the
City to construct and build the system in three years once the waiver survey is
completed. Since the waiver survey has to be signed and completed by
August 29, 2007, the City would need to start construction of the system by summer
of 2009, assuming one-year construction time. This would put January 2010 as the
mid -point of construction for cost estimate purposes.
9. Estimated project costs (2007 dollars) will be escalated with an annual rate of
8 percent to determine mid -point construction dollars (2010 dollars).
10. Amortized capital cost is based on 20 years and 6-percent interest rate.
11. O&M Costs will also be escalated to January 2010 using a standard inflation rate of
3 percent.
7.2 Equipment Capital Cost Estimates
The capital cost estimates of the treatment systems are based on various sources,
including quotes from commercial system providers, recent projects, and other standard
cost estimating tools available. Equipment costs from various vendors may not be
comparable since the equipment supplied from each vendor is configured differently, such
as chemical feed set-up, the number of vessels, etc.
Table 1.11 lists items included and excluded in the cost estimates.
Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
1. Items Included in the Cost Estimates:
• Equipment Purchase (vessels, valves, etc).
• Media.
• Delivery and Setup.
• Installation and Start-up Equipment.
• System Hook-up.
• Yard Piping.
• Electrical.
• Instrumentation.
• Engineering, Legal, and Administration.
• Contingency.
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Table 1.11 Treatment Cost Estimate Factors
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
12. Items Not Included in the Cost Estimates:
• Building.
• New Sewer Connection.
• Permitting.
• Disinfection Svstem.
7.3 Cost Estimates for the Iron and Manganese Oxidation and Filtration
Treatment System
7.3.1 Capital Cost Estimate of Iron and Manganese Treatment System
The unit equipment cost estimates for the oxidation and filtration systems offered by the
three vendors for each of the three sites are summarized in Tables 1.12 to 1.14.
Table 1.12 Iron/Manganese Equipment Cost -Alternative 1 Loprest System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Water Source Process Description and Items Equipment Costs
Wells 12 and 17 Greensand and anthracite filter vessel (two $400,000
horizontal pressure tank 8 ft by 16 ft); Chemical
feed system.
Well 14 Greensand and anthracite filter vessel (One $290,000
horizontal pressure tank 8 ft by 32 ft); Chemical
feed system.
Well 20 Greensand and anthracite filter vessel (one $260,000
horizontal pressure tank 8 ft by 24 ft); Chemical
feed system.
Total $950,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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Table 1.13
Iron/Manganese Equipment Cost -Alternative 2 Filtronics System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Equipment
Supplier
Process Description and Items
Costs
Well Nos. 12
Reaction Vessel No. 1 with sodium hypochlorite
$420,000
and 17
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 21-foot straight side shell, working pressure
of 60 psi) with chemical feed systems, plus reclaim
system (without the reclaim tank).
Well No. 14
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfite and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-foot straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Well No. 20
Reaction Vessel No. 1 with sodium hypochlorite
$345,000
and Reaction Vessel No. 2 sodium bisulfate and one
filter vessel with Electromedia I (7-foot diameter
with a 13.5-foot straight side shell, working
pressure of 60 psi) with chemical feed systems,
plus reclaim system (without the reclaim tank).
Total
$1,110,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
Table 1.14
Iron/Manganese Equipment Cost -Alternative 3 Pureflow System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Supplier
Process Description and Items
Equipment Costs
Well Nos. 12
One filter vessel (7-foot diameter with a 21-foot
$500,000
and 17
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 14
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Well No. 20
One filter vessel (7-foot diameter with a 21-foot
$500,000
straight side shell), back wash valve, chemical
feed system, and reclaim pump.
Total
$1,500,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
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The total capital cost estimate for the oxidation and filtration systems from the three
vendors are presented in Table 1.15. On an annualized basis, (amortized over 20 years at
6-percent interest rate) the capital cost varies between $440,000 and $600,000 per year.
Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and
Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Equipment Cost:
$950,000
$1,110,000
$1,500,00
• Vessels.
• Valves and Gauges.
• Flow Meters.
• Media.
• Chlorine Analyzer.
• Filter Control Panel.
• Start-up and Training Services.
• Backwash Reclaim Pump.
$30,000
Included
Include
• Sales Tax.
$76,000
$86,000
$116,00
• Freight Charge.
$20,000
$20,000
Included
• Subtotal (Oxidation/Filtration plus Backwash
$1,080,000
$1,220,000
$1,620,00
Reclaim Pump.
• Backwash Reclaim Tank.
$410,000
$410,000
$410,00
SUBTOTAL (EQUIPMENT COST)
$1,480,000
$1,620,000
$2,020,00
Contractor Markup Cost (15%)
$223,000
$244,000
$304,00
Installation Cost:
• Installation including Yard Piping and site
$670,000
$730,000
$910,00
work (45%).
SUBTOTAL (INSTALLED COST)
$2,370,000
$2,598,000
$3,239,00
Construction Cost:
• Electrical (15% of installed cost).
$360,000
$390,000
$486,000
• Instrumentation (10% of installed cost).
$237,000
$260,000
$324,000
SUBTOTAL (CONSTRUCTION COST)
$2,970,000
$3,250,000
$4,050,00
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Table 1.15 Iron/Manganese System Capital Cost Estimate
DHS Engineering Report on Iron and
Manganese
Treatment
City of Vernon
Alt 1 -
Alt 2 -
Alt 3 -
Items
Loprest
Filtronics
Pureflow
Project Cost:
• Engineering, Legal, and Administrative (25%).
$742,000
$812,000
$1,012,00
• Construction Management (10 %).
$297,000
$325,000
$405,00
• Contingency (35%).
$1,039,000
$1,137,000
$1,417,00
TOTAL PROJECTED CAPITAL COST
$5,050,000
$5,520,000
$6,880,00
AMORTIZED CAPITAL COST (20 years,
$440,000
$480,000
$600,00
6% interest rate)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
7.3.2 O&M Costs for the Fe/Mn Treatment Svstem
O&M requirements by each treatment system are listed in Table 1.16. Orders of magnitude
O&M costs for commercially available oxidation/filtration processes are presented in
Table 1.17. O&M costs include the use of oxidant, media replacement, and electrical costs,
sludge hauling and disposal costs, and labor. The annual O&M cost is estimated to be
between $260,000 to $320,000.
Table 1.16 Oxidation and Filtration O&M Requirements
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
O&M Items
Alt 1 - Loprest
Alt 2 - Filtronics
Alt 3 - Pureflow
Oxidant Usage - Chlorine
(12.5%)
• Well Nos. 12 and 17
Well 12 - 2.2 mg/L
NA
1.25 mg/L
(20 Ibs/day)
(26 Ibs/day)
Well 17 - 0.9 mg/L
(20 Ibs/day)
• Well No. 14
3.6 mg/L
NA
2.95 mg/L
(60 Ibs/day)
(48 Ibs/day)
• Well No. 20
1.5 mg/L
NA
1.61 mg/L
(27 Ibs/day)
(28 Ibs/day)
Sludge Disposal Volume (gal)
71,000
NA
NA
Electricity
NA
NA
268 kWh/day
Media Replacement
$60/ft3
NA
NA
1,150 ft3 (lasts for
10 years)
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Table 1.17 Iron/Manganese System Annual O&M Cost Estimate
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alt 1 Alt 2 - Alt 3 -
Category Loprest Filtronics Pureflow
Oxidant Use (e.g., chlorine)(') $50,000 $12,000 $49,00
Media Replacement(2) $8,500 $1,500 N
Electrical Costs (3) $10,000 $4,000 $6,50
Sludge Hauling CosO) $15,000 $15,000 $15,00
Sludge Disposal(5) $5,000 $5,000 $5,00
Replacement Parts and Valves (allowance - 5% $74,000 $76,000 $95,00
equipment cost)
Labor (8 hours per day, $60/hr)(6) $150,000 $150,000 $150,00
Total Annual O&M Cost $310,000 $264,000 $320,00
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%). Escalate at 3% to 2010.
(1) Assume $2.1/gallon for Sodium hypochlorite (12.5% assume 1.3 SG, Cost was
provided by the City.
(2) Media cost for Loprest was based on $60/ft3, media has shelf life of 10 years, for
Pureflow media, minimal media loss per year and no requirement of media change out.
(3) Assume control panel and chemical pump operating 24 hours/day, 6 days a week,
reclaim pump works 6 hours/day.
(4) Assume $0.25/gallon for sludge hauling.
(5) Estimated based on past projects. The final cost will depend on feed water quality,
which will affect chemical dosing and sludge volume. It will also depend on final
disposal site location.
(6) Assume about 8 hours per day of labor needed for these systems.
7.3.3 Total Annualized Cost for Oxidation and Filtration
Table 1.18 shows the total annualized costs of each oxidation and filtration system, capital
cost plus annual O&M cost in 2007 dollars and mid -point construction dollars (January
2010).
Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $440,000 $480,000 $600,000
Annual O&M Costs ($) (Year 2007) $310,000 $260,000 $320,000
Total Annualized Cost ($) 2007 $750,000 $740,000 $920,000
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Table 1.18 Total Annualized Costs for Oxidation and Filtration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Alt 1 - Loprest Alt 2 - Filtronics Alt 3 - Pureflow
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs ($) $6,200,000 $6,700,000 $8,400,000
Annualized Project Costs ($) $540,000 $590,000 $730,000
Annual O&M Costs ($) (Year 2010) $330,000 $280,000 $350,000
Total Annualized Cost ($) 2010 $870,000 $870,000 $1,100,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
Based on the total annualized costs listed above, Alternatives 1 and 2 have the lowest cost.
7.4 Cost Estimates for the Iron and Manganese Sequestration System
The sequestration system (same for all wells) consists only of an injection pump and cost of
installing an injection tap at the well site if using the liquid chemical. Additional equipment is
required as mentioned earlier if the granular form of the chemical is used. Table 1.19 lists
the estimated capital costs.
Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Items
Liquid
Granular
Equipment Costs:
• Injection Pumps.
$5,800
$5,800
• Injection Tap.
$800
$800
• Tank Assembly (200-gallon tank and mixing
NA
$17,000
system).
• Disinfection Control System Upgrade.
$40,000
$40,000
• Sales Tax (7.75%).
$3,600
$5,000
TOTAL EQUIPMENT COST
$50,000
$69,000
Contractor markup cost (15%).
$7,500
$10,00
Installation Costs:
$23,000
$31,000
• Installation Including Yard Piping and Site
Work (45%).
TOTAL INSTALLED COSTS
$80,000
$110,000
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Table 1.19 Estimated Capital Cost for Sequestration System
DHS Engineering Report on Iron and
Manganese Treatment
City of Vernon
Items
Liquid
Granular
Construction Cost:
• Electrical (15% of installed cost).
$12,000
$17,000
• Instrumentation (10% of installed cost).
$8,000
$11,000
TOTAL CONSTRUCTION COSTS
$100,000
$138,000
Project Cost:
• Engineering, Legal, and Administrative (25%).
$25,000
$34,000
• Construction Management (10%).
$10,000
$14,000
• Contingency (35%).
$35,000
$48,000
TOTAL PROJECTED CAPITAL COST
$170,000
$230,000
AMORTIZED CAPITAL COST (20 years,
$15,000
$20,000
6% interest)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to
-20%).
The estimated O&M costs based on the recommended chemical usage rate are shown in
Table 1.20.
Table 1.20 Estimated O&M Cost for Sequestration System (for High Concentration)
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Liquid Granular
Sequestering Chemical(') $104,000 $95,000
Freight Charges(2) $38,000 $20,300
Replacement Parts and Valves (Allowance - 5% $2,500 $3,500
equipment cost)
Labor (4 hours per day, $60/hr)(3) $74,900 $74,900
Total Annual O&M Costs $219,000 $194,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on vendor quotes, for liquid media $513 per 55-gal drum (625-Ibs poly drum), for
granular media $647 per 323 Ibs (30-gal steel drum), based on 24 hr/day, 6 days per
week.
(2) Freight charge - Granular: $190/drum, $521 per four drums, $878 per eight drums;
Liquid: $292 per drum, $836 per four drums, and $1,250 per eight drums.
(3) Assumed a maximum of 4 hours per day of labor at $60/hr rate.
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The total annualized costs for sequestration treatment system in June 2007 dollars and.
January 2010 dollars (mid -point construction) are summarized in Table 1.21.
Table 1.21 Total Annualized Costs for Sequestration System
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Annualized Cost Liquid
Granular
Project Costs (June 2007 Dollars)
Annualized Project Costs ($) $15,000
$20,000
Annual O&M Costs ($) (Year 2007) $219,000
$194,000
Total Annualized Cost ($) 2007 $234,000
$214,000
Mid -Point Construction Costs (January 2010 Dollars)
Project Capital Costs $207,000
$281,000
Annualized Project Costs ($) $18,000
$24,000
Annual O&M Costs ($) (Year 2010) $236,000
$209,000
Total Annualized Cost ($) 2010 $254,000
$233,000
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) Based on 20 years and 6-percent interest, escalation annual rate of 8% for capital
costs and standard inflation rate of 3% for O&M costs.
8.0 SUMMARY AND RECOMMENDATION
Based on the findings from the feasibility study, the following key points are presented in
this report:
• The iron level ranges from 140 to 2,200 lag/L and manganese level ranges from 110
to 430 pg/L. These were the historical maximum data and were used as the basis for
estimating the cost of treatment.
• The total design flow rate for all four wells averages about 4,560 gpm. Based on the
production data provided by the City for the last three years, the total average
production from these wells is estimated to be 3,200 AFY.
• An oxidation/filtration system is recommended to treat Fe and Mn from the well water.
Chlorine or potassium permanganate is recommended as the chemical to be used for
oxidation. Proprietary media or greensand media can be used for filtration.
• Based on DHS's requirement of 3 years to construct from the completion of the
waiver process, the mid -point of construction is estimated to be January 2010.
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• Three major equipment suppliers have been contacted and three estimates have
been obtained for oxidation and filtration. Filtronics, Loprest, and Pureflow have
provided costs.
• The total projected capital costs (2010 dollars) for the treatment plants
(oxidation/filtration system) are estimated to be in the range of $6,200,000 to
$8,400,000 and the amortized capital cost is expected to be between $540,000 and
$730,000. The capital costs include equipment, media, delivery and setup, installation
and start-up, instrumentation, engineering, legal, and administration, with a
35-percent contingency.
• The projected annual O&M costs (2010 dollars) are estimated to be approximately
$280,000 to $350,000. These O&M costs cover oxidant use, media replacement,
labor costs, and electrical costs. Sludge hauling and disposal cost allowances were
included, but refined costs are needed once the disposal facility is identified for this
project.
• The total annualized costs in 2010 (mid -point construction) dollars range from
$870,000 to $1,100,000.
• An oxidant demand test can be done at the bench scale to better estimate the
chemical dose requirement and the cost for such tests can be provided once the
scope of the test is defined if needed.
• Although sequestration is not a removal process and not considered as a compliance
alternative, the costs are included in the evaluation for comparison purposes per
City's request.
• The total projected capital costs (2010 dollars) for the sequestration system ranges
from $210,000 for a liquid phosphate system to $280,000 for a granular
polyphosphate system. The annual O&M costs (2010 dollars) are estimated to be
about $236,000 for liquid phosphate or $210,000 for granular polyphosphate.
Table 1.22 summarizes the pros and cons of doing nothing, using an oxidation filtration
treatment system, and using sequestration to treat/mitigate the Fe and Mn in the City water
supply.
DRAFT - July 9, 2007 1-27
H:\Client\Vemon_SAOW\7708A00\TM\TM01 FINAL.doc
Table 1.22 Pros and Cons of Alternatives for Fe and Mn
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change •
Does not cost anything. 0
Does not address iron and
Does not change the
manganese issue.
current condition of water. •
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning •
Removes the impact of •
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost
May precipitate out iron and
than full treatment (Alt 3).
manganese at high
•
Proven process for iron
temperature.
and manganese. .
May have negative impacts
on customers' internal
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and .
Full removal of iron and 0
Costs more than other
Filtration Treatment
manganese.
alternatives.
System (using
chlorine solution)
Proven process for iron •
Rate increase is expected.
and manganese.
Table 1.23 summarizes the cost estimates of each system for the recommended oxidation
and filtration treatment system and the sequestration treatment system in 2010 dollars. In
order to put these numbers into perspective, the unit costs of the product water are
calculated and presented in Table 1.23. The costs of the most expensive system for each
treatment method are used for the comparison. This is to provide the most conservative
estimates for the unit costs of the product water.
Table 1.23 Summary of Cost Estimates - in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/ System
Filtration System (Sequestration
Cost (Pureflow) - Liquid)
Project Capital Cost $8,400,000 $210,000
Amortized Capital Cost (20 years, 6% interest $730,000 $18,000
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Table 1.23 Summary of Cost Estimates - in 2010 Dollars
DHS Engineering Report on Iron and Manganese Treatment
City of Vernon
Conditioning
Oxidation/
System
Filtration System
(Sequestration
Cost (Pureflow)
- Liquid)
rate)
Annual O&M Cost $350,000
$236,000
Total Annualized Cost $1,100,000
$254,000
Additional Annual Water Treatment Cost ($/AF)(') $343.8
$79.4
Additional Annual Water Treatment Cost $1.05
$0.24
($/1,000 gal)(')
Additional Annual Water Treatment Cost $0.79
$0.18
($/100 ft)(1)
Notes:
Cost Estimate Disclaimer: See Section 7.0 (+30% to -20%).
(1) The Total water production is based on the last three years production data.
Based on the estimated project costs shown in Table 1.23, the City estimates that up to a
21 percent City-wide increase in the user rate would be required to undertake treatment of
the well water to remove Fe and Mn. The additional annual water treatment costs shown in
Table 1.23 are for the wells that require either treatment or conditioning, and the increase in
these costs for the subject wells was used by the City to calculate the City-wide increase in
the commodity cost of water. This will increase the current user rates from $1.16/100 ft3to
$1.41/100 ft3. If sequestration were used, the City estimates that up to a 5 percent increase
in the user rate would be required, from the current $1.16/100 ft3 to $1.22/100 W.
DRAFT - July 9, 2007 1-29
H:\Client\Vemon_SAOW\7708A00\TM\TM01 FINAL.doc
SURVEY VOTE FORM - CITY OF VERNON
IRON AND MANGANESE COMPLIANCE
Subject: Water Quality Compliance for Iron and Manganese
Please select one alternative. Not casting a vote will count as a vote for full treatment (Alt 3).
Iron and Manganese Compliance Vote - Select Only One Alternative
Increase in the
Commodity Cost
Check Only One
Alternative Processes
of Water
Box
Alt 1 - No Change (No Treatment)
• 0%
Alt 2 - Conditioning System
• Up to 5%
(Sequestration)
Alt 3 - Oxidation and Filtration
Up to 21 %
Treatment System
• Alt 1 - Existing water quality is acceptable in terms of iron and manganese. I VOTE
NO CHANGE.
• Alt 2 - Existing water quality is NOT acceptable. I WANT THE WATER
CONDITIONED WITH CHEMICALS (SEQUESTERATION), AND I ACCEPT AN
INCREASE IN THE WATER COMMODITY COST OF UP TO 5%. 1 understand that
this is a temporary measure (9 years) allowed by the State and that this option may
result in iron and manganese settling in water when it is heated and may otherwise
affect internal water treatment processes at my home or business.
Alt 3 - Existing water quality is NOT acceptable. I WANT THE WATER TREATED
TO REMOVE IRON AND MANGANESE WITH OXIDATION AND FILTRATION,
AND I ACCEPT AN INCREASE IN WATER COMMODITY COST OF UP TO 21 %.
Site Address
Print Name
Signature
Date
THIS SURVEY SHEET MUST BE PICKED UP BY THE CITY STAFF BY AUGUST 1, 2007 TO
BE VALID.
A PUBLIC HEARING WILL BE HELD ON AUGUST 20, 2007 AT 10 AM.
If you have any concerns or comments you may forward them to Scott B. Rigg at
4305 Santa Fe Ave, Vernon, CA 90058.
July 2, 2007
Subject: Iron and Manganese Compliance Survey Vote
Dear Customer:
INTRODUCTION
The State Department of Public Health (DHS) has ordered the City of Vernon to comply with the
regulations for iron and manganese levels in the City's drinking water. These regulations have
been established to improve the aesthetics of your drinking water. The median concentration of
iron in the City's wells ranges from 88 to 94 micrograms per liter (,ug/L) while the median for
manganese concentration ranges from 120 to 480 yg/L. The limits in terms of the regulations are
50 yg/L for iron and 300 yg/L for manganese. Currently, the levels of iron and manganese DO
NOT cause health issues but can cause aesthetic concerns such as taste, staining of cloths and
plumbing fixtures, and brown water events under certain conditions.
The DHS advised the City that treatment for removal of iron and manganese must be undertaken
unless a waiver is obtained through a customer survey and vote.
The basis for granting waivers is the degree of consumer acceptance of existing water quality and
the CUSTOMER'S WILLINGNESS (OR UNWILLINGNESS) TO PAY THE COST of meeting these
water quality standards.
PLEASE REMEMBER THAT IF YOU DO NOT VOTE, YOU WILL BE CONSIDERED TO BE IN
FAVOR OF FULL TREATMENT AND YOU WILL BE WILLING TO BEAR THE ADDITIONAL
COST. In other words, if a majority of customers do not respond to this survey or vote for
treatment, DHS will require compliance with the regulations through treatment. You are strongly
encouraged to evaluate this matter and vote by completing the attached "Survey Vote Form". The
survey form shall be picked up by the City staff no later than August 1, 2007.
BACKGROUND
The City retained Carollo Engineers to prepare an engineering report to comply with DHS
requirements. The report was completed by Carollo Engineers and reviewed by the City staff and
DHS. Copies of the full report are available for review at the City of Vernon located at 4305 Santa
Fe Avenue or at the City web -site www.citvofvernon.org.
The report indicates that either chemical conditioning to prevent iron and manganese from settling
in the water, or treatment of the water to remove iron and manganese using oxidation and
filtration are the most feasible methods to improve the water quality and comply with DHS
requirements. The advantages and disadvantages of three final alternatives are shown in Tablet.
Table 1 Pros and Cons of Alternatives for Iron and Manganese Compliance
Alternative
Processes
Advantages
Disadvantages
Alt 1. No Change .
Does not cost anything.
•
Does not address iron and
•
Does not change the
manganese issue.
current condition of water.
•
Waiver needs to be
reapplied every 9 years.
Alt 2. Conditioning .
Removes the impact of
•
Does not remove iron and
System
iron and manganese at a
manganese from water.
(Sequestration)
substantially lower cost
0
May precipitate out iron and
t
than full treatment (Alt 3).
manganese at high
•
Proven process for
temperature.
addressing elevated
,
May have negative impacts
levels of iron and
on customers' internal
manganese.
processes that involve
treating or heating water.
•
Waiver needs to be
reapplied every 9 years.
•
Rate increase is expected.
Alt 3. Oxidation and .
Full removal of iron and
0
Costs more than other
Filtration Treatment
manganese.
alternatives.
System (using
chlorine solution) •
Proven process for iron
0
Rate increase is expected.
and manganese removal.
The estimated project cost including loan fees and contingencies is estimated to be up to $8.4
million for the oxidation and filtration treatment system (Alt 3). The conditioning system (Alt 2)
using a polyphosphate chemical to help prevent iron and manganese precipitation is estimated to
cost up to $210,000.
The City staff has reviewed financing options and has found that THE LEAST EXPENSIVE
OPTION IS TO USE CONDITIONING CHEMICALS (Alt 2 - SEQUESTRATION) TO HELP
PREVENT IRON AND MANGANESE PRECIPITATION. Up to a 5 percent increase in the
commodity cost of water beyond the present minimum payment is expected. It should be noted,
however, that the performance of sequestration chemicals is sensitive to temperature, and iron
and manganese may settle out under certain conditions where water is heated for use. Water
conditioning may also have negative impacts on some customers' internal processes, such as
water filtration equipment.
FULL TREATMENT TO REMOVE IRON AND MANGANESE (Alt 3) WILL INCREASE THE
WATER COST BY UP TO 21 PERCENT. Since iron and manganese are removed from the water,
this option is NOT sensitive to temperature and iron and manganese WILL NOT settle out.
Chemical conditioning and full treatment both have proven track records. The DHS will review and
approve any treatment system to ensure it meets all drinking water standards.
ESTIMATED COMPLIANCE COSTS
The decision as to which course of action the City will pursue must be made by the City's
customers. The choices and cost associated with each alternative are shown in Table 2.
Table 2 Cost Estimates for Iron and Manganese Compliance
Alternative Processes
Commodity Cost of Water Expected Rate Increase
Alt 1. No Change (current rate)
$1.159 per 100 ft3 • 0%
Alt 2. Conditioning System .
(Sequestration)
Up to $1.216 per 100 ft3 5%
Alt 3. Oxidation and Filtration .
Treatment System
Up to $1.406 per 100 ft3 21 %
In making the decision, each customer will be entitled to a single vote. If a majority of customers
vote in favor of Alternative 1, it will be construed as acceptance of existing water quality (in terms
of iron and manganese) and a waiver from the regulations will be sought from DHS. It is critical
that you cast the vote you are entitled to.
A public meeting to discuss the survey results will be held at the City offices at 10 a.m. on
August 20, 2007.
Sincerely,
City of Vernon