Oregon DEQ eases methane-related precautions for Millpond Crossing residents

The Oregon Department of Environmental Quality this week rescinded recommended precautions for Millpond Crossing residents, a list that had advised no open flames, use of power tools, wood and charcoal fires, smoking or cutting grass with electric- or gas-powered lawn mowers.

The state agency advised the Philomath subdivision’s residents in August 2021 to implement those safety measures during the early stages of a methane investigation in consultation with Oregon Health Authority and Philomath Fire & Rescue.

“… Based on additional methane monitoring data, DEQ, OHA and Philomath Fire have reassessed the potential risk from these outdoor activities and are no longer advising homeowners to avoid them,” the agency said through the release of an updated fact sheet. “The safety precautions may be updated again as site investigations and gas monitoring continue.”

Millpond Crossing is being constructed north of Chapel Drive and east of South 15th Street at a former mill site, which operated from 1955 to 1998.

MPC Builders has constructed 61 homes with plans for a future mix of single-family residences and townhomes along with a neighborhood park. Existing homes were equipped with mitigation features, such as vents and fans to help prevent the accumulation of biogases, and methane alarms.

The developer submitted a preliminary methane remedial investigation report to DEQ last summer. The document summarized the environmental investigations that had taken place on the property since June 2020. Oregon DEQ also reported that MPC Builders had submitted work plans for approval, including, a plan for screening and monitoring existing homes, a methane mitigation plan for new home development, plans for utility retrofitting and methane mitigation, a targeted soil gas investigation for two areas with elevated methane, a work plan for a source removal and a contractor’s health and safety plan.

“To date, sustained levels of methane or other biogases of concern have not been detected beneath homes,” the report states. “The monitoring events will continue until at least the fall of 2023.”

MPC Builders plans to build a website for residents to access that provides real-time monitoring results after testing has been completed.

“We believe we have made great progress in the last 24 months on assessing the risks of the methane, preparing contingency mitigation plans and addressing the numerous issues DEQ has posed about site conditions,” MPC Builders wrote in a March 3 email to residents.

MPC Builders said it has spent just over $2 million on direct methane costs, including engineering controls, source removal, testing, design work, planning, additional studies and DEQ oversight costs. In addition, the company says another $1.5 million has been spent on indirect costs related to the methane.

The developer received funds through a Business Oregon brownfield loan in December and began a targeted investigation of two areas near existing homes with elevated biogas readings in soil. In May, MPC Builders will reportedly implement a pilot study to assess the effectiveness of additional remedial measures that may be needed to reduce risk to the existing homes from methane and other biogases in soil.

The developer said that while a large portion of the direct costs were funded by a brownfield loan, it is “personally guaranteed to be paid back by MPC and its owner, Levi Miller, and through the sale proceeds of new homes.”

MPC Builders started construction on homes on the east side of South 16th Street between Timothy Street and Chapel Drive following source removal plans and home mitigation designs that were approved on Oct. 7 by DEQ.

“This work has proven successful in removing buried organic source material,” the DEQ report stated. “It is anticipated that removal of this material will reduce biogas generation. MPC has planned additional biogas source material removal in 2023, as development activities progress.”

The city issued a stop order on Nov. 7 to correct a Phase 2B grading plan and also outlined requirements related to safety and other work that needed to be done. The developer said in its March 3 letter to residents that it had complied with the city’s requirements but voluntarily stopped working at the sites on Nov. 2.

The developer and city disagreed on various issues and a meeting occurred just this Wednesday that involved MPC Builders, city and county officials, attorneys and the company providing environmental consulting.

“The meeting included a very productive discussion about the project as a whole and specifically about the final grade elevations for the undeveloped portion once all the organic material is removed over the coming months,” MPC Builders wrote in its letter to residents.

According to the developer, several decisions were settled upon involving lot-line adjustments, stormwater trenching, flood plain elevations and producing a schedule for the city on the timing of completing construction activities.

The developer said it is “100% committed to the completion and full development” of the Millpond Crossing subdivision.