Experts say area rivers are healthier than ever, but there’s still work to do

By EMMA STANTON and NAOMI GIRSON TribLive

The rivers of Western Pennsylvania have a rich yet troubled history.

After years of acid mine drains, sewage leaks and environmental contamination, the region’s rivers have become habitable again thanks to the combined impact of federal legislation and local ecologists.

Today, anglers flock to the water’s edge to catch carp and trout. This week, in fact, the Pennsylvania Fish and Boat Commission released thousands of blue catfish into the Ohio River in an effort to further restore the native species that was once eradicated by toxic contaminants.

In addition to fishermen, kayakers and canoeists can be seen rowing down the Monongahela and Youghiogheny rivers.

Yet the question remains: Are the rivers truly clean?

If you ask the anglers, kayakers and regional biologists, the answer would be a resounding yes, given the level of pollution the contaminated waterways carried for decades.

In the early 1800s, the rivers had yet to feel the full impact of forestry, trade and the steel industry, according to Rick Spear, aquatic biologist for the state Department of Environmental Protection.

As the steel and mining industries boomed, more and more contaminants polluted the waters of Western Pennsylvania.

It wasn’t until 1972, after decades of industrial expansion and contamination, that positive change would be seen with the passing of the federal Clean Water Act.

Before the act’s passage, dissolved oxygen was nearly nonexistent in the rivers, especially during the summer months.

Dissolved oxygen in the water is necessary to sustain most aquatic species, and throughout the early 1900s very little life was seen in the rivers.

Today, the rivers’ dissolved oxygen levels have increased fivefold, meeting the minimum health thresholds required for a prospering ecosystem.

The same is true of the river’s acidity, which results from mining that exposes iron sulfide minerals to air. Coal and other mining caused drainage to leach into waterways that consistently stood at a pH of 5.0 — too acidic to support any species of fish.

Daniel Bain, associate professor of geology and environmental science at the University of Pittsburgh, said the Mining Reclamation and Control Act of 1977 addressed acid mine drainage that would leach into the rivers, allowing aluminum to dissolve in the water.

Aluminum is toxic to fish. When it became concentrated in local waters, Bain said, it suffocated the fish and, in the process, eliminated more than 20 species — among them trout, blue catfish, paddlefish, Tippecanoe darters and bluebreast darters.

The mining control act was a positive influence on river health. A 2020 report from the Pennsylvania Fish and Boat Commission shows a total of 4,501 fish representing 57 species were collected from several sites along the Monongahela and smaller tributaries.

Today, there are more than 100 species of fish present, including all of the above-mentioned species that were decimated a few decades ago.

Forever contaminants

Even though fish populations have rebounded, contaminants such as mercury, polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) still exist in the rivers.

These synthetic chemicals have been used across hundreds of industries since the 1940s to make products resistant to heat, oil, water and stains.

Described as “forever chemicals” by Carrie Mc-Donough, a professor of chemistry at Carnegie Mellon University, these human- made chemicals leach into the water, settle in the sediment at the bottom of the riverbed and are nearly impossible to remove.

Fish, especially those that feed from the bottom, accumulate contaminants in their bodies. The state tests the water to determine whether fish caught from the rivers are safe to eat.

“We go to a particular location, and we take three to five fish (of the same species). Then we take fillets from one side of the fish and grind them up to fish patties,” Spear explained. “We’ll send those patties to our lab in Harrisburg and test them for a suite of 36 different contaminants.

“Once the results come back, if they are above the levels healthy for human consumption, we flag them and issue a consumption warning. So, some fish could be safe to consume for a meal a week, a month, a year or not at all. That’s what our testing determines.”

In the state Fish and Boat Commission’s 2026 Pennsylvania Fishing Summary, the DEP’s consumption advisories are laid out by fish and water region, allowing anglers to check the safety of their catches.

For example, if someone were to catch a smallmouth bass from the Youghiogheny River, they’d be able to eat, at most, two meals per month before risking mercury contamination.

Spear told TribLive that of all contemporary and legacy contaminants still found in local waterways, PCBs and mercury are the most common.

“Mercury is probably going to (always) be around because it comes from air deposition,” Spear said. “I would like to think someday PCBs are going to go away, but that would require a complete overhaul in manufacturing, development, etc. We have enough issues trying to get sewage out of our rivers to worry about PCB contamination.”

Spear said raw sewage overflow is one of the main contamination issues rivers face today, especially when it rains.

“Sewage can overflow into the rivers after just one-tenth of an inch of rain,” he said.

E. coli contamination

In a typical year with average rainfall, Spear said, the sewage system in Pittsburgh overflows around 9 billion gallons of combined sewage.

The state is working with the Allegheny County Sanitary Authority to construct a new sewage intake pathway.

“The same sewer lines were utilized for decades to carry both stormwater and sewage to the treatment plant. It used to all flow into one pipe,” Pitt’s Bain said. “When a big rainstorm would hit, the sewage-water mix would be too much for the pipe, so it would reroute to the overflow valves and discharge into the rivers.”

In a $3.6 billion draft plan, the authority would construct a tunnel deep beneath the city to remedy sewage runoff, Bain said.

“So when it rains, instead of discharging a mixture of stormwater and sewage into the river, it’ll go down into the tunnel and sit there until it can be properly processed through the facility,” he said. “It is a massive engineering effort, but once it’s complete, our rivers will be much healthier … even though this project is still years away from completion.”

In the meantime, local biologists are testing water pathways constantly for E.coli levels and safe swim guides.

Youghiogheny Riverkeeper Eric Harder, a member of the Mountain Watershed Association, has noticed a rise in E. coli levels in recent years.

“Farm runoff, large sewage systems from municipal areas and on-lot septic systems are the main contamination culprits,” Harder said.

Like the other rivers, just half an inch of rainfall can contaminate the Yough, and this summer has been an especially stormy one.

Harder and his team conduct weekly sampling during the swimming season (May 1 to mid-October) on the parts of the Yough that are not designated swimming areas but are places people still visit, such as Meadow Run Slides in Ohiopyle.

Data reported on June 24 showed Ohiopyle as having an E. coli level of 1119.6, which is unsafe for swimming. Just a week earlier, data from the same location showed the E. coli level was in the green at a value of 209.8.

“My dream rural setting is to have people that have their own septic systems be able to take care of those and maintain them,” Harder said. “Maybe that’s through some grant funding, but also some ordinances at a local level that say if you’re going to sell your house, you need to inspect your septic system before it sells.”

A local angle

Despite local waters still fighting septic runoff and PCB contamination, the people who regularly fish say the conditions in the region have drastically improved.

Miles Carey, 18, of Aspinwall, who works at Harmar Bait & Tackle, says he has been fishing in Pittsburgh rivers his entire life, catching bass, walleye, musky, catfish and carp.

“When I’m on the river, I’m fishing. It’s been something I’ve done most of my life. In the roughly 15 years I’ve been fishing in Pittsburgh, there have always been fish.”

Bald eagles have been spotted in multiple rivers and urban waterways, said Heather Hulton VanTassel, executive director of Three Rivers Waterkeeper.

That’s often a sign that a waterway offers a steady supply of fish, which make up a large portion of a bald eagle’s diet. The predators’ presence near the rivers means fish populations are robust.

“We see endangered species like the mollusk start to come back in astounding numbers — all of which is a sign our water systems are starting to recover,” Hulton VanTassel said.

Fish that were at one time endangered, like the Tippecanoe darter and the bluebreast darter, have repopulated in Pittsburgh’s water systems to an astounding degree, she said.

John Andrejcik, a former Lower Burrell mayor and an avid fisherman, can attest to the changes in river conditions throughout the decades.

“You didn’t see gizzard shad 30 years ago. Now, if you go down to the bridge overlooking the (Kiski River), you see dozens of gizzards coming to the surface for flies,” he said. “You can fly fish on that river all day long if you want. I know many folks who do.”

The fish that have repopulated local waterways, however, go well beyond gizzard shad, he said.

“I always tell folks: Anything you want to catch, you can find in our waters today. Pittsburgh rivers treat us right.”