By Jack King
Remediation of ground-water contamination beneath the old Clovis landfill and sewage treatment site will begin in about six months. It could cost between $639,000 and $1.5 million, Clovis Public Works Director Harry Wang said Wednesday.
City officials said in May that a plume of perchloroethylene, a toxic solvent, has been found in ground water beneath the city’s old landfill and sewage treatment plant in concentrations about 10 times the standard set by the U.S. Environmental Protection Agency.
A half-mile long and a quarter-mile wide, the plume is found in ground water about 270 feet below the surface and seems to be moving east about 20 feet a year, said Ed Hansen, a hydrologist with the New Mexico Environment Department.
Hansen said the plume poses no immediate danger to humans or animals, because no one is consuming ground water in the area. However, because the plume is moving, the NMED was anxious to work with the city of Clovis to eliminate it, he said.
Engineers for the city’s remediation consultant, Camp Dresser & McKee Inc., said at a public meeting Tuesday that a single well set at the leading edge of the plume should be able to remedy the problem by pumping the contaminated ground water and cleaning it in the city’s waste water treatment plant.
Tests have shown that pumping the water, then treating it in the wastewater treatment plant, should reduce the concentration of solvent by 99 percent, said Robin Jones, a CDM engineer.
Termed “Phase I” of the project, it will cost $270,000 to drill and build the well and an additional $30,000 a year for two years to pump the water to the city’s wastewater treatment plant, Wang said.
In Phase II of the project an attempt will be made to identify and eliminate a source of the plume. However, if no source is identified, no further action will be taken. If action were taken, Phase II could include building a gas control system and a soil vapor extraction system at the landfill, as well as the use of bacteria to eliminate more of the solvent. It would cost about $889,000, Wang said.
Phase III of the project will include restoration of the aquifer beneath the landfill, once the plume has been eliminated. It will include putting clean water back into the aquifer and will cost about $309,000, Wang said.
Wang said the city has applied for grant money to fund the project and also has $600,000, collected from landfill fees, available in the city’s Financial Assurance Fund for landfill expenses.
The Assessment of Corrective Measures, an outline of the plan, will be available for public review at Clovis Carver Public Library for 30 days. Following the public review, the assessment will be reviewed by the NMED before final approval of a remedy. The approval process will take six months, Wang said.
Public comments can be submitted orally or in writing until July 10 to: Harry Wang, Public Works Director, 801 South Norris St., Clovis N.M., 88101, (505) 769-2376.
Butch Tongate of the NMED’s Solid Waste Division said the Clovis landfill is only one of several landfills with contamination problems NMED representatives are visiting this month. Included are landfills or old landfill sites at Tucumcari, Hobbs, Gallup, Las Vegas and Silver City, he said.