Bettendorf and Davenport would agree to make an estimated $160 million in sewer system upgrades over the next 20 years under a proposed consent order with the Iowa Department of Natural Resources (IDNR).
The agreement, currently under review by both cities, would address so-called sewage "bypass" flows at the Davenport treatment plant, which is one-quarter owned by Bettendorf.
During periods of heavy rain, water infiltrates sewer lines, creating flows which the plant can't handle and resulting in the dumping of partially treated sewage into the Mississippi River.
Davenport discharged a total of 548 million gallons of partially treated wastewater into the Mississippi River over 74 days in 2010. When the treatment plant was unable to process all the sewage flow in 2010, the sewage backed up and Bettendorf pumped more than 33 million gallons of untreated wastewater into the river.
And, in 2009 Davenport discharged a total of 724 million gallons of partially treated sewage into the Mississippi River during 90 separate days, according to the IDNR.
The IDNR and U.S. Environmental Protection Agency have been meeting with city officials over the past two years to work out an agreement to address the sewage system problems rather than pursue legal action against the cities over the discharges.
The IDNR had wanted the cities to begin construction of a large equalization basin (which would store the high flows to the plant during periods of heavy rain) as soon as 2017. But under the new proposed order, sewer line upgrades and treatment plant expansion/improvements would be built first with the equalization basin completion not required until July 2025.
The proposed order would require each city to submit yearly progress reports to the IDNR and provide a timeline for work to be accomplished each year.
According to the proposed order, the agreement "is intended to establish a schedule for the completion of wastewater collection, handling and treatment improvements necessary for Davenport and Bettendorf to achieve compliance with applicable regulations."
The issue of sewage bypass during times of heavy rains isn't unique to Davenport or Bettendorf. The Iowa League of Cities in recent years hired a Washington, D.C. firm to file a lawsuit challenging the U.S. EPA's authority to regulate such "wet weather" flows.
The league's initial lawsuit was thrown out, but it refiled last October in the 8th U.S. Court of Appeals in St. Louis. That lawsuit, which claims the EPA has implemented more restrictive sewage discharge rules without the necessary rulemaking authority, is expected to go to trial this fall.
Both cities have been under pressure from the IDNR to end bypass discharges during periods of heavy rains and upgrade the sewer lines to reduce infiltration of storm water.
Both cities received notices of violations pertaining to the bypass issue in 2010, which threatened the withholding of sewer connection approvals until the discharges were addressed.
According to the proposed order, the cities would submit yearly progress reports beginning Jan. 31, 2014 detailing progress toward compliance with the schedule of improvements.
Initial work outlined in the proposed order would be cleaning and televising of trunk (large primary) sewers to identify blockages, needed repairs and potential improvements to the trunk sewers.
By July 2013, the cities would be required to install permanent sanitary sewer monitoring devices and "determine the wastewater storage and treatment capacity needs of the cities."
City officials have argued the large amount of rain water infiltration would require construction of an equalization basin much larger than actually needed, and have urged the state to give them more time to complete infiltration studies and improvements to sewer lines.
Under the new timetable, Davenport would be required to submit by January 2014 all construction permits for a "wastewater treatment plant optimization project" which would include expansion of the plant's treatment capacity.
The plant upgrade would have to be completed by July 2016 under the proposed order.
By July 2021, Davenport is required to submit construction permits for an equalization basin "or such other modifications or improvements to the Davenport Water Pollution Control Plant" to comply with state and federal wastewater regulations.
