Construction has wrapped on the first phase of Storm Water Diversion Program which is a multi-phased, multi-year project. It is expected that the construction phase of the project which is concentrated within two geographical areas of Alma will occur over a period of three years.
The first phase of the project was to install storm interceptors within the street right-of-ways in areas where storm sewers do not presently exist within two specific focus areas of the City. The installation of the new storm interceptors will provide a point of connection for homes and buildings to dispose of storm water.
Originally the City of Alma, like nearly all communities, had a single sewer system installed which conducted waste, rain water and nearly anything else that would go down the pipe to the local river for disposal. Over time the sewer system evolved into two systems, one to transport clean water from rains and ground water (storm sewers) from basement areas directly to the river for disposal and a second system to transport sewage (sanitary sewer) to a treatment plant for processing. Many of the old connections remain and in some cases continue to send rain water or ground water to the sewage treatment plant. Also in many cases, the only available sewer to connect to was sanitary sewer. On normal days this does not present any specific problems to either the sewage system or to the treatment plant, but during heavy rain storms, unusually wet weather, or during large snow melts, flows at the treatment plant can exceed plant capacity and sewer mains can be over whelmed which cause’s back-ups into basements.
The project’s history starts in 2009 with complaints from city residents of sewer backups which occurred during a heavy rain storm. The City started monitoring flows in sewer mains and sanitary sewer lift stations. The data that was collected was analyzed and a report generated which was submitted to the public and the Michigan Department of Environmental Quality (MDEQ). Within the report, which presented the data regarding flows in the sewers, it also presented four possible solutions to the problem. These four possible solutions which varied from the disconnection of storm water connections in the sanitary sewer system to increasing both the size of the sanitary sewer mains in the streets and increasing the size of the sewer treatment plant. The report also indicated the estimated construction cost for each possible solution, with the least expensive one being disconnection of storm water connections to the sanitary sewers to the most expensive being to increase both the capacity of the treatment plant and the sewer mains located in the streets. The City of Alma, with the approval of MDEQ, has chosen the least expensive method to correct the problem so that we can eliminate sanitary sewer backups into resident’s basements.