Company officials said general contractor Schmueser and Associates will oversee construction projects including access road construction and plant upgrades for the Johnson mine camp. Some changes for the process facilities include enhanced controls and instrumentation, new rectifiers, increased solution heating capacity and other modifications to ensure a Grade A, 99.999% pure copper cathode.

The firm will also be handling the mine's pipeline distribution and infrastructure, a project that will involve a two-mile-long high-density polyethylene (HDPE) pipeline corridor to transport solution to the JCM processing facilities, and electrical distribution and infrastructure upgrades that will bring electrical distribution to the wellfield.

Also on the construction agenda: process pond upgrades and completions, with additional pregnant leach solution (PLS) capacity planned for operational flexibility, and new acid storage facilities to help Excelsior take advantage of market acid pricing opportunities.

Finally, Gunnison will see upgrades to its wellfield drilling and infrastructure for maximum operational flexibility.

Excelsior's partner Hydro Resources is drilling its production wellfield as well as compliance wells; a trio of drilling rigs is already on-site and two more will arrive next month. With 63 wells total (41 production and 22 compliance), the goal is to ensure groundwater protection.

"Our ability to move quickly from the close of project financing to the initiation of construction at our Gunnison copper project is a demonstration of the operational capacity and experience of the Excelsior team," president and CEO Stephen Twyerould said.

The 100%-owned Gunnison project, located in Cochise County southeast of Tuscon, has a 24-year mine life and is projected to produce 2.2 million pounds (997.9 kilograms) of pure copper cathode.