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{Vert EIk .Nine The discharge water was then mixed with the North Fork Upper water and compared to the suspect levels (Table 66). A11 of the mixed concentrations were well below the respective suspect levels. In addition. the mired concenhations were consisrent with the downstream North Fork water quality, thereby- confirming the methodology. There were several metals that sere not sampled for in the discharge water. Since none of the metals was detected in the upstream or downstream North Fork samples, the concentration of the metals in the dischazge water, if present, was determined to be very loco. Fttrdtermare, the detection levels in the downstream sample were all well below the respective suspect levels. NNE performed the same evaluation using a discharge rate of 2.0 cfs for the l~1\VT'F. This rate is considered to be the maximum rate that could be sustained Cor significant periods of time. Table 66 presen[s the results oC[his mixing zone ana[;5is. All of the mixed concentratiots are below the respective suspect levels for this scenario as well. \Vhile these analyses were performed considering short-term potential impacts, the evaluation could also be considered aworst-case scenario for long-[elm eftects. Based on this evaluation; the discharge of mine water to the North Fork will not adversely affect the use of the water by downstream agricultttral users. 1VWE has reviewed the salinity (I'DS) loading anah•sis in the 2001 Cumulative Hydrologic Impacts Analysis (CI-IIA) for the North Fork in the contest of 14fCC's 1996 discharges. In the CHIA, CDMG calculated the cumulative TDS (salinity) loading to the North Fork from coal mines located in the north Fork valley. The assumptions used for diCC's contribution were a discharge rate of 5,520 gpm (12.3 cfs) and a TDS concentration of 2,500 mglL. W\V~ has updated the evaluation of the salinity loading based on the TDS concentrations and flow rates shown in Table 66. Using the TDS concentration of 3;200 nr~/L and aflow- rate of 400 gpm (0.89 cfs), the salinity loading to the \orth Fork is 2,300 tons per year. Urine the maximum sustained flow- rate of 900 gpm (2.0 cfs); the salinity- loading to the North Fork is 6,300 tons per }-ear. Both loading rates are well below the value assumed in the CPIIA for \Vest Elk i4line. The sewage collected from the site will be domestic in nature and will consist of soluble B.O.D., volatile suspended solids, and inert solids, which will 6e treated using biological organisms to aerobically stabilize the waste. Since biological treatment will be ttsed, with no chemical treatment required, there should be no secondary by-products ufiich would not be similar to those existing in the North Fork of the Gunnison. The effluent from the treatment unit has the following characteristics: Soluble B.O.D. 1 b mg1L Suspended Solids B.O.D. 14 m 30 mg/[: Suspended Solids 30 mef L. Ammonia (NH}) 1.0 mg/L Nitrate (NO3) 29 mgrl, Combined Chlorine Residual 0.1 mg/L Fecal Colifonns 10,000/100m1 1.0670 Rnkt0lunt:005 PRIG; Rev. IfnrcA?006