The rain-swollen Mississippi River and one of its tributaries are now carrying untreated sewage downstream after flooding knocked out a treatment plant outside St. Louis.
The rising Meramec River, which joins the Mississippi about 20 miles south of the landmark Gateway Arch, swamped the Fenton Wastewater Treatment Plant late Monday, the Metropolitan St. Louis Sewer District reported. The plant normally handles less than 7 million gallons a day, but was treating nearly 24 million gallons a day when it was overrun, the agency said.
"Sewage that would normally be treated at this wastewater treatment plant is not being treated at this time," the agency said. "Sewage is being diverted into nearby rivers and streams. The public is asked to avoid contact with any flood water or sewage in low lying flooded areas near the plant.
The amount of water roaring untreated past the plant is a small fraction of the roughly 5 million gallons a second now coursing down the Mississippi. But Sewer District spokesman Sean Hadley said anyone exposed to floodwater should wash up afterward.
"Floodwaters are already polluted as is," he said. "You should definitely take precautions and try to avoid any contact."
The treatment plant outage has raised concerns among people like Alicia Lloyd, clean water policy coordinator for the Missouri Coalition for the Environment.
"When the sewage is going untreated into riverways, that comes from kitchen sources, bathrooms, and laundries," Lloyd said. "All that contains chemicals, detergents, bacteria, nutrients and other pollutants that are harmful to our waterways."
Hadley said the Fenton plant has been knocked out until the flood recedes and engineers are able to clean it up and repair it.
"It's going to take some time to get it fully operational again," he said. Crews are sandbagging another St. Louis-area plant to prevent it from being overrun as well, he added.
At least 13 people have died across the state as a result of days of heavy rain around the Christmas holiday, Missouri Gov. Jay Nixon's office says. The Army Corps of Engineers expects the Mississippi to crest Thursday afternoon at more than 43 feet — nearly 14 feet over flood stage at St. Louis. The Meramec is expected to crest at a record 42 feet, while the National Weather Service projects the Mississippi will tie a 49.7-foot record set downstream at Chester, Illinois that was set in the major floods of 1993.
Flooding along the Meramec also forced authorities to close Interstate 44, a major St. Louis-area artery. High water also forced numerous roads and bridges to close on the Illinois side of the Mississippi as well.
Lloyd said the flooding also highlights the hazards St. Louis and its surrounding communities are likely to face from climate change, which scientists say will bring more extreme weather in the coming century.
"We need to build greater climate resiliency in the future, because this is going to continue to happen," she said.
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