Officials in New Mexico Assess Plan to Curb Potash Pollution

Published on: 26 April 2022 04:46 PM
by KnowESG

Mosaic Potash has submitted proposals to state environmental regulators to examine and quantify the amount of groundwater contamination caused by discharges linked with potash mining along the Pecos River in southern New Mexico.

According to the state Environment Department, contamination was discovered in nearby groundwater monitoring wells between the company's Laguna Grande lake and the river. Hence, the company had to submit a plan for pollution monitoring and management.

Eddy County's main economic driver is potash mining. Potash is a potassium-rich salt primarily used in plant fertiliser and animal feed.

According to the Carlsbad Current-Argus, potash was first discovered in North America in 1925 while oil drilling. The finding sparked a construction boom in the former ranching community, which existed before the region's importance in fossil fuels.

The ore is mined both underground and on the surface at Mosaic's mine, located about 16 miles east of Carlsbad.

Waste from the ore mining process is carried about the complex and dumped in various locations, potentially contaminating groundwater supplies.

Tailings are generated when potash is extracted from the ground, and these are disposed of along with the salty brine water. The brine water and residual clay flow into a settling pond as the salt and clay settle. The brine is then pumped from the pond into Laguna Grande via a pipeline and finally into evaporation cells, where the chloride salt is extracted.

The discharge permit for Mosaic allows up to 7.5 million gallons (34 million litres) of tailings, brine, and other liquids per day, including 29,000 gallons (109,777 litres) of untreated household wastewater per day.

According to the state Ground Water Quality Bureau, these discharges have the potential to raise groundwater levels in the area above state guidelines for total dissolved solids, potentially affecting the Pecos River.

If this occurs, the Environment Department can shut down the site and order Mosaic to submit a plan to remediate pollution immediately.

If elevated contamination levels are detected, the government has an $82 million bond with Mosaic to fund a closure.

The discharge permit for Mosaic was last renewed in 2011. The abatement plan, which outlines how the corporation will lessen its environmental impact, is included in the permit.

Mosaic is obligated to take water samples from multiple monitoring wells in the area, as well as the Pecos River, and report the amounts of dissolved solids and other contaminants to the state quarterly.

The state may require Mosaic to develop a more detailed abatement that outlines strategies to clean up groundwater contamination between Laguna Grande and the Pecos River once Mosaic characterises the nature and extent of groundwater contamination from mine discharges between Laguna Grande and the Pecos River.