Portsmouth officials have approved authorizing a $75 million bond toward an $83 million plan to upgrade the existing Peirce Island wastewater plant.
The city council voted on Monday to pass the resolution. The vote had been delayed after residents spoke out against building the new plant at the city-owned island.
Residents had asked the council to consider building a new plant at the Pease International Tradeport. But officials said Peirce Island was the only "viable" location.
Officials say the city wants the $75 million authorization to pay for the plant out of the state's revolving fund loan program, which would be a 20-year term at 2.5 percent.
Officials announced earlier this month they reached a deal with the Environmental Protection Agency to build a new plant and reduce nitrogen discharge.