Charlestown, URI partner on septic management; goal is to reduce impact on watershed | Daily-news-alerts

KINGSTON – The City of Charlestown is partnering with wastewater management experts from the University of Rhode Island on a pilot project to develop a comprehensive approach to reducing the amount of nitrogen from sewage treatment plants that enters groundwater, drinking water and nearby salt ponds.

Employees received a five-year grant of $ 750,000 from the U.S. Environmental Protection Agency’s Southeast New England program to install, test, and monitor new nitrogen-reducing septic tank technology, install rainwater mitigation measures, an education and engagement plan for to develop the church and a summary document that enables other communities to follow suit.

“The City of Charlestown has been very proactive in its wastewater management and drainage basin management, and this grant builds on the successful approaches they have tried in the past,” said Alissa Cox, director of the New England Onsite Wastewater Training Program at URI. who will co-lead the project with Matthew Dowling, director of Charlestown’s Onsite Wastewater Management Program.

According to Cox, sewage treatment plants in coastal communities like Charlestown can have negative effects on groundwater, drinking water and public health. If nitrogen gets into the groundwater, it can affect drinking water quality and cause algal blooms in salt ponds, which can lead to oxygen starvation and the death of fish and shellfish.

“Many communities like Charlestown across the New England coast rely on local groundwater for drinking water and on-site sewage treatment plants for wastewater management,” said Dowling. “Unmanaged systems and intermingled septic tanks can impact not only drinking water quality but also the coastal ecosystems on which these communities depend as a major part of their economies. Therefore, investing in septic tank management becomes a priority. “

The new septic technology will be tested on up to 10 homes near the west end of Green Hill Pond and the east end of Ninigret Pond. It is called a nitrogen-reducing stratified soil treatment system, where the drainage field of a septic tank consists of a layer of sand over a layer of sand mixed with sawdust. As septic sewage moves through the layers, the sand layer converts the ammonium to nitrate nitrogen, and the sand and sawdust layer converts the nitrate nitrogen into a gas that escapes into the atmosphere instead of going into the groundwater.

Cox said this technology is far less expensive than the proprietary technologies that many companies want to install in similar locations, some of which can cost up to $ 40,000.

“We have seen this stratified soil treatment system work in other parts of North America, particularly Canada, Florida and Cape Cod, and we are trying to bring it to Rhode Island and other parts of New England,” said Cox. “Instead of using one of the expensive proprietary systems, you can use this non-proprietary drainage field to reduce nitrogen. It’s another option for homeowners to consider. “

URI’s role in the project is to help plan, install, and monitor the new stratified soil treatment systems and compare them to the performance of the more expensive, proprietary systems installed elsewhere. Other partners include Save The Bay, which will install rainwater reduction measures to reduce the effects of rainwater runoff on the salt ponds, and the Salt Ponds Coalition, which will monitor water quality to assess the impact of the facilities.

Cox and her colleagues will work with all partners on the public education and engagement component of the project.

“My vision is to celebrate a turning point where we will have a series of tours of the new stratification systems and rainwater management measures for people to see and learn more about,” said Cox. “It could be like a combined block party and tour to get the community involved. We will reach out to cultural and historical representatives of the watershed to work with other community groups to offer cultural perspectives and community engagement to make it a festival and bring people closer to these new tools to protect the watershed. “

By the end of the five-year project, Cox expects to have worked with the City of Charlestown on a blueprint of how other coastal communities with large numbers of wastewater treatment plants can improve their watershed management while meeting regulatory requirements.

“Our final report will be a case study of our achievements and the lessons we have learned so that it can be used in training other communities,” said Cox.