New Analytical Approaches to Long-Term Monitoring & Regulatory File Closure. Steve Hilfiker Environmental Risk Management, Inc.

Transcription

1 New Analytical Approaches to Long-Term Monitoring & Regulatory File Closure Steve Hilfiker Environmental Risk Management, Inc.

2 We have come a long way Right: Popular Science, 1963

3 Brownfield Success Story

4 Introduction Regulatory Trends Evaluate Long-Term Monitoring Degradation Analyses Solutions to Benzo(a)pyrene Regulatory Closure Methods

5 Regulatory Trend toward Passive Remediation The 2016 Florida legislature enabled passive remedial techniques, such as natural attenuation and risk-based corrective action. There have never been as many methods to close a discharge file as there are now. This presentation also outlines the many alternatives now available to consultants, developers and other Brownfield stakeholders.

6 Revisions to , FAC Summary: more risk assessment, RBCA, monitoring, and alternative cleanup target level procedures. The most significant revisions are in:.500 Emergency Response.525 Interim Source Removal.650 Risk Assessment.680 NFA & NFA with Controls.690 Natural Attenuation Monitoring

7 Summary of SB 100 (Florida) Effective July 1, 2016 Defining: "background concentration" and "long-term natural attenuation" DEP is to include protocols for the use of long-term natural attenuation where site conditions warrant; Provides that institutional controls are not required under certain circumstances if alternative cleanup target levels are used

8 (2) Legislative Intent More Risk Assessment, RBCA & NAM (g) Using risk-based corrective action principles, the department shall approve alternative cleanup target levels in conjunction with institutional and engineering controls, if needed, based upon an applicant s demonstration, using site- specific or other relevant data and information, risk assessment modeling results, including results from probabilistic risk assessment modeling, risk assessment studies, risk reduction techniques, or a combination thereof, provided that human health, public safety, and the environment are protected

9 Background concentration (4) Background concentration means the concentration of contaminants naturally occurring or resulting from anthropogenic impacts unrelated to the discharge of pollutants or hazardous substances at a contaminated site undergoing site rehabilitation. Common Examples: Benzo(a)pyrene Arsenic The same definition is now in (3) in the Brownfields Section

10 Long-term natural attenuation (LTNA) (24) Long-term natural attenuation means natural attenuation approved by the department as a site rehabilitation program task for a period of more than 5 years. The same definition is now in (13) in the Brownfields Section. Both of the (3) (background) and (13) (LTNA) definitions relate to Brownfields Redevelopment Act. As used in ss

11 RBCA & LTNA Application of risk-based corrective action principles to contaminated sites; applicability; legislative intent; (2) These rules must include protocols for the use of natural attenuation, including long-term natural attenuation where site conditions warrant, the use of institutional and engineering controls, and the issuance of No Further Action orders.

12 Balance Risk Management and Economic Development

13 Natural Attenuation Monitoring (NAM) One of the best uses of funds: NAM if attenuating One of the worst uses of funds: NAM if not attenuating Q: Where and when do site conditions warrant LTM? A: Low level impacts, risk-managed impacts, or where degradation has been confirmed.

14 Attenuation Factors MUST HAVE A GOOD ASSESSMENT Discharge facts: location, quantity and water table NAPL, soil impacts, leaching ongoing sources Bio/Geochemical conditions Lithology and hydrogeology Source removal or remediation

15 Long-Term Monitoring Evaluations Purpose: to assess natural attenuation success rates and time ARCADIS & ERMI evaluated 65 sites, all long-term NAM Strategic decision-making when to switch to remediation and when to amend natural attenuation monitoring scopes of work. Linear regression trend analyses chemical concentration versus time data

16 NAM Evaluation Results Closure Timeframe 86 Total Sites Evaluated 65 Linear Regression Analyses Completed Number of Sites Time to Reach GCTLS 43 >10 years years years 11 <2 years 3 Unknown 66% of the sites evaluated indicated > 10 years to get to GCTLs 17% of the sites evaluated indicated < 2 years to get to GCTLS

17 NAM Evaluation Results & Recommendations Number of Sites Recommendation 29 Site Assessment/LSRAP 16 Continue NAM 20 Continue NAM Modified 21 Site Didn t meet LR/other Criteria 45% of the sites evaluated recommended SA/LSRAP 31% of the sites evaluated recommended Modified NAM 32% of the sites didn t have sufficient data to conduct NAM evaluation Technical basis for decisions cost savings for continued monitoring or pursue additional remediation Administrative and site owner considerations

18 Natural Attenuation Monitoring (NAM) vs. Long Term Natural Attenuation (LTNA) Natural Attenuation Monitoring. (1) Natural Attenuation Monitoring and long-term natural attenuation monitoring are allowable strategies

19 Natural Attenuation Monitoring Endpoint estimated or known Conditions favorable Source areas addressed Low concentrations remain in groundwater Defined NAM plan

20 Long Term Natural Attenuation Expected long monitoring period Conditions may not be favorable Technical & cost considerations Monitoring for stability/conditional closure or regulatory considerations

21 Approaches for evaluating attenuation in groundwater How to determine if LTM will be a sufficient remediation approach? Is leaching ongoing, making LTM ineffective? How to determine if a site is actually degrading?

22 Compound Specific Isotope Analysis (CSIA) Source: Robert J. Pirkle, Pace Analytical Energy Services, LLC A division of Pace Analytical Services, Inc. CSIA is a method to assess biodegradation. Elements have a known isotopic ratio (i.e., C13 and C12). Degradation breaks bonds and causes isotopic change. CSIA measures the changes in isotopic ratios as a compound biodegrades.

23 Isotope Ratio MassSpectrometer (IRMS) FID Compound 1 Compound 2 P / T O 940 C CO from Compound 1 2 CO from Compound 2 2 Magnet Ion Source Faraday Cups Purge & Trap Gas Chromatograph Combustion Oven Isotope Ratio MassSpectrometer Combustion Oven Chemistry

24 Effective on most Volatile Organics Lighter benzene and toluene, elute early, effective. Ethyl benzene and xylenes have co-elution issues. Complex mixtures such as petroleum, not as effective Chlorinated solvents are usually not part of such complex mixtures, so yes, most of the time...

25 Stable Isotopes in In-Situ Degradation Significant Fractionation Occurs in: Biological Oxidation Biological Reduction Abiotic Degradation In-Situ Chemical Oxidation In-Situ Chemical Reduction

26 No Biodegradation No Fractionation: Dilution, Volatilization, Sorption Changes in isotopic ratio caused by breaking bonds. Dilution, diffusion and volatilization don't measurably change the isotopic ratio of VOC's in ground water.

27 Biodegradation Provided there is no new or ongoing release, NAPL, or desorption from soil For VOC's in ground water, degradation of a compound is the only significant cause of change to the isotopic ratio of the compound. How to confirm no new release? (Forensics )

28 Fresh gasoline

29 Weathered gasoline

30 The Before Condition

31 The After Condition

32 PIANO Analysis P Paraffin, Isoparaffin, Aromatic, Naphthene, Olefin 60% 50% 40% High Resolution Composition Analysis Gives a detailed fingerprint of specific hydrocarbons and is useful in product type identification: higher aromatic = higher octane O 30% 20% 10% 0% I Useful in estimating amount of weathering N A Gas Av Gas JP4

33 Degradation of Toluene 350 Concentration Toluene [nm] Time [days] Meckenstock, et al., 1999.

34 Degradation of Toluene Toluene [nm] Concentration δ 13 C δ 13 C [ 0 / 00 ] Time [days] -30 Meckenstock, et al., 1999.

35 Stable Isotopes in In-Situ Degradation Fractionation is proof of in-situ degradation Related to the mechanism of degradation Related to the fraction of component degraded Related to the rate of degradation Used in groundwater modeling

36 USEPA Guide for CSIA John Wilson USEPA Daniel Hunkeler U of Neuchatel, Switzerland Rainer Meckenstock Institute of Groundwater Ecology, Germany Torsten Schmidt U of Duisburg-Essen, Germany Barbara Sherwood-Lollar U of Toronto, Canada

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40 Benzo(a)pyrene the NFA Inhibitor Very prevalent and persistent in the Florida environment Common sources of BaP in Florida: natural anthropogenic pyrogenic (derived from combustion) petrogenic (derived from petroleum)

41 Common Sources Marinas where dredge and fill operations deposited marine sediments; Manufactured gas plants producing coal tars; Operations involving creosote or wood preservation; Sites located near sources of industrial combustion; & Sites located near historical structural or natural fires

42 Pyrogenic or Petrogenic? Parent (non-alkylated) PAHs (C 0 ) are more abundant than C 2 or C 3 alkylated PAH in pyrogenic sources. The opposite pattern is evident in petrogenic sources.

43 GCMS Full Scan Modified 8270 analysis using numerous hydrocarbon standards. Effective for distinguishing pyrogenic from petrogenic PAHs. Chromatograms evaluated by compound classes for fingerprinting. From distributions observed in the chromatography, source materials can often be distinguished. Sample must be homogenous and not a mixture.

44 Case Study BaPs could exist at any site, and an analysis of the site historical land uses and regional combustion sources would be necessary to evaluate the potential for impact.

45 Pyrogenic Characterization PAH characterization GC/MS Full Scan

46 File Closure Methods 1. LTM 2. Background or Anthropogenic 3. Low-Score Site Initiative (LSSI) 4. LSSI NFA 5. Limited Remediation via LSSI 6. FDOT MOU 7. RBCA w/wo RCs 8. Alternate CTLs 9. Remediation

47 Common Strategies Low-Score Site Initiative (LSSI) Voluntary assessment for No Further Action Successful Program in Florida Risk Management Options (RMO) Conditional No Further Action Restrictive Covenant prohibiting water use Engineering controls to prevent exposure to impacts. Long Term Monitoring

48 FDEP/FDOT Memorandum of Understanding (MOU) For sites with impacts that cross into Right of Way. Could qualify for closure if DOT approves. The MOU establishes criteria that would enable regulatory closure. Mapping location. Reopener provisions.

49 Education Since there are now more voluntary strategies than ever before, consulting has never been more important. Reliance on NFA Security for Lenders and Property Owners Local Government Transportation Facilities Reopeners The long term objectives for each site should be evaluated by a professional consultant to assist with the selection of the best strategy for each site.

50 Thanks! Thanks, Steve Steve Hilfiker President P: C: Environmental Risk Management, Inc.