Remediation of the former Upjohn site took another step forward Aug. 4 with a public hearing regarding Pfizer’s proposed cleanup efforts.

Held at the North Haven High School auditorium, Wednesday’s meeting included representatives from Pfizer, which now has ownership and legal responsibility for the polluted 78-acre property at 41 Stiles Lane, as well as officials from the state Department of Environmental Protection (DEP), the U.S. Environmental Protection Agency (EPA), and North Haven Town Hall.

Public comment was positive and constructive.

“For all of us that lived through the enormous exposure from the Upjohn plant in air and water, it is a pleasure tonight to see the government working with the town,” said resident Nancy Alderman, president of local non-profit Environment and Human Health Inc. “It’s looking like we’re really going to get this solved.”

Alderman was referring to well-documented contamination at 41 Stiles Lane, which has a long history of use by various chemical companies. Obtained by Pfizer from Pharmacia Corporation in 2003, the site was occupied until 1996 by Upjohn, which produced products used in pharmaceuticals, herbicides and photographic chemicals.

Past businesses also aided spoilage. A 19th century brickyard mined the site’s subterranean clay. As environmental understanding and laws were then limited, several subsequent chemical plants released copious contaminants and carcinogens into the soil, which was more susceptible to pervasive pollution because of its depleted clay.

Complicating contamination matters, 41 Stiles Lane abuts the Quinnipiac River.

In 1995, a citizens’ panel was formed to help guide remediation efforts. Additionally, $25 million was spent on 200-plus studies of the soil, groundwater and human and environmental health concerns.

From these measures Pfizer formed five clean-up plans, settling on a potential procedure estimated to cost $140 million and stretch into 2017.

The property’s most contaminated area, an acre significantly polluted 20-28 feet below the surface, will be addressed with thermal desorption. A series of thermal wells would be drilled and heated to between 200 and 600 degrees Fahrenheit, vaporizing and drawing out contaminates, so that pollutants can be destroyed at the surface.

Moreover, a cutoff wall would be implanted around the wells to contain cleaning processes. Pfizer officials estimate such activity will take 12-18 months.

Two other significantly polluted areas, sludge piles on the southern and northern ends, would be capped, being too contaminated for remediation and posing a substantial risk to workers and environmental surroundings. An impermeable cap would be placed around the piles, followed by clean soil and vegetation.

Further sections would also be capped, while others are capable of being completely cleaned. Other land would be dredged and excavated. To impede pollutants from entering the Quinnipiac, water elevations would be kept lower then the neighboring river.

According to a Pfizer video shown Aug. 4, nine areas at the former Upjohn property require corrective measures.

Commercial and residential development would be allowed on 17 western acres. Many remaining acres would be ecologically converted into tidal marshes, inland wetlands and upland meadows for passive use by prior arrangement, including bird-watching and hiking.

Speaking at Wednesday’s meeting, Martin Mador, member of the Quinnipiac River Watershed Association, favored open, unimpeded public use of the property.

“[Public use] could evolve over time,” replied Robert O’Meara, Pfizer project manager. “We are starting out with limited access because we don’t want all-terrain vehicles, or where people misuse the land. We’re looking to preserve the remedy.”

“The land use could evolve, but up here today, I can’t make that promise,” he added. “I need to consult with my management.”

Mador’s other concerns included whether dredging would conflict with fish-spawning seasons, the construction of kayak launch sites, whether paths built on-site could connect with a proposed Quinnipiac linear trail, transparency of all remediation operations, and whether Pfizer had sufficient funds to complete all proposals.

Mike Taylor, president of Vita Nuova, a company hired to construct digital grids of the site, pointed out that Pfizer was legally required, and fully insured, to fund and finish site remediation.

David Monz, chairman of the citizen’s advisory panel, endorsed Pfizer’s intentions, which he said satisfactorily considered protection of human health and environment.

“Although we didn’t always see eye-to-eye with Pfizer, they have always kept the panel fully aware of all methods and technologies employed,” Monz added. “In our opinion, the corrective measures will be successful because of the transparency and candor of Pfizer’s representatives.”

The meeting concluded a 45-day public comment period before Pfizer officially submits its clean-up plans to the state DEP and U.S. EPA. If authorized by state and federal organizations, Pfizer would then submit intentions to the town for final approval.

Pfizer also operates a cleansing facility at 41 Stiles Lane which was originally erected by Upjohn in 1995. Water is collected by 17 pumps spread over the site. As the tide rises in the Quinnipiac, pumps are shut off to avoid importing freshwater.

Pfizer’s plant routes waters through an intricate cleaning process, in which fluids are stripped of larger sediments, doused with peroxide, and sent through ultra-violet lights that activate peroxide to break off and destroy microscopic contaminated particles. Waters are then cleansed of peroxide, sent through monitoring instruments, and discharged into the Quinnipiac.

All remediation plans are available for public viewing at North Haven’s Memorial Library.