City discharges millions of gallons of sewage into Mississippi River each year

A series of pumps stand along Bettendorf's riverfront ready for use when heavy rain seeps into the Davenport and Bettendorf sewer system and creates peak flows the Davenport treatment plant is unable to handle. That's when the equipment begins pumping untreated sewage (diluted with the rain water) into storm water pipes that discharge into the Mississippi River.

Without the pumps, the sewer lines would fill and back up the untreated sewage into homes and businesses. So far this year, the pumping of sewage/storm water runoff into the river has occurred six times.

During 2009, pumping occurred 10 times, sending a total of more than 67 million gallons of sewage/storm water into the Mississippi River.

Such peak "wet weather" flows, which clog the Davenport sewage treatment plant and underground sewer interceptor lines to the facility, are the result of an aging and leaky system in both communities. Both communities have begun addressing the "infiltration and inflow" issues which have led to the bypassing of normal sewage treatment during periods of heavy rain.

The Iowa Department of Natural Resources (IDNR) has put both Davenport and Bettendorf on notice about the wastewater discharges. In letters sent last June, the state notified the cities the bypasses were considered violations of their permits and was referring the matter to its legal division "for review and additional compliance action."

• Notice of violation letter from Iowa Dept. of Natural Resources to City of Bettendorf
• Notice of violation letter from Iowa Dept. of Natural Resources to City of Davenport

With a full remedy to the infiltration still years away and the U.S. Environmental Protection Agency (EPA) and Iowa DNR stepping up enforcement of regulations concerning the blending and bypassing of sewage without full treatment, the city of Bettendorf opted to join a group of other Iowa communities suing the EPA over "bypass" regulations of the National Pollution Discharge Elimination System (NPDES).

The Iowa League of Cities plans to spend up to $200,000 to fund the lawsuit and has signed up other large cities to underwrite the federal lawsuit, filed July 26 in the 8th Circuit Court of Appeals in St. Louis. Bettendorf aldermen approved spending up to $25,000 on the lawsuit last month.

The lawsuit contends EPA is reinterpreting its own rules and seeking to enforce more restrictive sewage "bypass" regulations without proper rule-making.

Bettendorf relies on and is a part owner of the Davenport sewage treatment plant. The city uses about a third of the plant's capacity. While both Davenport and Bettendorf have separate underground pipes to carry sewage and storm water runoff, infiltration of storm water into sewer lines is a major problem, creating much higher flows to the treatment facility during and after heavy downpours.

The Davenport plant normally handles a flow of 16 to 17 million gallons per day, but a heavy rainfall can boost the inflow at the facility on South Concord Street to more than 80 million gallons. At 65 million gallons, the plant reaches its control limit and starts using "blending" and bypassing full treatment of the sewer/stormwater runoff to handle the overflow.

Blending involves combining sewage which has undergone primary (removal of solids and grit) and secondary (biological) treatment with sewage receiving only primary treatment. It is the use of blending and "bypassing" of some of the sewage from full treatment that is at issue in the lawsuit.

Even when blending is used and some sewage does not undergo the biological treatment, city officials say the wastewater discharged into the Mississippi River meets the facility's operating permit requirements on water quality, which includes 7-day and 30-day averages for E coli, ammonia and other pollutants.

The discharges by Bettendorf into the Mississippi River don't undergo any testing, but the frequency and quantity of the discharges are monitored by the Iowa Department of Natural Resources.

The city of Davenport has begun a 10-year, $175-million project to reduce storm water infiltration and expand the capacity of the system to accommodate the peak flows now being experienced. A large sewer interceptor line (along with a storm water line) is under construction along Howell Street in west Davenport. Overall, the sewer system is to be upgraded to reduce infiltration, and a new $30-million "equalization" basin is planned for the South Concord plant site that would provide greater capacity to handle peak flows.

(To view a video detailing the City of Davenport's planned sewer system upgrade, click here.)

Bettendorf has spent $500,000 to conduct a comprehensive infiltration study and complete work to address some of the most pressing inflow problems.

Click here to view an overview of the city's infiltration and inflow report and proposed infiltration upgrades/costs.

Blending, as interpreted by the EPA, is only allowed when no feasible alternative is available and it is necessary to prevent personal injury or property damage. In a 1999 federal case, the court ruled against the City of Toledo for bypass discharges during routine heavy rains. The decision backed the EPA's argument cities must take all feasible steps (including adding to plant capacity) to avoid bypassing partially treated (blended) sewage into streams and rivers.

But cities and wastewater treatment groups have argued blending should be allowed as long as the facility stays within its operating permit standards. Both sides agree blending and bypass is not an option during dry (normal) sewer treatment plant flows.

Des Moines and Clinton have recently entered into consent agreements with the EPA to upgrade their sewer systems to separate combined storm water and sewage lines, eliminate combined (sewage/storm water) overflows and expand treatment facilities to avoid bypassing of partially treated sewage during peak flows.

The order between Clinton and the EPA, which included a $100,000 fine, also involved violations of water quality standards of its discharge permit.

The Des Moines Metropolitan Wastewater Reclamation Authority serves 16 communities including Altoona, Waukee and Ankeny. The agreement commits the agency to a 13-year, $205-million sewer system upgrade plan. The agency spent three years and $300,000 in legal bills negotiating the agreement signed in April.

The only entity sure to come out ahead in the governmental wrangling appears to be the Washington law firm of Hill & Associates, which was retained by the Iowa League of Cities and has been involved in similar lawsuits on the West Coast, East Coast and the Midwest. The firm is a frequent contributor to wastewater journals on "blending" and "bypass" issues and represented Des Moines in its extended negotiations with the state and federal government.

Click here to download the Iowa League of Cities news release about suing the U.S. Environmental Protection Agency.