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The Big Picture DEP Problems at Dragon's Dumps Cement Kiln Dust
Clinker Dump
Putting Together the SOC
Cement Kiln Dust Management Practices, July 28, 1995.
Assessment ----------------------------------------
Hydrogeological objective: provide an understanding of groundwater and surface water flow at the site; establish background quality and develop a groundwater monitoring plan. Groundwater separation - the separation distance between the base of the waste and the groundwater will be achieved through continuous depression of the water table through pumping. EPA's analysis of the effects of CKD on groundwater found that about half of the cement kiln facilities were built on bedrock having characteristics that allow for the direct transport of groundwater offsite. In its analysis of 31 of these facilities, EPA found that dust from 13 of them could contaminate groundwater at levels that could exceed health standards. None of these 13 facilities had installed man-made liners under their dust piles and 11 lacked leachate collection systems. EPA also found that groundwater at three of these facilities was within 10 feet of the bottom of their dust piles; EPA did not have information on the depth to groundwater at the remaining 10 facilities, In addition, some facilities managed CKD in quarries that could subsequently fill with water, if this occurs, leachate could more readily contaminate groundwater. High pH leachate and runoff. In the March 1995 Work Plan, Dragon proposed to regularly pump treated leachate from the leachate ponds to Quarry #1 for process water, and for the purpose of maintaining reserve leachate storage capacity and containment of leachate generated. Leachate pond pumping provides the potential for creating inward groundwater flow gradients to the pond which, if maintained, would provide an effective hydrologic barrier to leachate migration out of the pond. Dragon installed staff gauges in both ponds to aid in recording water levels on a regular basis. As part of this work and considering data obtained during the active landfill groundwater and surface water monitoring program, Dragon WILL DEVELOP A PUMPING STRATEGY INTENDED TO MAINTAIN INWARD GROUNDWATER FLOW GRADIENTS TO THE LEACHATE PONDS, (DEP) Dragon needs to establish an maintain a drawdown elevation at the respective leachate pump stations which will insure that gradients remain inward toward the pumps from alf directions. A permanent cone of depression centered on the pump locations needs to be created and maintained. Successful demonstration may require additional observation wells. Leachate Potential: use the EPA HELP Model as the basis for evaluating the potential for leachate generation. This information -------------------------------- Page 3 will be used in the establishment of operating practices. The Model will be used to estimate the magnitudes of various components of the water budget including the volume of leachate produced. EPA used a model to analyze the effects of water running off of dust piles at 83 of the facilities, The model projected that 25 facilities could pose higher than acceptable cancer risks or noncancer threats to subsistence farmer and fishermen. Seven of the facilities did not have runoff controls. Flow of leachate from the respective pups to Quarry #5 needs to be contained in pipes. Overland flow of untreated leachate outside of the approved solid waste boundary is unacceptable. Analysis of water from the CKD leachate reservoir shows that kiln dust contributes to anomalously high values of several parameters with respect to any reasonably expected background, or natural water chemistry. The most obvious of these parameters are pH, conductivity, sulfate, sodium, chloride and potassium. In general terms, the clinker dump leachate shows similar chemistry. Engineering Design:
CKD Placement. Construct a perimeter berm, dress exterior with topsoil and vegetate. Cell completion - as the perimeter berm is constructed for each new lift of the landfill, the exterior slope of the berm will be dressed with topsoil and vegetated. Erosion Control (From Work Plan)
1. Construct swales at the crest of the landfill sideslopes to direct runoff from the top flatter areas away from flowing onto the steeper sideslopes. 2. Employ applicable "Best Management Practices" as specified in the Maine Erosion and Sediment Control Handbook for construction. The disposal areas are not graded in a uniform manner and there are signs of erosion in numerous areas. The disposal areas are flat ================= Page 4 on the top with very steep sideslopes (plateaus). The runoff from the active and inactive areas of the landfills should be transported and treated separately. Current sideslopes are approximately 2:1, need variance. Fugitive Dust Control - at a minimum, the Fugitive Dust Control Plan
(FDCP) will address the following:
The FDCP will address potential fugitive emissions resulting from vehicular traffic on the landfill, compaction of the monofill and wind erosion of exposed CKD surfaces. The EPA used a model to analyze the effect CKD could have at 52 facilities if they did not have adequate dust suppression controls for their waste piles. EPA's model projected that over half of these facilities would exceed EPA's health standards for fine particulate matter at plant boundaries and, potentially, at nearby residences. EPA officials noted that they saw CKD blowing during some visits to 20 facilities. Operational Final Cover may be utilized when an area of a landfill will be inactive for greater than six months but will become active at some time in the future. The selection of operational final cover material can vary depending on the specific conditions. DEP has approved the -use of temporary synthetics (geomembranes) of the installation of a clay barrier that can later become part of the final cover system. Closure Plan: The written closure plan will contain provisions to ensure that a final cover system is designed and installed to eliminate or minimize infiltration through the closed monofill and erosion of the final cover or cap, and to prevent the migration of constituents via groundwater, or surface water, In Dragon's December 31, 1991, application Section 15 "Escrow Account, Closure/Post Closure Plan, Kiln Dust Disposal Site", ================================================= Page 5 Dragon stated that they were preparing a plan for the closure and post- closure care of its kiln dust disposal area. "Dragon will submit for review and approval by July 1, 1992, the final plan for closure and post-closure care including a schedule for implementation, Upon approval by the DEP of the plan, an estimate of costs will be made in order to adequately fund the closure/post-closure escrow account." Financial Assurance: The owner must be able to demonstrate financial responsibility until 30 years after closure. Escrow account - a trust agreement to cover estimated costs for closure and post-closure care, sampling, leachate removal and treatment, testing and maintenance, established with a reputable bank (060096 CMR Chapter 400 Section 10 and Appendix I, SWMR. Operational records: The operator shall maintain, for the active life of the landfill, a record of operational information. The licensee shall submit an annual report documenting all of the information required in Chapter 401 Section 6(B)(22). Procedural Plans (from Work Plan)
Proposed schedule
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