Wastewater History

Wastewater Utility History
Sewage, or wastewater, is transported through the sanitary sewer system at a velocity of about two feet per second. Any slower and the solids in the wastewater would get stuck in the pipes. These sewer lines continue to flow sewage downhill, but once they approach 25 feet deep, pumps at lift stations pump the sewage back near the surface. The sewage then continues its path toward the Wastewater Treatment Plant.
The first treatment plant in Greenfield was built around 1932. Before this system was built, septic tanks were the only form of sewage treatment available. Eventually, this could have attributed to groundwater contamination. New sanitary sewers were often designed to also transport storm water during rain events.
These “combined sewers” caused enormous problems at the Treatment Plant, as the flow could increase 10 times the normal rates. Some of the water would also discharge sewage and storm water into open ditches, causing even more problems. The combined sewer overflows or “CSO’s became a major problem for the environment. Indianapolis and other cities will be spending billions of dollars to minimize the deleterious effects CSO’s have on our environment.
In 1991, a Long Term Control Plan (LTCP) for CSO’s had been submitted to the Indiana Department of Environmental Management (IDEM) for approval. This plan would have kept any combined sewers in service and a 1 million gallon over-flow pond would have been constructed just outside of the Treatment Plant. The big problem with this plan, in the estimation of the new Superintendent, was that the pond designed to contain the excess storm water would fill up in about an hour. History had shown that the plant and numerous storm water ditches would continue to be inundated with pollution problems.
Greenfield decided to ask IDEM to scrap the LTCP and commence with a new plan to separate the storm and sanitary sewers. Included with this paper, we have enclosed several letters and documents that dealt with the new plan.
Greenfield was one of, if not the first city to be removed from IDEM’s “Combine Sewer Overflow Cities” list. Although most Indiana cities are on this list, we wanted off of it. Thousands of dollars per year would have been spent to study the negative environmental impact CSO’s had on our town and treatment facility. Money not spent on the CSO problems could pay for upgrades to the plant and sanitary sewers.
Within the last five years, just over $8.5 million was spent to upgrade the treatment plant. About $300,000 is spent every year on rehabilitating the sanitary sewer mains and laterals to homes in Greenfield. We are definitely ahead of most other cities in Indiana and possibly the nation, when it comes to sewer rehabilitation. Methods used in our sewer program include pipe bursting, “cured-in-place” pipe and “fold & form” rehabilitation. Sewer manholes, a point of entry for sewer maintenance, are often replaced or externally patched with space-age sealants to prevent clear-water from entering the sanitary system.