HYDRO29784

• Permit No: M1977344
• IBM Index Class Name: Hydrology
• Doc Date: 11/22/2004
• Doc Name: Quarterly Groundwater Monitoring
• From: BBL
• To: DMG
• Media Type: D
• Archive: No

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 azea.
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
emissions control. With the addition of the pug mill, use of the sludge for CKD emissions 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 CKD. Descriptions of
the site geology and hydrogeology are provided in the Groundwater Monitoring Plan (BBL,
2002).
On July 30, 1999 the EPA proposed rules for the management of CKD under RCRA. The
proposed rule was published in [he Federal Register on August 20, 1999 and comments were
accepted until February 18, 2000. These proposed rules included technical standards for the
management of CKD. In Colorado, the regulatory responsibility for the new requirements has
been relegated to the DMG. Therefore, the requirements for CKD management have been
incorporated into each facility's Mined Land Reclamation Permit. These requirements include
specific requirements for protection of groundwater as described in Rule 3.1.7(7)(1) through (viii)
of the "Construction Material Rules and Regulations" (MLRB, 2001) and the Colorado
Department of Public Health and Environment (CDPHE), Water Quality Control Commission
(WQCC) Regulation No. 41 "Basic Standards for Ground Water" (CllPHE, 2001).
Holcim submitted a request for a Technical Revision (TR-06) to its permit on August 16, 1999
for the disposal of CKD in previously mined areas at the quany (K-S & Company, 1999). TR-06
included a description of CKD disposal procedures and facilities, a closure plan for the disposal
areas, a description of erosion control measures used at the site, a discussion of CKD sampling
and analysis, and a description of hydrogeologic conditions at the site. The DMG reviewed TR-
06 and responded with an initial adequacy review letter on January 18, 2000 (DMG, 2000). On
behalf of Holcim, K-S & Company submitted responses to DMG's adequacy review letter in May
2001 (Holnam, 2001). The DMG responded with a second adequacy review letter on October 22,
2002 (DMG, 2002). The GMP partially fulfilled requirements from DMG's first and second
adequacy reviews. With the submittal of this final quarter of data for monitoring well MW-10, all
requirements from DMG's adequacy reviews have been fulfilled.
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