Arsenic Removal from Drinking
j
Water by Adsorptive Media
USEPA Demonstration Project at Springfield, OH
Project Summary
Sarah E. McCall, Abraham S.C. Chen, Lili Wang
A project to demonstrate AdEdge Technologies' AD-33
media's ability to remove arsenic was conducted at the
Chateau Estates Mobile Home Park at Springfield, OH. The
project objectives were to evaluate: (1) the effectiveness of
the AdEdge Technologies' AD-33 media in removing arsenic
to meet the new arsenic maximum contaminant level
(MCL) of 10 micrograms per liter (|ag/L), (2) the reliability
of the treatment system, (3) the required system operation
and maintenance (O&M) and operator's skills, and (4) the
capital and O&M cost of the technology. The project also
characterizes the water in the distribution system and
process residuals produced by the treatment process.
Introduction
Amended in 1996, the Safe Drinking Water Act (SDWA)
required that the United States Environmental Protection
Agency (EPA) develop an arsenic research strategy and publish
a proposal to revise the arsenic MCL. On March 25,2003, EPA
revised the rule text to express the MCL as 0.010 milligrams
per liter (mg/L), or 10 |ag/L, and to require all community and
nontransient, noncommunity water systems to comply with the
new standard by January 23,2006 (EPA, 2003).
In October 2001, EPA announced an initiative for additional
research and development of cost-effective technologies
to help small community water systems (those with less
than 10,000 customers) meet the new arsenic MCL, and
to provide technical assistance to small system operators
to reduce compliance costs. As part of this Arsenic Rule
Implementation Research Program, EPA's Office of Research
and Development proposed a project to conduct a series
of full-scale, onsite demonstrations of arsenic removal
technologies, process modifications, and engineering
approaches applicable to small systems.
Site Information
The water system has a total of 226 connections and serves
a population of approximately 600 in the Chateau Estates
Mobile Home Park Community in Springfield, OH. Source
water is groundwater supplied from two bedrock wells. The
West Well produces about 130 gallons per minute (gpm).
The East Well produces about 90 gpm. Both wells are 8
inches in diameter and were originally installed to a depth
of 100 feet. In 2001, the East Well was extended to a depth of
220 feet. The pre-existing water treatment system consisted
of chlorination using a 12.5% sodium hypochlorite solution
-------
and addition of polyphosphate as a sequestering agent
for corrosion and scale control. Before the installation
of the water treatment system, the West Well typically
operated for approximately 5 hours per day and
produced 40,000 gallons of water.
Source water samples were collected on August 5, 2004,
for the West Well and on September 9, 2004, for the East
Well. The results of the analyses are presented in Table
1. Arsenic in the West Well existed almost entirely as
arsenic (III); while arsenic in the East Well existed as
arsenic (III), arsenic (V), and particulate arsenic. Total
arsenic concentration in the West Well was much higher
than that in the East Well (i.e., 24.6 versus 14.6 Lig/L).
Arsenic Treatment System
The treatment system consists of two integrated units
referred to as an AD-26 pretreatment system and an
AD-33 arsenic package unit (APU) adsorption system.
The AD-26 pretreatment system uses a manganese
dioxide mineral media commonly used for oxidation
and filtration of iron and manganese. Pretreatment is
followed in series by the APU adsorption system for
arsenic removal. Figure 1 contains a process flowchart
including sampling locations. Figure 2 contains photo of
the AD-26 treatment system.
Raw water was first treated with chlorine for disinfection
and oxidation. Chlorine precipitates soluble iron and
converts arsenic (III) to arsenic (V). The arsenic (V)
formed was adsorbed onto the precipitated iron solids,
which in turn, were filtered out by the AD-26 media.
The AD-26 pretreated water was sent to the APU system
as a polishing step. The APU is a fixed bed adsorption
system that uses Bayoxide E33 media, an iron-based
adsorptive media. Once reaching capacity, the spent
media may be removed and disposed of after being
tested for EPA's TCLP test.
Table 1. Springfield, OH Source Water Quality
Parameter Unit •«'—•«'-" ^-
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Total Alkalinity (as CaC03) mg/L
Hardness (as CaC03)
Chloride
Fluoride
Sulfate
Silica (as Si02)
Orthophosphate
Total As
As (particulate)
As(lll)
As(V)
Total Fe
Total Mn
TotalV
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^m
Total Na rng/L
319
343
381
14
^^^^^^^
1.5
27
19.4
<0.10
24.6
0.3
24.7
1,615
18.5
0.2
11.3
291
1.4
0.8
15
17.5
<0.10
14.6
5.7
l
2.8
636
62.3
0.41
14.8
CHLORINE ADDITION
After Chlorination
LEGEND
Unit Process/
System Component
Sampling Location
»- Process Flow
*~ Backwash Flow
h h h
AD-26 Backwash
AD-26
OXIDATION
VESSEL A
AD-26
OXIDATION
VESSEL B
AD-26
OXIDATION
VESSEL C
After AD-26 Vessels Combined
HYDRO-
NEUMATIC
TANK A
I
HYDRO-
NEUMATIC
TANKS
HYDRO-
NEUMATIC
TANKC
_|
I ! I"! I'":
ON-SITE
WASTEWATER
STORAGE
TANK
AD-33 Backwash
AD-33
ADSORPTION
VESSEL A
AD-33
ADSORPTION
VESSEL B
AD-33
ADSORPTION
VESSEL C
After Individual AD-33 Vessels
After AD-33 Vessels Combined
DISTRIBUTION SYSTEM
Figure 1. Process Flow (250 gpm) Diagram and
Sampling Locations
Both the AD-26 oxidation/filtration and the APU systems
are skid-mounted, each comprising of three carbon steel
pressure vessels. The AD-26 and AD-33 media are both
certified under NSF Standard 61. Table 2 presents the
key system design parameters. Key process components
include:
• Intake—Raw water was pumped from the supply
wells, alternating every cycle.
Figure 2. AD-26 Treatment System
-------
Chlorination- An automatic chlorine injection
system was used to chlorinate the water by injecting
12.5% liquid sodium hypochlorite solution to
the 4-inch PVC line. The proper operation of the
feed system was tracked by the operator through
measurements of free and total chlorine across the
treatment train and at the entry point. In spite of
repeated efforts, the automatic chlorine monitor/
controller failed to control free and total chlorine
residuals within the target level of 1.0 mg/L (as C12).
Iron/Manganese Removal—Prechlorinated water
entered the AD-26 oxidation/filtration system at an
average flowrate of 130 gpm. The AD-26 system
consisted of three 36-inch-diameter, 60-inch-sidewall
height carbon steel pressure vessels configured in
parallel. Each vessel was filled with 31 inches (19 cubic
feet) of media, which was underlain by 7 inches (5
cubic feet) of fine underbedding. Electrically actuated
butterfly valves and a centralized programmable logic
controller (PLC) unit controlled the AD-26 system.
Hydropneumatic Tanks—The filtered water from
the AD-26 system entered the three hydropneumatic
storage tanks. Each tank had a storage capacity of 528
gallons for a total capacity of 1,584 gallons.
Arsenic Adsorption— Upon demand, the water
stored in the hydropneumatic tanks flowed
through the AD-33 adsorption system. During a
pre-demonstration water demand study, flowrates
ranged from 18.1 to 58.2 gpm and averaged 33.0 gpm.
The APU system consisted of three 48-inch-diameter,
60-inch-sidewall height carbon steel pressure vessels
configured in parallel. Each APU vessel contained
approximately 38 cubic feet (114 cubic feet total)
of AD-33 media. The estimated media empty bed
contact time (EBCT) of 25.8 minutes is at least 5 times
higher than the vendor's recommendation.
Backwash—Both the AD-26 and APU systems
required backwashing. Each vessel was
backwashed one at a time using water stored in
the hydropneumatic tanks. Initially, the backwash
wastewater was stored in two on-site 6,000-gallon
storage tanks and hauled off-site for disposal on a
weekly basis. On September 14, 2006, the facility was
connected to the sewer system.
Table 2. Design Specifications for the AdEdge Treatment System
Peak Design Flowrate (gpm)
Average Throughput to System (gpd)
Chlorine Dosage (mg/L [as CI2])
250 System upsized from 150 gpm at Park Owner's request and expense
40,000 —
1.0 mg/L residual chlorine within distribution system
Number of Vessels
Vessel Size (inch)
Media Quantity (ftVvessel)
Flowrate through Each Vessel (gpm)
Backwash Flowrate through Each Vessel (gpm)
Backwash Duration (minutes)
Backwash Frequency (times/week)
Media Life (years)
43
130
15
3
Arranged in parallel
57 ft3 total of AD-26 media
Total flowrate of 130 gpm
18.4gpm/ft2
Per vessel
Actual frequency determined during system operation
Vendor provided estimate
Number of Vessels
Vessel Size (inch)
Media Quantity (ftVvessel)
Flowrate through Each Vessel (gpm)
Empty Bed Contact Time (minutes/vessel)
Backwash Flowrate (gpm)
Backwash Duration (minutes)
Backwash Frequency (times/60 days)
Bed Volumes (BV)/Day
WorkingCapacity(BV)
Volume to Breakthrough (gallons)
Media Life (years)
Arranged in parallel
114 ft3 total of AD-33 (Bayoxide E33) media
Average of 33 gpm measured prior to study
Based on average on-demand flowrate
10gpm/ft2
Per vessel
Actual frequency determined during system operation
Based on throughput of 40,000 gpd, 1 BV= 114ft3
Based on vendor estimate for breakthrough at 10 ug/L
Vendor provided estimate
Based on estimated media working capacity of 83,500 BVs and average
throughput of 40,000 gpd
-------
• Media Replacement—When the AD-33 adsorptive
media exhausts its capacity, the spent media will be
removed and disposed. Virgin media will be loaded
into the vessels.
The skills required to operate the APU-250 system were
relatively complex due to the problems associated with
the chlorine injection. The operator needed to adjust the
dosage of the chlorine, adjust the metering pump, and
change out the master chip within the control panel.
Under normal operating conditions, the operator spent
approximately 20 minutes daily to perform visual
inspection and record the system operating parameters
on the Daily Field Log Sheets. The operator also
performed routine weekly and monthly maintenance
according to the users' manual to ensure proper
system operation. Normal operation of the system
did not appear to require additional skills beyond
those necessary to operate the existing water supply
equipment. Ohio public water systems serving more
than 250 people must have a certified operator. Chateau
Estates has a Class III water system operator with Class
IV being the highest.
The only chemical required for the system operation
was the sodium hypochlorite solution. Every week
approximately 15 gallons of the solution was added to
the 75-gallon chlorine tank.
System Performance
Evaluation of system performance was based on analyses
of water samples collected from the treatment plant,
distribution system, and the media backwash.
Arsenic Removal. Figure 3 contains four bar charts
showing the concentrations of total arsenic, particulate
arsenic, arsenic (III), and arsenic (V) at the wellhead,
after chlorination, and in the combined effluent from
the AD-26 and AD-33 vessels, respectively. Total arsenic
concentrations in raw water averaged 22.7 |ag/L of the
soluble fraction. Arsenic (III) was the predominating
species, averaging 16.9 |ag/L. Arsenic (V) and particulate
arsenic concentrations were low, averaging 1.7 and 2.8
|jg/L, respectively.
Total arsenic concentrations were higher in West Well
than East Well (26.9 versus 20.2 |ag/L on average). Unlike
what was observed during the source water sampling
events, arsenic (III) was the predominating species in
both wells. The presence of elevated particulate arsenic
and particulate iron during some spetiation events and
the East Well source water sampling, most likely was
caused by inadvertent aeration of the samples.
Chlorine oxidized arsenic (III) to arsenic (V) that, in turn,
was attached effectively, to iron solids to form particulate
arsenic. The samples collected downstream of the chlorine
injection point showed a decrease in the average soluble
arsenic concentration from 18.5 |jg/L to 6.4 |jg/L and an
increase in average particulate arsenic concentration from
2.8 |jg/L to 15.3 |ag/L. The majority of particulate arsenic
was filtered out by the AD-26 media, leaving only 0.5 to
2.1 |jg/L of total arsenic, existing mainly as arsenic (V).
Total arsenic concentrations in the treated water after the
AD-33 vessels were reduced to less than 0.5 |-ig/L. Figure 4
presents arsenic breakthrough curves from the AD-26 and
AD-33 systems.
Free and total chlorine were monitored. After
chlorination, free and total chlorine levels averaged 1.7
mg/L and 1.5 mg/L (as C12), respectively. The residual
chlorine measured after the AD-26 and AD-33 vessels
indicated little or no chlorine consumption through the
vessels. Repeated attempts had been made to reduce the
levels of free and total chlorine residuals to the target
levels of 1.5 and 1 mg/L (as C12). The cartridge filter
placed just before the chlorine monitor/control module
appeared to control the chlorine levels.
Iron Removal Total iron concentrations at the
wellhead averaged 1,102 |ag/L. Iron concentrations
following the prechlorination step were similar with
concentrations averaging 1,171 |ag/L. Iron was removed
from the treatment train with concentrations ranging
from less than the method detection limit of 25 |ag/L
to 25.3 |jg/L after the AD-26 vessels and less than the
method detection limit of 25 |-ig/L after the AD-33 vessels.
Dissolved iron levels ranged from 217 to 1,475 |-ig/L at the
wellhead. After prechlorination, except for one outlier at
838 |-ig/L occurring on July 26, 2006, dissolved iron levels
ranged from less than the method detection limit of 25
|jg/L to 32.8 |ag/L. Dissolved iron levels were always less
than the method detection limit after the AD-33 vessels.
The backwash frequency of once every three days
appeared to be adequate.
Manganese Removal. Total manganese levels
in source water averaged 35.6 |ag/L and existed almost
entirely in the soluble form. After prechlorination, over
70% on average of soluble manganese was precipitated,
presumably, to form MnO2 solids, which, along with
unoxidized Mn2+, were removed by the AD-26 media to
less than 0.7 |ag/L. Total manganese concentrations were
further reduced to 0.2 |ag/L after the AD-33 adsorptive
media.
The amount of Mn2+ that precipitated upon chlorination
varied extensively during the 13 speriation events, with 9
events ranging from 85.0 to 98.0%, 2 ranging from 48.8 to
57.6%, and the remaining 2 ranging from 1.1 to 5.8%.
Other Water Quality Parameters. The pH
values of raw water measured at the wellhead varied
from 6.9 to 7.5. The pH values remained essentially
unchanged after the AD-26 and AD-33 vessels. Alkalinity,
total hardness, sulfate, and silica (as SiO2) remained
constant throughout the treatment train. Fluoride
concentrations did not appear to be affected by the AD-
33 media. Total phosphorous (as PO4) was below the
detection limit of 0.01 mg/L for all samples.
Distribution Water. Prior to the installation/
operation of the treatment system, first draw baseline
distribution system water samples were collected at
three locations (two residences and the mobile park
clubhouse). Following the installation of the treatment
system, distribution water sampling continued on a
monthly basis. The results of the distribution system
sampling are summarized in Table 3.
The most noticeable change in the distribution samples
after system startup was the decrease in arsenic,
-------
iron, and manganese concentrations. Baseline arsenic
concentrations averaged 23.7 |ag/L for all three locations.
After system startup, arsenic concentrations were
reduced to an average of 1.6 |ag/L. The baseline iron
averaged 1,359. After the treatment system became
operational, iron concentrations decreased to less than
Arsenic Speciation at Wellhead
30-
25-
20-
15-
10-
5-
n-
DAs (particulate)
• As (III)
• As(V)
I
~
— |
-
—
_
—
1
—
—
25
A A< \ \ \ x,\ \ \ \ \ \0 \0
Date
Arsenic Speciation after Chlorination
30-
25-
20-
15-
10-
5-
DAs (particulate)
• As (III)
• As(V)
n
a
—
-
n
!
„
,-,
"
-,
,-OP A* \CP X(3P X(3P .X«P A«P X<2P *3P X(2P X(2P &
^\///////////
Date
Arsenic Speciation after AD-26 Vessels
20-
15-
10-
5-
n •
• As (particulate)
• As (III)
•As 00
B B • B B • B _
Date
Arsenic Speciation after AD-33 Vessels
20-
15-
10-
DAs (particulate)
• As (III)
• As(V)
Date
the method detection limit of 25 |-ig/L in all samples
except for three. Manganese had a similar trend with
baseline concentrations averaging 15.2 |ag/L and after
startup samples averaging 0.2 |ag/L.
Lead concentrations ranged from less than 0.1 to 5.2 |ag/L.
Copper concentrations ranged from 0.3 to 1,353 |ag/L;
one sample exceeded the 1,300 |ag/L action level during
baseline sampling. The arsenic treatment system does not
seem to affect the lead or copper concentrations in the
distribution system.
Measured pH values averaged 7.5, and alkalinity levels
ranged from 198 to 364 mg/L (as CaCO3). The arsenic
treatment system does not seem to affect these water
quality parameters in the distribution system.
Backwash Water. Backwash was performed using
the AD-26 treated water stored in the hydropneumatic
tanks. The results of the unfiltered sample analysis
are presented in Table 4. The first AD-26 vessel was
sampled during 12 monthly events, while the second
and third vessels, were sampled on the last eleven and
last eight sampling events, respectively. Total dissolved
solids (TDS) concentrations averaged 408 mg/L. Total
suspended solids (TSS) concentrations averaged 83.4
mg/L. The several unusually low TSS values measured
during backwash of each AD-26 vessel were thought
to be the result of insufficient mixing of the backwash
wastewater. Note that lower TSS values also had lower
particulate arsenic, iron, and manganese concentrations.
The majority of the total arsenic, iron and manganese in
the backwash wastewater were in the particulate form.
Assuming that 83 mg/L of TSS (average of all TSS values
except for the outliers) was produced in 6,000 gallons
of backwash wastewater, approximately 4.2 pounds of
solids would be discharged during each AD-26 backwash
event. The solids discharged would be composed of 0.02,
1.51, and 0.03 pounds of arsenic, iron, and manganese,
respectively, assuming 450 |ag/L of particulate arsenic,
30,100 |-ig/L of particulate iron, and 500 |-ig/L of
particulate manganese in the backwash wastewater.
The AD-33 vessels were backwashed four times,
generating approximately 6,050 gallons of wastewater.
After reviewing the system operation, it was determined
that the media would not need to be backwashed on a
regular basis and that backwashing frequency would
be determined based on system pressures. Backwash
samples were not taken.
35
30-
25-
o 20-
15-
10
0
After Chlorination
-After AD-26 Vessels
-After AD-33 Vessels
AsMCL = 10
Figure 3. Concentrations of Arsenic Species
0 24 6 8 10 12 14 16 18 20
Bed Volume (103)
Figure 4.Total Arsenic Breakthrough Curves
-------
Table 3. Average Distribution System Sampling Results
pling Event pH Alkalinity Ar«
No.
Average
Baseline
Date
AprOS-JulOS
S.U.
7.4
mg/L
346.8
23.7
1359.8
15.2
M9/L
1.4
M9/L
401.1
7.5
7.8
7.5
7.4
7.4
7.6
7.5
7.5
7.4
7.4
7.4
7.5
One-half of the detection limit was used for non-detect samples for calculations.
System Cost
The cost of the system is based on the capital cost per
gpm (or gpd) of the design capacity and the O&M cost
per 1,000 gallons of water treated. At his own cost,
the park owner upgraded the system from 150 gpm
to 250 gpm in response to the Ohio EPA's redundancy
requirement and for future growth.
Capital Costs. Table 5 summarizes the capital
investment for the system. The equipment cost included
$144,136 for the 150-gpm system (EPA-funded) and
$68,690 for the system upgrades (facility-funded). The
$68,690 of equipment upgrades covered the cost of
upgrading the AD-26 and AD-33 vessels and adding 21
cubic feet of AD-26 and 38 cubic feet of AD-33 media,
three new hydropneumatic tanks, and a chlorine injection
system including a chlorine monitor/controller module.
The engineering cost included the cost for the
preparation of a process flow diagram of the treatment
system, mechanical drawings of the treatment
equipment, and a schematic of the building footprint and
equipment layout.
The installation cost included the equipment and
labor to unload and install the skid-mounted units,
perform piping tie-ins and electrical work, and load and
backwash the media.
The capital cost of $292,252 was normalized to $1,170/
gpm ($0.81 gpd) of design capacity using the system's
rated capacity of 250 gpm (or 360,000 gpd). The capital
cost also was converted to an annualized cost of $27,590/
year using a capital recovery factor (CRF) of 0.09439
based on a 7% interest rate and a 20-year return period.
Table 5. Summary of Capital Investment
Descripti
pH
IDS
TSS
As (total)
As (soluble)
As(particulate)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
AD-26 Media (36 ft3) and three 30-inch
diameter fiberglass vessels on skid*
AD-33 Media (76 ft3) and three 42-inch
diameter fiberglass vessels on skid*
Totalizer for Backwash Line
One-Year O&M Support and Manuals
Additional SampleTaps
Freight
Equipment for Upgrade to i
(Paid by Owner)
Labor,Travel,and Materials
System Upgrade (Paid by Owner)
$53,656
$82,640
$990
$3,640
$675
$2,535
$68,690
$22,454
$5,074
Labor,Travel,and Materials
System Upgrade (Paid by Owner)
Total Capital Investment (100%)
* Also includes gravel underbedding, process valves and piping,
and instrumentation and controls.
-------
Assuming that the system operated 24 hours/day, 7 days/
week at the design flowrate of 250 gpm, the unit capital
cost would be $0.21/1,000 gallons. During the year long
demonstration, the system produced 16,873,000 gallons
of water; at this reduced usage rate, the unit capital cost
increased to $1.64/1,000 gallons.
Operation and Maintenance Costs, The
O&M cost is summarized in Table 6. Although media
replacement did not occur during the study, the media
replacement cost would represent the majority of
the O&M cost. The AD-26 media has a 10-year life
expectancy before replacement. At the current water
use rate (i.e., 16,873,000 gallons for one year), the system
would treat 169 million gallons of water in a 10-year
period. Therefore, the AD-26 media replacement cost
would be $0.08/1,000 gallons of water treated. The AD-
33 media has a 4-year life expectancy. The estimated
cost of replacing the 114 cubic feet of AD-33 media is
$34,230, including the cost for media, freight, labor,
travel expenses, and media disposal. This cost was used
Table 6. O&M Costs
Cost Cat
Volume Processed
(1,000 gallons)
sumptio
16,873 Through 09/24/06
Replacement and Disp
Media unit cost ($/ft3)
Media volume (ft3)
Underbedding gravel ($)
Labor ($)
Freight ($)
Waste disposal and
analysis ($)
Cost ($71,000 gallons)
0.08
Vendor quote
To fill three 36-inch
diameter vessels
Vendor quote
Vendor quote
Vendor quote
Vendor quote
1 0-year media life,
treating 169 million
gallons
AD-33 Media Replacement and Disposal ($34,230)
Media unit cost ($/ft3)
Media volume (ft3)
Other costs ($)
260
114
Vendor quote
To fill three 48-in
diameter vessels
Same additional
costs as AD-26
Media
Chemical cost($/1,0
Power use ($71,000 gallons)
Approximately
$2,800 for one year
0.001 Electrical
costs assumed
negligible
Average weekly labor (hour)
Labor cost ($71,000 gallons)
Total O&M Cost
($71,000 gallons)
20 minutes/day
0.16 Labor rate = $217hr
See Figure 5 0.08 +AD-33
replacement cost +
0.17 + 0.16
to estimate the media replacement cost per 1,000 gallons
of water treated as a function of the projected media run
length to the 10-|jg/L arsenic breakthrough (Figure 5).
The cost for chlorination was approximately $2,800 or
$0.17/1,000 gallons of water treated. Electrical costs were
assumed to be negligible because electrical bills prior to
system installation and since startup did not indicate any
noticeable increase in power consumption. Under normal
operating conditions, routine labor activities to operate
and maintain the system consumed 20 minutes per day
(2.33 hours per week). Assuming a $21 per hour rate, the
estimated labor cost is $0.16/1,000 gallons of water treated.
Conclusions
The Chateau Estates demonstration project confirmed
that chlorination effectively oxidized arsenic (III) and iron
(II) and formed arsenic-laden particles filterable by the
AD-26 media. The AD-26 system alone was capable of
reducing total arsenic concentrations to less than 2.5 |ag/L.
Chlorination also was effective in precipitating Mn(II)
without an extended contact time, converting 85 to 98%
of Mn2+ to MnO2 in 9 of the 13 spetiation events. The AD-
33 system worked as a polisher, reducing total arsenic
concentrations from 2.1 |ag/L to less than 0.5 |ag/L.
Battelle submitted the full report in fulfillment Contract
68-C-00-185, Task Order 0029.
References
McCall, Sarah E.; Chen, Abraham S.C.; Wang, Lili. 2007.
Arsenic Removal from Drinking Water by Adsorptive
Media U.S. EPA Demonstration Project at Chateau
Estates Mobile Home Park in Springfield, OH Final
Performance Evaluation Report. EPA/600/R-07/072.
U.S. Environmental Protection Agency. 2003. Minor
Clarification of the National Primary Drinking Water
Regulation for Arsenic. Federal Register, 40 CFR Part 141.
March 25.
<;i 71
<51 SO
"ro
^$1 25
0
o
w
£ <07S
to -HJ./3-
O
U
-------
f
I
V \t
&.
\
LU
C9
Please make my changes on the below label,detach or copy,
and return to the address in the upper left-hand corner.
If you do not wish to receive these reports CHECK HERED;
detach, or copy this cover, and return to the address in the
upper left-hand corner.
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
EPA/600/S-07/072
June 2007
Recycled/Recyclable
Printed with vegetable-based ink on
paper that contains a minimum of
50% post-consumer fiber content
processed chlorine free.
------- |