3M Company (3M) is a Fortune 500 manufacturing company with corporate operations in 70 countries. Historically a mining company, 3M has evolved to an innovative science and technology manufacturing company responsible for more than 60,000 commonly used products for industries, hospitals, schools, businesses and homes.

For the last nine years, ECT has provided environmental assessment and permitting services to support 3M’s expansion of the Pittsboro Mine in Moncure, North Carolina. Current operations at the Pittsboro Mine involve extracting a green-colored andesite mineral from the quarry, then crushing and processing it for use in the roofing industry. Overburden and off-specification rock, considered unsuitable for commercial use, are stored in stockpiles onsite. The mine expansion, which will occur entirely within the 3M 2,200-acre property, will expand the quarry by approximately 180 acres to the north and extend the fines stockpile by approximately 174 acres to the east and north of the previous fines storage area.

Our team secured the necessary 404/401 permits from the U.S. Army Corps of Engineers (USACE) and the North Carolina Division of Water Resources (DWR) for the mine expansion in 2017 and conducted the required environmental assessment of nearly 800 acres. The approved expansion is ongoing and expected to cover 20 years. The mine permit is active until 2027.

In 2021 ECT updated 3M’s Spill Prevention, Control, and Countermeasure (SPCC) and Stormwater Pollution Prevention Plan (SWPPP) plans and assisted with a revised mine permit application for changes to stormwater control features on the mine property. Our team currently supports 3M’s mine through stormwater sampling, and survey services for various activities such as modifications to the perimeter berm and the stormwater basin.

To date, ECT has provided 3M with the following services to support the mine expansion:

• Hosted numerous meetings on behalf of 3M with the governing agencies, including the DWR; North Carolina Department of Energy, Minerals, and Land Resources; the USACE, and Chatham County.
• Deployed several wetland delineation teams that concurrently assessed threatened and endangered (T/E) species’ critical habitat.
• Assisted 3M with designing the layout of the mine expansion based on the field assessments.
• Oversaw a cultural resources survey conducted by a subcontractor.
• Oversaw the development of a subsurface study to design wet detention ponds.
• Developed an alternatives analysis, consistent with National Environmental Policy Act guidelines, as part of the wetland permitting process.
• Conducted nutrient modeling, as required by DWR.
• Secured a buffer impact variance from Chatham County.
• Developed a stormwater management plan and operations and maintenance plan for the facility, and secured a stormwater permit from Chatham County.
• Submitted a mine permit modification application.