Open Landfill Remediation
During operations prior to closing, a rock-like waste material called “slag” was generated during the lead smelting process. Regulations required the slag to meet certain treatment standards prior to disposal in the Open Landfill. Exide treated the slag and tested the slag after treatment pursuant to a sampling protocol.
The Open Landfill is comprised of 15 areas or cells. Cells 1 through 9 are filled with treated slag and have been capped. Cells 10 through 12 are active/open cells that are partially filled with treated slag. Cells 13 through 15 have been excavated and partially lined; however, no waste material has been placed in these cells yet.
Analytical data for treated slag deposited in the three open/active cells indicate that some of the treated slag deposited in these cells may not have met the applicable treatment standards. Exide sampled the material in these cells and a summary of this sampling is provided in the report titled “Results of the Class 2 Non-Hazardous Waste Landfill Investigation” dated March 13, 2012, which was submitted to TCEQ.
In 2013, Exide conducted a review of analytical data from the period the capped cells (1 to 9) were in operation. A small fraction of the analytical results during the period when the capped cells were in operation were above the applicable treatment standards for lead and/or cadmium. A smaller subset of analytical results above the applicable treatment standards was also above the concentrations for characterization as hazardous waste. Information regarding materials in the capped cells was submitted to TCEQ and USEPA.
The majority of the sampling results above applicable treatment standards for lead or cadmium in cells 10 to 12 were documented in the 0 to 0.5 foot depth interval with discrete areas above the applicable treatment standards for lead or cadmium identified at greater depths. A smaller subset of the material in cells 10 through 12 that was above the applicable treatment standards was also above the concentrations for characterization as hazardous waste. Exide submitted a work plan to the TCEQ titled “Response Action Work Plan, Class 2 Non-Hazardous Waste Landfill” (RAWP) dated March 1, 2103 to perform a re-treatment project, subject to a pilot test to determine whether it would be feasible to excavate, re-treat, test, and re-deposit this material in the Open Landfill.
Exide completed the pilot test under the TCEQ-approved RAWP, which included excavation and re-treatment of 20 roll off containers of slag material from the landfill and evaluation of the sampling results for the re-treated material. The pilot test resulted in some inconsistencies in sample results related primarily to results from a lab that ran the samples without following proper sample preparation procedures. TCEQ did not approve full-scale implementation of the RAWP for the active cells and instead determined the ultimate disposition of the material that does not meet applicable treatment standards as discussed below.
Following the pilot test for the active cells and discussions regarding the capped cells, TCEQ requested that Exide complete a risk evaluation of remediation alternatives for the Open Landfill, including the active and capped cells. Three remediation alternatives were evaluated: 1) excavate all landfill contents and haul it offsite for treatment and disposal in another landfill, 2) excavate all landfill contents, re-treat the excavated material onsite, and place re-treated material back in the landfill, and 3) close the landfill with the materials previously disposed remaining in place. The results of the risk assessment were presented to TCEQ in a report titled “Exide Class 2 Landfill Risk Evaluation of Remedial Alternatives” dated August 2014 (Risk Evaluation Report). The Risk Evaluation Report concluded that the alternative to allow the landfill contents to remain in place posed the least risk of the alternatives evaluated and was the most implementable alternative. On September 9, 2014, Exide made the Risk Evaluation Report available for public comment. No public comments regarding the Risk Evaluation Report were received either by Exide or TCEQ. On March 12, 2015, TCEQ approved the Risk Evaluation Report.
To address the material that does not meet applicable treatment standards in the Open landfill, Exide and TCEQ entered into an Agreed Order that provides for closure of the landfill material in place. Among other things, the Agreed Order requires that Exide install an interim cover on the exposed slag in cells 10 through 12; re-sample two piles of treated slag that had been staged in the Open Landfill; dispose offsite any treated slag in the two piles that does not meet treatment standards; develop several plans for the Open Landfill including procedures for placement of any remediation waste, collection and management of any liquid, monitoring of groundwater, dust suppression, specification of waste management practices, and contingency measures. The Agreed Order specifies which wastes can be placed in the Open Landfill before it is closed and capped. These include the treated slag in the two piles in the Open Landfill that meets treatment standards, the re-treated slag in the roll off containers in the Open Landfill (from the pilot test) which met treatment standards based on all sampling results from the three labs used for the pilot project, and waste generated during future remediation of the Exide site that meets specific standards for placement in the Open Landfill. On March 13, 2015, the TCEQ published notice of the proposed Agreed Order in the Texas Register; no comments were received. On April 15, 2015, the TCEQ approved the Agreed Order and it became effective on April 27, 2015. Exide is currently performing the activities required by the Agreed Order.
Regarding the two piles of treated slag in the Open Landfill, Exide submitted to the TCEQ a work plan titled “Revised Sampling & Analysis Plan; Stockpiled Treated Slag Adjacent to Class 2 Non-Hazardous Waste Landfill” dated March 24, 2015 (Slag Pile Sampling Plan). The Slag Pile Sampling Plan specifies procedures for reconfiguring and re-sampling the two piles, air monitoring during reconfiguration activities, and installation of a temporary cover on the exposed face of treated slag in cells 10 through 12. On April 27, 2015, the TCEQ conditionally approved the Slag Pile Sampling Plan. Exide is currently implementing the Slag Pile Sampling Plan.
Following remediation of the Former Operating Plant and the Undeveloped Buffer Property, the Open Landfill will be capped in accordance with TCEQ requirements and long term maintenance and monitoring will be performed to confirm the landfill remains protective. Exide expects to continue to retain ownership of the land on which the Open Landfill is located.
TCEQ Approval of the Risk Evaluation Report (dated March 12, 2015)
Exide Class 2 Landfill Risk Evaluation of Remedial Alternatives (dated August 2, 2014)
TCEQ Approval of Groundwater Monitoring Plan (dated April 4, 2014)
Revised Class 2 Landfill Groundwater Monitoring Plan (dated July 31, 2013)
TCEQ Approval of RAWP (dated March 5, 2013)
Response Action Work Plan, Class 2 Non-Hazardous Waste Landfill (updated March 1, 2013 - complete with appendices)
Response Action Work Plan, Class 2 Non-Hazardous Waste Landfill (dated January 31, 2013)
Results of the Class 2 Non-Hazardous Waste Landfill Investigation (dated March 13, 2012)
Open Landfill Re-Sampling and Temporary Cover
TCEQ Agreed Order for Open Landfill (dated April 24, 2015)
TCEQ Letter, Revised Slag Sampling and Analysis Plan Approval with Conditions (dated April 27, 2015)