Western Lake Erie Basin Nutrient Source Inventory
The goal of the nutrient source inventory is to identify areas within the Ohio portion of the Western Lake Erie Basin where wastewater infrastructure improvements are needed to reduce potential phosphorus sources. The inventory will estimate pollution caused by home sewage treatment systems (septic systems) and package plants.
View maps here.
Septic systems and package plants are not connected to municipal wastewater treatment facilities; they treat sewage on the property where it is generated, using aeration systems or simple infiltration systems. Many of these systems are old and poorly maintained; a survey completed in 2012 by the Ohio Department of Health demonstrates that approximately 31% of the systems are failing throughout Ohio, and 39% are failing in the Maumee River watershed.
In the first step, TMACOG identified those areas served by sanitary sewers and those without service. Staff attained information from municipalities, county engineers, and county health departments. Next, populations in the unsewered areas were estimated using 2010 census block data. Using these numbers, we estimated phosphorus loadings from septic systems in the unsewered areas at the county level and subwatershed level by implementing an approach similar to Ohio EPA’s Mass Balance Study of 2016.
The next steps of the project are to estimate the phosphorus loadings from package plants and combine this with the information on septic systems to identify critical sewage areas. Based on the results, recommendations will be provided to reduce phosphorus loads from the identified critical sewage areas.
For additional information, please contact TMACOG Water Quality Planner Kris Barnswell at 419.241.9155 ext. 1123.