Beyond TPH. John Fitzgerald Massachusetts Department of Environmental Protection

Transcription

1 Beyond TPH John Fitzgerald Massachusetts Department of Environmental Protection

2 Characterizing Petroleum Contamination Source Migration Screening: PID, TPH ID/Detailed: GC, GC/MS

3 Risks Posed by Hydrocarbons Impacts to water supplies Vapor Intrusion Direct Contact w/ Children Direct Contact w/ Workers Impacts to Aquatic Life

4 How do we characterize Risks? Test For/Focus on Indicator Compounds Test for/focus on Total Hydrocarbons Ignores many BTEX other hydrocarbon PAHs components Method Gravimetric Defined Gas No/Limited Chromatography Info on Toxicity

5 Is there a better way? to quantify ALL hydrocarbons consistently in a risk-based manner?

6 Hydrocarbon Range Approach 1994 MassDEP TPH Criteria Working Group

7 The Premise Petroleum is mostly made up of aliphatic and aromatic hydrocarbons Aromatic compounds are more toxic than aliphatic compounds The toxicity of aliphatic compounds is a function of molecular weight/number of carbon atoms

8 The Concept Break up TPH into collective fractions of aliphatic and aromatic compounds Break up aliphatic fractions by carbon number Assign a toxicity value to the fractions based upon a well characterized surrogate compound(s) contained within the fraction

9 BTEX & Target PAHs The Concept C 11 -C 22 Aromatics C 9 -C 18 Aliphatics C 19 -C 36 Aliphatics Average Values from Data Set of 145 Soils Samples impacted by #2 Fuel (MassDEP, 2007)

10 Toxicological Metrics [MassDEP] Hydrocarbon Fraction RfD (mg/kg/day) RfC (mg/m3) C5-C8 Aliphatics C9-C18 Aliphatics C19-C36 Aliphatics 2.0 NA C9-C22 Aromatics

11 What about BTEX/Target PAHs? Still Quantify and Evaluate Individually Continuation of Tradition! Addresses Carcinogenic Effects Quantify Aliphatic and Aromatic Hydrocarbon Fractions to Address The Rest of the Stuff

12 Making it Work Develop and validate analytical methods to provide needed data Develop generic Tier I cleanup standards for aliphatic/aromatic fractions 1997 Issue Implementation Guidance 1997 & 2002 Conduct training/outreach 1995 to present

13 Air/Vapor Soil & Groundwater $100 to $125 $180 to $200 $225 to $275 Analytical Methods (MassDEP) Volatile Petroleum Hydrocarbons (VPH) GC/PID/FID purge and trap technique PID selectivity to differentiate aliphatics from aromatics Extractable Petroleum Hydrocarbons (EPH) extract loaded onto silica gel, rinsed with hexane to strip aliphatic portion, then MeCl to strip aromatic portion both fractions analyzed separately via GC/FID Air-phase Petroleum Hydrocarbons (APH) Aromatic Range via extracted ions 120 & 134 m/z Aliphatic Range via Total Ion Chromatogram Each Method also quantifies BTEX/PAH Target Analytes

14 JP4 Contaminated Soil VPH by GC/FID/PID C5-C8 Aliphatics C9-C12 Aliphatics IS 4 6 Aliphatics & Aromatics GC/FID QC Compounds (mod.) IS - 2,4-Difluorotoluene SS1 - Fluorobenzene SS2-2-Fluorobiphenyl IS 2 SS1 5 C9-C10 Aromatics SS2 Aromatics GC/PID (10.2 ev) Target Compounds 1 - MtBE 2 - Benzene 3 - Toluene 4 - Ethylbenzene 5 - m/p-xylene 6 - o-xylene 7 - Naphthalene 0 10 Time (min.) 20 30

15 Diesel Contaminated Soil EPH by GC/FID 300K C9-C18 Range Aliphatics C19-C36 Range Aliphatics Aliphatics GC/FID QC Compounds (mod.) IS1 SS1 IS2 SS2 IS1-2,4-Dibromotoluene IS2 - o-terphenyl SS! - 5a-Androstane SS2-5a-Cholestane SS3 - Fluorobenzene SS4-2-Fluorobiphenyl 70K SS3 IS1 1 C11-C22 Range Aromatics 2 SS4 IS Aromatics GC/FID Target Analytes 1 - Naphthalene 2-2-Methylnaphthalene 3-1-Methylnaphthalene 4 - Acenaphthene 5 - Phenanthrene Time (min)

16 #2 Fuel Oil Vapors APH by GC/MS Total Ion Chromatogram Extracted ions 120 m/z & 134 m/z used to quantify C 9 -C 10 Aromatic Hydrocarbons

17 Generic (Tier I) Standards Developed for all aliphatic/aromatic fractions Developed for soil and groundwater Followed existing MassDEP approach soil stds address direct contact & leaching groundwater stds address ingestion, aquatic, and volatilization concerns

18 MassDEP Direct Contact Soil Standards [mg/kg] Fraction Residential Industrial C 5 -C 8 Aliphatics C 9 -C 12 Aliphatics C 9 -C 10 Aromatics C 9 -C 18 Aliphatics C 19 -C 36 Aliphatics C 11 -C 22 Aromatics

19 Benefits of Approach Allows for Risk-Based TPH Clean Ups Works no matter what the product, or mixture of products, or degree of weathering Relatively simple and cost effective Proven Track Record (1997 Present)

20 But Nothing is Perfect.. The totality of procedures, assumptions, and standards are designed to be reasonably but not excessively conservative (health protective) at most petroleum contaminated sites but Non-petroleum contaminant background can lead to overly conservative results at some sites Especially with indoor air (APH) data.

21 Air-Phase Petroleum Hydrocarbons (APH) APH bias is more problematic than VPH/EPH tests on soil and groundwater, given background stuff in indoor air: Fuel Oil/Gasoline if stored/used on-site Common household chemicals

22 Indoor Air Background

23 Air-Phase Petroleum Hydrocarbons (APH) Table 7 of the MassDEP Method Potential Non-APH Compounds C 5 -C 8 Aliphatic Hydrocarbons C 9 -C 12 Aliphatic Hydrocarbons C 9 -C 10 Aromatic Hydrocarbons Acetone may co-elute/interfere with isopentane. Isopropyl alcohol, methyl ethyl ketone, trichloroethene, tetrachloroethene, tetrahydrofuran, hexanal, 1-butanol, hexamethylsiloxane Terpenes (e.g., a-pinene, d-limonene), phenol, benzaldehyde, n-chain aldehydes, 2-ethyl-1- hexanol, siloxanes, dichlorobenzenes Siloxanes, a-pinene, and d-limonene may slightly interfere if present at high concentrations (contribute to the area of ions 120/134)

24 Toluene Example Fuel Oil Spill in Westfied, MA Basement Air APH Total Ion Chromatogram IS BFB C5-C8 Hydrocarbons? p/m Xylenes Very Low Fuel Oil Hydrocarbons

25 Example Fuel Oil Spill in Westfied, MA Basement Air APH Total Ion Chromatogram Ethanol Ethyl Acetate MEK PCE Freons And Similar Chromatogram for Second Floor

26 Take-Home Message Need to look at Chromatograms! Be aware of background organic compounds that will be quantified as TPH or Aliphatic/Aromatic Range Hydrocarbons

27 To Learn/Download More Google Mass DEP VPH/EPH/APH Contact Person - John Fitzgerald John.J.Fitzgerald@state.ma.us