REP49895 - Laserfiche WebLink

Home Browse Search

The one Grassy Creek alluvial well upstream of Seneca II (71) also displays high • values. It should be noted that, while the CDOH uses a standard of 0.2 mg/1, the EPA states that this standard is used to protect trope grown in soils with a i yH value lower than 6.0. Ia soils with a higher pH (ae are found is the Seneca II region), a m0=e appropriate ataadard mould be 10 mg/1 (EPA, 1976). This year, none of the Seneca SI alluvial malls displayed a value higher than 7.12 mg/1, sad ao spoil wells displayed a valve higher then 1.01 mg/1. Finally, water quality analyses performed oa samples obtained at the Seneca II shop well (STCS) for this year were compared against both human health (mandatory) and eecoadaxy (i.e., recommended but not mandatory) drinking water standards developed for ground water by the CDOH. No human health standards were exceeded. The CDOH secondary standard for aulfnte, 250 mg/1, was exceeded twice with values of 430 and 420 mg/1. Wall STC9 bee historically exhibited sulfate concentrations higher than the secondary drinking water standard for this Dnrameter. The CDOH secondary standard for iron, 0.3 mg/1, was exceeded once with a value of 0.63 mg/1. However, bottled water ie eoasumed at Seneca II. • Ground water Quality Summary. TDS values at ten out o£ the nineteen walla sampled the year displayed increasing TD9 treads. TD9 treads nt ell other wells were either stable or Sacreasiag. CDOH agricultural ground water atandarde for pH, fluoride, iron, and manganese were exceeded at certain monitoring walla. Noa-CDOH recommended standards for suliatea and TDS were also exceeded. Ia the area surrounding Seneca Ii, ground watez is not being pumped for irrigation or livestock watering Duryoaee, nor hee the CDOH clesaif ied any aquifer is this region £or any vas. The above diecuaeioa is provided only to serve as a comparative basis to judge ground mater quality. Domestic wells that Drovida drinking water for local residents are not from aquifers impacted by mining. Surface Water Table 7 lists pertinent information on all NPDES, stream, sad spring monitoring sites at Che Seneca II Mine. A complete description of the surface water monitoring program may be found oa Pages 7-336 to 7-355 of the Seneca II PAP, • and is summarized on pages 7-349/350. This program was revised in January 2000 10