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CGRS, Inc. <br />GROUNDWATER MONITORING WORK PLAN <br />VARRA COAL ASH BURIAL PROJECT <br />WELD COUNTY, COLORADO <br />CGRS NO. 1-135-2755 <br />1.0 INTRODUCTION <br />This document presents the proposed work scope for the evaluation of coal ash burial in saturated media. <br />This will be accomplished by conducting a pilot field program, which consists of burying 400 tons of coal <br />ash in water [able conditions in Weld County, Colorado. Rigorous water quality monitoring is proposed <br />over aone-year period to determine long-term leachability characteristics of coal ash under natural <br />conditions. Quarterly background water quality monitoring at the proposed test area is ongoing and has been <br />conducted over aone-year period. The field investigation will 6e performed in conjunction with a variety of <br />laboratory studies in order to evaluate potential liabilities or benefits associated with coal ash burial. <br />Specifically, this project addresses issues associated with the reclamation of gravel quarries under saturated <br />conditions. A variety of laboratory experiments were conducted in order to evaluate coal ash leaching <br />potentials. This work is performed under the authorization of Varra Companies. <br />1.1 Obiec[ives <br />The purpose of [his project is to identify potential liabilities with the reclamation of gravel quarries with <br />coal ash and to determine if coal ash meets the criteria for classification as an inert fill. Specific objectives - <br />for the Varra Coal Ash Burial Project are to determine: <br />• Leaching characteristics of coal ash with respect to varying water quality conditions; <br />• Permeabili[ies of various types of coal ash (bottom and fly ash); <br />• Affects of coal ash burial on local hydrology and water quality; <br />• Hydrogeologic properties of coal ash; and <br />• Physical characteristics of coal ash in saturated media. <br />1.2 Back>;round Information <br />The study area is an active gravel quarry located in the NW ll4, Section 3l, Township 3 North, Range 68 <br />West, 6'" P.M., Weld County, Colorado (Figure I). The su~cial geology of the area as documented by <br />Colton, 1978, vanes between wmd blown deposits of clay, silt and sand and sandy to gravelly alluvium, <br />which are Holocene in age. Colluviwn consisting of bouldery to pebbly sandy silt and clay may contain and <br />imerfinger with alluvium of various ages. The depth to groundwater at the site generally varies between <br />three and ten feet below ground surface (bgs). The inferred Groundwater Flow direction is to the northeast <br />roughly parallel to the St. Vrain River drainage. The Pierre Shalc underlies the unconsolidated alluvial <br />