The drought-parched Spokane River is getting about 14 percent of its water from sewage treatment plants this summer.
Industrial and municipal treatment plants discharge about 60 million gallons of treated water daily into the river. The discharges start near the river’s headwaters in Lake Coeur d’Alene and continue downstream to the city of Spokane’s treatment plant.
By the time the river passes through Riverside State Park, nearly a sixth of the flow is made up of water recycled from people flushing toilets, taking showers, running dishwaters, doing laundry and using water for industrial applications.
“A lot of people call it ‘wastewater,’ ” said BiJay Adams, general manager of the Liberty Lake Sewer and Water District. “We refer to it as reclaimed water – we’re not wasting it, we’re recycling it.”
With the Spokane River dropping to about 40 percent of normal this month, treated wastewater has emerged as an important source for sustaining summer flows. But under rules being developed in Washington, that water is about to get more valuable. In the future, there could be competing uses for it.
The Department of Ecology is developing rules that encourage reusing wastewater for irrigation and other purposes. The state’s goal is to conserve drinking water by giving treated effluent a bigger role in irrigating landscaping and even some food crops, said Dennis McDonald, the department’s reclaimed water rule coordinator.
But it’s a tricky scenario in the Spokane River basin and other places where effluent is augmenting river flows, he acknowledged.
“In some places it will work; in some places it won’t work,” McDonald said. As part of a permitting process, applicants would have to show that redirecting the water use wouldn’t affect existing water rights or minimum flows established for protecting fish habitat, he said.
At Spokane County, the discussion about other uses for reclaimed water has already started.
The county’s treatment plant discharges about 7.5 million gallons of treated effluent daily into the Spokane River. Near the edge of the plant, the water tumbles down a 4-foot-diameter pipe, which oxygenates the water like a natural waterfall, before the water is pumped a half-mile to the Spokane River.
But the $143 million plant, which opened in late 2011, also was designed with underground pipes to send that water to other destinations in the future. The county treats the water to Class A standards, allowing the water to be used for most purposes short of drinking water, said Dave Moss, the county’s water reclamation manager. Irrigation, restoring wetlands and industrial uses are possibilities.
“We anticipated there would be an interest,” but because of pumping costs, “it’s not inexpensive,” Moss said.
So far, the county has one inquiry. The city of Spokane is interested in using the county’s treated wastewater to irrigate Esmeralda Golf Course in northeast Spokane.
Moss said he hears competing messages about water reuse from Ecology Department officials. Some advocate for keeping the discharge in the Spokane River to increase flows. Others want the treated water used for irrigation, to decrease pumping from the Spokane Valley-Rathdrum Prairie Aquifer, which also diminishes the volume of water in the river.
“It’s a dilemma that hasn’t been reconciled,” Moss said.
Within six years, the stakes could be higher. Other treatment plants that discharge into the Spokane River must complete state-mandated upgrades. At that point, they will be producing Class A water as well, with the potential for options besides river discharge.
If there’s a big demand for that reclaimed water, studies would be needed to understand the impact of diverting the water from the Spokane River, said Diana Washington, a permit unit supervisor for the Ecology Department’s eastern regional office. Any negative effects would have to be mitigated before permits would be issued.
“This whole process is about trying to do the best we can with every drop of water we take out of nature,” Washington said. “It’s a valuable resource, and a limited resource.”
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