GENERAL35566 - Laserfiche WebLink

Home Browse Search

~------- _z- April 29, 1982 Mr. Ed Bischoff The placement of "coarse" reject material has followed that plan and compaction tests during the course of construction have indicated that the "coarse" material has been properly compacted to the degree specified in the Geotech report. The Geotech report however does not contemplate placement of the holding area for settled fines in the pile as it now exists. Dorchester fully recognizes its obligation Co construct the refuse dump according to an engineered plan which is designed to produce a stable embankment which can be reclaimed pursuant to the require- ments of the CMLR regulations. We view the present mode of operation as a stop-gap remedy to an unforeseen situation. As we have discussed with your staff, during the past two months. Dorchester has taken several steps to resolve both short-term and long-term issues regarding its disposal of preparation plant reject material. 1) Despite being settled in the pond, the fine material is still quite moist at the time of deposition and requires further dewatering. We have oriented the holding area [o provide positive water drainage from the surface of the holding area away from the remainder of the pile. This should minimize water infiltration into the pile, thereby minimizing any adverse consequences to the stability of the existing structure. 2) Dorchester has contracted with Rocky Mountain Geotechnical to conduct a study and prepare a refuse dump reconstruction plan. This plan will incorporate a remedy for the present situation, as well as delineating a comprehensive plan for long-term reject deposition. The field work for [he plan has been completed and material analyses are underway. We expect the plan to be complete and ready for your review by the end of May. 3) Dorchester is in the process of expanding its reject deposition options. The pile is being continued to the east in accordance with the presently approved plan. Initially only "coarse" reject material will be placed in this area. However, if material analyses indicate that a mix of coarse and fine material can achieve the required level of stability, fines will be included and mixed thoroughly at the appropriate ratio. This activity is crucial since the embankment will buttress the existing embankment surrounding the holding area. All activities will be conducted within the boundaries of the presently approved refuse dump and in accordance with the currently approved plan. In addition, Dorchester has concluded an agreement with GEC to allow reject material deposition in open pits on their property. Information supporting the revisions necessary to GEC's and Dorchester's permits was submitted to CMLR's offices on April 27, 1982. Both of these options are critical