The New Mexico Environment Department says Waste Management of New Mexico Inc. didn’t properly document and handle loads of sediment from brackish groundwater dumped at the local landfill in 2018, but there’s no concern of environmental contamination.

According to a news release from NMED, the department issued a notice of violation because Waste Management didn’t classify and dispose of the sludge in a way that met state requirements.

“We have received the notice of violation and are preparing our formal response to NMED, which we will submit within the required 10 days,” said Waste Management Four Corners Area Communications Director Jennifer Wargo.

She didn’t comment further.

“While the violations cited indicate a failure to adhere to state regulations and the facility’s permit, NMED’s routine inspections of the Rio Rancho landfill indicate that the landfill generally complies with these requirements, and we do not have cause for concern regarding the landfill’s ability to continue to safely isolate waste from the environment,” said NMED spokeswoman Maddy Hayden.

According to the release, in March 2018, Waste Management accepted about 288 tons of the solids left from the evaporation of water from treatment testing for two brackish wells west of Rio Rancho. Water was pumped into a lined surface impoundment during pilot tests in 2009 and 2011.

Analysis of the well water indicated the presence of arsenic and two forms of radium at levels higher than groundwater standards, as well as a high concentration of dissolved solids, according to the release. All of those substances can occur naturally in groundwater, but the federal government requires they be cleaned out of drinking water to safe levels.

Well-site owner IMH Financial Corporation hired waste hauler Alpha Southwest Inc. to transport the solids, which meet the legal definition of sludge, to the Rio Rancho landfill, according to the release.

Hayden said a concerned local resident raised a concern about the sludge to the department recently.

In July and August 2020, according to the release, the Waste Management district manager provided NMED with disposal tickets showing the sludge had been dropped off at the local landfill. However, he couldn’t show documentation that landfill staff followed the special requirements for sludge disposal, including getting a waste profile and special waste manifests, and using a state-approved disposal plan, according to the release.

The manager told NMED the loads were probably used for daily cover. The landfill is authorized to accept sludge.

“NMED is aware of the past operations at the well site that was the source of the sludge,” Hayden said. “The information we have to date indicates that the concentrations of contaminants of concern in this sludge were very low. We are awaiting additional information from the waste generator to understand more about the material.”

Hayden said the Rio Rancho landfill, like other permitted landfills, is designed and operated to isolate waste from the environment.

“In general, operations at the landfill are industry-standard best management practices that maintain the integrity of the liner system and otherwise ensure that the waste does not contaminate the surrounding environment,” she said.

The notice of violation, dated Oct. 28, gave Waste Management 10 days to respond with a description of actions taken to ensure the proper acceptance and documentation procedures were followed in the future.

Hayden said NMED would evaluate the response and determine whether the described actions were sufficient. If not, she said, the department would take additional enforcement action.