New EPA Arsenic Rule
to Impact Public Water Sources
November 9, 2005
Jan. 23, 2006 is the final implementation date
of the EPA's Arsenic Rule. Arsenic, a naturally occurring
element in rocks, soil, air, plants and animals, is a slow
poison that has been linked to numerous forms of cancer
resulting from long-term exposure. Public water systems
providing water to more than 25 people on a daily basis will be
required to meet the updated and more stringent rule, which
reduces acceptable arsenic levels from 50 ppb to 10 ppb.
Municipalities, managers and business owners may be wondering
what this new standard is, how this will affect their
operations, where to go for testing, or how to make sure their
systems are in compliance.
The 1996 Amendments to the Safe Water Drinking
Act require that several assessments be initially performed
before the EPA can determine whether setting a new standard is
appropriate for a particular contaminant. This evaluation
includes such factors as the contaminant’s natural occurrence in
the environment, human exposure and the risk of adverse health
effects, analytical methods of detection, technical feasibility
and the impacts of the regulation itself. Due to the health
risks associated with arsenic, the new drinking water standard
was installed, and January 23, 2006 was established as the date
by which all systems must comply.
Those affected by the new standard are public
water systems that provide water for human consumption through
at least 15 service connections, or regularly serve at least 25
individuals or more. Additional water systems that will be
monitored are community wells, such as municipalities, and
non-community wells that are labeled as non-transient. This type
of well classification is given to schools, for example, as the
population is at the location of the water system on a regular
basis. Private wells and non-community transient wells such as
those at gas stations and restaurants where patrons are not at
these establishments on a regular basis will not be monitored
for the new arsenic standard. However, the EPA and the
Department of Natural Resources (DNR) recommend that these well
users do perform annual testing for bacteria, nitrates and
organic and inorganic compounds.
According to Carol McCurry, a water supply
specialist with the Wisconsin Bureau of Drinking Water and
Ground Water, regular testing is required and monitored by the
DNR in each individual state. A typical testing cycle includes a
three-year rotation where all municipalities are tested the
first year, non-municipality entities the following year and
non-community non-transient firms the last year.
If a water system is found to be out of
compliance, quarterly testing is required. If, over the course
of the four quarterly tests, the average remains above the
standard, the firm or business must take action to achieve
compliance. If the initial test is high enough, the EPA or DNR
may recommend that immediate action be taken to bring the system
into compliance.
State-certified laboratories are the most
qualified source for water testing. Do-it-yourself test kits are
available on the market; however, these tests are not as
accurate or concise as state-certified lab tests, according to
McCurry. Clean Water Testing, a subsidiary of Water-Right, has
been testing for arsenic and other organic and inorganic
compounds for over 20 years.
As a state-certified laboratory, Clean Water
Testing lists the fact that arsenic does not follow a specific
pattern as the primary challenge of tracking arsenic in
groundwater. Elevated levels of arsenic may be found in one well
but not in a partner well located only 300 ft away. Further, a
well that tests normal one day may test at an unacceptable level
the next. Arsenic levels may change due to natural environmental
actions or agricultural activities such as mining or smelting.
Approximately 90% of the industrial arsenic in use is in the
form of wood preservatives; however, arsenic is also used in
soaps, metals, drugs, paints and dyes. These factors emphasize
the need for regular testing and monitoring.
Several tests used to identify arsenic in
drinking water include: mass spectrometry/inductively coupled
plasma, electro-thermal atomic absorption spectrometric method,
manual hydride generation/atomic absorption apectrometric method
and silver diethyldithiocarbamate method
An example of elevated arsenic levels
affecting public water systems recently occurred in Wisconsin’s
Fox Valley area. The Neenah Joint School District learned
arsenic levels in water from the well supplying the school
system were increasing. The discovery surfaced following regular
scheduled testing performed by Water-Right’s Clean Water
Testing.
An atomic absorption furnace utilized by Clean
Water Testing aided in the definitive test results. These
findings led to a decision by the school district to temporarily
bring in bottled water to Clayton Elementary School while a new
well was drilled. The temporary water supply was provided in the
form of 5-gal water coolers by Clean Water Testing.
With a new well now in place, Clean Water
Testing reports that continuing two-week arsenic baseline
samples are within the safe limits of both the current federal
arsenic limits as well as the new, more stringent EPA Arsenic
Rule guidelines. Development in the area has drawn down the
water table, which allowed oxygen to enter the aquifer
triggering chemical reactions that released arsenic into the
groundwater. To eliminate the problem, a new casing was
installed to seal off the upper aquifer.
While the EPA regulates public water systems,
it does not have the authority to monitor private drinking
wells. Approximately 15% of Americans rely on their own private
drinking water supplies. Some local government agencies set
regulations on these systems, but the private wells are not
subject to EPA standards. Consequently, the EPA and DNR agencies
highly recommend that private well owners follow a testing
routine similar to that of public wells in order to maintain the
highest quality drinking water.
Source: Clean Water Testing
November 9, 2005 |