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<br />' anaiysis. Can these su]fate data be considered representative? <br />Response: As noted on the top of each batch test result sheet in Appendix <br />F, the batch tests used hydrochloric acid not sulfuric acid. <br />L <br /> <br /> <br />I~ <br />1 <br /> <br /> <br />I~ <br /> <br /> <br /> <br /> <br />~~ <br /> <br /> <br />Corrected tailings test data sheets inserted in Appendix F. <br />22. Results for cyanide analysis indicate free cyanide to be greater than <br />total cyanide for Tai]ings Sample Number 1. Please exp)ain or correct. <br />Response: The reading is correct as written. We believe that the slightly <br />higher level of free cyanide measured is within the laboratory <br />error for the test. <br />No application change necessary. <br />23. On Page D-3T, the statement is made that the tests showed that the <br />tailings exhibit low potential for acid production with almost no acid <br />neutralization potential. The lab reports in Appendix F indicate a <br />significant potential for acid production and excess of acid-producing <br />potential over neutralization potential. The preliminary results from <br />the humidity-cell test indicate acid production to be evident.. Please <br />provide the final humidity cell test data, and please describe <br />mitigation measures proposed to limit the possible adverse impacts of <br />acidic ]eachate from the tailings. <br />Response: The preliminary humidity cell data submitted in the permit <br />application indicated no acid production. The final humidity cell <br />data confirmed that there is no potential for acid generation <br />from the tailings material. The final humidity cell data is now <br />available and included in revised Appendix F. <br />From the acidificationf neutralization test data the tailings <br />could appear to have some potential for acid generation, with low <br />acid neutralizing potential, assuming that the total pyritic <br />sulfur is, in fact, reactive. However, pyritic sulfur is not <br />necessarily 100% reactive and a peroxide oxidizable sulfur test <br />was performed on the tailings material to attempt to determine <br />the amount of pyritic sulfur which is reactive. Peroxide <br />oxidizable values are only about 35% of the total sulf"ur acid <br />producing potential. The peroxide oxidizable values of 26.3 and <br />24.4 tons CaC03 per K-Ton are not significant, but do represent <br />a potential for acid production, so BMR initiated a humidity cell <br />test on the tailings material. <br />We are unsure why the Division believes that the preliminary <br />humidity cell data submitted in the permit application shows acid <br />production to be evident. In spite of some sulfate generation, <br />pH's remained near neutral, dissolved iron remained below <br />detection limits and acidity actually decreased in the third <br />week. The final humidity cell data included in revised Appendix <br />F indicates no acid production. <br />Final humidity cell data added 2/15/89. <br />L <br />