The primary causes of nonpoint source impairment in Ohio streams are habitat alteration, hydro-modification to stream channels, sediment, and excessive nutrients.

What is nonpoint source pollution?

Traditional images of water pollution often consist of a pipe spewing industrial contaminants into a river. The Clean Water Act helped solve many of Ohio's traditional pollution problems. Remaining problems are more challenging and may be traced to two kinds of pollutants: polluted run off and physical alterations to a stream or river channel. These are referred to as nonpoint sources of pollution since they are the result of a land use and/or man-made changes to a river rather than flowing from a single point of discharge.

Polluted run off is rain or snow melt flowing across the land picking up contaminants such as sediment, nutrients, or bacteria, carrying these pollutants to small streams that eventually flow into a larger river. Physical alterations are changes made to a stream channel or stream banks and include activities such as the conversion of headwater streams into drainage ditches, constructing levees and dams, and straightening a stream to encourage improved drainage. Physical alterations also include activities such as removing trees along a river bank or installing rock rip-rap on a river bank to prevent erosion.

The primary causes of nonpoint source impairment in Ohio streams are habitat alteration, hydro-modification to stream channels, sediment, and excessive nutrients.

Streams in agricultural areas of Ohio appear most frequently to be impaired by physical alterations, such as ditching, and impairments caused from excessive sediment and nutrients.

Streams in urban and rapidly developing residential areas of the state are further impaired by nonpoint causes such as lowhead dams and nonpoint source contaminants carried off land surfaces by increased storm water runoff.

In the coalfield regions of southeastern Ohio, another cause of impairment is abandoned mine drainage, which has impaired more than 1,300 miles of streams in the region.

Fortunately, management practices to address nonpoint source pollution are becoming more effective. Previous efforts to address these types of problems often consisted of implementing demonstration practices and trying new techniques for managing the ubiquitous nature of nonpoint source pollutants. Years of trial and error are resulting in a much broader understanding of management practices needed to restore impaired waters and improve water quality.

Physical alterations may be addressed using restoration practices such as removing lowhead dams, eliminating or modifying levees, and restoring floodplains and riparian forest cover. Headwater streams previously converted into drainage ditches are effectively being restored using natural stream channel design techniques. Polluted run-off is being more effectively reduced using pollution prevention practices such as replacing failing home sewage treatment systems, installing riparian filter strips, and controlled drainage systems or restoring ditches to 2-stage channels to allow for more natural stream function. Many other practices designed to slow the flow of nutrients from croplands, and sediment from mining sites and construction sites are also available to improve the health of Ohio's rivers and streams.

NPS Management Plan

The U.S. Environmental Protection Agency approved Ohio EPA's update to the Ohio Nonpoint Source (NPS) Management Plan in September 2025. This important update provides direction and strategic focus to Ohio EPA's programs and activities geared toward reducing the impacts of nonpoint source pollution such as hydromodification, habitat alteration, and polluted runoff and adds other activities like invasive species management and innovative stormwater management demonstrations.

Management practices listed in the update are now eligible for federal Section 319 grant funding and grants awarded from other sources. Since Ohio EPA is not altering the scope of the previously updated nonpoint source management plan, a full revision to the management plan was not required. As a result, Ohio EPA focused updated strategies and practices only on programming actions for which Ohio EPA is the primary implementer and/or facilitator.

Ohio's approved NPS Management Plan update incorporates large sections from Ohio's Nutrient Reduction Strategy. This information was derived following collaboration and input from a large number of agricultural and urban stakeholders.

Moving forward, Ohio's NPS Management Plan will implement several provisions of the Nutrient Reduction Strategy. Ohio's updated plan also incorporates objectives for Ohio EPA's Lake Erie Program, as well as strategies for dealing with NPS issues in urban waters and protection activities critical to protecting high quality waters.

• Current: Ohio Nonpoint Source Management Plan (2025-2029)
• Previous: Ohio Nonpoint Source Management Plan (2019-2024)
• Ohio Nonpoint Source Management Plan (2014-2019)

Chloride Reduction Program

In December 2023, Ohio EPA announced the Chloride Reduction Program as part of the H2Ohio Rivers Program. The program aims to help communities upgrade road salt infrastructure and equipment to reduce the amount of salt runoff impacting Ohio surface and groundwater resources.

Reducing chloride in water is important for the health of freshwater ecosystems, keeping our fish and plants healthy. In total, the H2Ohio Rivers Chloride Reduction Grant program has awarded more than $6 million to 117 communities since the program’s launch in 2023.

Explore the story map below or view it in a new tab to learn about Ohio EPA’s Chloride Reduction Program and how to stay connected to learn about future grant opportunities.