U.S. Environmental Protection Agency
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Arsenic Treatment Technologies
Tlie U.S. EPA Environmental Technology Verification
(ETV) Program's Drinking Water Systems (DWS) Center,
operated by NSF International under a cooperative agree-
ment with EPA, has verified the performance of twelve
technologies for removing arsenic from drinking water.1
The ETV Program has focused on verifying drinking wa-
ter treatment technologies that are designed for small sys-
tem applications.
Technology Description and Verification Results
The ETV Program verified that most of the technologies
reduced arsenic concentration to an average of 5 parts per
billion (ppb) or less, and many of them reduced arsenic
levels to the minimum detection limit of 1 to 2 ppb. The
verified technologies include examples of four different
technology classes:
Coagulation/Filtration is a traditional treatment proc-
ess that adds a chemical coagulant (typically ferric sul-
fate or ferric chloride) to contaminated water. The co-
agulant modifies the physical or chemical properties of
dissolved or suspended contaminants so that they settle
from solution by gravity or can be removed by filtration.
Adsorptive Media processes pass contaminated water
through a bed of solid media on which the contaminants
are adsorbed.
Reverse Osmosis is a treatment process traditionally
used for desalination of brackish water and sea water.
Reverse osmosis is capable of separating dissolved or-
ganic compounds and ions from water by maintaining a
pressure gradient across a membrane with a very small
pore structure.
Ion Exchange is a treatment process in which the arse-
nic ion (such as arsenate, AsO43"), is removed from solu-
tion by exchange with a different ion associated with a
solid ion exchange media.
Table 1 is a list of verified arsenic treatment technologies.
Verification reports may be found at http://www .epa.gov/
etv/verifications/verification-index.html.
ETV Drinking Water Systems Center
Jeff Adams, EPA Project Officer,
adams.ieff@epa.gov. Tel: (513) 569-7835
Bruce Bartley, NSF International,
bartlev@,nsforg. Tel: (734) 769-5148
Arsenic and Its Regulatory
Background at a Glance
Arsenic occurs naturally in rocks, soil, wa-
ter, air, plants, and animals. It can be released
into water, including drinking water, through
natural processes such as erosion, or through
human actions, including agricultural applica-
tions (fungicides or rodenticides), mining, or
disposal of arsenic-laden consumer products
(wood preservative, paints, dyes, soaps, and
semiconductors). Studies have linked long-
term exposure to arsenic at various levels in
drinking water to cancer of the bladder, lungs,
skin, kidney, nasal passages, liver, and pros-
tate. Non-cancer effects of ingesting arsenic
include cardiovascular, pulmonary, immu-
nological, neurological, and endocrine (e.g.,
diabetes) effects.
In January 2001, based in part on the National
Academies of Science recommendation and to
protect consumers against the effects of long-
term, chronic exposure to arsenic in drinking
water, EPA set a new drinking water standard
for arsenic at 10 ppb with compliance by all
public water systems required by January 2006
(66 FR 6976). The new standard applies to
about 74,000 water systems, approximately 5%
of which will have to take actions, such
as installing treatment equipment, to meet the
new standard. Of the systems that will need to
take action to meet the new standard, EPA esti-
mates that 97% (or about 3,900) are small sys-
tems that serve fewer than 10,000 people each.
The ETV-verified technologies are designed
for use by these small systems.
Verified Arsenic Treatment Technology
The ETV Program operates largely as a public-private partnership through competitive cooperative agreements with non-profit research institutes. The
program provides objective quality-assured data on the performance of commercial-ready technologies. Verification does not imply product approval or
effectiveness. ETV does not endorse the purchase or sale of any products and services mentioned in this document.
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Table 1. Verified Arsenic Treatment Technologies
Technology Name
Pall Corporation Microza® Microfiltration
System
ORCA Water Technologies KemLoop
1000 Coagulation and Filtration Water
Treatment System
Delta Industrial Services, Inc. CampWater
Porta-5 System
Kinetico, Inc. Macrolite® Coagulation and
Filtration System, Model CPS100CPT
Watermark Technologies, LLC eVOX®
Model 5
ADI International Inc. Pilot Test Unit No.
2002-09 with MEDIA G2®
Kinetico Inc. and Alcan Chemicals Para-
FIOTM PF60 Model AA08AS with Actiguard
AAFS50
Hydranautics ESPA2-4040 Reverse Osmo-
sis Membrane Element Module
KOCH Membrane Systems TFC®-ULP4
Reverse Osmosis Membrane Module
Watts Premier M-Series M-1 5,000 Reverse
Osmosis Treatment System
Basin Water High Efficiency Ion Exchange
Treatment System
Advance Remediation Systems Arsenic
Removal System CFU-5
Technology Description
This technology is based on chemical coagulation, mixing, and microfiltration with no intermediate
solids separation process. The Microza System includes pretreatment with sodium hypochlorite to
oxidize any arsenic (III) to arsenic (V) and iron present in the water supply.
The ORCA process is based on chemical addition with mixing in a proprietary mixing loop to
optimize coagulation, and granular media filtration with no intermediate solids separation process.
The KemLoop System includes pretreatment with sodium hypochlorite to oxidize any arsenic (III)
to arsenic (V) and iron present in the water supply.
The CampWater System is a coagulation/filtration technology that utilizes ozone to oxidize natu-
rally occurring iron to form a ferric hydroxide solid, which is filtered directly without additional
flocculation, solid separation, or clarification.
This system is a coagulation/filtration technology that utilizes sodium hypochlorite and ferric chlo-
ride and a proprietary ceramic filtration material.
eVOX is a coagulation/filtration technology that utilizes sodium hypochlorite and ferric chloride to
produce an insoluble large particle hydroxide precipitate that can be removed using a simple non-
proprietary media filter or clarification.
The ADI system is an adsorptive media technology that utilizes a proprietary media consisting of
an inorganic, natural substrate upon which iron (ferric hydroxide) is chemically bonded.
Para-Flo™ is an adsorptive media technology that utilizes a proprietary granular iron-enhanced
activated alumina media.
These are reverse osmosis technologies designed to reject dissolved salts and ionic solids, such
as arsenic, sodium, chloride, and other dissolved materials from drinking water.
The Basin Water System is an ion exchange process in which a solution containing the ion (such
as arsenate, HAs042') is passed through an ion exchange resin and exchanged with a similarly
charged ion (such as chloride, Ch) attached to the resin.
This technology involves on-site generation of chemical coagulants with flocculation and filtration.
Selected Outcomes of Verified Arsenic Treatment Technologies
The market for ETV-verified arsenic treatment technologies includes small drinking water systems that need
to install or modify treatment processes to comply with the 10 ppb arsenic standard. ETV's analysis indi-
cates that 3900 small systems fall within this category. If 25% of these systems (980 systems) decide to use
an ETV-verified technology to help them comply with the new standards, ETV estimates that:
• The ETV-verified arsenic drinking water treatment technologies would prevent up to 4.8 cases of lung
and bladder cancer and up to 2.6 deaths from these cancers per year
• The technologies would result in economic benefits of up to $17.1 million per year due to the preven-
tion of the above cases of lung and bladder cancer
• Between $2.0 and $14.7 million in pilot testing could also be saved if ETV data are used to reduce pilot
testing requirements.
Twenty-five states reportedly use ETV verification data to reduce the frequency and/or length of site-
specific pilot tests for drinking water treatment. States such as Utah are willing to use ETV verification data
to support permitting and approval decisions.
References
U.S. EPA, 2006. ETV Case Studies: Demonstrating Program Outcomes. EPA/600/R-06/001. January.
(Primary source)
U. S. EPA ETV, http://www.epa.gov/etv/.
U.S. EPA Arsenic in Drinking Water, http://wvvw.epa.gov/safewater/arsenic/.
EPA/600/S-07/007
January 2007
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