Source: http://articles.philly.com, June 21, 2006
By: Sandy Bauers
A week after a contaminant was released into the Wissahickon Creek, killing more than 1,000 fish, malfunctions at the Ambler sewage treatment plant Monday night sent 55,000 gallons of raw sewage into the waterway.
No additional fish were killed, but “obviously, from a water-quality standpoint, this is adding insult to injury,” said Dan Tredinnick, spokesman for the state Fish and Boat Commission.
Meanwhile, a state Department of Environmental Protection lab has detected cyanide compounds in water samples taken last week from the Wissahickon after the fish kill was reported downstream of the Upper Gwynedd Township Wastewater Treatment Plant.
The level of 100 parts per billion was nearly five times the toxicity level for fish, spokesman Dennis Harney said yesterday, but was “below the regulatory limit” for human exposure, which is 700 parts per billion.
“This was more a risk to the aquatic life in the stream than to human health,” he said.
Although the cyanide could have killed the fish, officials do not know whether it did or whether other compounds in the water caused or contributed to the mortality.
He said yesterday’s results were “one small piece” of the information the agency seeks. “We’re having our samples analyzed for a broad spectrum of compounds.”
Harney said the tests showed cyanide compounds both entering the wastewater treatment plant and leaving it.
“What form of cyanide came in, what form left, and whether there was any chemical interaction within the plant will continue to be evaluated,” he said.
According to a federal government Web site, cyanide is used in electroplating, metallurgy, organic chemicals production, photographic developing, and plastics manufacturing.
Exposure to low levels of cyanide can cause breathing difficulties, heart pain, vomiting and headaches.
The creek remains under a health advisory – no recreational use – until lab results verify that conditions have returned to normal, Harney said.
The U.S Environmental Protection Agency, which has sampled industrial discharges into the sewage treatment system, got its first results yesterday, spokesman Roy Seneca said.
But he said, “We really can’t share them because it’s part of our investigation.”
Samples from the dead fish were being tested for cyanide and arsenic, Tredinnick said.
He said both substances “would be high on the list of suspects when you have a fish kill and chlorine appears to be involved.” Chlorine is used to destroy organic matter in wastewater at the plant.
“Arsenic, when it combines with chlorine, can be fatal to fish,” he said. “Same thing with cyanide.”
Officials are looking at dozens of industrial facilities that discharge wastewater into the Upper Gwynedd plant. The three largest are Merck Pharmaceuticals, Colorcon and Visteon.
Merck West Point spokeswoman Connie Wickersham said nothing unusual had occurred with the plant’s wastewater. Pharmaceuticals and vaccines are made at the site, which is Merck’s largest.
Jim Fisher, a spokesman for Visteon, which makes electronic components for vehicles at its North Penn plant, said, “We have no reason to believe this is related to our facility.”
Both firms said they were cooperating with the investigation.
Calls to Colorcon, a food dye company, were not returned.
Monday night’s releases from the Ambler plant began when a circuit switch failed and the plant switched to its backup generator, Harney said.
The generator failed at 8:15 p.m. Workers got a second generator to the site by 11 p.m. and restored power by midnight.
By then, 28,000 gallons of effluent had backed up through a manhole cover and flowed into the Wissahickon.
Later, 21,000 gallons of effluent flowed from a tank into the creek. And 6,000 more gallons were inadvertently pumped from another tank.
Harney said that by yesterday, operations were back to normal.
EPA records show the plant exceeded release limits for suspended solids or fecal coliform during five of the 12 quarters from 2003 to 2005.
The Philadelphia Water Department’s deputy commissioner of operations, Debra McCarty, said the biggest worry from the incident was bacteria. “If we need to make adjustments we will,” she said.
Unfortunately, she said, “it’s not that unusual for sewage spills to occur on the Wissahickon and the Schuylkill,” and she credited a computerized warning system with helping the department anticipate problems.
As planned earlier, officials from this weekend’s Philadelphia Insurance Triathlon gathered Schuylkill water samples yesterday to be tested for bacteria. Race director Lars Beck said he expected the results by tomorrow or Friday.
“I’m confident the numbers will come back low, as they always have,” he said.
Last week’s tests, he said, showed levels of 40 to 80 units per milliliter. The EPA’s allowable limit for freshwater swimming areas is 400 units.