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Larenn:o G.:r.~wr Stine - Sur,~~,'e «',;:rr rrrn¢cr.[ Report <br />Surface water sampling was initiated in January. 1996, a[ eleven stream monitoring sites. nine <br />springs and ten ponds. The stream stations are located on Lorencito Canvon. Jeff Canvon. <br />Puerteci[o Canyon, Chimney Canyon, Alamosa Canvon and Cow Canyon. Monitoring sites were <br />placed to characterize flows and water quality above andlor below projected disturbances. Flow <br />information collected during baseline is summarized in Table SW-~ and all data from the stations <br />is summarized in Appendix S`V-2. Hydrographs of spring flows are included in Appendix S~V-3. <br />Mater Quality <br />Applicable standards for [he Lorenci[o Canyon Mine are se[ forth by [he Colorado Department of <br />Public Health and Environment, Water Quality Control Commission document Classifications and <br />Numeric Standards for Arkansas River Basin (3.2.01, effective August 30. 1995. Receiving <br />stream standards from Region 7, Lower Arkansas River Basin. Stream Segment ~a were utilized. <br />These standards refer to the Mainstem of the Purgatoire River and the Ivliddle Fork of the <br />Purgatoire from the USGS gage at Stonewall to Interstate 2~. Standards included physical. <br />biological, inorganic, and metals. Each of these standards is compared to the analytical data <br />determined during the baseline monitoring period. <br />Surface Water Stations <br />Data was collected from each of the surface water stations and springs during the 1996 baseline <br />monitoring period. Each of the stations and springs were monitored monthly for field parameters <br />during this period and each quarter samples were obtained from the site for laboratory analyses. <br />A summary table showing the results from all the surface water and spring locations is included <br />in Appendix SW-3. <br />Results from the surface water laboratory analyses was interpreted through the use of Piper and <br />Stiff diagrams. These diagrams indicate principal cation and anion milliequivalents per liter and <br />are useful for determining water type. Copies of these diagrams are included in Appendix SW-5. <br />The principal water type in the surface waters is acalcium-sodium bicarbonate type. This water <br />is typically neutral [o partially alkaline, with low hardness, and low to moderate salinity. pH <br />ranges from 6.1~ to 8.79, and hardness ranges from 111 mg/L to 213 me/L. Total dissolved <br />solids in the samples ranged from ~0 - 650 mg/L (filterable residue). <br />The Colorado Department of Health. Water Quality Control Commission has assigned a "use <br />protection designation to the tributaries of the Purgatoire. and classified it for cold water aquatic <br />life, secondary recreation and agriculture. There are only three receiving stream physical <br />standards: dissolved oxygen: pH: and fecal coliforms. Fur metals standards. the table value <br />standards were calculated. To determine the table value standards, a hardness of 71 mg1L was <br />utilized. This value represents the lowest hardness measured at the site (site .4C-1): therefore, the <br />• standards are considered conservative. In addition. sodium absorption ratios (SARs) were <br />compared to the Mined Land Reclamation Standards Division Procedures for [he Assessment of <br />... ,;;..pt«.;,,,,~. ~. ~~~~ 16 (revised 6/30/971 <br />