c 



urrent Reclamation Efforts and water 

 Quality Status . 



With the exception of Swift Gulch, the DEQ believes that the surface and ground 

 water resources in the area are being protected by the current and proposed mine 

 reclamation and water treatment efforts. The purpose of the mine reclamation is 

 spelled out in the SEIS and in the Record of Decision. Essentially, the reclamation of 

 the mines has two primary components, both intended to address the protection of 

 surface and ground water quality. The first is the physical reclamation of the mine 

 pits, roads, waste rock dumps, and leach pads. This effort is designed to improve the 

 long-term stability of mine excavation features, isolate and cover acid-producing 

 materials, provide for proper drainage, reduce infiltration by precipitation and runoff, 

 reestablish vegetation, and improve aesthetics. The second effort is to capture and 

 treat surface and shallow ground water and leach pad drainage until contaminants can 

 be reduced to acceptable levels. The magnitude and duration of the water treatment 

 effort is largely dependent on the success of the land reclamation effort. But in no 

 case short of the physical encapsulation of the mine facilities will the need for long- 

 term water treatment be unnecessary. 



The mine operations, particularly the larger and deeper Landusky mine, exposed 

 sulfide rock that produces acid rock drainage when it is exposed to air and water. This 

 acid rock drainage, or ARD, in the presence of the exposed surfaces of mineralized 

 rocks, can mobilize metals in the rock and contaminate surface and ground water. 

 The reclamation plans focus on identifying the sources of acid-generating materials 

 and isolating them from surface and ground water infiltration to control the source of 

 contaminated water and reduce the amount that needs to be treated. 



Before the 1998 bankruptcy and in partial fulfillment of the requirements of the 

 Consent Decree, Pegasus was required to capture all surface and shallow ground 

 water at each discharge and construct a water treatment plant at each mine. Buried 

 capture systems collect water from beneath the leach pads and below the waste rock 

 dumps before it flows offsite and routes it to either the water treatment plant at the 

 Zortman mine or the one at Landusky. These plants use lime to treat the acidity and 

 precipitate metals out of the water collected by the capture systems. Since 1999, 

 these plants have captured and treated over a billion gallons of mine drainage." 



17 



