Mercury Tests
The goal of the Pollutant Minimization Program for Total Mercury is to maintain the effluent concentration of total mercury at or below 1.3 ng/L (nanograms per liter). As part of this program the wastewater treatment plant (WWTP) tests its effluent on a monthly basis for low-level mercury. The primary sludge and influent waste stream are also tested on a quarterly basis.

Sources of Mercury Pollution
Residential customers may unknowingly wash mercury products such as cosmetics, household cleaners and broken thermometers down the drain. Commercial facilities may also conduct activities that have the potential to discharge mercury, such as: dental offices that remove amalgams, medical and veterinary offices, hospitals, laboratories, automotive shops, car washes, dry cleaners and funeral homes. Since most fish contain high levels of mercury, fish cleaning stations discharging into the sewer system can also be a source of mercury pollution. The City of Manistee conducts an annual sampling of dental offices and other significant users. The WWTP currently meets the goal limit of 1.3 ng/L.