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conditions "in which reclamation is seasoned and in equilibrium." We agree that <br />there would be inconsistencies in data collected during mining compared to <br />predictions for the postmining conditions described. Please provide the Division <br />with an updated statement of probable hydrologic consequences which gives <br />predictions for TDS levels in ground and surface water for both long term and <br />short term to reflect and predict the current TDS levels observed at the mine <br />from 1985 to present. Long term predictions should be based on post mining <br />equilibrium conditions, and short term predictions should encompass the current <br />permit term (through 1996). <br />i. Statement 2 discusses the "annual average" term used in the original PHC. We <br />agree that an annual average should include data from an entire year, or should <br />be alternately labeled. P&M should update the predicted "annual average" to <br />exclude the winter months during which no sampling occurs. It may also be <br />appropriate to label the average accordingly. <br />2.a. The Division requested that P&M clarify whether electrical conductivity readings are <br />corrected for temperature. Your November 13, 1992 letter stated that specific <br />conductivity readings are corrected to 25 degrees Celsius, and electrical conductivity <br />readings are not corrected for temperature. Electrical conductivities should either be <br />corrected for temperature, or the temperature at which the conductivity was recorded <br />should be included in the monitoring results. An explanation of how these values are <br />reported should be included in the permit application, on Page 4.6-143. <br />b. The Division also requested that P&M clarify how TDS numbers for both surface and <br />alluvial well water samples were derived. The response in P&M's November 13, 1992 <br />letter should be included in Section 4.6 and in Appendix 2.5-A of the permit application. <br />c. The Division asked P&M to explain TDS values in excess of conductivity values, or <br />remove the equation on page 4.6-142a of the permit and correct any calculated TDS <br />values which have been derived using that equation. Your letter stated that since faulty <br />instruments were used for measurements, the TDS values could not be corrected. <br />Please include in Appendix 2.5-A, then, a brief history of the use of equations to derive <br />TDS levels from conductivity readings. Please also label the values on the charts of <br />Pages 2.5-A-13 and 2.5-A-14 as to which method (equation 2.5-95, equation 4.6-142a, or <br />laboratory analysis) was used to get each listed value. <br />3.a. The commitment to obtain valid flow data at TR-b, and the proposed methods for <br />ensuring the data be obtained aze adequate. <br />b. In order to verify the accuracy of TDS data, the Division also requests that the cation <br />Potassium be included in the analysis. An anion/cation balance should also be included <br />in the analysis, at least until such time that it can be demonstrated to the Division that <br />Susan Hoffineister 3 January 04, 1993 <br />