2014-12-05_INSPECTION - M2004051

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PERMIT #: M- 2004 -051 INSPECTOR'S INITIALS: PSH INSPECTION DATE: December 1, 2014 OBSERVATIONS The Wattenberg Lakes site was inspected by Peter Hays with the Division of Reclamation, Mining and Safety (Division /DRMS) as part of the Division's monitoring inspection program. Mrs. Connie Davis with Aggregate Industries, Inc. was present during the inspection. The site was previously inspected by the Division on March 31, 2010. The Wattenberg Lakes 112c permit was issued with conditions by the Division on February 10, 2005. The site is permitted for 420.8 acres with 245 acres of mining disturbance. No revisions to the original mining and reclamation plans have been submitted by the Operator. The Operator is required to notify adjoining landowners, including Peter L. Baurer and Carl C. Eiberger, of any technical revisions submitted to the Division per the permit approval stipulation. The required mine sign was observed at the entrance gate and the site boundaries were well defined. The site was actively mining aggregate during the inspection in the northern portion of Phase 3 — Pond 3. The Operator is not mining the site in the approved mining sequence per the Mining Plan: Phase 1— Pond 2, Mining Area 3 and Mining Area 3, Phase 2 — Pond 1 and Mining Area 1 and Phase 3 — Pond 3. The Phase 1 and 2 areas are undisturbed. During the inspection, the Operator stated the Corps of Engineers 404 permit, eagles nest location and the associated DOW restrictions caused the out of sequence mining. Additionally, the Operator stated portions of the approved Mining Plan area may not be mined at all. The Division recommends the Operator submit a Technical Revision to update the Mining Plan sequence for the site. The material mined at the site is conveyed to the adjacent Platte Valley operation for processing and stockpiling. The approved mining plan states the average mine depth is 24 feet with a maximum depth of 41 feet. The current excavation appeared less than 24 feet in depth in the northern portion of Phase 3. The approved Mining Plan states the active mining face will extend no more than 2,000 feet in length. Based on post inspection aerial photograph measurements, the Division estimated 3,150 feet of active mining face. As cited as a problem on the first page, the Operator must reduce the amount of active face to meet the current permit conditions or revise the permit to allow for more vertical highwall, which would result in an increase in the required financial surety amount. The Heutt Ditch realignment is complete as noted in the previous inspection report. Mrs. Davis stated the wetlands adjacent to the new ditch have established well. The slurry wall around Phase 3 — Pond 3 was installed in 2013. T -posts indicating the centerline of the slurry wall were observed during the inspection. As cited as a problem on the first page, the approved Mining Plan requires the Operator to provided specific specifications and quality control procedures to the Division for review, in the form of a technical revision, prior to construction of the slurry walls. In order to avoid a possible violation, the Division will require the technical revision to be submitted within 30 days of the mailing date of this inspection report. The Division does not have proof of SEO approval of the slurry wall. The approved mining plan states an offset of 40 feet will be maintained from the slurry wall. Survey stakes indicating the limits of mining near the slurry wall in the northwest corner of Phase 3 were observed. The required Platte River offset of 200 feet was not confirmed during the inspection, since mining activity did not appear to be closer than 300 feet from the river. The Division currently holds a financial warranty in the amount of $520,000.00. The financial warranty includes the cost to install slurry walls at the site to comply with the Division's long -term exposed groundwater requirement. The site is covered by a current SWSP for all short-term groundwater impacts. The Page 2 of 5