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7. Comment: Page 16, Paragraph 10 and Appendix A, Attachment 1:Monitoring <br /> detection limits set within the Consent Decree are fine. However, additional reference <br /> should be made to monitoring methods approved in 40 CFR Part 136. <br /> Response: As required by the Colorado Discharge Permit System Regulations, 6.1.0 <br /> (5 CCR 1002-2), the permits included in Appendix C contain the reference to <br /> analytical methods approved in 40 CFR Part 136. The Consent Decree contains <br /> actual detection limits which are extremely low and more specific that the methods <br /> contained in 40 CFR part 136. The WQCD believes that these limits provide an <br /> appropriate level of data quality control. <br /> Comment. Furthermore, diel (24-hour),fluctuations inflow and concentrations <br /> observed in the stakeholders sampling efforts make it difficult to compare data taken <br /> at different times of day within the Animas Basin. Therefore, we recommend that <br /> Appendix A, attachment I have time of day references and that all future sampling be <br /> taken within similar time frames, particularly during runoff periods. <br /> Response: The reference data set is made up of individual observations taken over a <br /> number of years without regard to diel fluctuations. The Division does not agree that <br /> there should be strict time-of-day limitations on data collection efforts within the <br /> Consent Decree. Comparison of a highly controlled data set with one that did not <br /> have those controls would introduce confounding and confusing factors for the <br /> analysis. There also maybe access and safety concerns for sampling during some <br /> seasons and times of day. <br /> 8. Comment: Page 17, Paragraph 10.a. (iii): The Consent Decree requires monthly <br /> sampling of the American Tunnel Treatment Facility Effluent. Is this the same <br /> location as outfall 004A specified in the permit? If so, it should so indicate. <br /> Response: Yes, the monthly sampling of the American Tunnel Treatment Facility <br /> Effluent is the same location as outfall 004 specified in the permit. The Consent <br /> Decree has been clarified. <br /> 9. Comment. Pages 17 and 18, Paragraph 10.b.: The sampling at the four mines <br /> identified in this section must include flow measurements in order to determine if the <br /> plugging has resulted in loading changes. <br /> Response: A commitment to carry out flow monitoring is included in each of the <br /> Work Plans for the four mentioned mines. <br /> Comment: The monitoring requirements of the MLR Permit should also be <br /> mentioned. <br /> Response: The Consent Decree already states in paragraph 10 that "[t]he monitoring <br /> 6 <br />