Groundwater cleanup set to begin

For a copy of a presentation made by city officials at last week's public hearing on the Griggs-Walnut Groundwater Plume Remediation Project, click here.

LAS CRUCES - After 12 years Las Cruces and Do-a Ana County officials are almost ready to begin construction of a facility that is expected to remediate a contaminated groundwater plume within the Las Cruces city limits.

Final design of a proposed facility that would allow water in the Griggs-Walnut Groundwater Plume to be cleaned, making it acceptable for public consumption and other uses, were unveiled last week at a public hearing at Lynn Middle School. The contaminated plume has forced city officials and engineers to shut down five city water wells near Griggs Avenue and Walnut Street.

Trace amounts of the chemical tetrachloroethylene, or PCE, were found in five water wells between 1993 and 1995. How the unacceptable levels of the chemical got into the water wells isn't known for sure, but city officials suspect the water could have become contaminated years ago when part of the plume was on land that served as an airport.

Regular monitoring of all other city wells have shown no traces of PCE, and independent engineering studies have determined the contaminated water is limited to the Griggs-Walnut plume.

Health issues?

A small number of

residents attended the public hearing at Lynn Middle School, and some of them complained to city officials that they and neighbors appeared to be suffering ill effects from the water they have been drinking.

However, city officials stressed that no city water customer was ever delivered water with PCE amounts that exceed U.S. Environmental Protection standards.

"I live within a mile north of that location, but I can't really say that I or anyone else in my family has gotten sick from drinking water," said Larry Chavez, a retired U.S. government employee who has lived relatively close to the Griggs-Walnut plume for more than 20 years. "I knew that the city shut down those wells, and didn't worry any more about the problems after that."

Cleanup to start

Now city and county officials are ready to begin remediation to remove the unacceptable levels of PCE from the water. City Utilities Director Jorge Garcia said the process would involve pumping the contaminated water from aquifers deep underground and bringing the water to the surface. He said exposing the affected water to oxygen would remove the unwanted chemicals.

"We're hoping to begin construction late next spring," Garcia said. "All the documents for construction are ready for public review and we're making those available."

The city and county have accepted responsibility for cleaning up the plume and will equally split the costs for remediation. Garcia said preliminary costs projected two years ago were estimated at as much as $6 million but those figures have been noticeably lowered.

"The city and county each obtained loans from the state for $7 million, or $3.5 million apiece, to cover all costs and potential contingencies," Garcia said. "But as we went through design, we were able to figure what and where we could cut back costs, and now the project is estimated at about $3.8 million.

"The good thing about the lower cost is that there will be a substantially lower pay back on those loans. We'll only have to end up pay back only what we ended up paying for."

Steve Ramirez can be reached at (575) 541-5452

Superfund

•The purpose of the Griggs-Walnut Remediation Project, perhaps more commonly known as the Superfund site, is to remove PCE, a manufactured chlorinated solvent chemically known as tetrachloroethylene, from contaminated groundwater.

•Trace amounts of PCE have been discovered in five city wells near Griggs Avenue and Walnut Street.

•Two of the wells were shut down in 1996 and 2000 and the remaining three were taken off of the city's water system in 2006.

•City officials have said the contaminated water was never delivered to residents with unacceptable PCE levels set by the U.S. Environmental Protection Agency.

•A facility to pump the contaminated water to the surface and expose it to air will remove the PCE, making the affected water acceptable for public consumption and use.

•The city and the county have obtained as much as $7 million in state loans to pay for the remediation.

•But city officials estimate the project cost at $3.8 million.

•Written public comments on the proposed design of the remediation project can be submitted by Dec. 30 to: Eric Johnson, Marron and Associates, 7511 Fourth St. NW, Albuquerque, N.M. 87107.

•Written e-mail comments will also be accepted by Dec. 30 to: eric@marroninc.com, and "Griggs Walnut Comment" should be written in the subject line of the e-mail.