Wyoming Town Struggles With Selenium

Work on lowering levels of selenium in water for Casper, WY, will be put to the test in 2018 when the city’s wastewater treatment plant will have to apply for a new permit from the Wyoming Department of Environmental Quality (DEQ).

According to the Casper Star-Tribune, if the agency finds that selenium levels are higher than normal, then Casper will have to construct a new facility in order to remove the chemical, which could cost the city nearly $50 million.

“We have been very concerned about pending potential EPA regulations that might require us to make some major upgrades," Councilman Charlie Powell told the Tribune at a council meeting last month.

Though DEQ gives permits to wastewater plants, the agency relies on U.S. EPA guidelines. Small levels of selenium can be healthy, however, while high levels of the metal can be toxic, not only to humans but aquatic life as well.

Lisa Ogden of the Natrona County Conservation District told the Tribune that “her organization encourages converting dirt ditches to pipelines and using sprinkler systems instead of flood irrigation to cut down on the amount of sitting water on land around the county.”

“That does minimize how much selenium is taken up into the water,” Ogden added.

Ogden also said that the county has seen a minimization in selenium levels since the early '90s. The issue that Casper faces “is that new EPA recommendations might no longer allow the current pollution mitigation strategy of cutting down on selenium runoff across the county.”

Casper may have to treat high selenium levels at a single point instead, which leads to a new wastewater treatment facility. The 1999 regulations from the EPA at the moment allows the county to treat the high levels by working with local landowners.

According to the Tribune, the federal regulations that are currently in place require that selenium “be kept below five micrograms per liter in waterways and below 50 micrograms per liter in drinking water.”

Bruce Martin, public utilities manager, said that Casper’s current wastewater treatment plant takes in water that has 8 to 12 micrograms of selenium per liter.

However, Ogden said that “once treated water, with its high selenium levels, is deposited into the river, it disperses and falls below the EPA limits.”

The new recommendations from the EPA are a little more detailed than the ones from 1999, but states are not actually required to adopt them. States can set their own “site-specific” regulations for selenium.

The hope, Ogden said, is that when the time comes for the wastewater treatment plant’s permit review next year, “the DEQ will take into account the county’s unique circumstances.”