Chesapeake Bay Watershed Pollution Limits


If fully implemented, the Chesapeake Clean Water Blueprint—the federal/state effort enacted in late 2010—will ensure programs to reduce nitrogen, phosphorus, and sediment pollution sufficiently to get the Bay and its tributaries off the Clean Water Act "Impaired Waters" list are in place by 2025.

The Environmental Protection Agency (EPA) established the following science-based limits (also called the Total Maximum Daily Load or TMDL) for nitrogen, phosphorus, and sediment necessary for the Chesapeake Bay watershed to restore the Bay and its tidal rivers to health.

What It Will Take to Restore the Bay and Its Tidal Rivers to Health

Reduce Bay-wide nitrogen loads to:Reduce Bay-wide phosphorus loads to:Reduce Bay-wide sediment loads to:
219.53 million lbs/year by 2017 16.35 million lbs/year by 2017 7.87 million lbs/year by 2017
192.39 million lbs/year by 2025 14.45 million lbs/year by 2025 7.34 million lbs/year by 2025

~ Source: Chesapeake Bay Program, Watershed Model 5.3.2

Pollution Reduction Progress Toward 2025 Goals

Nitrogen Loads
to the Bay
(million lbs/year)
Phosphorus Loads
to the Bay
(million lbs/year)
Sediment Loads
to the Bay
(million lbs/year)
1985 369.78 25.62



282.66 19.23 8.68
2012 264.14 17.97 8.24
2016 240.24 15.37 7.92
2017 233.10 14.95 7.79
2025* 207.57 14.45 7.34
  Source: Chesapeake Bay Program Source: Chesapeake Bay Program Source: Chesapeake Bay Program

~ Source: Chesapeake Bay Program, Watershed Model 5.3.2

NEXT: The Bay states' role in the Chesapeake Clean Water Blueprint 

Pollution Limits by State

Decades of Success: The 1970s

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Do you enjoy working with others to help clean the Chesapeake Bay? Do you have a few hours to spare? Whether growing oysters, planting trees, or helping in our offices, there are plenty of ways you can contribute.