SWANSEA — To doubters, the notion of building the Northeast’s first desalinization plant here might have seemed a pipe dream. But this month, pipes went into the ground.

The pipes, about 700 feet of a system planned to eventually extend two miles, will run to the plant slated to be built in the Vinnicum Road area. The Swansea Water District, with persistent water-supply problems, backed desalinization (or desalination, as some call it), and this year ratepayers authorized borrowing a combined $18 million through a state revolving fund to build the plant and related facilities.

Robert Marquis, the Water District superintendent, said the district has applied for four needed permits and perhaps meet a September 2008 construction date.

One is a permit to allow discharge — salty water — from the desalinization plant. Another permit is a water-quality certificate, which the state Department of Environmental Protection weighs whether to grant. There is a “Section 4040” permit, under the Army Corps of Engineers’ purview, which determines that an intake system for the desalinization plant will not interfere with navigating a water way. And there is the “Chapter 91” permit, through the state Department of Environmental Protection, which allows the building of the desalinization intake system along the river bottom.

Marquis said project design, by Virginia-based HDR Engineering, is about 75-percent complete. In February, he expects bids will be sought to choose a company to build the project.

Marquis also said that he testified this month before the Department of Environmental Protection and came away assured the $18 million in state revolving funds is slotted for Swansea’s project.

“The DEP has committed to [financing] the total project cost of $18 million,” Marquis said.

The state revolving fund — through the state Water Pollution Abatement Trust — receives a sum from the federal government to cover projects in the state. It uses a low 2-percent interest rate, and Marquis said that would bring savings over the life of the 20-year borrowing.