Seeking to come into compliance with orders set forth by the Indiana Department of Environmental Management (IDEM), the city of Decatur has informed some downtown businesses and a few residences in other areas that they will have to disconnect their downspouts from the city's sanitary sewer system.
Approximately 25 businesses and homes have received letters spelling out the needed change, according to Ann Butcher, who heads the city's sewage treatment plant and wastewater department.
Butcher told city council at its meeting on Tuesday night that the recipients were determined by visual inspections and that the area concentrated on goes from First St. to Tenth St., and Adams St. to Dayton Ave.
Property/business owners are being given 60 days to comply by getting their storm water out of the sanitary sewer system and into the storm water system.
"Decatur has spent millions of dollars and thousands of man-hours over the last 30 years to get storm water out of the sanitary system," Butcher said. "We are now down to what could be categorized as the small stuff, because this will make or break whether Decatur achieves sufficient reduction of CSO overflows."
When Decatur separated its storm and sanitary sewers over two multi-million dollar projects, and completely revamped its sewage treatment plant, it was left with just three combined sewer overflows (CSOs). During unusually heavy rains, some of the rainwater will overflow through the CSOs into the St. Marys River.
That was okay for a number of years, but now IDEM has established a new goal of no overflow when there is a "10-year event" of 1.6 inches of rain in 30 minutes. The city does not meet that goal.
The city has signed an agreed order with IDEM which says the city will meet the 1.6-30 goal within three years.
A number of downspouts in the downtown area are still sending storm water into the sanitary system. By correcting that situation and making some other small changes, city officials think the 1.6-30 goal can be reached.
"Jeremy Gilbert and the street department have taken (it) on themselves the job of rehabbing manholes and laying new storm pipe in areas where we needed correction...," Butcher said. Some of the manholes were allowing storm water to leak through and into the sanitary system.
"We have been able to measure a significant reduction in overflow volume," Butcher said, "but it still is not sufficient for IDEM and we will continue working for more reduction."