Iowa DNR News Environmental Services Division For immediate release June 22, 2007 HEAVY STORMS IN SOUTHEAST IOWA CAUSE NUMEROUS WASTEWATER BYPASSES MEDIA CONTACT: Paul Brandt at 319-653-2135 WASHINGTON – Heavy rain caused several cities in Southeast Iowa to discharge wastewater Friday morning. The following cities reported bypasses to the DNR Friday morning: Cedar County West Branch: The City of West Branch reported discharging untreated wastewater after heavy rain inundated the local treatment facility. The wastewater began bypassing to a nearby farm field at a rate of 30,000 gallons per hour around 7:15 a.m. Friday morning. The discharge was finished by 11:00 a.m. Friday morning. Des Moines County Burlington: The City of Burlington’s four sanitary sewers were overflowing due to heavy rain accumulation in the area. Approximately 624,000 gallons of wastewater were bypassed from the location of Brooks, Gunnison, Burlington Northern and Lucas sanitary sewers. The 8-hour discharge began around 1:00 a.m. Friday morning and was finished by 9:00 a.m. Johnson County Coralville: One of Coralville’s lift stations is recovering after pumping wastewater to Clear Creek Friday morning. With over five inches of rain falling in the area, a pump was placed at the 3rd street lift station in order to keep up with the flow. From 6:00 – 6:30 a.m., the pump discharged sewage to the creek. DNR and University of Iowa Water Plant officials were notified of the occurrence. Iowa City: Cornstalks, rainwater and sewage from a privately owned treatment system are causing Snyder Creek in Iowa City to back up. With over six inches of rain accumulation, Sunrise Village Mobile Home Park’s third sewage treatment lagoon is overflowing to the creek. An undisclosed amount of partially-treated wastewater reached the creek Friday morning. Cornstalks from nearby fields are causing the creek to back up. By 9:15 a.m. Friday morning, the lagoon had stopped overflowing. Clean-up of the cornstalks was underway to ensure Lone Tree: Sanitary Sewers are swelling to capacity in the City of Lone Tree as storm water continues to accumulate. At 7:45 a.m. Friday morning, the City began bypassing wastewater to a local ditch in order to protect its sewers and residents. Localized flooding in Johnson County is apparent, with a rain gauge in the community reporting more than 3.5 inches of rain falling Friday morning alone. DNR staff anticipates the bypass will continue until the storm system passes the area. Muscatine County West Liberty: The City of West Liberty reported bypassing wastewater Friday morning at 2:30 a.m. after 6 inches of rain overwhelmed the treatment plant. Between 7:30-8:00 a.m. Friday morning, the plant bypassed wastewater to a ditch that flows to the Wapsinonoc Creek in order to prevent residents’ basement flooding. Wapello County Wapello: A lift station was reported discharging in the City of Wapello after lightning struck it sometime Friday night. The combined sewer overflow was reported to DNR staff around 9:00 a.m. this morning. Alliant Energy had power was restored to the lift station by 10:50 a.m. Friday. Washington County Washington: The City of Washington reported discharging wastewater to a nearby farm field after rainfall totals overwhelmed its treatment facility. The bypass started 9:30 a.m. Friday morning at a rate of 15,000 gallons per hour. The bypass was completed by 10:10 a.m. Friday, however untreated effluent was still being forced out of the system because of high flows. Bypasses can occur when heavy rain overloads wastewater collection systems, which are the underground pipes that carry sewage to a treatment plant. When sewer pipes are overwhelmed, the excess rainwater and sewage have nowhere to go. Cities bypass to lower the wastewater level in the collection system and prevent backups into basements through floor drains. Although discharging wastewater to a stream is not desirable, it does prevent a greater and more immediate health risk in people’s homes. Collection systems are most likely to be overwhelmed when heavy rainfalls or excess snow melts, saturates the ground and enters a sanitary sewer system through cracks in the underground sewer pipes. Storm water can also enter piping through improper connections, such as roof drains or sump pumps that are hooked up to the sanitary sewer system instead of the storm water system. If the storm water entered the storm sewer system, it would flow directly into a nearby stream or lake. When it enters the sanitary sewer system it flows to a wastewater treatment system. When heavy rains or snowmelt occurs, the volume of storm water entering the sanitary sewer system can be more than the wastewater treatment system can treat. According to DNR design standards for construction of new wastewater treatment systems, facilities should be able to handle the amount of water in the collection system from all three of these events happening at the same time: § Peak sewage flows from homes, businesses and industry § Peak groundwater levels § A storm that drops two inches of water in an hour. While many collection systems in Iowa already have or are in the process of upgrading their collection systems to handle these events, many more need to upgrade. The DNR tracks bypass reports submitted by facilities and follows up with the facility to determine problems and help them upgrade their systems, although it can be a long-term process. The DNR has also formed a committee to discuss how it handles wet weather bypasses. - 30 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - To unsubscribe from the IOWA-TOPICS list, send any message to: [log in to unmask] Check out our Listserv Lists support site for more information: http://www.sierraclub.org/lists/faq.asp Sign up to receive Sierra Club Insider, the flagship e-newsletter. Sent out twice a month, it features the Club's latest news and activities. Subscribe and view recent editions at http://www.sierraclub.org/insider/