With the Davenport Wastewater Treatment Plant unable to handle the inflows, the city of Bettendorf has been forced to pump more than 200 million gallons of diluted untreated sewage into the Mississippi River so far this year.
Five times this spring and summer the wastewater treatment plant has been unable to handle the sewer flows and crews have partially closed the riverfront interceptor lines between Bettendorf and Davenport. Then, to prevent sewage from backing up into homes and businesses along the riverfront, Bettendorf runs six to nine large pumps to flush the wastewater into stormwater pipes, which discharge into the Mississippi River.
A total of 201 million gallons of "sanitary sewer overflows" has been dumped into the river so far this year, according to reports filed with the Iowa Department of Natural Resources (IDNR). Between April 17 and April 27, 98 million gallons of sewage was pumped into the river, and another 68 million gallons of sewage was dumped between May 26 and June 3. Between May 3 and May 5, 16 million gallons of sewage was pumped into the river, 9.4 million gallons was flushed into the river from April 10 through April 12, and 8.8 million gallons went into the river on March 10.
All the pumping – "sewage overflow events" as they are termed by the IDNR – must be reported by the city to the state.
While Bettendorf is not alone among communities which dump sewage into rivers and streams during periods of heavy rainfalls this spring, the quantity of sewage pumped into the river is more than six times as much as in 2010 – the last time heavy rainfall flooded sewer lines and resulted in 33 million gallons of wastewater being pumped into the Mississippi.
The cities of Davenport and Bettendorf signed a consent order earlier this year outlining a 20-year, $160-million upgrade to the shared sewage treatment system (Bettendorf has 25 percent ownership interest in the wastewater treatment plant along Concord Street in Davenport). Initial sewage system work currently under way is aimed at identifying and repairing blockages to the trunk (main) sewer lines and reducing infiltration from storm water into sanitary sewer lines.
Under the consent order timetable, Davenport must submit all construction permits for a "wastewater treatment plant optimization project" that would include expansion of the plant's treatment capacity by January 2014. The plant upgrade would have to be in service by July 2016 under the consent order.
CLICK HERE to download a copy of the Bettendorf sewage overflow events (SSO).
