Thursday, August 12, 2004
Merced city airport water cleanup is set
The Modesto (CA) Bee
MERCED — While many eyes near Merced Municipal Airport are drawn skyward, this week the city of Merced is looking underground. Crews soon will begin working to clean up polluted groundwater at the airport. City officials said the contamination does not pose any significant threat to public health and safety.
A contractor will inject a substance resembling molasses into the aquifer to speed the natural process of eliminating contaminants in the groundwater.
Hydrogen Releasing Compound, a patented chemical that helps break down solvents, is a new technology that is quicker and cheaper than old cleansing methods, water experts said.
Before the new substance was developed, cleaning groundwater meant pumping it out, treating it and finding a way to dispose of it, said Wendy Cohen, a senior engineer with the state Regional Water Quality Control Board.
Cleanup plan OK’d in June In June, the water board approved a request to clean up the Merced airport site using the new injection method.
Tuesday, contractors spent the day probing the soil in an area where contaminants remain from an old crop-dusting operation and a former Fire Department training program.
The work is the first phase in a $384,000 effort that aims to drastically reduce tetrachloroethylene, trichloroethyleneand another chemical in the site’s groundwater. Measurements of these substances at the site far exceed federal standards for human consumption.
The work area, near Riggs Avenue, is contained by an asphalt cap. It has several monitoring wells that the city uses to check contamination levels four times a year.
The nearest well providing some of the city’s drinking water is about a mile from the airport site and is not contaminated, city officials have said.
Even though the contaminants are contained, the Regional Water Quality Control Board still wants the area cleaned up.
The city anticipates lower levels of the chemicals in several months. Levels could become undetectable within a few years, officials said.