MONROVIA — The discovery of contamination in two city wells could double residents' water bills unless rain falls soon to reduce the pollution, officials said this week.
Tests showing rising levels of trichloroethylene, also known as TCE, in the wells came as a blow to city water managers, who have been combining water from the two wells with contaminated water from Monrovia's three other wells to produce a safe, drinkable blend.
The U.S. Environmental Protection Agency, concerned by contamination levels in the two wells noted late last year, agreed Monday to dispatch a regional water investigator to examine the wells, located at Myrtle and California avenues.
Although the current TCE levels in the wells--measured at 2.6 parts per billion--are allowable under state standards, they may soon become too high for blending, which could force the city to purchase large quantities of clean water from the Metropolitan Water District of Southern California.
The city currently draws about 9,000 acre feet of water from its wells each year. It would have to purchase an equivalent amount from the water district if the well contamination increases, as is expected unless rainfall dilutes the water supply, city officials said.
The Main San Gabriel Basin has been on the U.S. Environmental Protection Agency's Superfund list since 1985, with cleanup costs estimated at $800 million. Investigators believe that a massive underground plume of contamination is moving southward through the valley toward Whittier Narrows at a rate of one mile every five years.
Monrovia now spends $108 per acre foot--about 326,000 gallons--to pump and deliver its water to 8,500 customers. MWD water costs $233 an acre foot, said Paul Smith, Monrovia's utilities division manager.
A household consuming 1,500 cubic feet of water--11,250 gallons--per month pays about $15, Smith said. If the city has to buy water, the monthly bill per household would increase to about $30.
Another alternative would be to build a $1-million treatment facility, an option that the city put off two years ago because regional water authorities believed then that the plume of contamination was migrating from the area, Public Works Director Bob Sandwick said. The city also had reservations about the cost of constructing the facility.
