Aldicarb is a common insecticide that is applied to a wide variety of crops to control all types of insects. Aldicarb enters drinking water resources through soil runoff and leaching. The short-term effects of aldicarb ingestion are completely reversible, and range from gastrointestinal discomfort to minor neurological problems. Long-term effects of exposure to aldicarb include sweating, pupillary constriction, and leg weakness. Although it is still unclear whether aldicarb is a carcinogen, EPA has determined that the health effects posed by aldicarb and its two biodegradation byproducts, aldicarb sulfone and aldicarb sulfoxide, are significant enough to warrant regulation under the Safe Drinking Water Act.

Does the Aldicarb Regulation Apply to Your Community?

Yes. EPA established Maximum Contaminant Levels (MCLs) for aldicarb, aldicarb sulfone, and aldicarb sulfate in 1991. The MCLs are as follows:

Maximum Contaminant Levels (MCLs)

mg/l = milligrams per liter

A year later, however, EPA received new data concerning the health effects of aldicarb which indicated that the existing MCLs were too stringent. In light of this new data, EPA stayed the effective date of these MCLs indefinitely and announced that it is planning to repropose National Primary Drinking Water Regulations for aldicarb and its breakdown products. This means that even though MCLs for aldicarb, aldicarb sulfone, and aldicarb sulfoxide have been codified, your community is not yet responsible for meeting those levels.

Actions Your Community Should Be Taking

Even though the MCLs for aldicarb and its breakdown products are not currently in effect, your community was nevertheless required to test your water for the presence of aldicarb and its two break-down products by December 31, 1995. You should have conducted four initial quarterly samples at each designated sampling point and reported your testing results to your state agency. Once final MCLs for aldicarb have been re-issued, you will have to comply with whatever additional monitoring requirements are specified.

Since the MCLs for aldicarb, aldicarb sulfone, and aldicarb sulfoxide are currently stayed, you need not limit the levels of these substances in your drinking water. However, once new MCLs are promulgated you will be required to comply with the specified levels just as you do with any other regulated drinking water contaminant.

The only treatment technology currently available to reduce aldicarb levels in drinking water is the use of Granular Activated Charcoal. Additional Information

Additional Information

The aldicarb requirements are published in Title 40 Code of Federal Regulations, Parts 141 and 142.

For further information on the federal requirements, contact the EPA Safe Drinking Water Hotline at 1/800/426-4791.

(See Resource Section for drinking water contacts)