Page 13 - HMCSocialResponsibility

WATER & AIR PROTECTION AND ENHANCEMENT
We work hard to protect water quality and to conserve usage through e cient operations, engineering, and training. Both Lucky Friday and Greens Creek must meet rigorous federal and state water quality standards, which are monitored through meticulous water quality analyses and in-stream biodiversity sampling.
ENERGY CONSERVATION In the remote locations
where Hecla operates, energy conservation is not just good for the environment, it’s good business. At Greens Creek, the mine provided its local utility with justi cation for an expansion of hydropower capability, essentially eliminating the seasonal diesel generation necessary to supply Juneau’s electric demands. Since then, Greens Creek’s use of lower-cost interruptible hydropower has increased from 14% in 2007 to 86% in 2010. Energy-e cient lighting upgrades during 2010 and planned for 2011 will save Greens Creek over 1.3 million kWh of power annually and the lights will last 5-10 times as long.
WASTE REDUCTION Waste management is a challenge for all mining operations. Mineral waste includes rock from mining activities and mill tailings; non-mineral waste includes batteries, light bulbs, paper, lubricants, solvents, used oil, used coolants, and scrap metal, which are recycled to the extent practicable.
At Lucky Friday, approximately half of the mill tailings are mixed with cement and pumped back into the underground workings as paste back ll, providing structural support while reducing the surface land required for disposal. Development rock from the mining cycle is used as a source of construction material.
Greens Creek manages development rock by sorting it by its acid- generating and acid-neutralizing potential. Rock with the greatest potential for acid generation is contained underground. Greens Creek also places half of its tailings underground for structural support, with the remainder going into a contained surface disposal facility.
In the remote locations where Hecla operates, energy conservation is not just good for the environment, it’s good business.
Lucky Friday implemented water treatment improvements that dramatically reduced lead and zinc in the discharge by 84% and 92%, respectively, over the past three years. Conservation measures are incorporated in operations planning, such as the closed-loop chilling system associated with the new #4 Sha project that, when operational, will reduce water used for underground temperature control by up to 75%. Lucky Friday’s air emissions are below federal and state thresholds and are considered an insigni cant source not requiring an operating permit.
At Greens Creek, all mine water and water used in the milling process is treated in water treatment plants and then released into Hawk Inlet under strict discharge permit limits. Air emissions, regulated through State of Alaska permits, are well within permitting thresholds.
Tailings impoundment reclamation activity at Grouse Creek, central Idaho.
11 Hecla Mining Company