2002-12-16_REVISION - M1977344 - Laserfiche WebLink

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7, Introduction Blasland, Bouck & Lee, Inc. (BBL) was retained by Holcim, Inc. to provide technical support for Mine Permit Technical Revision TR-06 to State of Colorado Mining Permit No. M-77-344 for the Holcim Portland plant and quarry. The Holcim Portland plant and quarry is located in Fremont County, Colorado (Figure 1). The total area of the Holcim property is approximately 3,400 acres. The portion of the Holcim property addressed by this Groundwater Monitoring Plan (GNP) is the approximately 1,330 acres included within the boundaries of the mining permit (Site) (Figure 2). This GMP partially fulfills requvements set forth by the Colorado Department of Minerals and Geology (DMG) in their October 22, 2002 second adequacy review letter regarding Technical Revision TR-06 to Permit No. M-77-344 (DMG, 2002). The main purpose of this GMP is to meet the requirements of the Colorado Mined Land Reclamation Board's (NLRB) Construction Materials Rules and Regulations Rule 3.1.7 for the protection of existing and reasonably potential future uses of the unclassified groundwater located beneath the quarry (NLRB, 2001). These requirements have been triggered by the disposal of cement kiln dust (GIGO) into previously mined sections of the Site, and the potential for leachate from CICD to adversely impact ambient groundwater quality for existing and reasonably potential future uses. 1.1 Site History The Portland plant, located on the southern side of the Arkansas River, until recently consisted of three (3) long, wet kilns with a combined cement production of approximately 937,000 tons per year (tpy). The Plant currently uses a single dry kiln process for production of cement with a capacity of 2,094,000 tpy. The facility utilizes a five-stage preheater/precalciner tower to prepaze material for the kiln. The tower includes heat-exchanging cyclones (i.e., preheater) in which the dry feed is preheated and partially calcined by the kiln's hot exit gasses prior to entering the actual kiln. A secondary firing device (i.e., precalciner) in the lower stage of the preheater further calcinates the materials. CICD, a waste material from cement production, is dust that is generated in the cement kiln and associated equipment. Using the prior wet kiln process, approximately 100,000 tpy of cement kiln dust (GIGO) was generated dwing the production of cement at the Portland plant (Resource Geoscience, Inc. (RGI), 1999)). The current CKD production rate ranges from 28,000 tpy to 72,000 tpy. The production of CKD strongly depends upon the chemistry of raw materials, type of process and the design of gas velocities in the kiln. Other factors such as kiln performance and dust collection systems play vital roles. To reduce dust emissions, a pug mill is used to add water to CKD prior to transporting it to the disposal area. Historically, sludge from nearby Fremont Sanitation District wastewater treatment plant had been added to the CKD disposal area as a daily cover. The sludge also served as a means of CKD dust control. With the addition of the pug mill, use of the sludge for CI{D dust control was no longer required and has not been utilized since the startup of the new plant in 2001. The quarry is located on the northern side of the Arkansas River. The CKD is currently disposed of in previously mined sections (cuts) of the limestone quarry. The location of cuts previously used for CKD disposal is indicated on Figure 2. CKD is currently being disposed in the cut adjacent to (to the south of) monitoring well MW-10. The bottoms of these cuts coincide with the top of the underlying Codell sandstone, which is the primary water-bearing unit in the quarry area. To prevent contact of CKD with regional groundwater, approximately 10 feet of shale is backfilled and compacted in the bottom of these cuts prior to placement of CICD. On July 30, 1999 the EPA proposed rules for the management of CICD under RCRA. The proposed rule was published in the Federal Register on August 20, 1999 and comments were accepted until February 18, 2000. These proposed rules included technical standards for the management of CICD. In Colorado, the regulatory responsibility for the new requirements has been relegated to the DMG. Therefore, the requirements for CKD BLASLAND, BOUCK & LEE, INC. ~2isaioz engineers 8 scientists 1-1 Caoundwun Monitoring PIm- dot