Tanker trucks will begin hauling away a few million gallons of sludge from Middletown’s Frog Hollow wastewater treatment facility early next month.

Tanker trucks will begin hauling away a few million gallons of sludge from Middletown’s Frog Hollow wastewater treatment facility early next month.

Middletown Town Council on Monday unanimously approved a contract with Synagro Central of Baltimore to conduct the town’s first sludge removal operation since the wastewater lagoon came online in 1998.

“Residents won’t smell a thing and the traffic impact should be minimal,” Mayor Kenneth Branner said of the roughly month-long sludge removal and disposal project that’s slated to begin around Oct. 1. “This is a normal part of operating wastewater lagoons and the fact that we haven’t had to do it in 15 years means the operation is working effectively.”

Town Public Works Director Wayne Kersey estimates about two million gallons of the mostly non-organic, semi-solid material – commonly referred to as sludge – has built up on the bottom of the Frog Hollow facility’s 5.5 million gallon main intake lagoon with depths reaching 8 feet in some places.

“It’s not human waste, like most people probably think of when you say sludge,” he said. “All that organic material has been removed by bacteria used specifically for that purpose and this is just the by-product that’s left over. It’s mostly plastics, sand, dead bacteria and other debris that can’t be broken down. Over time it builds up and reduces the efficiency of the treatment process.”

During the removal process, the sludge at the bottom of the lagoon will be vacuumed into hoses that will carry the material a few hundred feet to tanker trucks stationed at the Frog Hollow Golf Course maintenance building off Cedar Lane Road.

Once fully loaded, each truck will then transport the material about four miles to a 90-acre portion of a town-owned property off Green Giant Road known as the Ford Farm.

There, the sludge will be mixed with agricultural lime to kill any remaining pathogens before being injected about 6 to 8 inches into the ground, according to town officials.

“We have to follow very strict guidelines set out in our DNREC permit that sets the limits on how much material can be injected per square acre,” Branner said.  “The state will then inspect what we’re doing to be sure it meets those requirements.”

The Frog Hollow treatment plant typically accepts about 250,000 gallons of sewage per day from neighborhoods in the northeast section of town.

During the sludge removal process, about 210,000 gallons of that daily intake will be diverted to the town’s much larger treatment facility off of Industrial Drive. The remaining 40,000 gallons per day will continue to be treated at the Frog Hollow facility.

The sludge removal and disposal contract approved by town council on Monday will be billed on a per gallon basis, with the total cost estimated at about $262,000.

The town also has hired Rohm & Associates of Greenwood to act as a consultant on the project, although the exact price tag of that bill also won’t be known until work is complete.

“Since this is the first time we’ve gone through this process, we wanted to have someone working with us to make sure it’s all done correctly and everything goes smoothly,” Kersey said.

It could be a quite few years before the town has to undertake a sludge removal project again.

The Frog Hollow treatment facility shouldn’t require a second sludge for another 20 years, while the 13-year-old, 2.5-million-gallon Industrial Drive facility won’t be due for at least that long, if not more, Kersey said.