ENVIRO-NEWS: EPA Arsenic Research

---------- Forwarded message ----------
From: "Makuch, Joseph" <Joseph.Makuch@ars.usda.gov>
Date: Jul 1, 2010 11:27 AM
Subject: [ENVIRO-NEWS] EPA Arsenic Research
To: <Enviro-News@nal.usda.gov>

From: Peggy Heimbrock [mailto:heimbrock.peggy@epamail.epa.gov]
Sent: Thursday, July 01, 2010 8:30 AM
Subject: [nrmrl] NRMRL News - July 2010

From Lab to Consumer-EPA Research at Work

Some environmental scientists never see the end result of their work;
typically, their findings become a piece of a larger puzzle. But for
drinking water specialists at EPA's National Risk Management Research
Laboratory, the effort to discover the best available technology for
arsenic removal in small communities can be readily traced from the
laboratory studies to the actual adoption by local water utilities.

Background

Arsenic is an odorless, tasteless element that enters ground water
drinking sources (wells) through erosion of natural deposits or from
human-made sources such as agricultural and industrial runoff. Arsenic
is a human carcinogen. Chronic exposure to low levels of arsenic has
been linked to skin, kidney, lung and bladder cancers, as well as
neurological and cardiovascular effects. The 1974 Safe Drinking Water
Act lead to an EPA allowable limit for arsenic in drinking water of 50
parts per billion (0.05 milligrams per liter). By the 1990s,
increasingly sophisticated detection techniques and health effects
research had established a need for more stringent controls. A new,
lower level of 10 parts per billion, established by EPA in 2001,
impacted around 5,000 water systems, the majority of them small systems
serving fewer than 10,000 people.

Out of the Lab . . .

Recognizing the technical and financial burden the new standard could
impose on small drinking water systems, EPA, with additional
Congressional earmark funding, conducted a technology demonstration
program to test a variety of arsenic-removal technologies in small
systems across the country. Beginning in 2003, EPA drinking water
specialists worked with communities at 50 sites in 27 states to select
an optimum removal technology. The selection depended on variables such
as the quality of the local source waters, the estimated capital and
operating cost, the quantity and type of waste produced and the disposal
options available.

Into the Field. . .

The majority of the sites were located in the northern and western
states; they varied from the very small (treating 10 gallons per minute)
to the largest (treating 640 gallons per minute). Because it is simple
and cost effective to operate, the most commonly selected technology (55
per cent) was adsorptive media in which arsenic adsorbs to media for
subsequent removal. Other technologies selected included
coagulation/filtration, iron removal, reverse osmosis, ion exchange and
point-of-use. With 10 different media products selected for study, the
total number of technologies evaluated amounted to around 20.
The demonstration projects lasted from one year to as long as five
years. While local utilities handled the actual operation of the
selected test systems, EPA researchers and contractors:

*       Contributed advice and support during equipment installation,
shakedown and operation

*       Analyzed water samples collected weekly or monthly through the
whole treatment train(s) and from the distribution system receiving the
treated water

*       Evaluated long-term performance data on the technology
*       Developed long-term cost and operational data used to support
management decisions

*       Developed detailed project reports for each test site (60-plus
reports)

*       Made more than 50 presentations at training courses, conferences
and meetings with government permitting agencies, water utility
officials, technology vendors, and other stakeholders

And Beyond. . .

Concurrent with the full-scale, "real-world" testing of the arsenic
demonstration program, NRMRL researchers conducted lab and pilot studies
on ways to reduce costs and improve the performance of the technologies.
In one example, lab and pilot testing of onsite regeneration of the
media led to substantial reductions in the operational cost of the
adsorptive media process. Following the successful testing, which showed
that regeneration works, the State of California approved the technique
for a full-scale demonstration at Twentynine Palms, CA. Success at this
site led to a second full-scale test at a demonstration project in New
Hampshire. Other utilities have now expressed interest in the process.

In another example, pilot testing of a pretreatment system to remove
iron and oxidize arsenic III to arsenic V in a one-column system led a
vendor to modify its proposed adsorptive media system to include the
pretreatment system. At an EPA demonstration site in Utah, the
pretreatment step proposed by NRMRL researchers has been extremely
effective and found to extend the life of the adsorptive media treatment
system, thereby reducing operational costs. In many cases, adoption of
the demonstrated technology has speeded the state permitting process by
as much as two years.

These projects are unique in that they show EPA researchers at work-not
only in the laboratory, but also in the on-site application of research
results and their real-world impacts on communities.

For more information, please go to the Arsenic Research website <
http://www.epa.gov/nrmrl/wswrd/dw/arsenic >.

Contact
Jane Ice <mailto:ice.jane@epa.gov> , NRMRL Office of Public Affairs
(513) 569-7311

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