Synthetic Volatile Organic Chemicals (VOCs) are man?made compounds used for a variety of industrial and manufacturing purposes. Among the most common VOCs are chemicals used as solvents, degreasers, fumigants, and dry cleaning chemicals. VOCs have detrimental effects on the liver, kidneys, and nervous system and may pose a cancer risk to humans. As a result, EPA has established concentration limits for VOCs in your community's water supply.

Do The VOC Regulations Apply To Your Community?

Yes, your community water system must monitor for regulated VOCs in the water supply. At present, there are 21 regulated VOCs (see list on following page) that must be monitored for by each community and non-transient, non-community water system. Non-transient, non-community public water systems are those that are not community water systems and that regularly serve at least 25 of the same persons over 6 months per year, (e.g., schools, businesses with their own system).

Actions Your Community Should Be Taking

Your community is required to monitor the levels of regulated VOCs in your water system. A special timetable was developed for these regulations, and it is divided into "compliance periods" of three years each. Initial monitoring began in the 1993-1995 compliance period for all community water systems and non-transient, non-community water systems. During the initial compliance period, your water system was required to take four consecutive quarterly samples for each regulated VOC.

If, after completing the initial sampling requirements, your public water supply system does not detect any VOCs, it may apply to the state for a waiver from the sampling requirements for the second compliance period (1996-1998). If a waiver is granted, monitoring may not be required for up to two compliance periods or six years for groundwater systems. There are several types of waivers available, and the type that is applicable to your community will depend on such factors as whether a contaminant has been found in your water supply area, the number of people served by your drinking water system, and whether your system is vulnerable to contamination.

If your tests indicate levels of a VOCs higher than the maximum contaminant level (MCL) (average over the year) at any sampling point, you are in violation of the VOC requirements. If you determine that you are in violation, you are required to perform the following actions:

• Begin quarterly sampling at that sampling point in the next calendar quarter.
• Continue sampling quarterly until the state determines that levels are reliably and consistently below the MCL.
• Take at least four consecutive quarterly samples at sampling points where levels exceed the maximum contaminant level.
• Notify the state agency and complete public notices as required.
• Request an exemption from the state agency to allow the community to continue to use the water supply while solutions to the violation are being explored and any needed financing is being planned.

In addition, the following recommendations should be observed:

• Work with the state agency and/or an engineer to determine how volatile organic chemicals are getting into your water supply. If possible, eliminate the source of contamination.
• If you must treat your water supply to remove volatile organic chemicals, work with an engineer or technical consultant to choose the best available technology for treatment. Filtering through Granular Activated Carbon and Packed Tower Aeration are common treatments for the removal of most volatile organic chemicals.
• Consider changing the source of your water supply as one option. This may be the most economical solution when available.
• After three years of sampling with no detection, however, sampling at that point may be further reduced to one sample every three years.

New Contaminants

EPA is required by law to add new contaminants to the list to be regulated on a regular schedule, so additional VOCs may be added to the list from year to year. Changes to the VOC monitoring list should not have much of an economic impact on small water systems, since testing for all VOCs is done from the same water sample.

Congress has determined that new contaminants to be monitored will be added to the list in several distinct phases. The most recently promulgated phase, Phase V, included three new VOCs (see the list of regulated VOCs at the end of this section).

Additional Information

The volatile organic chemicals requirements are published in Title 40 Code of Federal Regulations, Parts 141.24, 141.61, and 141.62.

Your state agency will be able to provide additional fact sheets on volatile organic chemicals.

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

(See Resource Section for drinking water contacts)

Regulated VOC MCLs Currently In Effect

mg/l = milligrams per liter