The primary digester at Corry's wastewater treatment plant was recently cleaned out and two methane cannons were brought back into working order.
A problem arose when the methane cannons stopped firing, which called for a complete clean out. The digester was emptied of about 350,000 gallons of sewage so the methane cannons could be accessed for possible repairs.
The clean out costs were $29,575.26 and include everything associated with cleaning out the digester material — supplies, pumps, chemicals, equipment, labor and dewatering bags, which double the holding capacity of a standard drying bed.
Compared to the estimate of $269,500 the city received three years ago from Agri-Sludge Inc., of Shreve, Ohio, to clean out both digesters, doing the job in-house saved a lot and allowed the city to purchase equipment to clean out digesters in the future.
"The methane cannons were completely full and not functional, but they did get it all cleaned out," Corry Public Works Department Lead Operator Mark Leofsky said.
It was plugged with rags, rock hard solids of compressed sand and human hair. Treatment plant employees had to use chisels and hammers on the buildup of materials to break them apart.
It took a day, once chiseling started, to break apart all materials and get both cannons cleaned out.
Once the plug was cleared, the cannons were found to be still in working order and no further repairs were needed.
The primary digester is getting filled up again with waste and once it reaches a certain level, the methane cannons will be refired.
Going forward, city officials plan to have both the primary and the secondary digesters cleaned out on a rotating schedule of every two to four years.
The cannons in the primary digester could be turned back on as soon as today, Leofsky said.