City reveals earlier sewage dump

The pipe responsible for spewing 53,000 gallons of raw sewage into the Spokane River last month also gushed thousands of gallons of untreated waste in June, new documents show.

The disclosure, contained in a Wastewater Management report released Tuesday, is the first indication that the problem was greater than originally known.

City officials, however, say they can only work to ensure overflows are monitored so the public is informed about potential health risks. They won’t know until next week whether their efforts have been enough to avoid state-imposed penalties.

The July 11 spill near the Downriver Golf Course dumped an estimated 53,000 gallons of untreated sewage into the river over a three-day period, according to city officials. The actual amount released might be higher because the overflow bypassed one of the city’s 21 sensors that monitor sewage flow into the river.

Eyewitnesses reported seeing sewage debris in the river as early as May.

The city’s latest overflow logs show about 48 million gallons of wastewater entered the river in June. About 90,000 gallons of that was raw sewage that flowed in June.

Nearly half of that raw waste flowed from the same group of pipes that spilled in July.

Under the city’s National Pollution Discharge Elimination System permit, it is allowed to discharge a combination of sewage and runoff during rainstorms. However, it is subject to fines from the Washington State Department of Ecology for dry weather dumping.

The department plans to release the results of its investigation early next week, said department spokeswoman Jani Gilbert. She previously said Ecology officials don’t levy fines if the city responds quickly and properly, fixing the problem.

While the city can’t entirely stop the flow of raw sewage until it finishes an overhaul of the sewage system in 2017, it can make sure flows are monitored and caught earlier, said Dale Arnold, director of the city’s Wastewater Management Department.

“If we know what’s happening, we know how to fix it,” he said.

The July spill went undetected because a blocked pipe caused sewage to back up, bypassing the sensor.

Although city officials estimated the duration of the spill at three days, Richard Koch, a senior engineer with the state Department of Ecology’s water quality program, said algae growing at the 24-inch sewer pipe where the spill occurred suggested it had been going on for days or weeks. It remains unclear whether that algae could be a result of the June spill as well.

Arnold said the city has plugged the pipe that caused the problem, forcing any future spillage at the site to flow past the sensor.

After the July spill, workers identified seven other areas where sewage might spill unnoticed, Arnold said. They have since narrowed the field to three sites along the river, and they plan to inspect them within the next 45 days, he said.

Arnold said there is a good chance those pipes also don’t pose a threat.

River users can check the wastewater department’s Web site, www.spokanewastewater.org, to see when sewage is entering the water and avoid those areas. Warning signs posted near overflow pipes at the riverbank give a phone number for river users to call in case they notice a spill.

Bacteria in sewage can sicken people who swallow river water, and it can be hazardous to aquatic life.