Riverkeeper update: Initial radioactivity scan shows no elevated levels, but oily residue still prevalent near Williamsport river spill site

Doug Fessler, of Fessler IT Consulting, measures radioactivity using a Geiger Counter along the banks of the Susquehanna River below the Williamsport Dam Wednesday morning. Results showed no elevated detection of radioactive activity beyond normal background levels.

​Riverkeeper note: This is the second report by the Middle Susquehanna Riverkeeper Association. The first was shared on Tuesday, August 19, 2025, and can be read here.

Preliminary scans of oily substances along the shoreline of the West Branch of the Susquehanna River just below the Williamsport Dam Wednesday morning for indications of radioactivity using a GMC-320 Plus Geiger Muller Counter Data Logger showed no elevated detection of radiation beyond normal background radiation levels.

"We scanned shoreline areas where oil residue was most concentrated and checked skimmer bags that were actively collecting the oily materials," said Doug Fessler, of Fessler's IT Consulting, who assisted the Middle Susquehanna Riverkeeper Association with the assessment.

"All readings were within the normal background radiation range and no elevated levels were detected in either the oil residue or the collection materials. I take this, for now, as a positive sign that the contamination in this case appears to be limited to petroleum-based pollutants without radioactive byproducts."

"This is just one of many more tests and assessments and reads to a level that Geiger counters can assess such a variable, but it is encouraging nonetheless," added Middle Susquehanna Riverkeeper John Zaktansky. "It doesn't rule out anything conclusively, but it does offer some reassurance - at least more than if it was ticking off the chart down there."

As rain spread through the area, oily residue continued to be visible throughout the river bank just below the dam mid-Wednesday morning, with rainbow-colored sheens in pools along the edge of the water and on various rocks along the shore. A strong smell of oil continued in this area, as well.

"Other testing is being done for different elements and parameters, some of which take quite a bit of time for results," said Zaktansky. "We won't know the scope of the impact for quite some time." 

Which is why the association is encouraging people to avoid using the immediate stretch of river for recreational purposes.

"We didn't get to explore every nook and cranny around every island and pool just below the source of the pollution, but it was encouraging this morning to see that river water as close as Greevy's Boat Launch looks visibly improved with a variety of active macroinvertebrates and a lack of oily sheen in the area," said Zaktansky. "However, it will take time for the residue around the Hepburn Street pump house area of the river just below the dam to work its way downstream. It is best from a safety standpoint to just avoid that stretch a while longer until more is known and things are cleaned up more thoroughly."

Workers from the Williamsport Municipal Water Authority and a Hazmat cleaning group have been working for several days to clean up the spill, first reported by a pair of fishermen Sunday night just below the Williamsport Dam. It was traced back to the Eureka Resources complex on Second Street where upwards of 16,000 gallons of \wastewater leaked out of a 26,000-gallon storage tank, with upwards of 8,000 gallons of that being outside of the tank's containment area and into a building on site, according to a release from the Department of Environmental Protection.

"A pollution event of this magnitude is disappointing, but I think we need to be thankful for the quick action by the Williamsport Fire Department and city's water authority for shutting off the spill via the pump house when they did so more of this oily substance didn't wind up in the river," said Zaktansky. "And, it is much appreciated to see the long hours and dedicated work of these same groups and Eagle's Hazmat team to work on cleanup and rectifying things as much as they have since then ... everyone is responding the best they can to tackle a mess caused by someone else."

That, Zaktansky added, needs to be focus of the growing attention this case is getting online and social media.

​"This goes back to the negligence of the property owners of this site. Frustrations need to be directed at them, at banding together to helping regulatory groups locate those responsible so that they can be held accountable and cover the growing cost of cleaning up this mess and better protecting our resources from future events like this," he said.

If you have any comments, feedback or information concerning this situation, please contact Riverkeeper John Zaktansky directly via email at [email protected]

Photos specifically from Wednesday morning's visit at both the site below the Williamsport dam and Greevy's boat launch farther downstream: