Laserfiche WebLink
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division <br />Rationale - Page 8. Permit No. CO-0042161 <br />DISCUSSION: (Cont.) <br />I. Additional Monitoring (Cont.) <br />This other facility has had difficulty in the past in meeting the limits <br />for manganese. Although the one sample result submitted from the Foidel <br />Creek Mine for this parameter (see Appendix B) does not indicate any <br />problems, the data is not based on actual treated effluent from the new <br />pond, and so is not an accurate reflection of the final discharge. <br />Therefore, the permittee will be required to perform three sets of <br />additional analyses for manganese. If the data indicates a potential <br />problem, then the Division reserves the right to reopen the permit to <br />incorporate additional monitoring and/or limits as needed. (See Part <br />I.B.12 of the permit.) <br />J. Dissolved Metals <br />As of July 31, 1988, changes to the Basic Standards and Methodologies for <br />Surface Water became effective. As part of these changes, the <br />establishment of in-stream standards for metals will be based on a <br />hardness-dependent equation. In many cases, "dissolved" standards will be <br />applied rather than "total recoverable." The changes to the system will <br />• be instituted on a case-by-case basis, or else as river basin triennial <br />reviews are held. The permittee is advised that these changes could <br />result in changes in the limitations for this permit in the future. <br />In addition, the Water Quality Control Commission has determined that, in <br />translating these new standards into permit requirements, the calculated <br />limitations will be "potentially dissolved" rather than "dissolver <br />To facilitate the drafting of a new permit, as well as to establish the <br />facility's ability to meet new numbers, it is suggested that the permittee <br />begin periodic monitoring of its effluent and the receiving stream for <br />applicable dissolved and potentially dissolved metals (i.e., iron), as <br />well as for hardness. This data will prove useful to the permittee in <br />subsequent stream standard hearings, as well as in the development of <br />appropriate permit limitations. <br />K. Flocculants <br />The permittee has indicated on their application that they might use a <br />flocculant to treat the discharge, if necessary. The proposed 1locculant <br />is Nalco Enact 7883, an aluminum sulfate compound. This permit allows the <br />use of this chemical, providing that it is not applied in toxic amounts. <br />However, if the permittee plans to use any other chemical treatment, <br />including other flocculants, that would fall under the Change in Discharge <br />provision (Part II.A.1 of the permit), and will necessitate Division <br />^otification and approval. In addition, each such notification shall <br />• include the Material Safety Data Sheet for each compound. <br />