The Town of Mashpee is located in a wellhead protection area, and its wastewater discharges contribute to water supply aquifers. The town is has successfully reduced high nitrogen levels in the community’s septic system effluent to comply with water quality regulations.
Mashpee faced the challenge of meeting a strict 10 mg/L maximum TN concentration in its wastewater effluent in a cost-effective manner. Nitrogen levels in the septic tank were averaging 57 mg/L.
The town implemented a new passive nitrogen removal process in the septic system that includes a biofilter and a nitrogen filter. Operation and maintenance costs are minimal and can be monitored from a remote location. The effluent discharged from the system now averages 3.53 mg/L (State-EPA Nutrient Innovations Task Group 2009).
Reference:
State-EPA Nutrient Innovations Task Group. 2009. An Urgent Call to Action – Report of the State-EPA Nutrient Innovations Task Group. U.S. Environmental Protection Agency. Accessed October 16. https://www.epa.gov/sites/production/files/documents/nitgreport.pdf.