fb pixel

Log In

Reset Password

A Chilling Effect

The city of Medford is going green while saving some green at its wastewater-treatment plant as it prepares to comply with new standards meant to help make the Rogue River Basin more friendly to wild salmon.

Over the next two decades, the city wants to rehabilitate and enhance 38 miles of stream-cooling riparian lands to more than make up for the too-warm treated effluent water its Regional Water Reclamation Facility releases into the Rogue.

But Medford's proposal goes one step further than past mitigation programs, in which agencies and businesses got credit for projects completed whether they survived or not.

These new projects must be proven to cool the basin's water, must be verified as effective by a neutral third party and be maintained for up to 20 years.

In doing so, the city would earn thermal "credits" to offset warm effluent, which is harmful to fish. Medford's plant does not have the capability to cool the effluent as required by Department of Environmental Quality standards.

At an estimated $8.3 million, the program would cost almost half of what it would to install two large "chillers" to cool the effluent to needed levels. And it wouldn't use electricity or add to greenhouse emissions.

"We've analyzed just about every alternative and this was the most cost-effective and the most practical," says Cory Crebbin, manager of the city's public works department. "If you can do something naturally, then it's better than engineering it.

"Nature's more resilient," he says.

The Thermal Credit Trading Program is offered as part of a permit renewal for the facility off Kirtland Road now up for consideration by the DEQ.

Patterned after a similar pilot project along the Tualatin River in 2004, this program is the first created under the state's new and more rigid rules about creating such mitigation programs — many of which carried no maintenance requirements in the past.

The city of Ashland also is in the process of putting together a similar program for a new permit to operate its water-treatment plant in the Bear Creek Basin, a major Rogue sub-basin, says Jon Gasik, a DEQ senior engineer working on both projects.

As water-treatment facilities in the basin come up for new operating permits, the DEQ is systematically setting lower temperature targets for the treated effluent releases. The reason is how warmer-than-natural water affects incubating chinook salmon eggs in gravel nests, called redds, through fall and winter.

Water temperatures dictate how fast the eggs incubate. If they incubate too quickly from warmer water, they hatch too early into the Rogue when food availability for them is low.

The Medford plant releases up to 20 million gallons of treated water per day into the Rogue at river mile 130.5 just downstream from TouVelle State Park. The new DEQ standard allows the treated effluent to raise the river's temperature by a fraction of 1 degree Celsius, and the current plant's configuration cannot achieve that during low-flow periods in the fall with mid-October the worst, according to DEQ documents.

Knowing these new standards were coming, the city has looked the past six years at various ways to cool that effluent, with such options as holding it in large ponds to trading it for agricultural water to building large chillers that mechanically cool the water.

Instead, it has settled on the new program that focuses on restoring riparian lands to provide shade against the sun on tributaries or the main-stem Rogue.

The city plans to hire the Freshwater Trust to operate this program, focusing on private lands along south stream banks to take full advantage of the shading capability of foliage.

The DEQ has developed a computer program called "Shade-a-later" to calculate how much shade and temperature reduction that specific riparian plantings will provide in specific areas. Then the city gets credit for that cooling effect to offset the treatment plant's warming effect, Gasik says.

It is also on a 2-to-1 ratio, so the projects must create twice the cooling effect for each thermal credit the city receives, Gasik says.

But this is not your father's mitigation program.

Old reforestation projects and the building of wetlands to offset those lost to development carried requirements just to build them, not ensure their survival.

This program has built-in maintenance budgets and specific standards to garner those credits during the life of the projects, Gasik says.

"If they walk away, they lose the credits," Gasik says.

The DEQ is taking public comment on this and other aspects of the permit, which could be authorized as early as mid-December, Gasik says.

Then the Freshwater Trust will start recruiting private landowners to join the program, with projects primarily focusing on 60-foot-wide strips of streamside land, says David Primozich, the trust's director of ecosystem services.

Possible projects could be from the mouth of the Illinois River near river mile 62 up to the treatment plant and include the Bear Creek Basin, according to the program draft.

The trust will even pay landowners for control of the riparian zone for 20 years, Primozich says.

That caveat likely will cause many landowners to at least listen to the trust's pitch, says Frances Oyung, coordinator of the Bear Creek Watershed Council.

"In our system, money talks," Oyung says.

If the DEQ issues Medford its treatment facility permit with this program, other utilities could use it as a blueprint for how to create similar programs to offset thermal problems now, Primozich says. Communities that don't yet have thermal issues with their treated effluent also could start riparian projects now to bank thermal credits for when their needs arise, he says.

"This is really an opportunity to save utilities a bunch of money while restoring riparian vegetation and create more environmental benefits," Primozich says.

"There are a lot more opportunities to achieve temperature reduction by restoring riparian vegetation than there is at the end of a pipe," he says.

Reach reporter Mark Freeman at 541-776-4470, or email mfreeman@mailtribune.com.

A Chilling Effect