Treating the water right
EAGLE COUNTY – The three wastewater treatment plants operated by the Eagle River Water and Sanitation District in Avon, Vail and Edwards serve as many as 40,500 people during the peak of tourist season. About 5.5 million gallons of wastewater flow from people’s sinks, showers and toilets down to the plants each day. But what do these plants do?
As wastewater flows into the plant, waste is strained out and air is added, providing oxygen at the right temperature for the bugs that eat organic matter. Any remaining sediment settles and is removed again. A chemical conversion makes the clarified water less toxic for fish. Finally, the water is disinfected with a chlorine solution in Avon and ultraviolet light in Vail and Edwards.
The Colorado Department of Public Health and Environment’s Water Quality Control Division issues permits that allow the plants to release treated water containing certain quantities of nutrients ” such as plant food, fish food, ammonia and metals ” into the river, said Ray Merry, the environmental health director for Eagle County.
A certain amount of nutrients is good for fish. The Colorado Wildlife Commission designated part of Gore Creek as a gold medal trout stream, meaning its fish are large and healthy. This is in part because that water runs directly downstream from the Vail plant, said Diane Johnson, spokeswoman for the Water and Sanitation District.
“Not only have we not adversely affected the aquatic habitat, we actually, if we do our jobs well, enhance it,” Johnson said.
Bill Perry, owner of Flyfishing Outfitters, located 500 yards from the Avon treatment plant, said the river, as it flows by his store in the winter, hasn’t frozen over since the plant was enlarged about 15 years ago.
“It’s open year round, which enhances the fishery because the fish feed year round when they’re not covered in ice,” Perry said. “We tell people it’s the warm springs, but really it’s the wastewater treatment plant.”
If there are too many nutrients ” or if the water level goes down, making it easier for the river to overheat ” fish will begin to die off, Merry said.
The Eagle River contains few nutrients, being higher up, but it could still be in danger of over-treatment, Merry said.
“Most mountain streams are kind of nutrient-deficient, but at some point, there’s a breaking point,” he said.
Perry said he has noticed “fish kill” from the treatment plant a couple winters ago when the river flows were low, but things have changed.
“It seems like it’s going good now because we have good flows,” Perry said.
Johnson said the treatment plants cause minimal nutrient-loading in the river. That problem is usually the result of things like stormwater run-off. Nutrients released by the treatment plants are controlled.
“We’re highly regulated (by the state), the District monitors the stream and the effluent to make sure the treatment plants are operating properly and that water quality standards are being maintained,” she said, adding that the District’s plants operate well within the effluent limits set by the state.
The nutrient levels, which are determined by existing water conditions, are stricter in the Eagle River than other Colorado streams because the water quality is so high, Johnson said.
Vail Daily, Vail, Colorado