TIVERTON — While lawyers work on a potential settlement in a federal lawsuit brought by residents seeking remediation of contaminated soil on their properties, a parallel administrative case at the state Department of Environmental Management remains in limbo.

The administrative action crawled to a halt late last fall, as the DEM anticipated a pretrial ruling by U.S. District Senior Judge Ernest C. Torres in the residents’ federal case.

Those homeowners in the Bay Street neighborhood of North Tiverton have asked the court to order the Texas-based utility Southern Union to clean up toxic wastes in about 100 properties covering 50 acres.

In late January, Torres sent the DEM’s chief legal counsel a letter in which he said he wanted to ensure that the agency “is not under the mistaken impression that it is under any obligation to refrain from pursuing whatever course of action it deems appropriate to remediate the Tiverton site as expeditiously as possible.”

“On the contrary,” Torres told the DEM’s in-house lawyer, Patty Alison Fairweather, “I would encourage DEM to take whatever steps it considers necessary to effect prompt remediation.”

Through a spokeswoman, DEM Director W. Michael Sullivan declined any direct comment on Torres’ January letter, or the status of the DEM case in light of the potential court settlement, which was sealed by the judge last week.

Earlier this month, Sullivan confirmed that Fairweather has left the agency, saying the parting was a mutual decision.

Fairweather had been involved in several controversies during the last few years, including the hiring of a Washington law firm to buttress her own staff in the Tiverton case. The outside firm has billed the state a total of $1.2 million in fees that were not budgeted, although much of that money has been paid through available funds.

Torres placed his letter to Fairweather on the public record Jan. 24.

Nearly a week later, he rejected an argument by Southern Union that the residents could not obtain relief from their situation by appealing to the court because soil remediation fell under the exclusive purview of DEM.

The next day, Jan. 31, Torres invited DEM to participate in mediation that was hoped would resolve the contamination dispute.

The administrative proceedings were halted pending the outcome of the mediation which DEM hoped would also resolve its enforcement action against Southern Union.

The mediation was unsuccessful, but meanwhile, lawyers arrived at a conditional settlement last Tuesday in the resident’s case, the day before jury selection was to begin in the federal trail.

The stay in the DEM case expired April 19. The hearing officer, Kathleen Lanphear, has indicated she would entertain another 30-day extension in the stay, but as of Friday, such a request had not been made.

gmacris@projo.com