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COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT -Water Quality Control Division <br />Rationale -Page 3 Permit No. COR-040000 <br />IV. STORMWATER DISCHARGES ASSOCIATED WITH MINING OPERATIONS <br />The stormwater regulations require that stormwater discharges associated with certain industrial activities be covered <br />under the permit program. Mining operations are specifically included in the listed industrial activities. This general <br />permit is intended to cover stormwater discharges from most active and inaaive metal mines. It is also intended to cover <br />stormwater discharges from mines (e.g., coal mines) which have individual CDPS permits for discharge of process <br />waters. <br />A. Types of Sites Covered <br />This permit is intended to authorize most new and existing discharges composed entirely of storrnwater from mining <br />operations that are within Standard Industrial Classification (SIC) Code 10 -Metal Mining and Milling, at sites <br />that discharge stormwater only. This category includes active and inactive mining and milling operations, and <br />remediation projects at such sites. <br />This permit is intended to cover those portions of a metal mining or milling site that are not already subject to <br />effluent limitations under 40 CFR 440. Those previously uncontrolled areas which discharge stormwater that <br />comes in comact with overburden, raw material, intermediate products, byproducts, finished products ar waste <br />products may be covered by this permit. Division policy number WQP-17 describes the difference between <br />stormwater and process water at a mine site. <br />This permit may also be used to cover existing discharges composed entirely of stormwater from any other metal or <br />coal mining operations that are currently covered by an individual CDPS permits for discharge of process water. <br />At the time of reissuance or amendment of the individual CDPS permit, terms and limitation from both permits may <br />be combined into a new individual permit. Table 1 presems the categories of the mining industry and their CDPS <br />Stormwater permit coverage. <br />The Division intends to continue its practice to cover only one area with each permit certification. As long as the <br />operations or inactive mines are contiguous, one permit certiftcation is sufficient. However, if a mine-waste <br />remediation plan calls for removal of material and disposal at a location away from the mine-waste site, separate <br />permit coverage must be obtained for the disposal sire. <br />B. Mine-Waste Remediation Projects <br />This permit is intended to authorize mast siormwater discharges from mine-waste remediation projects. There are <br />numerous inactive mine sites located throughout the State that may undergo remediation operations to reduce <br />impacts to water quality, to relieve the obligation for permit coverage, or to return land to a differem land use. <br />These types of sites and their stormwater discharges were not specifically addressed in the preceding version of this <br />permit: This permit has been revised to address the special considerations of these types of operations. This <br />permit now contains additional SWMP requiremems for remediation projects. These are detailed at Pan 1. C of the <br />permit, and summarized at VLB.2 below. The Division foresees three general cases where permittees will use these <br />provisions: <br />Inactive mine sites where the permittee begins a remediation project in order to terminate coverage under an <br />existing. In this case, the permittee will amend their SWMP to address the remediation concerns as outlined <br />in Part I.C.S of the permit, and proceed with remediation. Certification under this permit would be <br />terminated when the termination criteria and other conditions listed at Part I.F of the permit are met. <br />2. Inactive mine sites where no previous stormwater permit coverage exists, and the owner or a third parry (with <br />permission of the owner) plans to remediate the site. In this case, the SWMP would be prepared, including <br />the items in Part I. C.5 of the permit, and the owner or third parry would submit the completed permit <br />application. After the permit certification is issued, stormwater discharges from the remediation project <br />would be authorized. Certification under this permit would be terminated when the termination criteria and <br />other conditions listed at Part !.F of the permit are met. <br />