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'* t <br />• <br />Letter to Evan Freirich -2- Aoril 23. 1996 <br />meets the agricultural standards for all parameters analyzed with the <br />exception of Selenium, which exceeded the agricultural standard by only <br />.009 mg/L. It is the Division's position that process water which meets <br />the agricultural standards is acceptable for land application, and that <br />even process water that exceeds agricultural standards may be acceptable <br />with certain limitations. Please note that the Division has required COM, <br />Inc. to sample and analyze Hazel-A water once per week during the time <br />period that the land application system is in operation. The results of <br />these analyses will allow the quality of the land applied water to be <br />tracked, and this tracking will be used to curtail any unacceptable <br />contamination of topsoil or ground cover. <br />3. In addition, what will be the affects on air quality as a result of <br />evapotranspiration? If you cannot drink it, won't land application risk <br />worker, wildlife and public inhalation? <br />Division Response: Any water evaporated or evapotranspirated from the <br />land application site will be free of metals because of the inability of <br />water vapor to transport metals. Based on the analytical results from the <br />single sample of Hazel-A water currently available, the mist that will be <br />produced at the land application site will not pose an inhalation hazard. <br />Based on the single sample of Hazel-A water analyzed to date, this water <br />exceeds drinking water standards for manganese and iron. The drinking <br />water standards for these metals were not established based on any direct <br />hazard to human health, but rather to avoid, in household water use, <br />problems associated with precipitates and stains that form because the <br />oxides of these metals are relatively insoluble. The Hazel-A water <br />analysis also exceeds human health standards for mercury and selenium. <br />This water would pose a health hazard if a person were to ingest 2 <br />litersl of this water per day over an extended period of time, but does <br />not pose an inhalation hazard at the Gold Hill Mill land application site. <br />Please note that land application at the Gold Hill Mill is only proposed <br />as a mechanism to maintain a negative site water balance during the period <br />of spring runoff, and that spray evaporation within the confines of the <br />lined tailing pond is to be used as the priority process water disposal <br />method, with land application held in reserve as a contingency measure to <br />prevent an unpermitted discharge to Cash Gulch. <br />4. Should not the water discharged from the Hazel A meet the same <br />standards as the water in the tailings pond? <br />Diviaioa Response: No standards have been established for either the pond <br />water or the Hazel-A water. The Gold Hill Mill is permitted as a zero- <br />discharge facility, and must maintain a negative water balance regardless <br />of the quality of the process waters. <br />1 2 liters per day over a lifetime exposure is the ingestion rate <br />used in establishing maximum contaminant levels protective of human <br />health. <br />