The city of Warden will use a $75,750 grant from the state Department of Ecology to take temporary measures to protect the public from EDB-contaminated drinking water.

EDB, or ethylene dibromide, is a pesticide and gasoline additive that stays in underground water and soil for a long time but breaks down quickly in the air. In the 1970s and early 1980s, it was used in soil to kill insects and worms that get on fruits, vegetables and grain crops. The U.S. Environmental Protection Agency stopped most of these uses in 1984.

Last year, Warden found that one of its main drinking-water wells was contaminated with EDB. Another contaminated well had already been taken out of commission because of high levels of EDB and because of its proximity to the railroad and a potato-processing plant. The wells are located approximately 1,000 feet apart.

The source of the contamination is unknown.

The city will use the grant money to fix the contaminated wells to make the water safe until a new well and water lines are constructed east of town. If the source of the EDB is identified and the city is reimbursed by the source for the cost of this work, the grant money would be returned to the state.

Drinking water should not have more than 50 parts per trillion of EBD to be safe. From June to November 2003, the city collected samples from its well #5 with up to 92 parts per trillion. The city blended this water with uncontaminated water from well #6 in order to serve its customers safe water while more permanent solutions were explored.

"We know that blending water sources to lower contamination levels is not a long-term solution to the problem," said Flora Goldstein who manages Ecology's toxics cleanup program in Spokane. "But while the city officials are looking for the resources to drill a new well, this money can help pay for an interim fix so residents feel more secure about their drinking water."

According to Goldstein, the city's well #6 is sufficient to serve residents during the winter but needs to be supplemented during the warmer months, so interim measures had to be taken.