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COLORADO DEPARTMENT OF HEALTH, Water Quality Comrol Division Rationale -Page S. Permit No. COG-500000 V. TERMS AND CONDITIONS OF PERMIT respectisrly, in order to determine compliance with the limits. Since the 7S5 monitoring frequency is momhly, a 7SS limit of 60 mg// was added so that rompliana rou[d be determined based on one sample. The Division has amended the definitions jot a 30 day outrage or 7 day average, to be determined by the arithmetic mean of aU samples rollected during a 30 day or 7 day period. Therefore, the need jot a daily maximum TSS limit has been eliminated, and so is not included in this renewal permit. The other 7SS limits shall remain the same, jot the applicable categories. c. Phosphorus: The previous permit included Phosphorus (PJ monitoring for the Dillon Reservoir drainage area only. This has been changed to also include Cherry Creek Eosin, Bear Creek basin and those state waters Mburary to Chatfield Resmnir downstream of the USGS gags at Waterton and on Plum Creek. These segmems alJ have or will have P limits on discharges. In general, the types ofjacilities rovered under this permit are not espected to Rase problems with P; however, monitoring will be required on a quarterly basis for all proses water discharges to there basins. /f the data indicate any potemial problems with P levels at a specific farility, then art individual permit with P limits may be required for. that facility. d. Cmphite: /n the case ojgraphire mining, the federal e~luem guidelines (40 CFR 436.382) cal! for a limit jot Total /ton. Since the Di~uian has Water Quality Standards in many areas of the state which may be stricter than the federal limits, rosrragc ojprocrss water discharges from this type of facility must be under an individual permit. B. Stormwtuer Ducharees Starmwater vs. Process water When stormwater mizrs with proress water, the process water limitations (Part LB of the permit) apply to the discharge ojthat mi.ced water. The stormwmer section (Part T.C ojthe permit) is intended to cover those portions of a nonmetallic minerals production operation (escrpr fuel) shat arc not already subject to ejJluem limitations under 40 CFR 436, and to rom stormwater runoff from asphalt and concrete batch plants. 2. Srnnnxarer Mnnnrement Plan /SWMPI The stormwater regulations primarily apply ro areas not covered by 40 CFR Part 436. They require permiaees to develop and implemem a Stormwmer Managemem Plan (SWMP) to protect the quality of stormwater leaving the sire. The plan shall idemijy potemial sources ajpollution including sedimemJ which may reasonably be e_spected ro affect the quality of stormwarer discharges associated with mining activity. /n addition, the plan shall describe the best mnnagemem practices (BMPsJ which will be used to reduce the pollutanu in stormwater discharges from the mining site. Some activities required under the SWMP may already 6e in place. However, the SWMP will require the permitree to roordiruue these actitiries with airy necessary new activities in an orderly manner, so that the resuh is the reduction or elimination of pollutants reaching state waters from areas not limited by ejjIuem limitations. Facilities muss imp(emcnt fhe provisions of she SWMP rrquind under this part as o condition ojshis permit. /t is the peimiuee's responsibility to notify the Colorado Division ojMining and Geology (formerly the Colorado Mined Land Reclamation DisisionJ of any sign~cam changes m their sire resulting from the implememarion of the SWMP. This is so that the Division of Mining and Ceobgy may review the SWMP and incorporate any potemial revi.rionr imo the jaeility'r reclamation permit which might be needed. The SWMP shall include the following items, m o minimum