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<br />Comments by Harry Posey <br />1. There needs to be a sampling point on the Rito Seco downstream of the tailings <br />impoundment. The present RS-5 point is in a dry alluvial valley and ylields no water. <br />The proposed sampling point would need to be outside the permit boundary. I <br />recommend a point just downstream of where the light duty road cro9ses the stream <br />as shown on Figure 1 in the Protocol Proposal. <br />2. Although many monitor wells have been installed, only three routinely yield water <br />enough for sampling: M-4 and M-10 on the Rito Seco, and M-9 west of the tailings <br />impoundment area. Although M-9 is apparently downgradient of the tailings ponds, <br />M-4 and M-10 are also down gradient of the tailings. Whether a leak from the <br />tailings would flow toward the north (toward M-4 and M-10) or whether it would <br />flow toward the west (toward M-9), or whether it would flow in odher directions <br />cannot be determined either from the permit or from the Monitpring Protocol <br />Proposal. <br />The April 1992 NOV abatement plan calls for sampling M-2, M-6, M~7, M-8 and M- <br />9. However, because M-2, 6, 7, and 8 are dry, and because we do not know the <br />specific flow path from the tailings area to the Rito Seco, there should be more <br />sampling. Therefore, M-4, M-10, and RS-4 should be routinely sarripled until the <br />hydrologic gradient is established and until other down-gradient monitor wells are <br />installed. <br />3. Chain of custody should begin with the commercial laboratory that prepares the <br />sample containers for field sampling personnel. Third party samplens and vendors <br />should supply all collection devices, sample containers, and reagents ihtcluding wash <br />solutions. <br />4. Free cyanide in the form of cyanide gas is, of course, a hazard to breathing, <br />particularly in closed spaces. According to MSHA personnel, in some settings, wind <br />may cause high concentrations of cyanide gas to be introduced to persgns or animals. <br />However, in many outdoor settings, the gas may be dispersed to a level that would <br />be considered non-toxic. <br />Free cyanide in solution or any of the weak acid dissociable cyanide compounds may <br />also be hazardous if consumed. Animals, in particular, need to be protected from <br />the hazards of drinking water containing HCN. <br />Battle Mountain has raised the issue of the difficulty of analyzing foa free cyanide, <br />and although we have yet to receive real proof of the accuracy of theee statements, <br />the Division is inclined to believe that the statements bear some con6ideration. <br />