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6/15/2016 <br />STATE OF <br />COLORADIS <br />State.co.us Executive Branch Mail - Re: PSCM hydro monitor plan proposal <br />Re: PSCM hydro monitor plan proposal <br />1 message <br />Ebert - DNR, Jared <jared.ebert@state.co.us> <br />To: Dennis <ddjones@hotmail.com> <br />Cc: Brian Watterson <bwatterson@peabodyenergy.com> <br />Dennis, <br />Hernandez - DNR, Alysha <alysha.hernandez@state.co.us> <br />Tue, Jun 14, 2016 at 7:43 AM <br />Below is the list of proposed changes to the water monitoring plan for the Peabody Sage Creek Mine that you sent to <br />me. I have reviewed the changes and have made comments to each proposed change. Each of the proposed changes <br />is listed followed by my response. Please review and let me know if you have questions. Please remember that the <br />water monitoring plan as approved in the permit must continue to be followed until a technical revision to the permit for <br />any change has been approved and issued by the Division. <br />1. Item 1 - Discontinue all monitoring at surface water site SSC10 on lower Cow Camp Creek just above the <br />confluence of Fish Creek. Monitoring here began in 1987. This site is below Outfall 004. The Pond 004 basin <br />was originally mined in the Seneca II Mine, and most of the area has received final bond release in 2015. Data <br />from this site indicated that, although Pond 004 flows continuously, Site SSC10 would often dry up in the early <br />summer, and remain dry until the following spring snow melt runoff. This reduction in flow is due to stream <br />channel infiltration and evapotranspiration. It appears that the Pond 004 basin has little impact on Fish Creek. <br />Water discharged from the mine is lost to stock ponds, evapotranspiration, and the alluvium as it flows through <br />Twentymile Park. Dissolved solids from mine discharges are diluted during the snowmelt runoff in March and <br />April (prior to the irrigation season) by high stream flows with relatively low TDS concentrations. Flow values in <br />Fish Creek are several orders of magnitude greater than the flow values at Site SSC10. <br />a. Table 2.04.7-T11 indicates that site SSC10 is a surface water monitoring site, however this site is <br />not depicted on Map 2.04.7 M1 of the permit which depicts the water monitoring site locations. This <br />map will need to be updated to depict this site. One site which is below pond 004 on Cow Camp Creek <br />is shown on the map, this is site SW -S2-6. This site is not listed on Table 2.04.7-T11 as a required <br />monitoring site for Cow Camo Creek. As the entire disturbed basin that contributes flow to site SSC10 <br />has not been Phase III bond released, this site should continue to be monitored in accordance with <br />Rule 4.05.13(2)(1). This site should be used to demonstrate that impacts to Cow Camp Creek have <br />been minimized outside of the permit area which is a finding the Division would have to make prior to <br />final Phase III bond release of areas contributing flow to this site. <br />b. Is site SW -S2-6 being monitored? <br />2. Item 2 - Suspend monitoring (until mining resumes) at surface water site SSG2 on Grassy Creek. This site <br />in downstream of Outfalls 002 and 003 on Grassy Creek. However, there is a site further downstream, YSGS, <br />where monitoring will continue. Also suspend monitoring at surface water site SSLG5. This site is located on <br />upper Little Grassy Creek upstream of all mining activities. It has been monitored since 1980, and exhibits very <br />little change in water quality. <br />a. Similar to Item #1 above, there are areas from the former Seneca II mine that PSCM will likely <br />request for Phase III bond release in the near future that contribute flow to Little Grassy Creek which <br />feeds Grassy Creek. In order for the Division to make a finding that offsite surface water impacts have <br />been minimized to Grassy Creek, site SSG2 should continue to be monitored. <br />b. Three small area exemptions (mine office, parts building pad and old "bone yard") exist at the site <br />that do not report drainage to a treatment pond but do report to SSG2. Given this, in order for the <br />Division to make the finding that the affected area is not impacting water before leaving the permit area, <br />site SSG2 will need to continue to be monitored even while the mine is idled. Also, site SSG2 is not on <br />https:Hm ai l.google.com/m ai I/u/0/?ui =2&i k=e29129fcb5&vi ew=pt&search=i nbox&th=1554f26bbd7a68d4&si m I=1554f26bbd7a68d4 1/5 <br />