Kalispell welcomes phased-in pollution standards

Federal approval of Montana’s plan to phase in strict new water pollution standards is welcome news for the city of Kalispell, and likely other municipalities that said they would not be able to meet the standards without spending large amounts of money.

“We never dodge the bullet ... It’s going a little slower,” said Kalispell Water Resource Manager Susie Turner, who oversees the city’s water and wastewater treatment operations.

Developed as part of the Clean Water Act, Montana’s new standards are for phosphorus and nitrogen. At high enough concentrations, the naturally occurring nutrients can cause algae blooms harmful to fish and other water life.

Montana pushed for the phased-in approach, as directed by the state’s Legislature in 2011, because of the “substantial and widespread economic impacts” that would result if the new nutrient standards were imposed immediately.

Some municipalities argued they would be forced to spend tens of millions of dollars to meet the rules using existing technologies.

The phased-in approach should provide time for removal technologies to improve and become more affordable, and also allow more time for nonpoint sources of the two nutrients to be better addressed, according to the Montana Department of Environmental Quality.

The nutrient standards and implementation plan are still being finalized by the state agency, pending approval by the Board of Environmental Review later this year and the issuance of a final rule.

Standards are expected to vary for bodies of water in different regions of the state.

According to state documents, the nutrient standards for wadeable streams in the Northern Rockies region would be .025 milligrams per liter for total phosphorus and .3 milligrams per liter for total nitrogen.

That region includes Ashley Creek, where Kalispell’s wastewater treatment plant discharges. The creek flows into Flathead Lake.

Kalispell’s wastewater treatment plant presently can bring its discharges down to about .12 milligrams per liter for total phosphorus and 7 to 9 milligrams per liter for total nitrogen. A milligram is one-thousandth of a gram.

“Right now, the limits of technology don’t get us down to those levels they’re going to require us to go to,” Turner said.

“They’re really low limits and it’s not something we can achieve at our plant. And neither can any other plants in the state of Montana. There’s just not the technology out there for us to do that yet.”

As part of the state’s proposed plan, Kalispell would be able to apply for a general variance to avoid having to meet the strict new standards when it goes to renew its 5-year discharge permit, which expires in August 2013.

That variance would let Kalispell discharge up to 1 milligram per liter of total phosphorus and 10 milligrams per liter of total nitrogen.

“Those are standards we can meet,” Turner said.

Discharge limits in the general variance would be reviewed every three years by the state, and could be reduced if lower-cost options emerge to better treat for nitrogen and phosphorus.

As part of the variance process, Kalispell would have to perform an optimization study to determine if its operations can be adjusted to better reduce phosphorus and nitrogen levels.

“The optimization study will look at our processes to see if they can be improved internally without big budget items — thousands instead of millions of dollars,” Turner said.

Kalispell’s wastewater treatment plant — expanded for greater treatment capacities just a few years ago — has been designed to treat for phosphorus for years. More recently, its operations were modified to be able to treat for nitrogen.

Both nutrients are reduced through separate, but intertwined, biological removal processes. One requires an oxygen-rich condition for microbes to absorb phosphorus; the other requires oxygen-free conditions for microbes to absorb and expel nitrogen as a gas.

“The nitrogen treatment is our biggest challenge right now,” Turner said. “If our flows were to increase we possibly would not even be able to meet the variance [limits].”

Knowing that new nitrogen standards were on the horizon, a study is already under way to see if Kalispell’s plant operations can be adjusted to improve its denitrification process, Turner said.

“The variance gives us a little more time to optimize our plant and do it in a better way, to spend people’s money better, and not so fast up front. It gives us time to study and use technologies we know will be effective,” Turner said.

The state’s plan for a phased-in approach is a good thing for the city, she said.

“We’ll still have to stay involved with new technologies and look at our processes and maybe side-stream some treatments as new things come about. We always kind of stay on top of those things and what we can do to improve our facility.”

Reporter Tom Lotshaw may be reached at 758-4483 or by email at tlotshaw@dailyinterlake.com.