By Brad Segall and Jan Carabeo

VALLEY FORGE, Pa. (CBS) — Work continues today to repair a broken sewer main in Valley Forge Park, Chester County, that resulted in at least five million of gallons of raw sewage running off into the Valley Creek (see previous story).

READ MORE: Abortion Rights Advocates Gather For Bans Off Our Bodies Protest In Philadelphia After SCOTUS Overturned Roe v. Wade

As soon as this sewer main burst at the Intersection of Routes 252 and 23 at  Valley Forge, conservation officers and a club that takes care of Valley Creek knew they had work to do.

“They have walked approximately two miles of this stream from the pump house to where we are now and have reported to me no dead fish, which is a good thing,” Waterways Conservation Officer Bob Bonney said.

After all, the Department of Environmental Protection estimates that more than five million gallons of raw sewage has flowed into the water here.

As crews cut and fit the 30-inch replacement pipe, environmental officials are keeping a close eye on the creek, which is home to wild brown trout.  The creek runs into the Schuylkill River, down to Philadelphia, and then into the Delaware River.

“This is a wild brown trout stream and the wild brown trout eggs are in the process of hatching right now, so we have a concern about this year’s class fish,” Bonney said.

But he says it’s a good thing this break happened during cold weather. Trout thrive in cold water.

“If this had happened in the summertime, it’s possible that we could have a different result here, we might have a lot of dead fish,” he said.

Bonney says the environmental impact may not be known for some time.

“Right now, the immediate impact — we’re fortunate that this time of the year it’s cold,” he tells KYW Newsradio.  “There’s high oxygen levels in the water, still, and we have not observed any dead fish.  And that’s our main concern.”

READ MORE: Brandywine Valley SPCA, Other Shelters Holding Mega Adoption Event This Weekend

All the snow we’ve had this winter is also working in their favor. He says that has increased water levels, which will help dilute the raw sewage.

Bonney says crews also worked hard to contain this spill quickly.  Some roads through the park remained shut down today.

In the meantime, Tredyffrin Township is responsible for the clean-up.

“We’ll certainly work with the park and DEP to make sure any environmental remediation is done properly,” Tredyffrin Township Manager William Martin said.

And so far the DEP and Aqua Pennsylvania say there are no reported problems with drinking water.

“By the time this water hits the Schuylkill River it’ll be pretty well diluted at that point,” Alan Roth of Aqua Pennsylvania said.

This is the second time in the last few weeks that the 45-year-old main has ruptured.

Tredyffrin Township actually already started a long-term study to find out what’s wrong with the pipe here before this latest break.

The manager tells CBS 3 one likely cause is age, this pipe dates back to the 1970s.

MORE NEWS: Hundreds Rally For Abortion Rights In Philadelphia With Democratic Gov. Nominee Josh Shapiro, Planned Parenthood