MEDIA CONTACT: Heidi Griesmer

Ohio EPA Updates Findings on Sources of Nutrients Impacting Ohio Waters

As required by state legislation signed in 2015 (House Bill 64), Ohio EPA has completed its second statewide study identifying sources and estimating the annual amount of phosphorus and other nutrients flowing from the state’s watersheds into Lake Erie and the Ohio River. The study covers the Maumee, Portage, Sandusky, Vermilion, Cuyahoga, Great Miami, Scioto and Muskingum watersheds, and includes some direct tributaries to Lake Erie, which collectively represent surface water quality from 66 percent of the entire state. 

The study examined phosphorus and other nutrients from agriculture and other nonpoint sources, municipal and industrial wastewater systems, as well as home sewage systems, which make up the vast majority of nutrient sources.

Highlights of the study include:

  • The Muskingum River and Sandusky River watersheds had substantial reductions in loading from industrial and municipal sources over the five years in the latest Nutrient Mass Balance Study. Annual nutrient loads from industrial and municipal sources decreased 34 percent between water years 2013 and 2017. 
  • In the Sandusky River watershed there was a 25 percent decrease in phosphorus loads from water year 2013 to 2017, but the change was not a result of regulatory action. 
  • In the Maumee watershed, there has been no discernable decrease in phosphorous or nutrient loading to Lake Erie, which continues to exceed the 40 percent phosphorous reduction requirement. 
  • Also in the Maumee watershed, 88 percent of the phosphorous contributed to Lake Erie is from nonpoint sources including agriculture. 

Overall, the results of this study show no clear trend of an overall decrease in loading in most watersheds, especially in nonpoint source dominated watersheds like the Maumee where the loading in 2017 was the highest of the years reported.

Ohio has spent more than $6 billion statewide, including more than $3 billion spent in the Lake Erie watershed to improve water quality since 2011 and protect Lake Erie. The results of this study are key in assisting the State in identifying the most environmentally beneficial and cost-effective legislative, policy, and financial mechanisms to reduce phosphorous and nutrients impacting state waters. The study serves as a baseline and will aid 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. Ohio EPA is required by state law to update this study every two years.

The report is available online: epa.ohio.gov/Portals/35/documents/Nutrient%20Mass%20Balance%20Study%202018_Final.pdf.


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