By Marianne Metzger

In March, US EPA administrator Lisa Jackson announced there were going to be major changes to how drinking water is regulated. There are four strategies the agency hopes to implement in order to improve protection of our drinking water.

Strategy 1. Contaminant groups

New adjustments in policy will allow regulators to look at groups of contaminants that are similar, and issue new regulations that would apply to several contaminants. Current regulations call for examination of one pollutant at a time, which is painstakingly slow and allows many people to be exposed to chemicals that pose health risks during the evaluation process.

Strategy 2. Technology promotion

The agency will promote development of new drinking water technologies to address health concerns posed by the broad spectrum of contaminants being found in drinking water. It expects to accomplish this by collaborating with universities, technology developers and the private sector to develop new or improved water and energy-efficient treatment technologies to reduce health-based contaminants that are and will continue to confront water utilities.

Strategy 3. Statute authority

US EPA will use the authority of other statutes in an effort to help protect drinking water. Specifically, the Federal Insecticide, Fungicide, Rodenticide Act (FIFRA) requires registration of chemicals being used as pesticides. US EPA plans to use these registrations to develop risk assessments and analytical methods in support of developing new drinking water regulations. Toxic Substance Control Act (TSCA) is another statute that would be useful in the development of new drinking water regulations, as it addresses production, importation, use and disposal of
specific chemicals.
Strategy 4. Partnership formation
The agency will seek to form partnerships with states to
share access to all public water systems monitoring data. Through
the use of advanced information technology, US EPA wants to
facilitate data exchange capability between the states and the
agency without imposing further burden on states for information
collection.
Additionally, US EPA announced it will look to make four
contaminants in drinking water more strictly regulated. These
contaminants include: trichloroethylene (TCE), tetrachloroethylene
(PCE), acrylamide and epicholohydrin, all of which are
known carcinogens. They are being considered due to the results
of the second Six Year Review of the National Primary Drinking
Water Regulations. It was found that, with currently available
technology, these four contaminants can be further regulated to
protect public health.
An in-depth look at the contaminants
Trichloroethylene is a volatile organic chemical used mainly
as a degreasing agent for fabricated metals parts. It is also used
in many other applications including: dry cleaning operations;
textile production; organic synthesis; aerospace operations; as a
household cleaner for walls, carpets and rugs; a refrigerant; a heatexchange
liquid and a fumigant. It is also used as an ingredient
in paints and varnishes, adhesives, pesticides, gums, resins and
tar. TCE in water can be a result of the breakdown of its parent
compound tetrachloroethylene (PCE). Toxicological studies
indicate that animals that were exposed to levels of TCE above
typical environmental levels exhibited changes in the nervous
system, liver and kidney damage, tumors in the liver, kidney,
lung and possibly leukemia.
US EPA is currently reviewing TCE to determine which class
of carcinogen it will fall under. Under the Safe Drinking Water Act
(SDWA), the agency has established a maximum contaminant
level goal (MCLG) of zero for trichloroethylene. A MCLG is the
level at which there are no observed health affects. The agency
has established a maximum contaminant level (MCL) of 0.005
mg/L (or five parts per billion). An MCL is the enforceable
standard which public water supplies are required to meet. This
level is set as close to the MCLG as possible, considering available
technology cost and benefit, and possible occurrence levels
in drinking water.
Tetrachloroethylene (also known as PCE, Perchloroethylene
and PERC) is primarily used in the dry cleaning business and
textile industry. It is also used for metal degreasing and in various
consumer products. Toxicological studies on animals indicate
that exposure to higher PCE levels caused damage to the kidney
and liver. The US Department of Health and Human Services has
determined it is reasonable to conclude that PCE is a carcinogen.
Currently the MCLG for tetrachloroethylene is zero, and the MCL
is 0.0052 mg/L or five parts per billion.
According to the Agency for Toxic Substances and Disease
Registry (ATSDR), trichloroethylene is found in 852 of 1430
National Priorities List (NPL) sites; tetrachloroethylene is found
in 771 of the NPL sites, as identified by US EPA. The US Geological Survey (USGS) conducted a study about volatile organic
chemicals in about 3,500 water supplies (including private wells
and public water supplies), sampled between 1985 and 2002. The
most commonly detected VOCs were chloroform, TCE, PCE and
Methyl tert-butyl ether (MTBE). In that same study, TCE and PCE
were among the VOCs that were most frequently detected above
federal standards. Given the fact that TCE is a known carcinogen,
and its occurrence in our water supply as well as the technology
available for monitoring and treating TCE in water, the US EPA
is looking at stricter requirements. In the second Six Year Review of
the US EPA Primary Standards, it was found that current analytical
methods would allow for laboratories to detect even lower levels,
which means the agency could lower the MCL.
This will require testing methods be refined so labs are able
to meet levels significantly lower than the established guideline.
Public water supplies with TCE or PCE contamination may have
to further upgrade water treatment technologies to reduce current
levels to below the new federal standard. US EPA will start
the process to revise the standards for these two compounds,
but it won’t happen overnight. It could take several years before
completion and implementation.
Additionally, US EPA is also considering stricter regulations
for epichlorohydrin and acrylamide. Both are classified as
probable carcinogens, so the agency has established an MCLG
for both at a level of zero. These two compounds are, however,
regulated differently than TCE and PCE; they are regulated by
Treatment Techniques and have no established MCL. US EPA
regulated them as treatment techniques because there were no
standard analytical methods available for measurement in water.
These two compounds constitute impurities in polymers and
copolymers used in treating some municipal water. In order to
meet the regulations, systems must certify in writing to the state
(using either the manufacturer or third-party certification) that
they are not exceeding specified levels. US EPA chose to regulate
these compounds because methods were readily available for
measurement of the residual monomer in polymer products.
This was already being done by the manufacturers on a routine
basis. The levels are specified as follows:
• Acrylamide = 0.05 percent residual acrylamide in
polymer/copolymers and a maximum dosage of one
mg/L (or equivalent)
• Epichlorohydrin = 0.01 percent residual epichlorohydrin
in polymer/copolymer and a maximum dosage of 20
mg/L (or equivalent)
The residual monomer level for each was set at the lowest
level manufacturers could feasibly achieve at the time the regulations
were promulgated. New information obtained during
the Six-Year Review 2 indicates that improved technology and
manufacturing could now allow production of the polymer
with lower residual monomer content, which means systems
using these chemicals will have to meet stricter requirements
on the amount of residual allowed. What does this mean for the
water treatment industry? Any polymer certified by NSF 60 as a
coagulant aid will need to undergo new testing in order to prove
lower residual monomer levels.
While the US EPA is applauded for its outside-of-the-box
thinking for upcoming regulations to protect our drinking water,
only time will tell if it will indeed work. As technology advances,
so should our regulations, and proposed methods of regulating
these contaminants could prove to be quite beneficial to human
health.
References
1. US EPA, Office of Water, Analytical Feasibiity Support Document for
the Second Six -Year Review of Existing National Primary Drinking Water
Regulations. October 2009
2. US EPA, Enesta Jones, EPA Admistrator Jackson Outlines New Vision for
Clean, Safe Drinking Water, March 22, 2010
3. United States Geological Survey, Volatile Organic Compounds in the
Nation’s Ground Water and Drinking Water Supply Wells—A Summary.
April 2006
4. US EPA, www.epa.gov/safewater/contaminants/basicinformation/
trichloroethylene.html
5. US EPA, www.epa.gov/safewater/contaminants/basicinformation/
tetrachloroethylene.html
About the author
S Marianne R. Metzger recently rejoined National Testing Laboratories,
Ltd. as the GPG Business Manager. She handles various market segments
including water treatment, well drilling, public water supplies
and homeowners. Metzger has a degree in environmental geology and
political science from Case Western Reserve University of Cleveland. She
was employed at Accent Control Systems as a sales engineer, working
with water treatment equipment on commercial and industrial applications.
Previously, Metzger spent over 10 years with NTL in a variety
of positions including customer service, technical support and Business
Group Manager. She can be reached by phone at (800) 458-3330 ext.
223 or via email at mmetzger@ntllabs.com

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