Theme: Continuing Challenges
Northeast Ohio has experienced some improvement in surface water quality in specific areas, but data suggests that other water sources throughout the region continue to need remediation.
Northeast Ohio’s Watersheds
Assessed Health of Watersheds by Type of Beneficial Use
According to the U.S. Environmental Protection Agency (EPA), a watershed is the area where all of the water that is under the land or drains off of the land goes into the same place. There are 234 watershed units in Northeast Ohio. The table below breaks out the impairment status of Northeast Ohio’s watershed units by three beneficial uses:
- Human Consumption,
- Recreation and
- Aquatic Life
Impairment of Northeast Ohio Watersheds
The Ohio 2012 Integrated Water Quality Monitoring and Assessment Report lists the impairment status for Northeast Ohio’s watersheds. More than half of Northeast Ohio watersheds are impaired for human health and require a Total Maximum Daily Load (TMDL) assessment.
Under the Clean Water Act, a TMDL is a written, quantitative assessment of water quality problems in a body of water and the sources that contribute to its pollution. A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards. It is also an allocation of how much the various sources of that pollutant can add to the waterbody on a daily basis.
By definition, a body of water that requires a TMDL is not meeting the water quality standard (WQS) for at least one pollutant. The goal of developing a TMDL is to end up with an implementation plan or a watershed plan designed to meet water quality standards and restore impaired waterbodies.
A majority of Northeast Ohio watersheds are impaired for recreation and aquatic life, but only 26% and 34% of these watersheds require a TMDL, respectively. Most are not used for public drinking water supply; none are impaired.
Most Impaired Watersheds
Thirteen watershed units in Northeast Ohio are impaired for human health, recreation, and aquatic life and all require Total Maximum Daily Load (TMDL) assessments.