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The State-of-the-Practice of Characterization and Remediation of Contaminated Sites. Jeffrey A. Adams, PhD, PE Krishna R. Reddy, PhD, PE, D.GE. Presentation Outline. Historical context and regulatory framework Evolution in practice Site characterization Risk assessment Site remediation
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The State-of-the-Practice of Characterization and Remediation of Contaminated Sites Jeffrey A. Adams, PhD, PE Krishna R. Reddy, PhD, PE, D.GE
Presentation Outline • Historical context and regulatory framework • Evolution in practice • Site characterization • Risk assessment • Site remediation • Questions
Presentation Outline • Historical context and regulatory framework • Evolution in practice • Site characterization • Risk assessment • Site remediation • Questions
Petroleum Industry • Between 1950 and 1972, world energy consumption increased 179% • Doubled per capita consumption • Oil consumption rose from 29% of energy consumption in 1950 to 46% in 1972 • 47% of US energy consumption by 1973 • 64% of western Europe; 80% of Japan energy consumption by 1973 • Petrochemicals were rapidly replacing glass, wood, natural rubber, iron, copper, aluminum, and paper
Pesticide Use • Tenfold in pesticide expenditures between 1945 and 1972 • Pesticide production • Less than 100 million pounds in 1945 • Over 600 million pounds by 1960 • Herbicide use • 1952, 11% of corn and 5% of cotton acreage • 1982, risen to 95% of corn and 93% of cotton Source: livinghistoryfarm.org
Donora 1948 Smog Disaster • Monongahela River Valley mill town • In 5 days, 20 died and 7,000 became sick • Temperature inversion trapped noxious emissions • Sulfur dioxide • Carbon monoxide • Metal dust Source: www.pollutionissues.com
Air Pollution Control Act • Passed in 1955 • Initial attempt at addressing growing air pollution • Acknowledged air pollution was a growing threat to public health • Limitations • Deferred authority to states • Did not include power to sanction or penalize
1969 Santa Barbara Oil Spill • Blowout of oil well • 3 million gallons of crude oil spilled, fouling beachesand wildlife • Inspired the formation of Earth Day • Sierra Club membership reportedly doubled in the following 2 years
Grass Roots Inspiration and Reaction • 1962 – Silent Spring • Reaction to DDT spraying for mosquitoes • Contributed to ban in US • 1968 Apollo 8 mission • 1970 – Earth Day • Political groups • Business groups • Activist groups
Solid Waste Disposal Act (SWDA) • 1965, 1970 –first federal legislation regulating municipal solid waste • Reduction of solid waste volumes to protect human health and environment • Improvement of waste disposal practices • Provisions funds to individual states for solid waste management • 1970 Amendments • Encouraged further waste reduction and waste recovery • Created system of national disposal sites for hazardous waste National Environmental Policy Act (1969) • Council of Environmental Quality, a new executive branch agency Environmental Protection Agency • Environmental Impact Statement (EIS) for any federal project
Clean Water Act (CWA) and Safe Drinking Water Act (SDWA) • CWA 1977, 1981, and 1987 – Regulates discharges into U.S. waters • 129 priority pollutants were identified as hazardous wastes • National Pollutant Discharge Elimination System (NPDES) permitting • Dredged material discharge only allowed with permit • Wastewater discharge treatment requirements • Discharges from POTWs must meet pre-treatment standards • SDWA 1974, 1977, and 1986 – Protection of drinking water quality • MCLs, primary and secondary goals • Regulation of hazardous waste injections into subsurface • Designation and protection of aquifers
Toxic Substances Control Act (TSCA) • 1976 – Regulation and use of hazardous chemicals • Industries required to report/test chemicals that may pose an environmental or human health threat • Prohibition of the manufacture and import of chemicals that pose an unreasonable risk • Requirement of pre-manufacture notifications to the USEPA • Prohibition of PCBs • Management of asbestos
Unintended Consequences… • Many of the previous acts lacked enforcement ability and had loopholes • Encouraged “shortcut” behaviors • Few landfill regulations
Resource Conservation and Recovery Act (RCRA) - 1976 • Passed to manage nonhazardous/hazardous wastes, USTs • Emphasis on recovery/recycling instead of disposal • Subtitle C – control of hazardous wastes • Subtitle D – management of nonhazardous wastes • Subtitle I – UST regulations • Amendments in 1984 • Restrictions on liquid waste • New UST regulations • Landfill liner, leachate collection, and monitoring requirements • Small generator and TSDF requirements • USEPA authorized to inspect, enforce, and penalize
Love Canal • Toxics placed in canal; capped with clay • Residential and school construction on top of canal • Noxious odors and acute health problems observed • Confirmed presence of widespread soil and groundwater contamination • U.S. government paid for the relocation of hundreds of residents
Comprehensive Environmental Response, Compensation, and Liabilities Act (CERCLA), or “Superfund” (1980) • Addresses abandoned/uncontrolled hazardous waste sites necessitating immediate cleanup • Fund from taxes on chemical/petroleum companies • $1.6 Billion ($5 Billion in 2011 dollars) • Identified PRPs as current or past owners of site as well as generators and transporters • Hazard Ranking System • Population, degree/nature of contamination, pathways • Sites scoring “high enough” added to National Priorities List • Methods evolved to study sites • Remedial Investigation – characterizes site • Feasibility Study – considers remediation alternatives
Superfund Amendments and Reauthorization Act (SARA) • $8.5 billion for site cleanup; $500 million for USTs • $18.9 billion and $1.1 billion in 2011 dollars, respectively • Established community right-to-know provisions • Standard framework – Applicable or relevant and appropriate requirements (ARARs) – chemical specific, action specific, and location specific • Established liability for innocent purchasers and landowners • Gave rise to Phase I, II, and III studies • Also, annual hazardous substance release reporting requirements
CERCLA/RCRA – ESA1 • Often driven by property transaction • Many “flavors” (screen, update, PEA); “strongest” flavor provides liability protection – AAI – ASTM 1527-05 • Clear requirements about content, shelf life, etc. • Report summarizes site history • Radius report • Aerial photographs • Topographic maps • Title reports/lien search • File reviews of numerous agencies • Interviews • Identify data gaps • Recognized Environmental Conditions (RECs)
CERCLA/RCRA – ESA2 • Follow-up on findings of Phase One ESA • Field characterization • Soil, groundwater, soil vapor • First efforts often general; follow-up work may occur • Soil, groundwater, and/or soil vapor sampling • Laboratory analysis for target analytes • Consider results with screening values • MCLs, PRGs/RSLs, state criteria
CERCLA/RCRA – ESA3 • Goal: remediate the site to an acceptable level of risk for future use • Dependent on anticipated land use • Regulatory oversight – NFA status • Develop a remedial approach to mitigate site contamination • Cost-benefit analysis • Cash flow considerations • Tax incentives • “Real time” and post-remediation monitoring
CERCLA Progress • When enacted, 36,000 sites identified; 1,200 placed on NPL • As of end of FY 2010 • 1,627 sites remain on NPL • 475 sites have been closed • $40 million per site (2011 $); 11 years on average to close • $40 million x 1,627 = $65.1 billion • $1.2 billion / 400,000 LUSTs = $3,000 per LUST • $6 billion in trust in 1996 exhausted by 2003 (general Congressional appropriations since 2003)
CERCLA Progress (Cont.) • EPA Superfund 2008 FY progress: • Controlled all identified unacceptable human exposures at a net total of 24 sites, exceeding the annual target of 10” • “Controlled the migration of contaminated ground water through engineered remedies or natural processes at a net total of 20 sites, exceeding the target of 15 for the year” • Spent $500 million
Brownfields Concepts and Framework • Desire to pursue “land recycling” • remediate to anticipated land use and exposure • Small Business Liability Relief and Brownfields Revitalization Act (2002) • Promotes cleanup and reuse of brownfields • Liability relief to small businesses • Provides financial assistance • Enhanced state programs • Liability protection for prospective purchasers, contiguous property owners, and innocent landowners
Legal and Engineering Controls • Land use legal controls • Deed restrictions • Easements for long-term monitoring • Engineering controls • Vapor barriers • Venting systems • Long-term collection and treatment
Voluntary Site Remediation Programs • Collaborative local/state framework • Voluntary agreement between RP and agency • Often feature a formal agreement w/ timeline, cleanup goals, and reimbursement • Goal is to achieve a No Further Action (NFA) Status • Cost-benefit analyses are common to select remediation alternative
Presentation Outline • Historical context and regulatory framework • Evolution in practice • Site characterization • Risk assessment • Site remediation • Questions
“Traditional” Soil and Groundwater Characterization • Soil sampling and laboratory analysis • Groundwater • Monitoring wells • “Grab samples” • Precise, quantitative (and expensive) data • USEPA SW-846 • Guidance for compliance with RCRA regulations • Basis for other methods
Direct Push Soil and Groundwater Sampling • Cost-effective alternative to conventional rotary drilling • Reduces IDW volume • Soil • Groundwater • “Grab” sampling • Temporary or permanent packed wells
Innovative Characterization Technologies • Analytics • Membrane Interface Probe • X-ray Fluorescence • Fiber Optic Chemical Sensors • Laser-induced Fluorescence • Immunoassays • Geophysics • Ground Penetrating Radar • Magnetics
Membrane Interface Probe (MIP) • Advanced with direct push rig • Continuous, real-time profile of hydrocarbon/VOC impacts • Three detectors used to analyze a range of contaminants • Electron capture detector (ECD) • Photo ionization detector (PID) • Flame ionization detector (FID) • Semi-quantitative locating of “hot spots”
X-Ray Fluorescence • Hand-held field unit or direct-push system • Soil bombarded with x-rays; induces fluorescence • “Hits” are unique to element (more hits = higher concentration) • Portable, fast, multiple analyses; best for metals • Detection limits exceed action levels for some analytes • Licensing issues due to radioactive source
Fiber Optic Chemical Sensors (FOCS) • Optical fiber used to transport light • Interaction of the analyte with fiber creates a detected reaction • Absorbance • Reflectance • Fluorescence • Light polarization • Detected intrinsically or extrinsically • Real-time, transmits a long distance, multi-compound analysis • High detection limits, gross estimation, time and temperature sensitivities
Laser-Induced Fluorescence • Fiber optic-based, direct push system • Induces fluorescence of aromatic compounds or PAHs • Peak wavelength and intensity used to infer contaminant type or relative concentration • Real-time; semi-quantitative • No cuttings, continuous logging, minimally invasive • Cost-prohibitive on small projects • Select minerals and organic matter may cause interference
Immunoassays • Use of biological systems to detect target analytes (organic compounds, some metals) • Colorimetric analysis based on analyte and relative concentration • Compared with standard chart or with photometer • Fast, easy, portable, inexpensive low detection limits • Pre-prediction of target analytes, some analytes yield questionable results, field conditions can affect reactions
Ground Penetrating Radar (GPR) • GPR uses high frequency pulsed electromagnetic waves • Energy is propagated downward and reflected back, showing contrasts • Locate pipes, drums, tanks, cables, and boulders, landfill and trench boundaries, mapping contaminants • Easy; non-intrusive; in-field data review possible • Interpretation requires skilled personnel; depth of penetration affected by subsurface conditions
Magnetics • Used for locating subsurface ferrous alloys • The stronger the force, the greater the ferrous mass • Used to locate drums, tanks, pipes, ordnance, abandoned well casings, boundaries of landfills (if ferrous metal present), and mineralized iron ores • Simple, portable, easy to operate, accurate, less susceptible to interference • Limited information on depth, specific applicability
Fractured Rock • Contamination presents several challenges • Contaminant movement along bedding planes, joints, fractures • Fluid diffusion into the matrix • NAPL flow very complex • Capillarity, gravity, viscosity considerations • Downhole geophysical methods • Televiewers (optical and acoustic) • Coring methods • Groundwater flow modeling • Pumping tests • Monitoring wells • Tracer testing • Flowmeter testing
Dense Nonaqueous Phase Liquids (DNAPLs) • Heavier than water; low solubility; pooling issues • Often difficult to find source • Traditional soil and groundwater sampling is “hit-or-miss” • Geophysical methods • Innovative characterization technologies • Membrane interface probe • Laser-induced fluorescence
Triad - EPA • EPA framework for site characterization and remediation that incorporates three key principles: • Systemic planning – key decisions, conceptual site model, identifying and mitigating potential uncertainty • Dynamic work strategies – characterization and monitoring; flexibility to make decisions based on incoming data • Real-time measurement – rapid lab TAT, mobile lab, characterization technologies
Soil Vapor Sampling • Vapor samples collected directly from subsurface • Temporary or permanent sampling wells • Replacing modeling and passive indoor sampling • Leak detection methods • Common compounds applied at connections • Positive pressure inert gas environment (“shroud”)
Mass Flux/Mass Discharge Approach • Alternative to analysis based on point concentrations • Mass flux – mass/time/area • Mass discharge – mass/time • Parameters can help answer: • Is plume stable? • How will remediation affect fate/transport? • When to introduce additional remedial technologies? • Transect method, well pumping, or in-well meters
Presentation Outline • Historical context and regulatory framework • Evolution in practice • Site characterization • Risk assessment • Site remediation • Questions
Pre-Risk Era (Early 80s) • Remediation goals often set to “pristine” condition/restoration • e.g., groundwater MCLs • Proved to be cost and time prohibitive
Emergence of Risk Era • National Research Council/National Academy of Sciences (NRC/NAS) • RED BOOK (1983) Risk Assessment in the Federal Government: Managing the Process • Addressed health risk assessments across all Federal Agencies • Defined four-step risk assessment process • Steps used in several EPA statutes but with different methods (e.g., RCRA, CERCLA, FIFRA, TSCA)
Hazard Identification • Determines if a compound is causally linked to health effects at environmentally relevant concentrations • Select Chemicals of Potential Concern (COPC) • Establish relationship between each COPC and adverse health effects (review tox. data) • Determine “critical” health effect for each COPC • Evaluate scientific weight-of-evidence for “critical” health effects (cancer and non-cancer)