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above the old tailings and any other confounding sources (except those to the north of <br /> the Animas River). <br /> A downstream surface water monitoring site is proposed in the Animas River adjacent <br /> to groundwater well 10. This site will monitor downstream water characteristics, and <br /> will allow comparison with the mid-site station above the old tailings. This site is <br /> located above the CDMG suggested downstream sample site (24). Based on <br /> observations of additional confounding surfaces water sources and influences not <br /> attributable to the mill, site 24 was dismissed as non-representative. <br /> Monitoring Frequency <br /> Surface water will be monitored on a quarterly basis with one sample from each <br /> monitoring location being collected and analyzed once per calendar quarter. An <br /> attempt will be made to sample during high flow conditions (spring runoff) and low <br /> flow conditions (late summer) during the year. Quarterly sampling is proposed for one <br /> year (four quarters) after which it will be reduced to semi-annual sampling, once during <br /> high flow and once during low flow. <br /> Sampling Parameters <br /> The following parameters will be sampled and analyzed for each surface water sample <br /> during the first year: <br /> pH Electrical Conductivity Total Suspended Solids <br /> Major cations Alkalinity Total Dissolved Solids <br /> Major anions Hardness WAD CN <br /> SO4 Chloride Nitrate <br /> Nitrite Ammonia Aluminum <br /> Arsenic Barium Boron <br /> Cadmium Chromium Iron <br /> Lead Manganese Mercury <br /> Molybdenum Nickel Selenium <br /> Silver Sodium Zinc <br /> After completion of the first four quarters of sampling, the chemical analysis list will <br /> be modified to best reflect those constituents that characterize the source and movement <br /> of contaminants attributable to the mill. <br /> Analysis will be undertaken by a competent laboratory which is familiar with analysis <br /> for the above constituents. Analysis methods and detection limits will be in accordance <br /> with industry and regulatory agency standards. <br /> -2- <br />