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In TRIM <br />COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division <br />Fact Sheet- Page 22, Permit No. C00000906 <br />Outfalls 007, 008, and 010: a qualitative monitoring determination was made because the outfalls convey <br />surface flow from the active mining area. The treatment provided by sedimentation ponds approved under <br />the SMCRA authority are not expressly designed for all pollutants regulated under the WQCA, including <br />metals removal, and for outfall 010, no treatment technology is implemented. A semi-annual monitoring <br />requirement has been added to the permit for these outfalls for the collection of data to support future RP <br />determinations. <br />Boron <br />Outfall 001: A quantitative RP analysis was conducted for outfall 001 based on facility data and the WQBEL <br />and ADBAC as calculated in the WQA. The MEPC was greater than the MAPC and therefore limitations are <br />required. A 30 -day average and 2 -year average requirement is included in the permit. This is a new <br />limitation, and previous monitoring indicates that the permittee may not be able to consistently meet the <br />limitation for the 30 -day average; therefore, a compliance schedule with interim limits based on <br />monitoring data (the highest actual 30 -day average) was added to the permit. <br />Outfalls 007, 008, and 010: A qualitative monitoring determination was made based on the presence of <br />boron in the discharge from outfall 001 at levels that resulted in permit limitations for outfall. The <br />treatment provided by sedimentation ponds approved under the SMCRA authority are not expressly <br />designed for all pollutants regulated under the WQCA, including metals removal, and for outfall 010, no <br />treatment technology is implemented. A quarterly monitoring requirement has been added to the permit <br />for these outfalls for the collection of data to support future RP determinations. <br />Chloride <br />Outfalls 001 007, 008 and 010: there are no data available regarding the presence/ absence or <br />quantification of this parameter in the discharge. Although chloride is not included in the list of pollutants <br />in the ELG Development Document, TDS is included in the list. Dissolved solids are composed of many <br />constituents, including chloride. Additionally, monitoring data for EC indicate the facility at times has <br />elevated levels of EC, which can include chloride. A quarterly monitoring requirement is included in the <br />permit for collection of data to support future RP determinations. <br />Sulfide <br />Outfall 001: there are no data available regarding the presence/ absence or quantification of this <br />parameter in the discharge. Sulfide compounds can form as a result of coal mining operations. A quarterly <br />monitoring requirement is included in the permit for collection of data to support future RP <br />determinations. <br />Outfalls 007, 008 and 010: a qualitative determination of no RP has been made as sulfide is not identified <br />in the ELG Development Document. <br />Temperature <br />Outfall 001: there are no data available regarding the effluent temperature at outfall 001. Pond 001 <br />receives mine water from relatively shallow depths which is not expected to differ significantly from the <br />receiving stream. However, the pond liner is black which has the potential to absorb heat and increase the <br />temperature of the discharge. A monitoring requirement is included in the permit to collect data for a RP <br />analysis. A delayed effective date for temperature monitoring is included in the permit to allow the <br />facility time to install appropriate temperature monitoring equipment. <br />Outfalls 007, 008 and 010: outfalls 007, 008 and 010 transmit stormwater and ponds 007 and 008 are <br />unlined; therefore, the temperature of these discharges is not expected to differ significantly from the <br />receiving stream, and temperature monitoring is not necessary at this time. <br />Electrical Conductivity (EC) <br />Outfall 001: the MEPC is greater than the MAPC and therefore limitations are required. A 30 -day average <br />Limitation is included in the permit for outfall 001. This limitation is more stringent than the previous permit <br />limit of 3 dS/m and the permittee may not be able to consistently meet the limitation. Therefore, a <br />compliance schedule with an interim limit from the previous permit is included in the permit for outfall 001. <br />