GLADSTONE — The Gladstone City Commission voted to accept a proposal from engineering firm C2AE for professional services for a Sewer System Evaluation Survey (SSES). According to Wastewater Plant Superintendent Rodney Schwartz, the Michigan Department of Environment, Great Lakes, & Energy (EGLE) required the survey to identify and address potential problems in the city’s collection system that have caused sanitary sewer overflows (SSOs). These overflows put the city in violation of the National Pollutant Discharge Elimination System (NPDES).

The survey will help identify areas in the collection system that are experiencing excess infiltration and inflow (I&I). Infiltration refers to groundwater entering sewer facilities through unintended pathways, such as pipes that are old and cracking. Older infrastructures or those that have been poorly maintained are more likely to allow infiltration into sewer facilities. Preventative measures such as inspections and survey help minimize the damage posed by infiltration.

Inflow refers to stormwater runoff that can get into the sewer from gutters, downspouts, streams, building foundations, and residential driveways. Inflow can lead to overflow or flooding, which can overtax treatment facilities and lower wastewater facility life-spans. Finding and removing unapproved drainage outlets that connect to municipal sewers lowers the risk of excessive runoff.

I&I can also clog collection system pipes, pumps, filters, and valves, due to materials excess or misguided runoff can bring with it.

Although according to the Environmental Protection Agency, almost every sewer system experiences I&I, it can lead to higher plant operation costs and higher service rates. If it causes sewer overflows, there is also increased potential for water contamination. As a result, the city and EGLE reviewing an Administrative Consent Order (ACO) for the city’s wastewater system. The consent order requires the survey, as well as an I&I amendment to add new information gained to the current study.

The SES will involve development of work plans that show how flow monitoring and smoke testing will be performed to asses the collection system. Approval of these work plans is required by EGLE before the survey is begun.