Trees over Technology

West Coast wastewater plant chooses trees over technology

Five years ago Medford, Oregon, had a problem common for most cities—treating sewage without hurting fish.

The city’s wastewater treatment plant was discharging warm water into the Rogue River. Fish weren’t dying, but salmon in the Rogue rely on cold water. And the Environmental Protection Agency has rules to make sure they get it.

So, instead of spending millions on expensive machinery to cool the water to federal standards, the city of Medford tried something much simpler: planting trees.

It bought credits that paid others to handle the tree planting, countering the utility's continued warm-water discharges. Shady trees cool rivers, and the end goal is 10 to 15 miles of new native vegetation along the Rogue.

Pollution-trading programs are common in other industries, such as caps on sulfur dioxide from U.S. power plants. A regulator, say the EPA, issues or sells to polluters permits allowing a set amount of emissions. Firms must own permits to match their emissions, but the total amount is capped. If a coal plant owner can't or won't cut emissions from its stacks, it buys permits, or credits, from other utilities that have chopped emissions and don't need as many.

But using credits to curb warm discharges is novel and water-quality trading to protect stream temperatures is gaining traction in Oregon.

Supporters say it’s a win-win: wastewater plants save money, streams stay cool and the trees do other good things like provide habitat and suck up carbon.

“Traditional environmental practices, litigation, advocacy, got us a long way, but not too much further,” said Joe Whitworth, president of The Freshwater Trust, which spearheaded the Medford project.

“We thought, what else is out there, what can we do different to enhance the entire watershed?”

However, some say it’s not enough to protect the states’ fish.

“It is a get-out-of-jail card,” said Nina Bell, executive director of the nonprofit, Portland, Oregon,-based Northwest Environmental Advocates. “It takes care of [wastewater] plant’s responsibility but doesn’t have the kind of real water quality benefits we need.”

Using trees to save green

Medford is situated on the Rogue River—famous for its runs of salmon and steelhead. The wastewater plant, serving roughly 170,000 people, adds to the overall warming of the river, which can make eggs incubate earlier, affecting survival rates.

With discharge likely to increase—by 2030 the plant is estimated to serve an additional 30,000 people—Medford started looking for ways to lessen their discharge footprint.

Cooling towers and chillers are a traditional solution, said Walt Meyer of West Yost Associates, the city's engineering consultant. But shady riverbanks can accomplish the same goal as expensive engineering. “It turned out trading was the most cost-effective and the most environmentally compatible,” he said.

Chillers run somewhere around $15 million to $20 million and require massive amounts of energy to

run, while tree planting will cost the city about $8 million.

Not without controversy

The upper temperature limit, as set by the Oregon Department of Environmental Quality (DEQ), for the Rogue in summer is 64 degrees Fahrenheit. In the fall, when the fish spawn, and into the winter that limit is 55ºF, said Dennis Ades, the former water quality trading coordinator with the Oregon Department of Environmental Quality.

Many factors influence stream temperature—both natural fluctuations in temperature and precipitation, and human causes such as discharges and removing vegetation from riverbanks.

Ades estimates that of the human warming sources, wastewater treatment plants typically account for 5 to 10 percent in Oregon. The remainder is from what’s called non-point sources—such as agriculturally driven losses of streamside vegetation and river diversions.

This is where some of the controversy comes in. That 90 percent remainder is a big number.

“Some say this [Medford project] is a great idea as it will restore some riparian areas,” Bell said. “It might restore some areas, but it’s such a drop in the bucket and distracts from real question: what are we doing to achieve widespread non-point source controls?”

“Point sources" such as wastewater treatment plants are where states have the most authority to make a difference, Ades said. “The Clean Water Act doesn’t give us a lot of non-point tools."

Oregon has some local ordinances and voluntary reductions, he added. For instance, farmers can participate in water quality trading projects, accelerating their voluntary reductions.

Medford's initial round of credit-buying and tree-planting will be completed by 2020. The water from Medford is discharged in White City, and the trees are planted elsewhere in the Rogue River’s basin.

Saving money in environmental programs is key, said Larry Karp, a professor of agricultural and resource economics at the University of California. “By doing it cheaply, you can do more of it. You’re more likely to achieve environmental benefits if you go about it in efficient ways.”

And someone else pretty important agrees with Karp. In a 2012 speech, before the program had really gotten underway, President Obama praised the Medford project as an example helping the environment without putting unnecessary financial pressure on industry.

“It worked for business, it worked for farmers, it worked for salmon,” President Obama said. “Those are the kinds of ideas we need in this country.”

The idea of water quality trading was hatched a little more than a decade ago, born out of thinking of how to lessen not only the impact of wastewater treatment plants but also that other 90 percent of sources that are contributing to warming the river but not fully regulated.

Trees don’t discriminate: Planting them helps the whole watershed—removing both pollutants and climate-warming gasses from the air and providing shelter and habitat for creatures.

Chillers require about 6,000 horsepower of connected load, Meyer said, which would have been an energy suck.

Bell, the critic, admits trees are good. But location matters—the trees are being planted on the main stem of the Rogue River, while shading smaller offshoot streams would have much more impact, she said.

Primozich agrees smaller tributaries would be more influenced by shade, but regulators require thermal reductions where the heat is being added, on the Rogue's main stem.

Source: Environmental Health News

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