The Prince William County Health Department, which found traces of two potentially hazardous chemicals in one of three wells serving Independent Hill Elementary School several weeks ago, recently discovered traces of two related chemicals in wells serving Gainesville Elementary School in western Prince William and Woodbine, a midcounty preschool facility for handicapped children. The chemicals were found during a check of all school wells after the Independent Hill well was found to be contaminated.

Traces of dichloroethane were found at 8 parts per billion in the well at Gainesville Elementary, according to health director Dr. Jared Florance. Traces of tetrachlorethane at 5 parts per billion were found in the Woodbine well. Both are solvents and belong to the same family as the two chemicals recently found. Florance said that the wells at Gainesville and Woodbine are closed and that students and staff are using bottled water supplied by the county.

According to school spokesman Kristy Larsen, the wells serving the Independent Hill school, which sits on land that was once a military base, have been closed and the area is now hooked up to county water.

While the chemicals, all solvents, could possibly cause cancer in laboratory animals, there is no evidence that they are human carcinogens, according to the Environmental Protection Agency.

Florance and Coles District Supervisor G. Richard Pfitzer held an informational meeting for midcounty residents last Thursday. A second meeting is slated for 10 a.m. tomorrow in the old supervisors meeting room on Lee Street in Manassas. School board members and representatives from the county's service authority are expected to attend.

According to Florance, state Del. John Rollison (R-Prince William) has introduced an emergency measure in the state legislature that would provide $150,000 for further well testing in the county.

The sites that would be tested include all known areas of contamination, industrial sites that have never been sampled, 10 percent of the wells included in 1986 real estate transactions and water found to be contaminated last year at the IBM plant in Manassas.