What is Ethylene Dibromide (EDB)?

Transcription

1 What is Ethylene Dibromide (EDB)? EDB is a synthetic chemical that has been used as a lead scavenger in aviation gas and leaded gasoline. EDB was also used as a fumigant in agriculture. EDB was in aviation gas that was used at Kirtland Air Force Base. Fuel leaked into the ground and contaminated groundwater. EDB is a known carcinogen and is regulated at.5 g/l (parts per billion) by the U.S. Environmental Protection Agency and the New Mexico Environment Department. EDB has not been detected in Albuquerque drinking water supply wells. Legend Drinking Water Well Sentinel Well or Well Nest Extraction Well Proposed Extraction Well Monitoring Well New Monitoring Well EDB Plume

2 REGULATORY PROCESS OVERVIEW For Kirtland Air Force Base Bulk Fuels Facility Remediation New Mexico Environment Department The U.S. Environmental Protection Agency is the federal agency that writes and enforces federal regulations based on laws passed by Congress. The New Mexico Environment Department (NMED) is the state agency that operates under a variety of state statutes, rules and federal regulations. Laws and statutes are enforceable legal standards passed by New Mexico Legislature and signed by the governor, or passed by the United States Congress and signed by the President of the United States. Rules are adopted by state agencies or governing boards which prescribe additional legal standards. NMED also operates under policies and guidance documents. These are not enforceable, but lay the foundation for how our programs carry out their responsibilities. To ensure compliance with federal and state regulations, permits are issued to entities who operate with significant impact to the environment. What Environmental Regulations Apply to the KAFB Bulk Fuels Facility Remediation Process and How? RCRA Resource Conservation and Recovery Act (Federal Law) Law describes the waste management program mandated by Congress giving EPA authority to develop RCRA program. EPA developed RCRA regulations to carry out the Act. EPA developed guidance and policy for implementing and complying with regulations. Corrective action is required for all releases of KAFB Hazardous Waste Treatment Facility Operating Permit (Issued in 21 by NMED) KAFB RCRA permit renewed and modified in 21 to consolidate previously separate permits (3 year process). Provisions in the permit guided by RCRA. The RCRA permit issued to KAFB is the governing authority for the corrective action process. Permit Section establishes overall Safe Drinking Water Act (Federal) Drinking Water Regulations (NM State Rule) NM Water Quality Act (NM State Statute) The Hazardous Waste Permit requires that groundwater be cleaned up to the more stringent of federal drinking water standards and state groundwater standards. EPA sets federal water quality standards and the state sets additional state water quality standards. EDB Drinking Water Standards hazardous waste or constituents from any solid corrective action process. U.S. EPA.5 µg/l waste management unit (SWMU) at a KAFB Bulk Fuel Facility Spill is cited as a SWMU State of New Mexico.5 µg/l permitted facility. requiring corrective action in the KAFB permit. The EPA Superfund / CERCLA process does not apply in this incident. Superfund = CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act Law and associated funding applies only to abandoned hazardous waste sites

3 REGULATORY PROCESS CORRECTIVE ACTION For Kirtland Air Force Base Bulk Fuels Facility Remediation New Mexico Environment Department Process for Corrective Action EPA decided not to issue regulations governing the corrective action process in favor of allowing case by case flexibility. EPA continues to direct states to look to the proposed 4 CFR 264 Subpart S for guidance and has issued guidance documents. Code of Federal Regulations: Title 4 (Protection of Environment); Part 264 (Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities; Proposed Subpart S (Special Provisions for Cleanup) Regulatory Agency RCRA Regulatory Review Interim Review RFI RFI Reports Class 3 Permit Modification Oversight (Permit) Measures Reports Approval Statement of Basis Public Participation Public Hearing Remedy(ies) Selected RCRA Facility RCRA Facility Further NO Corrective Measures Corrective Measures Assessment Investigations characterization? Evaluation Implementation (RFA) (RFI) (CME) (CMI) YES Facility (permitee) Interim RFI Work Plans Identify and evaluate CMI Plan Measure(s) begin cleanup Facility Investigations RFI Reports alternatives Recommend corrective measures Design & Construction CMI Report Interim Measures CME Report Operations/Maintenance Interim Measures Monitoring Cleanup Phase

4 Progress In Plume Definition and Contaminant Extraction Location of Conceptual Section West Conceptual Section Along Gibson Blvd. A A EXT East N A KAFB-1629 KAFB-163 KAFB-1631 KAFB-1691 KAFB-1692 KAFB-1693 KAFB-1622 KAFB KAFB KAFB A Gibson Blvd. ALLUVIAL FAN 1 KAFB-1635 KAFB-1636 KAFB-1637 KAFB KAFB Conceptual Cross Section Key Alluvial Fan Sediments KAFB KAFB KAFB High Permeability Low Permeability 5 New Q2 215 data informing plume shape and updating our understanding. Map Key Q2 215 EDB Concentrations Non-Detect Detection, Below MCL Detection Above MCL Q1 215 Shallow EDB Plume Contour feet Elevation (Feet Above Mean Sea Level) 5,2 5, ANCESTRAL RIO GRANDE SEDIMENTS VADOSE (UNSATURATED) ZONE Feet Below Ground Surface Water Ancestral Rio Grande Sediments EDB Plume High Permeability Low Permeability Q2 215 EDB Concentrations 4,8 EDB Extraction Well GROUNDWATER 5 Table Non-Detect Detection, Below MCL The cross section geology show here is typical of the area. It is conceptual in that it was derived from an adaptation of section T5 directly to the south. T5 lithological interpretation was adjusted to be consistent with the boring logs of monitoring wells shown. Detection Above MCL 1, 2, 3, Distance (Feet)

5 Groundwater Treatment System Example of a Pump & Treat System Collapsing the Dissolved EDB Plume Treatment Building Irrigation of KAFB Golf Course Reinjection at KAFB 7 Pipeline Access Vault KAFB Fence Well Vault EDB Extracted Water Conveyance Line EDB Treatment System Using Granular Ac vated Carbon Groundwater Extraction Well Treated Water: Aquifer recharge Landscape Irrigation Non-potable Reuse Ethylene Dibromide Contaminated water moves toward extraction well KAFP_12_8 Well 234 Driller inserting bit into well Directional drilling for installation of underground HDPE piping from extraction well KAFB to Kirtland AFB. Well 234 Drilling well in mud mode Looking at split spoon for lithologic description Holding tanks with carbon vessels and associated Holding tanks store treated water and are used for system balancing. being installed beneath the ground surface and connects the existing valve vault to the full-scale treatment building. Skid containing the pump that will be used to operate of the full-scale treatment system. 2M1214D_1b_

6 Source Excavations at the Former Fuel Offloading Rack First Excavation after leak was detected in 2, removed ~ 12 tons (76 yd3). Second Excavation in 21 removed 1,18 tons (611 yd3) of contaminated soil. The former underground and aboveground fuel transfer lines were removed as part of this effort. Third Excavation in 214 removed 3,684 tons Excavation (2,34 yd3) of contaminated soil to meet NMED residential soil standards to a depth of 2 feet. Trench Box Installation KIRTLAND AIR FORCE BASE 214 Excavated Area Existing Structure Existing Fuel Transfer Lines ± FFOR FFOR Former Buried Fuel Transfer Lines Former Aboveground Fuel Transfer Lines Former Fuel Offloading Rack 2 4 Confirmation Sampling Compaction Feet Current Bulk Fuels Facility Former Bulk Fuels Facility Completed Excavation Site

7 How We Collect Data From the Vadose Zone A network of Soil Vapor Monitoring (SVM) wells is used to measure and monitor vapor concentrations in the vadose zone. Nested SVM Well Clusters Each SVM nested well cluster contains individual wells that are screened at different depths in the vadose zone. This allows data to be collected from a variety of depths at one geographic location. Vadose Zone Soil Vapor Plume GROUNDWATER FLOW Field analytical instruments, such as this air emissions analyzer, are used to measure concentrations of hydrocarbons, oxygen, and carbon dioxide in the subsurface. Field and laboratory data are analyzed and interpreted to evaluate current remediation methods and determine future remediation methods for the vadose zone. Soil vapor samples are collected for in-depth analyses of specific fuel hydrocarbon compounds by a certified laboratory. Nested SVM wells and soil vapor sampling system.

8 Soil Vapor Extraction (SVE) Application and Performance SVE is an energy intensive technology designed to quickly remove volatile contaminants from soils to disrupt potential exposure pathways Vapor Separator Vacuum Injection/ Blower Ambient Air To Atmosphere Performance Highlights Very effective at fuel-spill sites Uses vacuum and high vapor flowrates to transfer COCs from soil to above the ground surface Soil Vapor Extraction Wells Catalytic Thermal Oxidizer Total of 774, gallons of fuel removed Often requires off-gas treatment prior to discharge to atmosphere 566, gallons extracted 28, gallons biodegraded Promotes biodegradation Typically applied in conjunction with follow-up technologies NAPL O 2 O 2 Soil Par cles EDB Fuel VOCs Benzene Residual O 2 Groundwater Flow Numbers are conservative Bioventing or monitored natural attenuation O 2 CO 2 Induced Vapor Flow SVE Operated for 12 Years Original SVE unit installed in 23 containing 9 soil-vapor extraction wells Off-gas treatment with two internal combustion engines (ICE) units Three additional extraction wells brought online in 28/29 Off-gas treatment with individual ICE units ICE Units moved to optimized locations in 212 New SVE system brought online in January 213 containing two vapor extraction wells Off-gas treatment with catalytic oxidizer Three extraction wells added in 214 Gallons of Fuel Removed SVE Startup April 23 9 Extrac on Wells SVE Performance Added 3 Extrac on Wells { System Op mized 2 Extrac on Wells and CATOX Online System Off Sep-2 Jan-4 May-5 Oct-6 Feb-8 Jul-9 Nov-1 Apr-12 Aug-13 Dec-14 May-16 Mass Removed by SVE Cumula ve Mass Removed Es mated Mass Biodegraded { Added 3 Extrac on Wells SVE Shutdown Test

9 SVE System Shutdown Test Soil Vapor Extraction Wells Vapor Separator Vacuum Injection/ Blower Ambient Air Catalytic Thermal Oxidizer To Atmosphere After SVE shutdown, hydrocarbon concentration trends at soil-vapor monitoring points are evaluated to determine areas of residual contamination. Hydrocarbon ppmv SV-3-25 Hydrocarbon ppmv KAFB Groundwater Flow Days elapsed from SVE shutdown Days elapsed from SVE shutdown Rebound No Rebound During SVE operation, many vapor-flow pathways are established as soil-gas is pulled through the vadose zone to extraction well screens. After shutdown, artificial flow patterns are replaced by natural flow patterns as the vadose zone returns to equilibrium. Vapor Separator Vacuum Injection/ Blower Ambient Air Catalytic Thermal Oxidizer To Atmosphere Benzene CO 2 CO 2 C O O CO O 2 O 2 CO 2 Naturally occurring bacteria in the vadose zone consume benzene and other hydrocarbons. This activity is observed through bacterial respiration when in soil-vapor samples drops and C rises. Respiration is a direct result of hydrocarbon degradation. Percent and C C SV Days elapsed from SVE shutdown Many parts of the vadose zone at the BFF site have been treated and are now clean. These locations can be identified by their very-low hydrocarbon concentrations and sustained atmospheric and C signatures. KAFB KAFB Soil Vapor Extraction Wells Groundwater Flow Hydrocarbon ppmv Percent and C Days elapsed from SVE shutdown C Days elapsed from SVE shutdown

10 Vadose Zone Remediation Technologies Bioventing Bioventing works by injecting oxygen into the vadose zone to increase bacterial growth and biodegradation rates, leading to faster degradation of fuel contaminants. Some types of bioventing may also use nutrients or moisture to enhance biodegradation. Low-flow Air Injection Blower Contaminant Mass O O Microbial Population Air Injection Wells GroundwaterFlow KAFP_15_ 7 = Air Flow Ambient Air To Atmosphere Vapor Separator Vacuum Injection/ Blower Soil Vapor Extraction (SVE) Catalytic Thermal Oxidizer Soil Vapor Extraction Wells Groundwater Flow KAFP_15_5 The SVE system pulls contaminated vapor from the ground and uses high temperatures to burn off contaminants. Treated air is tested to ensure it is clean and then released to the atmosphere. SVE is most effective for treating moderately high levels of hydrocarbon vapor.