The Answers
1. Question: For number 2 fuel oil (No. 2 fuel oil) and diesel fuel oil (diesel) soil contamination, why the switch to base neutral (BN) compound testing from volatile organic (VO) compound testing when extractable petroleum hydrocarbon (EPH) contamination exceeds 1,000 mg/kg?
Answer: The basis for this change is two-fold.
First, it is reported that soil testing at homeowner No. 2 fuel oil cases is not detecting VO compound concentrations above regulatory concern, and that BN compound concentrations of regulatory concern might be present. The absence of VO compounds in No. 2 fuel oil is not entirely unexpected as they are present at relatively low levels in the pure product which has a relatively high boiling point range of 200 to 350 degrees Centigrade (note that gasoline has a boiling point range of 40 to 200 degrees Centigrade). The Total Petroleum Hydrocarbon Criteria Working Group (Volume 2, Composition of Petroleum Mixtures by T. Potter and K. Simmons, 1998) reports the following average levels of VO compounds for No. 2 fuel oil: Benzene (0.03%); Toluene (0.2%); Ethylbenzene (0.07%); Total Xylenes (0.5%), and 1,3,5-Trimethylbenzene (0.2%). Also, these low level VO compounds contaminants are subject to degradation once the discharge has occurred, potentially further reducing their presence.
Second, the BN compound analysis is needed to monitor on a contaminant-specific basis two known components of No. 2 fuel oil/diesel: naphthalene and 2-methylnaphthalene. The reasons why the New Jersey Department of Environmental Protection (Department) is interested in these specific compounds are explained further under Questions and Responses 4 and 5. Consequently, the change to BN compound analysis has been implemented.
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2. Question: Will the changing of the requirement to test for BN compounds rather than VO compounds for No. 2 fuel oil/diesel soil contamination result in the need to issue deed notices for compounds such as benzo(a)pyrene at residential sites?
Answer: Because the soil remediation standards for polyaromatic hydrocarbon (PAH) compounds are very low (i.e., the soil remediation standard for benzo(a)pyrene is 0.2 mg/kg), the presence of PAHs may trigger the need for remedial actions. However, investigation by the Department indicates that PAHs are not expected to be found in No. 2 fuel oil (and similarly diesel) except at trace levels. Also, because No. 2 fuel oil and diesel are distillate products, the Department does not anticipate that PAH compounds like benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, and indeno(1,2,3-cd)pyrene would be major components of these mixtures. The results obtained at 14 New Jersey residential sites contaminated by No. 2 fuel oil (described in http://www.nj.gov/dep/srp/guidance/rs/phcguidance.pdf) indicate that PAHs were typically below detection limits and if observed, not above levels of regulatory concern.
Therefore, the Department has determined, based on the weight of the available information, that at residential sites the BN compound analysis and any subsequent remedial actions will be restricted to only those compounds of interest associated with No. 2 fuel oil (and similarly for diesel). Specifically, this means the required BN compound analysis triggered at 1,000 mg EPH/kg need only consist of naphthalene and 2-methylnaphthalene.
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3. Question: How will naphthalene be regulated? A recommendation was made that if naphthalene contamination above levels of regulatory concern (6 mg/kg for a residential exposure scenario) is present at 5 feet or more below grade and there is no adverse impact to ground water, an institutional control should not be required.
Answer: The Department is required to evaluate whether changes in future use of the site will lead to adverse risks to human health and the environment. While the contamination currently may not be a concern (because of its depth), that is true only if the status quo is maintained. If brought to the surface, the contamination would represent an adverse impact to human health and the environment. Consequently, an institutional control (i.e., deed notice) is needed to inform the public of the presence of the contamination as well as to assure that the contamination remains under its current circumstances and continues to not pose a hazard. Irrespectively, the Department does not at this time expect naphthalene to be a significant issue with regards to No. 2 fuel oil or diesel remediations. The reader is referred to Question and Response 4.
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4. Question: How is naphthalene, which has a low soil remediation standard, being addressed?
Answer: The results of the Department study involving 14 residential No. 2 fuel oil discharges (described in http://www.nj.gov/dep/srp/guidance/rs/phcguidance.pdf) indicate that levels of regulatory concern for naphthalene (6 mg/kg for a residential exposure scenario) only were observed where the 5,100 mg/kg EPH criterion was exceeded, and therefore, where remediation would already be required. Consequently, a BN compound scan at 1,000 mg EPH/kg allows naphthalene to be evaluated on a compound-specific basis well before the EPH concentration at which the Department believes naphthalene becomes a real concern.
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5. Question: How will potential impacts to ground water by No. 2 fuel oil or diesel be addressed?
Answer: The Department has concluded that residual No. 2 fuel oil (and therefore diesel as well) does not appear to be a threat via the impact to ground water exposure pathway except for 2-methylnaphthalene. This position is in large part based on the mobility and toxicity of 2-methylnaphthalene. Using the soil-water partition equation, the impact to ground water guidance criterion for this compound is 5 mg/kg. The results of the Department study involving 14 residential No. 2 fuel oil discharges (described in http://www.nj.gov/dep/srp/guidance/rs/phcguidance.pdf) suggest that levels of regulatory concern for 2-methylnaphthalene as relates to the impact to ground water exposure pathway may be exceeded when the EPH concentration exceeds 1,200 to 1,600 mg/kg. This is below the remedial goal for EPH and is why contaminant specific monitoring for 2-methylnaphthalene (via the BN compound analysis) is recommended at 1,000 mg EPH/kg or greater. In this way the compound-specific risk may be assessed directly.
The Synthetic Precipitation Leaching Procedure option may be applied to 2-methylnaphthalene (see http://www.nj.gov/dep/srp/guidance/rs/splp_guidance.pdf). This may allow the use of a value other than the soil-water partition equation value of 5 mg/kg in combination with 5,100 mg EPH/kg. The Department has determined that only samples in excess of 1,000 mg EPH/kg may be subjected to SPLP analysis.
Where the tank volume is 550 gallons or less, it is expected that a limited number of samples will be available for base neutral (BN) compound analysis and SPLP evaluation. Consequently, a worst case approach will be followed for these situations.
BN compound analysis is required on the highest EPH concentration(s) for 25 percent of all samples with EPH concentrations above 1,000 mg/kg. If the 5 mg/kg standard for 2-methylnaphthalene is exceeded by any of these results, the options are to:
- Remove/treat additional materials to eliminate all BN compound exceedances as verified by post-excavation/treatment sampling and testing, or
- Determine compliance using the SPLP protocol.
If the second option is employed, the SPLP evaluation will be performed on the sample with the highest 2-methylnaphthalene concentration (if in fact there is more than one). If the 2-methylnaphthalene leachate concentration from the SPLP analysis is equal to or less than the 2-methylnaphthalene leachate criterion (the ground water quality standard [30 ug/L] adjusted for the dilution attenuation factor [13], equals 390 ug/L for Class II ground water), the remediation is considered acceptable. If the 2-methylnaphthalene leachate concentration from the SPLP exceeds the 390 ug/L leachate criterion, removal/treatment of contaminated material will be required and the options to verify compliance using BN compound analysis or the SPLP protocol are again permitted to be employed. Recognize that this is a departure from the SPLP protocol found in the Impact to Ground Water Guidance and is unique to the conditions defined here.
For UHOT residential sites with tanks between 550 and 2,000 gallons, where the sample with the highest EPH value in excess of 1,000 mg/kg also exceeds 5 mg 2-methylnaphthalene/kg and there are at least two other samples with EPH values in excess of 1,000 mg/kg, the Impact to Ground Water Guidance for the SPLP option (http://www.nj.gov/dep/srp/guidance/rs/splp_guidance.pdf) applies as written. Three SPLP analyses are then required using the three highest EPH samples.
For UHOT residential sites with tanks between 550 and 2,000 gallons, where the sample with the highest EPH value in excess of 1,000 mg/kg also exceeds 5 mg 2-methylnaphthalene/kg and there is only one other sample with EPH values in excess of 1,000 mg/kg, then only a total of two samples will be required by the Department to be subjected to SPLP analysis. Similarly, if there is only the one sample with an EPH value in excess of 1,000 mg/kg, then that is the only sample that will be required by the Department to be subject to SPLP analysis.
If a No. 2 fuel oil discharge is from a tank greater than 2,000 gallons, the Department will require that the No. 2 fuel oil discharge be remediated following the sampling and compliance process described for Category 3 petroleum hydrocarbon compound mixtures found in the "Guidance for Extractable Petroleum Hydrocarbon Sampling and Compliance for Petroleum Hydrocarbon Compounds (Soil Only)" available at http://www.nj.gov/dep/srp/guidance/rs.
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6. Question: Will UHOT participants be allowed to generate an alternative remediation standard (ARS)? It is recognized that on the Department web page entitled "Information for Environmental Professionals about the Unregulated Heating Oil Tank Program (UHOT)" (http://www.nj.gov/dep/srp/unregulatedtanks/professionals.htm), Item 7 states, "Cases that will be remediated to an Alternative Remediation Standard" are excluded from the UHOT program.
Answer: Specific to naphthalene, the residential scenario direct contact soil remediation standard is determined by the inhalation exposure pathway. The Department has made available an electronic spreadsheet calculator which automates the ARS generation for this exposure pathway. Pursuant to the Remediation Standards, N.J.A.C. 7:26D, only four variables can be changed to calculate this ARS. Because the generation of the ARS will be virtually automatic, the Department prohibition for UHOT participants to generate these ARS values will be waived for naphthalene for homeowner No. 2 fuel oil cases (and similarly diesel).
Likewise, the generation by UHOT participants of a site-specific impact to ground water criterion with a Department provided spreadsheet is permissible. However, for the application of models, such as SESOIL, AT123, or the 4 Phase Model, spreadsheet calculators will not be provided by the Department. Department participation in and oversight of the calculations for these and similar models are required.
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7. Question: Will the 5,100 mg EPH/kg No. 2 fuel oil /diesel value be applied to other petroleum hydrocarbon compound mixtures?
Answer: No. The Department is currently in the process of establishing a certified laboratory analytical method that will allow for the development of site-specific remediation standards for the different types of petroleum hydrocarbon compound mixtures to determine if additional remediation (delineation, remedial action, etc.) is required. Until such time that this method is certified, the existing 10,000 mg/kg criterion will be the applicable remediation goal for all petroleum hydrocarbon compound mixtures (other than No. 2 fuel oil or diesel) subject to total petroleum hydrocarbon soil testing as per Table 2-1 of the Technical Requirements for Site Remediation (N.J.A.C. 7:26E). Updates on the status of method certification will be provided through the Department website.
In addition, changes to this guidance will be announced by email to the Department staff and posted on the Department's website to inform the regulated community.
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