Drinking
Water Standards Do Not Adequately Protect Public Health
Under the
Safe Drinking Water Act, EPA sets enforceable standards for allowable levels of pesticides in drinking water, and requires
water utilities to monitor for these contaminants. Standards are set as a two part process.
First, the EPA sets a non-enforceable Maximum Contaminant Level Goal (MCLG), based purely
on health considerations. These MCLGs are set at levels "at which no known or anticipated adverse
effects on the health of persons occur, and which allows an adequate margin of safety." The agency then sets enforceable standards,
known as Maximum Contaminant Levels (MCLs), which are based upon the MCLGs, but are usually
adjusted to ensure that they are technically and financially feasible. For a number of
reasons, standards for the herbicides commonly found in drinking water -- atrazine, cyanazine,
acetochlor, alachlor, and metolachlor -- fail to adequately protect public health.
Drinking
water standards allow excessive cancer risks.
Because of
an outdated methodology used to set drinking water standards for these chemicals, they allow 10 to 30 times greater cancer
risks than EPA's Office of Pesticides allows for the same pesticides in food. Thus, even
when pesticide contamination levels are within EPA's drinking water standards, they may
still pose cancer risks that exceed the federal governments "negligible" (See Note 1.) risk standard by a factor of 10 or more.
Standards
do not take the risk of exposure to multiple pesticides or pesticide metabolites into account.
Water supplies
are often contaminated by multiple pesticides, and this study shows that a single glass from the tap can contain up to nine
pesticides or metabolites. In the case of the triazine herbicides -- which, according
to EPA all act by the same toxicological mechanism -- multiple exposures can significantly
increase health risks. Unfortunately, the standard setting process makes the unrealistic assumption that we are always exposed to pesticides in isolation, never more than one at a time.
Standards
fail to protect children.
After a five-year
study, the National Academy of Sciences concluded in 1993 that because of differences in physiology children are usually at
greater risk from pesticides than adults. On top of this, they are exposed to higher amounts
of pesticides relative to their size. For example, infants drink more than twice as much
water per unit of body weight than adults, meaning that they receive more than twice the exposure to toxic agents in drinking water. Since the release of the NAS study, no drinking water standard has been set or adjusted
specifically to protect infants or young children.
Safe Drinking
Water Act monitoring requirements are inadequate.
The Act only
requires water utilities to test their water once every three months for these herbicides (and many other contaminants). This
quarterly monitoring is an ineffective measure of contamination for seasonal contaminants
like the herbicides found in this study, which have peak runoff periods in the spring
and summer. Under the current quarterly monitoring scheme, water utilities are able to avoid peak contamination periods during May, June, and July. As a result, utilities that are performing all required testing often
significantly underestimate the levels of these herbicides in their drinking water.
Enforceable
standards do not even exist for some pesticides.
EPA has set
enforceable drinking water standards (MCLs) for three of the pesticides of primary concern: atrazine, alachlor and simazine.
For the three other major herbicide contaminants, cyanazine, metolachlor, and acetochlor,
EPA has yet to set enforceable drinking water standards. (See Note 2.) Instead, the EPA has issued non-enforceable Lifetime Health Advisories (LHAs).
Consequently, water utilities are not required to test their water for these pesticides,
and if they do test they are not required to inform their customers if the chemicals are found at levels that exceed federal health advisories.
Congressional
Action To Weaken the Law
Just as EPA
has begun to address some of the important shortcomings of the current standard setting process, and ensure that public health
is protected, Congress is acting in numerous ways to derail these efforts and weaken current
law. As this report goes to press, there are ongoing efforts in Congress to:
Weaken
pesticide law, making it more difficult for EPA to keep triazine herbicides from contaminating tap water.
On June 19
the House Agriculture Committee passed HR 1627, a sweeping rollback of current pesticide laws supported by the pesticide and
agriculture industry, as well as sellers of fruit and vegetables. Among other setbacks,
this bill would make it far more difficult for the EPA to restrict or ban the use of any
pesticide in order to protect public health.
Weaken
the Safe Drinking Water Act, making it more difficult for EPA to set adequate health standards and ensure that affected water
utilities are testing their water for herbicide contamination.
Senator Dirk
Kempthorne (R-ID) has circulated draft legislation supported by water utilities that will relax health standards and monitoring
requirements for chemicals in drinking water, including these herbicides. Representative
Thomas Bliley (R-VA) the chairman of the House Commerce Committee, is expected to introduce
similar legislation to weaken the Safe Drinking Water Act in the House of Representatives.
Defund
EPA's Special Review of the triazines.
The non-binding
resolution accompanying the May budget approved by the House Budge committee specifically cites the EPA review of atrazine as a "Federal Mandate that Warrants Elimination or Reform." And Representative David McIntosh
(R-IN), has included the triazine special review on a list of regulations that need to
be "captured or stopped," by possible actions in the House of Representatives.
The FY
1996 appropriations bill passed by the House of Representatives would delay or undermine much of EPA's ability to remove weed killers from tap water.
The bill
cuts the EPA budget by one-third, effectively short-circuiting the Agency's ability to set and enforce standards for pesticides
in drinking water, or to continue the special regulatory review of the triazine herbicides.
The bill eliminates a $1.8 billion revolving fund set up specifically to help smaller
communities treat contaminated drinking water as it abolishes the EPA's monitoring program and holds up $100 million in grants
given to states and communities used to minimize water pollution by runoff such as herbicides.
Conclusions
Federal
Drinking Water Monitoring Requirements are Fundamentally Flawed.
Federal drinking
water monitoring requirements provide regulators and public health officials with a fundamentally distorted picture of contamination levels in water. Extended periods of exposure above federal standards are not identified
by federal monitoring requirements, nor are peak exposures that may exceed these standards
by 10-fold to 30-fold or more.
Within the
peak contamination period extended and repeated exposure to weed killers at levels above federal health standards is common
in the cities we studied. Federal monitoring requirements, in contrast, treat all seasons
the same and mandate only one sample during each quarter of the year, including the three
month heavy contamination period. Even this lone sample can be taken before herbicides are applied and while contamination levels are low, or after pesticides have been largely flushed downstream.
On top of
this, there is no monitoring requirement for so-called "unregulated contaminants" such as cyanazine, even though cyanazine
was found at levels exceeding federal health advisories more often than any other herbicide.
These failings
are particularly disturbing because federal drinking water standards do not incorporate safety factors to protect the public
from extended periods of exposure above the MCL or LHA. The standards also do not consider
the risks of exposure to multiple herbicides simultaneously, and they do not explicitly
take into account the special risks to children. Finally, EPA's standard-setting methodology does not adequately protect the public from cancer risks.
Conventional
Water Treatment Does Not Remove Weed Killers.
Following
the release of Tap Water Blues, many water
utilities claimed that the water treatment techniques they were using were able to adequately
remove herbicides from contaminated source water. This is not the case.
All of the
water tested in this study was treated tap water. In most cases, utilities are using only conventional water treatment --
chlorination and sand filtration -- which does nothing to reduce weed killer levels in
water delivered to the community.
In a few
communities, including Springfield, IL, and Kansas City, MO, water utilities are spending hundreds of thousands of taxpayer
dollars using powdered activated carbon (PAC) in an attempt to reduce the levels of atrazine.
While PAC can be used to reduce contamination levels of individual weed killers, it is
not a solution to the problem. Springfield, Illinois, which utilizes vast amounts of PAC, still had the second highest cyanazine concentration of any city that was tested. PAC reacts differently with different chemicals,
and its effectiveness in treating complex mixtures of contaminants in tap water is unproven.
In Bowling
Green, the water utility uses a holding tank that they claim helps to reduce herbicide concentrations. In fact, the holding
tank had just the opposite effect. By holding highly contaminated water in the tank, Bowling
Green water authorities actually increased the levels of atrazine and cyanazine from below
federal health standards on May 15, to levels three times higher than federal health standards by June 26th.
The only
technology that can adequately remove pesticides once they have contaminated water supplies is the more expensive Granular
Activated Carbon. Instead of costly technical fixes to the problem, the pollution prevention
approach of restricting pesticide use is the most efficient and effective means of ensuring
the safety of water supplies.
Recommendations
Parents in
the most contaminated communities should seriously consider alternatives to tap water for infant formula, reconstituted juices
or drinks for their infants and children from May 1 through August 30. The most contaminated
cities identified in this study include:
Danville,
Decatur, Granite City and Springfield, Illinois
Columbus and Bowling Green, Ohio
Indianapolis and Fort Wayne, Indiana
Kansas City, Kansas
Jefferson City, Missouri
Omaha, Nebraska
New Orleans, Louisiana
All of these
cities had average contamination levels that exceeded at least one federal health standard for the study period, with the
exception of New Orleans, LA, which did not exceed any individual health standard for
the period but had a combined triazine average contamination level above the atrazine
MCL of 3 parts per billion.
The EPA should
require daily monitoring for triazine herbicides with inexpensive immunoassay tests for all surface-water-supplied drinking
water systems in the corn belt. The monitoring cost is about $1,500 per city; less than
10 cents per person in a city of 20,000.
The EPA should
phase out the use of the triazine herbicides by September 1996.
Congress
must strengthen federal pesticide and drinking water laws so that they explicitly protect infants and children from acute
and chronic effects of these contaminants.
Absent Congressional
action, the EPA should move to set pesticide and drinking water standards to protect infants and children.
When setting
drinking water standards to protect infants and children the EPA must strictly follow the recommendations of the National
Academy of Sciences Report, Pesticides in the Diets
of Infants and Children. At a minimum the EPA must specifically account for contamination of tap water with many different pesticides and metabolites. The agency (1) must explicitly
account for additive or synergistic risks that may result from pesticides that act via
a similar toxic mechanism or cause a similar toxic effect, (2) it must specifically account for any increased sensitivity or risk associated with infant or childhood exposure to these mixtures of compounds, and (3) it
must consider all routes of exposure to the pesticides that a infant or child might encounter.