MEDIA CONTACT: Dina Pierce or Heidi Griesmer

2020 Edition of Statewide Watershed Nutrient Study Released

Ohio EPA has released its 2020 Nutrient Mass Balance study.

The study, required to be issued every two years under House Bill 64 (passed in 2015), examines phosphorus and other nutrients from agricultural and other nonpoint sources, municipal and industrial wastewater systems, and home sewage treatment systems, which make up the majority of nutrient sources. The study encompasses 11 watersheds across the state, which drain 66 percent of Ohio’s land area: Cedar-Toussaint, Cuyahoga, Great Miami, Huron, Maumee, Muskingum, Old Woman Creek, Portage, Sandusky, Scioto, and Vermilion. This includes a more detailed study of the Huron and Old Woman Creek Lake Erie watersheds than in the previous reports.

Highlights from the 2020 report include:

  • Averaged over the last five years, the largest annual nonpoint sources of phosphorus were in the Maumee and Scioto river watersheds.
  • Nutrient loads from point sources (wastewater treatment plants plus home sewage systems) were higher in the Ohio River basin than the Lake Erie basin.
  • The watersheds with the highest nonpoint source contribution of phosphorus and nitrogen had the highest proportion of land area dedicated to agricultural production. The highest nonpoint yields were in Northwest Ohio where nearly 80 percent of the land area is used for agriculture.
  • The increased nonpoint source loads in 2019 further document that hydrology – especially due to wet weather – drives a large share of the nutrient loads.

Substantial state and federal dollars, including Governor DeWine’s H2Ohio Plan, continue to be allocated to nutrient reduction efforts to address both point and nonpoint sources in many of the watersheds referenced in the report, especially those in the Western Lake Erie basin. Launched by Governor Mike DeWine in 2019, H2Ohio is a collaborative water quality effort to provide clean and safe water to Ohio. The Ohio Department of Natural Resources, Ohio Department of Agriculture, Ohio Environmental Protection Agency, and Ohio Lake Erie Commission each has a significant role in H2Ohio through the natural infrastructure of wetlands, the reduction in nutrient runoff, and increasing access to clean drinking water and quality sewer systems. To learn more, go to h2.ohio.gov.

Monitoring programs are tracking potential water quality improvements from these nutrient management practices.

The nutrient study results will assist the state in identifying the most environmentally beneficial and cost-effective legislative, policy, and financial mechanisms to reduce phosphorus and other nutrients affecting state waters. The study aids in tracking progress to goals established by the 2012 Great Lakes Water Quality Agreement and the Gulf of Mexico Hypoxia Task Force 2001 Action Plan.


The Ohio Environmental Protection Agency was created in 1972 to consolidate efforts to protect and improve air quality, water quality and waste management in Ohio. Since then, air pollutants dropped by as much as 90 percent; large rivers meeting standards improved from 21 percent to 89 percent; and hundreds of polluting, open dumps were replaced with engineered landfills and an increased emphasis on waste reduction and recycling.

Get to the
Right Person Faster
Notify us about
Non-emergency Issues