Just under three years ago, the Franklin Township Municipal Sanitary Authority delivered a model to state environmental officials mapping out the flow of sewage through its 330-mile system.
It was among the mandatory goals in a 2019 consent order entered into by FTMSA as well as its client communities, with the overall goal of addressing inflow and infiltration: stormwater making its way into sewage pipes.
Stormwater in the system is essentially a waste of FTMSA’s resources — it is filtered by the ground and does not need to be treated — and to date, efforts to clear it out of the system have resulted in about 4 million fewer gallons entering the plant during rainstorms, according to authority manager Nicholas Kerr.
“In the past, anytime it rained, we experienced about 20 million gallons of flow at the plant,” Kerr said.
In 2020, the average daily flow into the plant was about 3.7 million gallons; today, is 2.5 million, which is a roughly 35% reduction.
Following the various goalposts laid out in the consent order, the board of directors and manager at FTMSA — which today are all completely different than the group that entered into the order — have only a few more marks to hit before satisfying all of its requirements.
“We started out by identifying really bad areas, in some cases entire neighborhoods, that were on the old package plants installed before FTMSA was built in 1969,” Kerr said. “They were put in by developers in the ’50s and ’60s, and there just wasn’t a lot of inspection when those homes were built.”
Those Murrysville neighborhoods included Rustic Ridge, Pheasant Run, Mystic Hills, Bel Aire and Surrey Farms.
“Our assessment showed inflow was really excessive in those spots,” Kerr said. “So instead of putting a Band-Aid on a gunshot wound, we did total replacement.”
Those repairs were done to infrastructure determined to have what the National Association of Sewer Service Companies refers to as grade 4 and 5 defects.
“Ones and twos are, maybe, a little crack,” said FTMSA Operations Manager Bob Swarmer III. “Fours and fives are big cracks with water dripping or pouring in, or a pipe that’s on the verge of collapse.”
FTMSA has repaired all such defects in the pipe it owns, and recently signed agreements with Salem and Export to do the same. In addition, Kerr said Monroeville officials have agreed to turn over a small section of their sewage infrastructure that include portions of the Asbury Park and Shangri-La neighborhoods.
“They opted to just turn it over to us, and we’ll put it on our to-do list,” Kerr said.
Some other work that still needs done includes straightening a handful of areas where sewage pipes make a drastic turn of more than 90 degrees.
“If you have a bend like that, the flow starts to swirl and you’re restarting from zero to try and get that flow velocity going again,” Kerr said. “Our Haymaker interceptor, for example, behind Giant Plumbing on Sardis Road, has areas with bends greater than 90 degrees, where the water is stopping and restarting.
“We’re planning to straighten out two sections this coming year, and that should make a big difference.”
Anaerobic to aerobic
Kerr said FTMSA is also planning to switch its sewage processing over from anaerobic (without oxygen) to aerobic. The plant currently uses a massive, egg-shaped digester to treat sewage sludge.
“We did a cost analysis. And the issue with the egg, in my opinion, is that the heat rating for a lot of its parts is 160 degrees, and beyond that, you need parts that are quite a bit more expensive,” he said.
The original idea for the digester was that FTMSA could create treated sludge and sell it as fertilizer.
“The market for that just hasn’t worked out how we’d hoped,” Kerr said.
The egg-shaped digester, an anaerobic system, cost more than $11.5 million to purchase and install in the early 2000s. The EnviroMix system which will break down and treat sludge using an aerobic process costs $2.5 million.
The authority secured a 20-year loan for the full $7.5 million cost of the conversion project.
“In addition, the byproduct from the “egg” is methane and hydrogen sulfide,” Kerr said. “The byproduct from the aerobic system will simply be carbon dioxide.”