CSO (Combined Sewer Overflows)

During the early years of sewer system design it was common practice to install combined sewers. Combined sewers collect and transport both storm water and sanitary water through the same pipe. This saved money because only one pipe had to be buried instead of two. During certain storm events the flow in these combined sewers exceed the capacity of the pipe.

CSO's (Combined Sewer Overflows) are overflow points within a combined sewer system that discharge during these high flow conditions. This helps prevent some basement backups and surcharging of sewer manholes.

At one time, the Town of Speedway had three CSO's. Over the last 15 years, the town has been able to eliminate two of these overflows by taking a proactive approach and completing several sewer improvement projects, the largest being the Lynhurst Drive project in the mid 1990's. The one remaining CSO is located at the wastewater treatment plant.

CSO's have become a major water quality issue. Many rules and regulations have been established over the last ten years that affect the Town of Speedway and its rate payers.