Flood sends sewage, pollution and chemicals to Bellingham Bay

Recent storms have sent nearly 30 million gallons of raw sewage into Bellingham Bay over the past three weeks, according to the town of Bellingham.

The sewage overflow events – one for about 30 hours from November 14 to 15 and another for 7.5 hours from November 28 to 29 – have alarmed some local environmentalists, who are concerned about the impact on the quality of water. water and wildlife health. Raw sewage contains everything you can imagine pouring down a sink or toilet, including fecal bacteria, chemical contaminants, and excess nutrients.

Bellingham’s sewage and stormwater systems are connected, the result of an archaic infrastructure decision in the early 1900s, according to Shawn McKone, an environmental engineer in the state’s Department of Ecology. Many older cities in Washington have similar layouts, including Anacortes and Everett.

On a typical day, all of Bellingham’s wastewater goes to the Post Point wastewater treatment plant. But when the plant is operating at its full capacity of 75 million gallons per day, sewage may need to be dumped into the bay, said Eric Johnston, public works manager for Bellingham. The alternative is to risk it retreating into people’s homes.

“Sometimes we just can’t keep up with the glory of Mother Nature,” said Johnston.

Combine the sewage with the other pollutants that the heavy rains have washed away into local waterways, and you have life-threatening results for organisms that need clean water to thrive, said Kirsten McDade, a specialist in the field. pollution prevention at RE Local non-profit environmental sources.

“I called these rainy events a toxic tidal wave,” she said in an email to the Bellingham Herald.

But city officials said in a November 28 press release that the water quality impacts from the sewage overflow are expected to be minimal.

“I was surprised at the laissez-faire tone of the city blog,” McDade said.

Cumulative impact

Assessing the impact of these “acute toxicity events” is difficult, she admitted, unless dead fish start appearing in the water or someone is actively monitoring the water quality. But over time, the cumulative environmental impacts will become clear, she said.

“It’s only much later that we realize the consequences,” McDade said. “It’s kind of like heart disease – it takes hold of you slowly after years of unhealthy behavior.”

It’s not that city officials don’t care about the sewage pouring into the bay, Bellingham public works manager Johnston said. But he pointed out that the sewage is usually mostly water, and the pollution released last month has been further diluted by the massive amounts of water flowing into the bay from local streams.

During the sewage overflow in mid-November, Whatcom Creek dumped 650 million gallons of water into the bay, compared to 26.5 million gallons of raw sewage. During the overflow in late November, Whatcom Creek dumped 206 million gallons of water into the bay, compared to 2.75 million gallons of sewage overflow.

Dilution helps

“The solution to pollution is not dilution,” said Johnston. “But the reality of the situation is that it is.”

While they can dilute pollution, these high flow rates aren’t completely harmless, even on their own, said McDade, pollution prevention specialist at RE Sources. They can produce sediment that suffocates fish and interferes with their ability to navigate.

Washington state allows Bellingham to dump sewage into the bay, provided it only happens once a year on average. Currently, the city is well within those limits, with its last overflow before November being in 2009, during an equally intense storm, Johnston said.

But as human-caused climate change results in more intense and frequent storms in the region, officials from the Department of Ecology are cautiously monitoring a potential increase in sewage overflow events. Washington cities can no longer rely solely on historical overflow data when planning the capacity of sewage and stormwater systems, McKone said.

“Trying to rely on past data is going to give a false sense of security,” he said. “But how to project which will be the right number to use in the future is almost an impossibility.”

“Getting ready for something bigger is about all we can do right now,” added Steve Hood, also an environmental engineer in the Department of Ecology.

Separation of storm water, sewers

McDade said Bellingham needed to “completely separate our storm water and sewers, like yesterday.” That’s the goal, Johnston said, but there is no timeline for the separation to end. As the city undertakes sewer rehabilitation projects, it is slowly separating the storm and sewer lines. Work has also been done to reduce the amount of stormwater entering the system, which includes creating rain gardens that can help some precipitation to seep into the ground.

Bellingham takes a “standard approach” to reducing its sewage overflow events, especially compared to cities like Seattle and Everett, said McKone of the Department of Ecology.

McDade, the pollution prevention specialist, hopes to see a day when Bellingham can completely remove the sewage from the bay.

“Ideally, we don’t want to see any spillover events,” she said. “We want all the wastewater to go to the treatment plant.

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Ysabelle Kempe joined the Bellingham Herald in the summer of 2021 to cover environmental affairs. She graduated from Northeastern University in Boston and worked for the Boston Globe and Grist.

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