A Pennsylvania environmental board has essentially scrapped two state actions that would have paved the way for developer Brian O’Neill to build housing on a contaminated Chester County site.

The ruling on Friday appears to be a major setback for Constitution Drive Partners, a limited partnership involving O’Neill. The company wants to build housing at the defunct Bishop Tube site, contaminated by a variety of hazardous compounds.

The Pennsylvania Environmental Hearing Board concluded that amendments to an agreement with the developer stretching back to 2007 and 2010 not only are “arbitrary and capricious, ” but also “are void."

“This is yet another environmental David and Goliath story,” said Maya van Rossum, leader of the Delaware Riverkeeper Network.

The Delaware Riverkeeper Network filed a legal challenge to the amendments granted by the state Department of Environmental Protection. The amendments would have allowed Constitution Drive Partners to develop the 13.7-acre Bishop Tube site on Malin Road in Frazer, East Whiteland Township, after some cleanup.

Bishop Tube Site in Chester County

Bishop Tube was a manufacturing operation that began in the 1950s and left behind hazardous substances, including trichloroethene or TCE, in the process of making stainless steel and other metals into tubes and pipes. The DEP collected evidence that TCE permeated soil and groundwater in the mid-1960s. Monitoring wells have also found levels of fluoride, chromium, and nickel that exceeded standards. Other chemicals have also been detected at the site.

The property is listed as a hazardous site under the state’s Hazardous Sites Cleanup Act.

Constitution Drive Partners did not pollute the site. Rather, it purchased it from the Central and Western Chester County Industrial Development Authority as part of a brownfield redevelopment plan.

Representatives for O’Neill Properties Group could not be reached immediately to comment.

Elizabeth Rementer, a spokesperson for the DEP, said the agency is still reviewing the decision and determining next steps.

On Friday, the board agreed with the environmentalists that the two amendments to an initial agreement with Constitution Drive Partners to clean up and develop the site were not properly executed because two key factors never spelled out to the public had changed.

The board said the DEP failed to inform the public that technology installed to control air and soil pollution at the site had been damaged and never repaired. Nor did it announce that the site’s zoning had been changed from commercial to residential after the initial agreement. The environmental board also took the DEP to task for an “egregiously late public notice” made years after the facts emerged.

The board said it did not “wish to erect unnecessary barriers to cleaning up a site or discourage innocent purchasers from contributing to cleaning up and redeveloping contaminated property.” In its response to the board during the appeal, the DEP blamed part of its failure on administrative oversight.

The Environmental Hearing Board, though not part of the judicial branch of state government, operates as a court. It was set up for people and corporations to appeal DEP actions. It is composed of five administrative law judges.

Even East Whiteland officials, who approved the residential zoning change in 2014, questioned why the change had been left out of the amendments.

“As DEP is aware, the proposed use of the site is now residential,” East Whiteland officials wrote. “How will DEP address this change of use at the site within the context of the existing [agreement], which was based upon a non-residential use of the site?” The officials noted that residential use requires “more stringent remediation standards.”

Nevertheless, the DEP approved both amendments and never mentioned the zoning change.

Relations between the Delaware Riverkeeper Network and O’Neill have grown rancorous over the years. O’Neill sued the nonprofit network in a case that was eventually dismissed.

The Riverkeeper Network’s mission is to protect the Delaware River Watershed, meaning all the land and waterways that ultimately feed into the river. Bishop Tube is bordered by Little Valley Creek, part of the watershed.

The Riverkeeper Network has also filed separate legal action against the DEP over the cleanup and believes the site still poses a health risk.