The new public toilets currently under construction on Tillson Avenue in Rockland are scheduled to open June 30. Located one block from Main Street on the route of the city Harbor Trail, the New England-style building will be heated for free, using heat generated as a byproduct of the nearby wastewater treatment plant.

"Right now, we are throwing that heat away," said Terry Pinto, director of the Rockland Wastewater Treatment plant.

Rockland's waste is treated by microorganisms that require temperatures between 40 and 56 degrees to live, so the water coming out of the plant reaches those temperatures, at a minimum. Added to that, nearby FMC, which processes seaweed, releases 100-degree wastewater that must be cooled in order to not kill the microorganisms at the plant. The result is that the treatment plant is essentially a big georthermal system that is not being utilized for heat. Currently, the value of available heat that is discharged annually from the treatment plant is equal to approximately 7,500 barrels of oil, with a retail value of approximately $1.9 million, according to Pinto.

The public restroom building will have an in-floor heating system, with the outside entryway also heated to keep it free of ice and snow in the winter, said Pinto.The heat-pump system design could also be used for cooling in summer.

"It won't cost any money to heat it," said Pinto, noting that the amount of heat that is generated at the plant and not currently captured could heat and cool every building on one side of Main Street from Tillson Avenue to the ferry terminal.

Using the excess heat at the public toilets will also add to the quality of wastewater treatment at the plant, said Pinto.