[Note: This post has been changed regarding prevalence of groundwater contamination at dairies.]
The state will require a Dexter dairy to monitor nearby private water wells as part of its efforts to deal with groundwater contamination at its site, according to a New Mexico Environment Department representative.
The Environment Department has indicated that public water supplies are not affected at this time.
“Based on current data and information available to NMED, groundwater contamination has not impacted any public drinking water systems,” the agency stated when announcing the public release of the first version of the Stage 1 Abatement Plan submitted by Rockhill Dairy.
Located on East Ojibwa Road, about 4 miles southwest of Dexter, Rockhill Dairy is one of five dairies in the Dexter area that the Environment Department has recently required to file abatement plans.
Rockhill’s plan was posted Feb. 12 on the “Dairy Discharge Permitting” section of the Environment Department’s website, www.env.nm.gov.
The Stage 1 plan outlines how the dairy and its consultants, Glorieta Geoscience Inc. of Santa Fe, will collect and report data on the extent of groundwater contamination in the area, how it will determine whether contaminants also can be found in the soil, and how the situation can be rectified to ensure safe water supplies.
Representatives of the dairy who answered calls could not speak to the issue, and phone messages and a fax seeking comment were not responded to by press time.
According to the plan submitted on behalf of the dairy by the Santa Fe consulting firm Glorieta Geoscience Inc., the dairy is allowed by state permit to discharge 80,000 gallons a day of greenwater, or used water from its dairy operations.
But four of its monitoring wells at various times during the past five years have had excessive levels of nitrate, chloride, sulfate and Total Dissolved Solids (TDS). Nitrate is considered dangerous if consumed by humans, while nitrate and sulfate can be harmful to animals, the plan indicates.
Public Information Officer Maddy Hayden of the Environment Department said that all dairies produce wastewater with contaminant levels above standards, but that dairies usually keep the wastewater from contaminating groundwater. The state requires dairies to have discharge permits and to conduct quarterly testing of monitoring wells. Enforcement efforts by the state begin if the dairies’ data indicate that the wells have contamination levels above what is allowed.
She added that past farming practices in the area, such as flood irrigation, have resulted in the groundwater contamination at Rockhill and other nearby dairies.
“This shallow groundwater contamination does not usually affect the deeper artesian aquifer that most drinking water in the area comes from,” she said.
As part of its abatement efforts, Rockhill will have to make arrangements to monitor other nearby private wells at its own expense, she added.
The dairy’s Stage 1 abatement plan reiterated that a public water well nearby was found not to have contaminants exceeding allowed levels, but the document stated that the dairy would conduct research with the New Mexico Office of the State Engineer to determine if other private water wells are nearby and if access to them can be obtained for testing.
According to Rockhill’s report, the dairy has about 2,200 milking cows and another 200 non-milking cows and heifers.
Its plan now calls for the first stage to be completed in about 10 months, with Stage 2 to begin about 40 days thereafter.
“A Stage 2 Abatement Plan is required after the Stage 1 AP identifies the magnitude and extent of the contamination,” Hayden said, “and the responsible party submits a Final Site Investigation Report to identify the most appropriate remedial strategy to clean up the site.”
Senior Writer Lisa Dunlap can be reached at 575-622-7710, ext. 351, or at email@example.com.