By SHERRY VAN ARSDALL
THE GOSHEN NEWS
Two blue domes at the Goshen Wastewater Treatment Plant can be seen from a distance while venturing down Wilden Avenue.
They are membrane covers to capture and store methane gas that is produced during the digestion process for sewer sludge, said Maintenance Manager Bob Elliott.
There are two digesters that take raw sewage and put it through a process referred to as anaerobic digestion. One digester is bigger than the other and needs more power for the process, Elliott added.
“The end product is treated sludge (biosolids) ready to be land applied,” said Assistant Maintenance Manager Charlie Riggs. “The final product goes out to a lagoon, which can hold 1.5 million gallons, and sent out twice a year to be put in fields for fertilizer.”
Microorganisms break down biodegradable material in the absence of oxygen to produce energy.
The two digesters can store up to 833,000 gallons, which calculates to nearly two months of holding time for proper pathogen reduction of the sludge.
There are pipelines upon pipelines within the buildings for the heat exchangers, boilers, sludge, water, natural gas and methane gas. The red lines are for natural gas and the orange lines are for methane gas, Riggs added.
“All in-house repairs are done by us,” Riggs said.
Elliott said the cost for both of the blue domes was approximately $1 million.
“The boilers run off the methane gas and we heat just the facility here in winter,” Elliott said.
The facility is located on the north side of Goshen along the Elkhart River.