Section 303(d) of the Clean Water Act (CWA) requires that states assess surface waters and compile a list of those that have become polluted to the point that they no longer support their Use Classification (e.g., Fish & Wildlife, Public Water Supply, Swimming & Whole-Body Contact, etc.). This list of impaired waters is known as the 303(d) List.
Every two years, the Alabama Department of Environmental Management (ADEM) releases a list of Alabama’s impaired waterbodies that they find out of the rivers, streams, lakes, and coastlines they assess. A waterbody is considered “impaired” when it does not meet the water quality standard designated for its use classification.
The 303(d) list provides information about a waterbody’s location and size, use classification, and sources and causes of impairments. Below is a small sample from the list, and a breakdown of the information in each column.
To view the Final 2020 303(d) List, go to: http://www.adem.state.al.us/programs/water/wquality/2020AL303dList.pdf
What are use classifications?
Water use classifications are the “reasonable and necessary uses” of a waterbody as defined by the Clean Water Act. Waterbodies can be classified as the following:
- Outstanding Alabama Water (OAW)
- Public Water Supply
- Swimming & Other Whole Body Water-Contact Sports (S)
- Shellfish Harvesting
- Fish & Wildlife (F&W)
- Limited Warmwater Fishery
- Agricultural & Industrial Water Supply (A&I)
Waterbodies can have several use classifications. For example, a waterbody can be classified as Fish & Wildlife and Swimming.
In 2020, 443 waterbodies were listed on the Alabama 303(d) list of impaired waters. Out of these, 9 were listed as Outstanding Alabama Waters, 169 for Swimming, 52 for Public Water Supply, 416 for Fish & Wildlife, 12 for Shellfish Harvesting, 3 for Limited Warmwater Fishery, and 4 for Agricultural and Industrial uses.
The Outstanding Alabama Waters are located in the Cahaba River Basin, Coosa River Basin, Mobile River Basin, and Tallapoosa River Basin.
Below is a comparison of the impaired waters listed by each river basin.
What impairments can waterbodies be listed for?
There are many potential causes of impairment in a waterbody. The 2020 list includes the following impairments:
Metals (Arsenic, Cyanide, Iron, Lead, Mercury,
Organic enrichment (BOD)
PFOS (Perfluorooctanesulfonic acid)
Priority organics (PCBs –
Total Dissolved Solids
There are also many potential sources of impairments. The 2020 list includes the following sources:
Animal feeding operations
Collection system failure
Crop production (non-irrigated)
|Nonpoint source runoff|
On-site wastewater systems
Sources outside state
Surface mining – abandoned
Urban runoff/storm sewers
Wet weather discharge
You can view 303(d) listed streams and waterbodies on Alabama Water Watch’s maps: and selecting to view “ADEM 303 Impaired (2018)” from the map menu.