WILMINGTON - On a 3 to 2 vote this week, the Board of Selectmen accepted an intermunicipal agreement with Woburn, which would allow for the construction of a pipeline to permanently connect Wilmington to the Massachusetts Water Resources Authority (MWRA).

Discussion centered around the proposed route of the pipeline, approximately 3,500 feet of which will travel through Woburn's Industri-plex Superfund Site.

Within the Superfund site, approximately 650 feet of the pipeline will travel through a "clean corridor" of soil located on top of a "geotextile" covering placed above highly contaminated soils.

The perimeters of Woburn's 245-acre Industri-plex Superfund Site, which has been remediated and redeveloped, includes a Target department store, Marriott Residence Inns, Petco, Starbucks, Raytheon, and the Anderson Regional Transportation Center.

According to Anthony Zuena, President of SEA Consultants, Inc.; the engineering firm overseeing for the project, only clean soil is expected to be encountered during construction.

However, in the unlikely event that contaminated soils are discovered, they would be carted off the site and replaced with clean soil.

"There will be no contaminated soils bedding the pipeline," Zuena told selectmen.

SEA worked with Wilmington, Woburn, the Environmental Protection Agency (EPA), and the Industri-plex Trusts throughout the two-year period in which six possible pipeline routes in Woburn and Reading were evaluated.

In rating the alternatives, SEA evaluated technical feasibility, cost, and environmental impacts. Selectmen were assured that cost was not a determining factor over safety.

Selectmen Michael McCoy and Suzanne Sullivan were not ready, however, to condone a pipeline routed through a designated Superfund site. Sullivan stated that areas of the site had become re-contaminated - particularly in the vicinity of North Pond. She also expressed concern that the geotextile covering on top of the contaminated soils, which she estimated having a life of only 35 years, may eventually need to be replaced.

Zuena explained that, despite a possible misperception of the purpose of a geotextile covering, it is not an impermeable membrane like those used to cover some solid waste sites. A geotextile covering is a fabric that allows water to flow through and is used, primarily, as a demarcation.

"There is no driving force for contaminants to migrate upwards," Zuena said.

Furthermore, replacing the geotextile covering would not be a consideration, as it would necessitate the demolition of all the buildings, parking lots, and infrastructure on the entire site.

Michael Woods, Wilmington Water & Sewer Superintendent, stated that there would be virtually no way for contamination to enter into a pipeline with 90 to 100 pounds per square inch of constant water pressure.

"Pipelines all over the country and this state are running through contamination and there is no migration into the pipes," Woods said. "These pipes generate a large amount of pressure - materials migrate out, not in."

All appropriate safeguards, according to Zuena, will be put into place. Pipes passing over Class C/D soils will be constructed with restrained joints. Even if the pipe were ever to experience a break, sensors would recognize a sudden decrease in pressure and would isolate the area. The affected area of pipe would be drained, cleaned, and tested before bringing it back online.

Chairman Raymond Lepore pointed to the fact that the installation of Wilmington's connecting pipeline would not be a pioneering venture - there are currently water mains servicing all of the buildings currently on the site.

"We're just going parallel to the existing infrastructure," Lepore remarked.

Selectman Michael Newhouse supported moving forward and accepting the intermunicipal agreement.

"It is essential for the Town of Wilmington to move forward in finding an adequate supply of safe drinking water for the residents," Newhouse said. "I am prepared to rely on the qualified experts that we've hired to determine the best route."

McCoy and Sullivan were also concerned with the costs associated with the construction of the pipeline. Several years ago, Olin Corporation agreed to pay $3 million worth of construction costs associated with the project.

The estimated costs have gone up since that agreement was reached and are now estimated at between $4.2 million and $4.5 million.

According to Woods and Town Manager Michael Caira, Olin has verbally agreed to cover the increased costs as recently as this past Friday. A written agreement to that effect is being put together.

"Verbal agreements mean nothing to me," McCoy said.

Woods pointed out that the intermunicipal agreement itself did not obligate the town to any costs, but would simply enable Wilmington to put the project out to bid.

Additionally, McCoy stated that the taxpayers should not foot the bill for a membership to MWRA, which could run $9 million.

Woods and Caira do expect Olin to fund a large portion of that membership and that there have been preliminary discussions with Olin about it.

"We can't get to the next step without getting past this one," Caira said. "I would urge the Board to take the step that it can now, so that we can move toward the next step."

Lepore, Newhouse, and Selectman Charles Fiore voted in favor of the intermunicipal agreement; McCoy and Sullivan voted against.

With the agreement signed, Wilmington will obtain street opening permits from Woburn in July and will put the project out to bid in August.

The project will likely be awarded to a contractor in September with construction beginning in October. The project is expected to take nine months, and, with a planned winter shutdown, should be completed by October 2007.

The move toward MWRA as a supplemental water source, contrary to popular belief, did not begin with the closing of five of Wilmington's nine wells.

The Town first identified such a need in1996. The services of SEA Consultants were engaged from 2001 to 2003 to identify pipeline routes.

Upon the February 2003 discovery of N-nitrosodimethylamine (NDMA) in the Maple Meadow Brook Aquifer, SEA began designing the emergency pipeline connection to the MWRA as a permanent connection.