A skyline of Philadelphia
Philadelphia, the largest city on the Delaware River, contributes the lion's share of the river's dissolved oxygen problem. PHOTO BY MEG MCGUIRE

Latest salvo in the battle to save endangered sturgeon comes from the Philadelphia Water Department

| January 16, 2024

As the largest single source of treated wastewater in the Delaware Estuary, the Philadelphia Water Department contributes the lion’s share of a problem with dissolved oxygen that, according to the U.S. Environmental Protection Agency, threatens the endangered Atlantic sturgeon.

The EPA, building its case on the science developed by the Delaware River Basin Commission, has recently proposed new standards for dissolved oxygen.

The Philadelphia Water Department released a statement on Friday, ahead of a three-day weekend, responding to the EPA’s proposal.

In summary, it says: Not so fast, EPA. Or maybe, not so high.

“PWD supports recognition of the existing propagation use (of sturgeon) in the Delaware River but does not support raising DO criteria to the highest possible levels without more careful consideration of the benefits and costs of further increases in DO for sturgeon and other fish in the Delaware River.”

Problem dates back years

Fish, like us, need oxygen to survive. They get it in the water they swim in. Too much wastewater that’s high in nitrogen overwhelms the ability of various microscopic critters in all waterways to “treat” the problem naturally.

That dissolved oxygen is plentiful in cold, clear water, and gets diminished as the water slows down and becomes warm. In the summer, especially, the young of sturgeon struggle in the urban section of the river, according to some scientific analysis.

That’s part of what the PWD is arguing.

“PWD’s preliminary analysis of more than 5,000 fish collected and measured in the Delaware River showed that sturgeon are already spawning and growing in Zones 3, 4 and 5 at current DO levels,” the department said, referring to the zones that make up the urban core and are the target of these proposed rules.

“Based on actual fish measurements, years with higher or lower DO levels showed no statistically significant difference in sturgeon growth or condition.”

The Water Department has had a front-row seat in the ongoing conversation about solving the problem that its wastewater creates for the river.

And depending on whom you talk to, recognition of the problem dates back to 1967, the date referenced by the Delaware Riverkeeper’s restoration director, Erik Silldorff.

Since 2017, members of the Delaware River Basin Commission staff have been working on the science of the problem, what it is and how to solve it.

Complaints that the process has been too fast or too slow

There have been complaints about the process.

The dissolved oxygen standards suggested by that science are too high, says PWD.

“PWD is concerned, however, that in proposing new federal DO criteria to support propagation, EPA has relied on inappropriate laboratory and modeling studies while failing to evaluate and fully consider the most up-to-date scientific data on actual fish spawning and juvenile growth in the Delaware River,” it said.

On the other hand, the DRBC process has been too slow for environmental advocates, such as the Delaware Riverkeeper, which brought the case for the EPA to act.

These proposed rules from the EPA stem from its agreement with those activists.

In addition, PWD cites the impact on ratepayers of building the infrastructure needed to reach those new dissolved oxygen criteria.

“Decision makers must consider and balance the possible benefits of even higher DO with the costs of building and indefinitely operating new processes to remove ammonia at wastewater treatment plants,” the department said. “Proposed new wastewater processes needed to comply with strict ammonia limits would have a significant financial impact on water rates.”

According to statista.com, Philadelphia has one of the highest percentages of people who live below the poverty line in the United States, at 22.8%, so that’s not a baseless concern.

The next step in the EPA’s rule-making will be two public hearings set for Feb. 6 and 7th. Check the link for times and to see how to sign up to comment.

Meg McGuire

Meg McGuire

Meg McGuire has been a journalist for 30 years in New York and Connecticut. She started in weekly newspapers and moved to full-time work in dailies 25 years ago. She knows about the tectonic changes in journalism firsthand, having been part of what was euphemistically called a "reduction in force" six years ago. Now she's working to find new ways to "do" the news as an independent online publisher of news about the Delaware River, its watershed and its people.

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