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1.0 InWduction <br />The United States Geological Survey (USGS) monitored the flow of the Middle Fork of the Purgatoire at <br />Stonewall (07124050), approximately four miles upstream from the New Elk Mine, from May 1978 to <br />September 1981. The Purgatoire River at Madrid (07124200), approximately 15 miles downstream of the <br />Golden Eagle Mine, has been monitored since 1972. The size of the drainage area above the Stonewall station <br />is 52.1 square miles (miZ). There are some diversions for irrigation above the station. Recorded discharges <br />during the three-and-a-half year period ranged from 2.8 cfs to 522 cfs (USGS, Water Resources Division, <br />1982). The size of the drainage area above the Madrid station is 505 miz. There are diversions for irrigation <br />for about 6,000 acres upstream of the Madrid station. The average annual discharge between 1972 and 1995 at <br />Madrid was 71.4 cfs and the average annual runoff was 51,740 ac ft (Crowfoot et al, 1996). The annual runoff <br />in the Purgatoire is dominated by snowmelt, with peak flows occurring in May and June. Summer and fall <br />thunderstorms generally produce smaller peaks of short duration. <br />1.2 MONITORING PROGRAM <br />Monitoring programs have been conducted since February 1984 to assess the effects of past, present, and <br />future mining operations on surface and groundwater quality and quantity. These programs provide <br />information to Basin and to regulatory agencies such as the Colorado Division of Minerals and Geology <br />(CDMG). CDMG programs are designed to monitor past and present, and to anticipate future, effects of <br />mining and reclamation activities on the hydrologic regime of the area. <br />The monitoring program has undergone several revisions. As a result of site reclamation and Phase II bond <br />release, the monitoring program was reduced (Technical Revision 54) to those stations and parameters <br />presented in Tables 1.2-1 and 1.2-2. The following aze descriptions of the current sampling stations, their <br />locations, and their purpose. These stations are shown in Maps 7A and 7B, Regional Hydrology (see Permit <br />Document). <br />1.2.1. Springs and Seeps <br />The spring and seep stations have been eliminated from the monitoring program. <br />1.2.2. Surface Water (streams and rivers) <br />All surface water stations have been eliminated from the monitoring program. <br />292-34 Golden Eagle Mine Rpt (32.05).doc 1-4 <br />