Sewer failure issue nearing end

RUMFORD -- The Prospect Avenue sewer failure problem, which the town has been trying to resolve since June 8, was very much on the minds of the Board of Selectmen when they met last Thursday.

There were many questions, from the board and from citizens, but Board Chairman Greg Buccina noted, "Once this issue is taken care of, I'm sure there will be an in-depth report by the state on how we could have done this better. All questions will be addressed but the priority right now is repairing."

Public Works Supt. Andy Russell gave an overview of the problem and where they're at now. "Anywhere else, this would have been a one- or two-day job, but this was beyond the scope of what we'd dealt with before."

He said he is hopes that the sewer failure problem will be fixed this week. That would depend on the ongoing efforts to remove water from the site long enough to allow a crew to replace a broken sewer pipe and manhole that are within a huge aquifer some 18.5 feet below street level.

"We can do it," Russell assured the board. "We just have to get rid of that water."

He recapped the history of this issue, which began on June 8. Because it was on a Friday, the town crew marked the sinkhole

off with safety cones, and began work the following Monday. They excavated in and around the sinkhole until they found a sewer pipe with a hole in it on the Sunnyside Terrace side of the sewer line.

"As we exposed the lower side toward Sunnyside Terrace, we briefly saw a hole in the pipe before we were inundated with flooding groundwater," said Russell.

Efforts to drain the work site failed, so he rented some trench boxes to keep his crew safe due to the depth of the dig, where the sewer is, at 18.5 feet, is much deeper than the rest of the sewer lines in town, which generally run about six feet deep.

On June 28, they contacted an engineer, which recommended using larger pumps to drain the site, which they brought in and tried. However, that didn't work either. On July 2, they called a company that specializes in de-watering. That company came in on July 11 and drilled a 12-inch well on the Androscoggin River side of the cofferdam to drain the area, but that didn't extract enough water. The engineer suggested drilling on the other side of the sewer line, but that didn't pan out.

They continued to work inside the cofferdam to extract more soil and even went below the sewer pipe to pump water out of the pipe. However, while doing this on July 17, groundwater and sand outside the cofferdam suddenly came in, buckling a six-inch water main. Water District employees had to immediately put a valve on the line to stop the break.

Then on Wednesday, the crew had the hole in the sewer pipe exposed and were ready to connect a new pipe to it when water and mud again poured in.

Selectman Brad Adley asked Russell about the status of the Maine Department of Environmental Protection action against the town.

In June, raw sewage was pumped from the dig site onto Prospect Avenue homeowner Eric Davis's land — not once, but twice.

Davis filed a complaint with the DEP, which led to a state investigation that is still in the correspondence stage, Russell said.

"We did pump some sewage, and it wasn't just sewage," said Russell. "It was 90 percent groundwater from the trench that we didn't want to pump back into our sewer main, because we were afraid we were just going to create another problem further downstream and go through this all over again."

He said it was pumped into a catch basin until that clogged with soil, and then pumped along the edge of grass on Davis's property.

At this meeting, Davis asked why they didn't install silt fences. Russell said he spoke with DEP and they didn't recommend silt fences.

He said he bought some 10x15-foot dirt bags that catch soil and filter out water. "Those exploded on us the first day we used them."

"We're back trying to de-water it again. It may take a day or two to dry the area up. We need to get the pipe in, get the manhole in, and that should be it," said Russell.