Upgrading the Delaware River’s Water Quality Standards
The U.S. Department of Environmental Protection (EPA) took a bold step issuing revised water quality standards for a critical part of the Delaware River on December 13, 2023. This was the culmination of years of work by Clean Air Council and our partners.
The draft rule strengthens water quality standards for Zones 3, 4, and 5 of the Delaware River to include aquatic wildlife propagation as a designated use that must be protected under the Clean Water Act (CWA). Zones 3, 4, and 5 of the Delaware roughly covers from Philadelphia, PA to Wilmington, DE and includes multiple environmental justice communities that have been impacted by years of under-investment and poor water quality. EPA’s draft rule would protect critically endangered animals such as the Atlantic Sturgeon, which are genetically unique to the Delaware River, and already protected by the Endangered Species Act.
Dissolved oxygen is the amount of oxygen in a specific body of water and is what aquatic plants and wildlife breathe to live. Therefore, dissolved oxygen is an important indicator of overall water quality. This is vital to oxygen-sensitive species, such as the Atlantic Sturgeon, as well as public health. Low levels of oxygen can create “dead zones” that cannot support aquatic wildlife and also allow for more bacteria and algae in water. These bacteria and algae can sometimes be toxic, which threatens the health of people in the region who recreate in the Delaware River and depend on it as a source of drinking water.
A 60-day public comment period on EPA’s draft is closing today, and the Council mobilized our members and partner organizations to submit comments asking for the rule to be strengthened in three key ways:
1. The rule should establish a minimum threshold for dissolved oxygen. The current proposal uses median and average oxygen levels that can allow for periods where the actual level is below the standards required by aquatic life.
2. The rule should implement monthly assessment periods. The current proposal has created three “seasons” based on the life stages of the Atlantic Sturgeon during which new water quality standards can’t be exceeded. However, this again allows for potentially extended periods where water quality levels are below the standard.
3. The rule should establish 80% saturation value of dissolved oxygen, or the amount of oxygen the water can hold, to support all life stages of the Atlantic Sturgeon. The proposed rule sets the value between 66% and 74% saturation, which falls below recommendations from current research.
The Council will continue to monitor this draft rule and plans from Pennsylvania on how to implement the new water quality standards. While water quality in the Delaware River has vastly improved over the past 50 years, we need stronger standards and the public’s involvement to ensure the highest quality water for our communities. For more information, feel free to contact Susan Sunhee Volz, Advocacy Coordinator, at svolz@cleanair.org.
