2016-01-13_INSPECTION - M1985112

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PERMIT #: M-1985-112 INSPECTOR’S INITIALS: PSH INSPECTION DATE: January 13, 2016 Page 4 of 10 Operator since the April 2015 measurement, so recent groundwater elevations are not available for the well. The change in water elevation from 5 feet to 20 feet, 9inches below grade is greater than the required 2 feet elevation change required to implement the approved mitigation plan. Loloff Mine The Division met with Mr. Kelly Hodge with Northern Colorado Gravel & Sand, LLC and J.C. York with J&T Consulting, Inc. to discuss the citizen complaint at the Loloff Mine site. Mr. Hodge had met with Mr. Francis the day before to discuss his complaints. The mine site was actively mining and dewatering during the inspection. Dewatering pumps with 8” diameter discharge pipes were observed in the southwest corner of the mine site. The water was discharged into the channel which continues through the Francis property. The ditch runs southeast from the site, crosses under Balsam Ave and East 8th St. and into the Ogilvy Ditch. The discharge activity is permitted under NPDES permit # COG500375. Conclusions Channel and culvert As cited as a problem requiring corrective action by the Operator on Page 1, the dewatering of the site into the ditch through Mr. Francis’ property has caused the culvert under the land bridge on Mr. Francis’ property to become silted in. The Operator stated they would coordinate with Mr. Francis to clean out the silt in the channel and replace or repair the culvert pipe as needed. The Operator stated Mr. Francis prefers to have the work done when the soil is not frozen. The Operator may be required to repair the land bridge as part of the culvert replacement or repair project. The Operator stated material and equipment were available at the mine site to complete the work and would coordinate with Mr. Francis to complete the work. The Operator must update the Division on the status of the repairs within 60 days of the mailing date of this inspection report. Wells The Francis wells are located approximately 400 feet (Wells #3 and #2) and 450 feet (Well #2) from the south permit boundary. All three wells are located within the estimated cone of depression / radius of influence calculations, with recharge, of 566 feet. The radius of influence calculation, dated July 3, 2013, was submitted with TR‐01. The Division believes the dewatering of the Loloff Mine has impacted the groundwater wells on the Francis property based on the radius of influence model, the change in water elevation from the static levels reported in the DWR well permits compared to the limited groundwater monitoring data collected by the Operator and the observation for this report. As cited as a problem requiring corrective action by the Operator on Page 1, Loloff Construction, Inc. must implement the approved mitigation plan for the site and work with Mr. Francis to investigate and rehabilitate the well(s) on this property within 60 days of the mailing date of this inspection report. Failure to comply with the corrective action may result in the problem escalating to possible violation and an enforcement hearing being scheduled in front of the Mined Land Reclamation Board. The Operator stated they believe the impacts to the Francis wells are temporary and groundwater elevations will return to pre‐mining levels once the proposed slurry wall at the mine site is installed. The Slurry Wall Assessment report, dated July 13, 2015, by McGrane Water Engineering, LLC submitted as part of AM‐01 indicates the Francis wells will not be impacted by shadowing or mounding effects from the slurry wall