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III. COMMENTS -COMPLIANCE <br />Below are comments on the inspection. The comments include discussion of observations made <br />during the inspection. Comments also describe any enforcement actions taken d~uing the inspection <br />and the facts or evidence supporting the enforcement action. <br />permanent Southeast and Northwest perimeter ditch segments, above junction of the - <br />perimeter ditches with Terrace Drain #3. Perimeter ditch segments below Terrace Drain #3 <br />had been completed in 1994. Final reclamation in 2002 included extensive roughening to <br />enhance vegetation establishment, and rock placement for small animal habitat. <br />DMG documented compliance of the lower reclaimed benches and perimeter ditches during <br />a special focus oversight inspection conducted with OSM in August 1997. Extensive slope <br />and ditch measurements were taken, and results were described in the DMG inspection <br />report of August 29, 1997 and report addendum of October 17, 1997. <br />Adequate soil cover thickness 118") on the lower benches was documented in the DMG <br />inspection report of June 29, 1994. Adequate soil cover thickness on the upper benches <br />(top of pile and side slopes) was documented in DMG inspection report of January 31, <br />2003. <br />Construction certification for the new segments of the Southeast and Northwest perimeter <br />ditches was included in the 3rd quarter 2002 refuse area P.E. certification by Jim Stover. <br />DMG measurements of various segments of the S.E. and N.W, perimeter ditches Iboth <br />1994 and 2002 construction segments) are documented in the Ditch and Channel <br />Measurements section of this report. <br />General configuration of the final graded upper bench slopes and top of pile appeared to be <br />in accordance with the approved design. The top of pile is mildly crowned, with bench <br />outslopes in general conformance with design slope gradients and bench heights. DMG <br />slope measurements taken during this inspection are documented in the Refuse Area Slope <br />and Terrace Drain Measurements section of this report. <br />Construction design for CRDA-1 did include installation of an underdrain. For a number of <br />years, the only seepage from the underdrain has been in the immediate vicinity of the <br />Southeast Perimeter ditch inlet to Pond 6. At the time of the inspection, soil in this <br />underdrain outlet area was very moist, but seepage water was not evident. Documentation <br />concerning installation of the underdrain is described on page 12 of the September 28, <br />2001 DMG inspection report. In summary, correspondence and inspection reports from the <br />early 1980's indicate that the underdrain was apparently completed and observed to be <br />functional, but the installation was apparently not properly certified by a professional <br />engineer. A notice of violation was issued by DMG in 1993, for the failure to certify <br />underdrain installation. <br />On CRDA-1, the operator monitors water levels at multiple zones within the pile to <br />document conformance with stability analysis assumptions. 30 piezometers on the two <br />lower refuse benches are monitored and water levels are reported quarterly, to ensure that <br />permit specified "critical levels" are not exceeded. The piezometers were installed in 1994, <br />and monitoring that has been conducted since installation has not documented a single <br />exceedance of a critical level (apparent exceedances for PZ #406 in the 2n° and 3rtl quarter <br />of 1998 were determined to be erroneous). There periodically have been problems with <br />monitoring certain of the piezometers (#307 prior to 1997, and additionally #107and #303 <br />since that time) due to occasional constriction or obstruction. For an assessment of this <br />