There are three types of sewers - Separate sanitary sewers that transport sanitary waste only; separate storm sewers that transport storm water only; and combined sewers that transport sanitary wastewater and storm water. The Butler Wastewater System has more than 8 miles of sewers, of which about 60% are combined sewers. No new combined sewers have been constructed since the late '50's.
Combined sewers transport only sanitary wastewater during periods of dry weather. However, during periods of wet weather - i.e., when there is rain or snow melt - the combined sewers transport storm water along with the sanitary wastewater. The problem with combined sewers is that their capacity is limited and when the volume of storm water entering the combined sewers exceeds the capacity of the combined sewer, an overflow at a designated outfall may occur into Big Run Ditch. There is only 1 permitted combined sewer overflow (CSO) Outfall in the Butler sewer system.
The overflow may contain untreated sanitary wastewater. The untreated sanitary wastewater contains large amounts of bacteria and those bacteria represent a risk to human health if a person ingests or comes into contact with the untreated wastewater in the receiving stream.
The Butler Wastewater Department will notify the public and those people living adjacent to or downstream of the CSO Outfall when an overflow occurs. The notice of any discharge will be provided within 24 hours of the discharge occurring. The notice may be provided via e-mail, the City's website, a telephone call or the US Mail. In addition, public service announcements will be provided to the local media.
All citizens are advised to avoid contact with Big Run Ditch from the US 6 Bridge to County Road 28 for at least 24 hours after a CSO discharge has occurred. Studies indicate that the bacterial populations do not survive in receiving streams longer than 24 hours. If a CSO occurs after a precipitation event that lasts several days, citizens are advised to avoid contact with the water for at least 24 hours after the cessation of the storm event.
In addition, parents are advised to keep their children away from Big Run Ditch after precipitation events. Parents should also remind their children not to play in flooded streets as the flood waters in the streets can contain bacteria and other substances that can cause health problems.
The Wastewater Department has taken steps to eliminate as many of the CSO discharges as possible. The Utility upgraded the wastewater treatment plant and now can process more than 3 million gallons per day of wastewater and storm water. In addition, a CSO Long Term Control Plan (LCTP) was submitted to the Indiana Department of Environmental Management and the Butler Wastewater Department will be implementing a collection system capital improvement program in the near future.
Public meetings will be held to keep all citizens and wastewater customers informed of the progress being made in addressing these issues. The Department will be developing a long term financing program to accomplish the mandated CSO control measures. Citizen input will be essential to the success of this effort.