Challenge

For more than 20 years, the owners of the Marigold Mine have relied on our team to support the safe, efficient expansion and operation of critical mining infrastructure. As the site evolved, the client needed integrated civil, geotechnical, and water infrastructure solutions that would support new facilities, manage stormwater, optimize heap leach operations, and maintain regulatory compliance throughout multiple phases of development.

Solution

Our multidisciplinary engineers provided comprehensive planning, design, permitting, construction support, and quality assurance services across the mine. We designed the septic system and waterline extension for the new Access Building, including field percolation and mantle testing, septic tank and leach field sizing, utility layout, construction documents, permitting, construction observation, and as-built documentation.

To protect site infrastructure, we designed two riprap-lined trapezoidal stormwater diversion channels capable of conveying peak runoff flows. Our team also delivered geotechnical characterization, engineering design, construction documentation, and construction quality assurance (CQA) for more than 300 acres of heap leach facility expansions, process ponds, and a tailings storage facility, including closure planning. Throughout the engagement, we collaborated closely with the client to optimize heap leach pad designs in response to changing operational priorities and market conditions.

Results

Our long-standing partnership has helped the Marigold Mine develop and maintain reliable infrastructure that supports safe operations, regulatory compliance, and continued production. By combining civil, geotechnical, hydrologic, and construction engineering expertise, we delivered practical, adaptable solutions that improved site performance while providing the flexibility to respond to evolving operational needs over more than two decades.

Mining operations are constantly evolving, and engineering solutions need to evolve with them. We work alongside our clients to develop practical, technically sound infrastructure that performs today while adapting to tomorrow’s operational challenges—helping projects move forward safely, efficiently, and with confidence.

- Jason Heffner, PE - Project Manager