City seeks nutrient variance for new wastewater plant

The city of Whitefish is asking the state for a variance from nutrient criteria that likely couldn’t be met with the city’s planned new wastewater treatment plant currently being designed.

The Montana Department of Environmental Quality is responsible for establishing water quality standards for protecting the waters of the state. Whitefish is in the Northern Rockies Ecoregion for which “tremendously low” nitrogen and phosphorus limits were set in 2014, according to city Public Works Director Craig Workman, and now limits are expected to be ratcheted down even further.

“The Ecoregion based standards set for Whitefish cannot be met by conventional wastewater treatment technologies,” Workman said.

The city is in the midst of designing a new wastewater treatment plant estimated to cost $17.5 million.

“Our sequencing batch reactor we are designing will not meet the requirements,” Workman said. “We know we can’t harm the Whitefish River, but we have to look at what we can do to meet wastewater requirements.”

Workman estimates that the change to “much lower” discharge standards could add up to $10 million in additional costs to the new wastewater plant, if the city doesn’t receive a variance.

City Council March 20 approved sending the variance request to the state.

Whitefish received a general variance in its latest discharge permit that sets the nitrogen limit of 10 milligrams per liter and phosphorus limit of 1 milligrams per liter. The latest information from DEQ, according to Workman, indicates that the limits will be reduced for nitrogen to 7 mg/l and eventually 3 mg/l, and for phosphorus down to .1 mg/l and eventually .05 mg/l.

DEQ in 2012 issued the city of Whitefish an administrative order on consent as the result of several violations of the city’s wastewater discharge permit. The order was updated two years ago to incorporate a compliance plan detailing the completion dates that must be met in order to bring the treatment plant up to the new standards by November 2021.

In October the city submitted a preliminary engineering report to DEQ detailing its plans for a new wastewater treatment plant and the limits in the original variance were used as the basis for planning.

Currently, the DEQ and the U.S. Environmental Protection Agency and a group of municipal entities are in the process of reviewing and likely lowering the general variance limits allowed. The review comes after the EPA adopted a rule that regulates the variance process and officials have indicated that Montana’s process may not comply with the federal rule, according to Workman. The DEQ recommended Whitefish apply for the variance.

“Montana law allows for the granting of nutrient standards variances based on the particular economic and financial situation of the permitee,” Workman said. “Individual nutrient standards variances may be granted on a case-by-case basis because the attainment of the base numeric nutrient standards is precluded due to economic impacts, limits of technology, or both.”

Whitefish is the only city in the state currently in the process of designing a new plant while the new regulations are being determined, according to Workman.

“DEQ is aware that this will delay our plant design for the next three to four months for the review of the variance,” he said. “This will likely extend our wastewater plant out a year.”

A previous timeline for the compliance plan sets a deadline of February 2018 for design plans for the new plant to be submitted to the state. Construction of a new facility had been estimated for completion in 2021.