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Summary <br />Based on our observations and compaction tests conducted at the site during the construction of the subject <br />embankment, it is our opinion that the embankment was constructed to a stable configuration and with <br />adequate freeboard. The embankment was actually constructed with a downstream slope configuration of 8 <br />(Horizontal) to 1 (Vertical) and an upstream slope configuration of 4 (Horizontal) to 1 (Vertical). The <br />flatter slope configurations will actually increase the minimum factors of safety against slope failure that <br />were discussed in the previous section of this report. <br />Therefore, based on the design, this structure appears to comply with the appropriate regulations for a <br />sedimentation structure. It is our understanding that Seneca Coal Company will periodically inspect the <br />structure for sediment storage, structural integrity and hazardous conditions. Maintenance and remedial <br />work will be performed in accordance with the approved mine permit. <br />Construction Summary <br />In accordance with Rule 4, Part 4.05.9(14) of the Rules and Regulations of the Colorado Mined Land <br />Reclamation Board pursuant to the Colorado Surface Coal Mining Reclamation Act 34-33-001 et seq., I, <br />Brian Len, state that during construction of Sedimentation Pond 012A observations and tests were <br />conducted by NWCC personnel under my direct supervision. Seneca Coal Company constructed Pond <br />012A under the supervision of Mr. Roy Karo, Reclamation Manager. Mr. Karo ensured that all work was <br />performed in accordance with the design and the specifications. <br />NWCC personnel inspected the structure on a regular basis to verify the compaction of the embankment <br />materials as they were placed and to make sure that the embankment was being constructed in general <br />accordance with Rule 4, Part 4.05.9(14). Mr. Roy Karo (Seneca) and/or Mr. Jay James (Seneca) were also <br />on the site at several critical occasions during the construction of this pond. The field and laboratory test <br />results, including our daily field reports and compaction test results for the Pond 012A embankment are <br />provided in Attachment B. <br />The purpose of our observations and testing were to verify that the construction of Sedimentation Pond <br />012A was completed in general accordance with the requirements of Rule 4.05.9(14) of the Colorado <br />Mined Land Reclamation Board. The fill materials placed in the embankment met or exceeded the design <br />specifications (see Attachment B for compaction). This as-built report confirms that the construction of <br /> <br />Job Number: 07-7600 NWCC, Inc. Page 2