State plans large grouting project to stabilize voids under Bunting Park

Don Newton, administrator of the Abandoned Mine Land Division at the Wyoming Department of Environmental Quality, told the Rock Springs City Council that the agency will perform a large grouting project to fill undermining beneath Bunting Park and nearby streets beginning after Labor Day 2025.

The work is aimed at increasing public safety by filling underground voids that in places are as shallow as about 30 feet; the AML Division estimated roughly 35,000 cubic yards of grout will be used overall, with about 12,000 cubic yards in the park itself. AML representatives said the park work is scheduled to run through mid‑November 2025 with a winter shutdown and to resume in spring 2026 so the park can be available by Memorial Day 2026.

The project matters because portions of the former mine workings beneath the park and surrounding streets are shallow and fractured, creating a risk of ground collapse. “Our number one priority is increasing public safety,” Richard McPeek, AML grouting project manager, told the council. He said the southeast portions of the undermining are “as low as 30, really 50 to 75 feet,” while other parts are deeper.

AML described the scope and methods: a program of drill‑holes spaced roughly 35 feet apart, geophysical logging of holes to detect fracturing, and monitoring with ground‑movement sensors capable of detecting movements down to one‑hundredth of a foot. The team plans to angle‑drill from streets where possible to avoid tree root systems; the agency has contracted an arborist to help site drill holes and, where needed, will pothole beneath trees to inspect roots before drilling. “A lot of the holes we will angle drill in from the street to avoid any damage in the park,” McPeek said.

AML proposed a roughly 485‑day contract interval for the work. The agency expects to begin after Labor Day 2025, work in the park through about Nov. 15, 2025, pause for winter, then resume in 2026 to complete the park and then move to perimeter streets (Evans Street, J Street, K Street, Noble Drive) and two city lots adjacent to those roads.

Mayor Max Mickelson and council members asked technical questions about grout routing and how AML will direct grout within mine openings; AML said they prefer to use gravity and generally follow downslope directions but will rely on geophysical logs to determine fracturing and grout placement. AML also said it will use grout‑volume and ground‑motion monitoring during injection to reduce the risk of unintended ground movement.

AML said it will conduct public outreach including press releases (for example, Sweetwater Now), signs in the park, and an on‑site public outreach session where residents can ask questions. “This is the opportunity we have with so many people here to start our public outreach for the project,” Don Newton said.

Council members and the mayor expressed appreciation for AML’s tree‑protection measures and for limiting full‑park closures. AML stated it will stage work in targeted areas so the park remains usable to the public in other portions during the work.

The council did not take a formal vote on the presentation; AML requested the public’s patience and said contracting and scheduling remain subject to the agency’s procurement and contracting timelines.

For information about public outreach and scheduled meetings, AML said it will post notices and hold a park outreach session before major work begins.