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I `~ the use ct ±he truck wash facilities. Surface water quality varied depending on the proximity of the sampl iriy point to mining and the amount of dilution occurring in the receiving tributaries. In the Grassy Creek drainage, NPDES Sites 002 and 003 showed very slight to slight TDS increases, respectively in comparison to the historic record (refer to table 17 ). the significance of. these slight TD5 increases to the receiving tributaries was urimeasurablc as surface water sites SW-52-2 and SN'-52-5 showed drops in mea r. TDS values for 1986. Surface water Site SW-S2-1, which measures upstream background water chemistry on Crassy Creek, showed a mean TDS increase of 32 mg/1 (refer to Table 18). One-half mile downstream of Site SW-52-1 on Grassy Creek, surface water Site SW-52-2 showed a mean TDS drop of 400 mg/1. Surface rvater monitoring at the furthest downgradient site (SW-52-2) indicates that discharges from the Seneca II Mine are not diminishing the water quality for any appreciable distance and are in no way precluding the use of the water as livestock drinking water. Mean TDS levels at NPDES Site 004 increased approximately 400 mg/1. TDS levels measured at Site SVi-52-6 below the 004 site on Cow Camp Creek showed a similar increase (refer to Tables 17 and 19). This would be expected as ai most all the flow in Cow Camp Creek at this point is from the 004 pond. Surface water monitoring in bond Creek nas initiated in 1986. This site, located below the OG7 pond which was completed during the fall of 1966, will be used to provide future impact assessments to the Bond Creek drainaoe as mining progresses updrainage from this site and the 007 and proposed 008 pends. Both Cow Camp and Bond Creeks are tributary to Fish Creek. The monitori no sites on these tributaries are app roxi na tely four to five miles upstream of the confluences of these tributaries with Fish Creek. The impacts of higher TDS runoff from the mined area appears to be of negligible significance to the Hater uses and quality in the tributaries and Fish Creek. During the low flow sunener season, flows from the NPDES ponds completely infiltrate into the tributary al 7uvial aquifer systems or are impounded in a series of stock ponds along the tributaries above (heir confluences. During the high flow spring runoff period, flows are so diluted that chemical contributions from the mined areas are of no consequence. The mine discharges are in no way precluding the water use (livestock water) along the tr+o tributaries. The portion of the mine di sefiarges that reaches Fish Creek during the higher flow periods does not inhibit the irrigation or other agricultural uses of Fish Creek water. 54