Dissolved Oxygen & Delaware River Water Quality

The EPA has finalized more stringent dissolved oxygen (DO) criteria that apply to the Delaware River from Philadelphia to Wilmington. The EPA determined in 2022 that this regulation was necessary based on the theory that existing DO conditions in the Delaware River are not sufficient to protect reproduction and health of fish species that inhabit the river, including the endangered Atlantic sturgeon. The new standards for DO are specified here.

To increase DO in the river, the EPA is proposing large-scale reduction of ammonia in the discharges from municipal wastewater treatment facilities on the Pennsylvania and New Jersey sides of the Delaware River. Ammonia is a natural component of human waste, and when wastewater enters the river, it reduces oxygen levels in the water. Wastewater treatment plants are the primary source of ammonia to the Delaware River. PWD operates three large wastewater treatment plants that would require costly new infrastructure to comply with this new rule.

To build and indefinitely operate the treatment technologies necessary to meet the level of ammonia removal required by the EPA’s new regulation, PWD estimates $3.6 billion in capital costs and annual operation and maintenance costs of $36 million per year.

PWD estimates the EPA’s regulation will cost customers an additional $22.17 per month on water bills—not $1.50 per month as calculated by the EPA. That amounts to more than $265 per year in new costs for PWD customers.

PWD calculated these costs by identifying average wastewater and stormwater fees in residential water bills, and then factored in the new costs (capital, operations, and maintenance) required for PWD to design, build, and indefinitely operate advanced ammonia removal processes at its three Water Pollution Control Plants.

The EPA affordability assessment for Philadelphia is deeply flawed and does not correctly forecast the increased financial burden of the new rule. EPA’s cost of compliance estimate is $2.5 billion less than PWD’s estimate. This is due to discrepancies between the EPA Economic Analysis assumptions and PWD’s own understanding of its facilities, costs, operations, and billing practices. For example, EPA incorrectly calculates its estimate of the residential share of wastewater costs. The EPA estimate is 15%, while PWD estimates the residential share of wastewater costs is 51.6%. PWD reached this estimate based on its FY24 cost of service analysis. For more detail, see comments 22-32 in the PWD Comments on Draft EPA Rulemaking document submitted to the EPA.

Federal funding opportunities such as the Bipartisan Infrastructure Law (BIL) do not provide enough funding to make PWD compliance with the new EPA standards affordable. The BIL provides $344 billion over five years for wastewater, water, and water quality projects—or about $9 billion annually to be allocated among U.S. states, territories, and tribal governments. While $9 billion is certainly a big number, it’s important to consider how much Pennsylvania actually receives.

In the 2022 federal fiscal year, the BIL allocated $240 million to Pennsylvania for wastewater, water, and water quality projects. Of that $240 million, $74.2 million was designated for Clean Water Act related projects across Pennsylvania. It is not realistic to assume that PWD would obtain all of Pennsylvania’s wastewater funding from the BIL for all five years. Even if that assumption were true, such funds would only pay for 10.3% of the funding needed. PWD is recommending that the EPA work with Congress and other stakeholders to ensure adequate funding is made available for this rulemaking to be more affordable for PWD ratepayers, particularly those residing in environmental justice communities.

No. PWD is a public municipal utility operated by the City of Philadelphia and does not profit from rate increases. We only request the amount needed to cover the cost of services and to achieve compliance with state and federal regulations.

PWD agrees that water quality standards need to be updated to reflect the fact that “propagation” of Atlantic sturgeon is occurring. The current DO standard of 3.5 mg/L as a daily average has not only been met, but has been greatly exceeded, with summer DO levels almost always above 5 mg/L or 60% saturation. PWD supports updating the DO standard based on scientific evidence for levels that protect spawning and growth of fish and other aquatic life in the Delaware River.

PWD compiled and analyzed more than 5,000 juvenile sturgeon collection records from the Delaware River between 2009-2022 and concluded that dissolved oxygen conditions support spawning and growth of juvenile sturgeon:

• Total length measurements of young-of-year (YOY) Delaware River Atlantic sturgeon were found to be within the expected range for the species.
• The average length of 4,593 YOY sturgeon collected from the Delaware River between 2009 and 2022 was 13.5 inches long.
• These rapid rates of juvenile sturgeon growth, which were measured consistently from year to year from thousands of fish collected and measured, would not be observed if sturgeon lacked adequate levels of dissolved oxygen.
• PWD performed 560 statistical tests comparing sturgeon growth measurements with DO statistics for 2009-2022 and found no significant correlations between growth and DO.
• Delaware River sturgeon also appear to be growing as well as similar age fish in upstate New York’s Hudson River, where dissolved oxygen levels are typically higher.

Yes, absolutely! PWD shares the goals of ensuring that fish and other aquatic life can not only survive, but thrive, and rebuilding populations of our iconic native species such as Atlantic sturgeon, striped bass, and American shad.

PWD is a resilient utility dedicated to ensuring Philadelphia thrives by delivering reliable, safe drinking water, wastewater, and stormwater services, protecting the environment, and supporting public health and quality of life. To keep water bills affordable for our customers, PWD must be strategic in where, when, and how it invests its resources. The significant costs associated with removing ammonia would force PWD to devote fewer resources to issues that directly affect the public health and daily lives of Philadelphians, such as flooding, pipe replacement, emerging contaminants, and combined sewer overflows (CSO).

No. State and federal agencies measure bacteria (i.e., not ammonia) to determine if a waterway meets swimmable water quality. Bacteria in the Delaware River is attributed to combined sewer overflows (CSO), stormwater runoff, and animal sources. The ammonia removal processes needed to meet EPA’s new DO regulation would not reduce bacteria concentrations in the Delaware River and would compete with state and federal funding for CSO mitigation in Philadelphia.

No. The EPA’s new DO regulation pertains to Philadelphia’s three wastewater treatment plants that discharge to the Delaware River downstream of Philadelphia’s drinking water intakes. There are no drinking water treatment plants located in close proximity to PWD’s wastewater treatment plants. Drinking water in Philadelphia will not benefit from this regulation. In fact, complying with the new DO regulation could force PWD to direct limited ratepayer funding away from, or otherwise delay, drinking water facility and pipe replacement projects.