N.J. Admin. Code § Tit. 7, ch. 26D, app 8
DEVELOPMENT OF ALTERNATIVE REMEDIATION STANDARDS FOR SOIL FOR THE MIGRATION TO GROUND WATER EXPOSURE PATHWAY
Pursuant to N.J.A.C. 7:26D-8.3(a)1iii, an alternative remediation standard (ARS) for soil for the migration to ground water exposure pathway may be developed for a site or an area of concern in accordance with the procedures provided in this appendix.
I. Overview
(a) An ARS for soil for this exposure pathway may be developed at any time.
(b) An ARS may be developed based on the site-specific options described in III of this appendix and submitted to the Department with the appropriate form(s).
II. Required Approvals and Permits
(a) An ARS developed in accordance with III(a), III(b), and III(c) of this appendix must be approved by the Department prior to use at the specific site or area of concern.
(b) An ARS developed in accordance with III(d), III(e), III(f), and III(g) of this appendix does not require approval by the Department prior to use at the specific site or area of concern.
(c) With prior approval by the Department, an ARS may also be developed using scientific methods other than those described in III(a) though (g) below including relevant guidance from the USEPA, other states, and other relevant, applicable, and appropriate methods and practices that ensure the protection of public health and safety and of the environment.
(d) With the exception noted in III(c) of this appendix, an ARS developed pursuant to this appendix does not require the use of an institutional control, engineering control, and a remedial action permit, pursuant to N.J. A.C. 7:26C-7.
III. Options and Procedures
(a) Determination of a site-specific Dilution-Attenuation Factor (DAF) as follows:
1. Measure the length of the area of concern parallel to the ground water flow, the aquifer hydraulic conductivity, the aquifer gradient and, if necessary, aquifer thickness in accordance with the appropriate Department guidance.
2. Input the appropriate values into the Department's calculators (DAF calculator or Soil-Water Partition Equation calculator) located on the Department's website.
3. Provide the following to the Department in addition to the applicable form found on the Department's website:
i. The resultant ARS and the modified input parameters used in the Department's DAF calculator or the Department's Soil-Water Partition Equation calculator; and
ii. Documentation of the determination and basis of the site-specific parameters used to determine the DAF including all related tables, figures, and laboratory results.
(b) Seasonal Soil Compartment Model (SESOIL) modeling as follows:
1. Delineate contamination and determine the depth to ground water in accordance with the appropriate Department guidance.
2. If desired, determine soil texture in accordance with the appropriate Department guidance.
3. If desired, determine soil organic carbon content according to III(d) of this appendix.
4. Input the appropriate parameters into the SESOIL model in accordance with the appropriate Department guidance.
5. Provide the following to the Department in addition to the applicable form found on the Department's website:
i. For each ARS determined using the SESOIL model, a SESOIL model table showing the measured contaminant concentrations as a function of depth and the modeled SESOIL concentrations, results from the most current version of the SEVIEW model software of the SESOIL CLIMATE report, the SESOIL HYDROLOGIC CYCLE report, the SESOIL PROFILE AND LOAD REPORT, and the SESOIL POLLUTANT CYCLE report. The project file (.prj file) from the SEVIEW project shall also be submitted; and
ii. A description and basis of how the SESOIL input parameters were determined, including all related tables, figures, and laboratory results.
6. An alternative software package equivalent to SEVIEW that has been authorized by the Department may be used as a substitute for SEVIEW in application of III(b) of this appendix.
(c) Seasonal Soil Compartment Model/Analytical Transient 1 ,2-,3-Dimensional (SESOIL/AT123D) modeling as follows:
1. The SESOIL/AT123D model shall only be used when:
i. The contaminated ground water plume has been delineated in accordance with the Technical Requirements for Site Remediation, N.J.A.C. 7:26E and appropriate Department guidance;
ii. A Classification Exception Area (CEA) exists for contaminated ground water on the site; and
iii. An impermeable cap does not and will not exist above the vadose zone contamination. Any permeable cap used shall allow unrestricted ground water recharge.
2. Delineate the vadose zone contamination and determine the depth to ground water in accordance with the appropriate Department guidance.
3. Determine the soil organic carbon for both the vadose zone and the aquifer according to III(d) of this appendix.
4. Determine the soil texture for the vadose zone in accordance with the appropriate Department guidance.
5. If desired, determine the aquifer texture in accordance with the appropriate Department guidance.
6. Input the appropriate parameters into the SESOIL/AT123D model in accordance with the appropriate Department guidance.
7. Provide the following to the Department, in addition to the applicable form found on the Department's website:
i. For each ARS determined using the combined SESOIL/AT123D model, a SESOIL model table showing the measured vadose zone contaminant concentrations as a function of depth and the modeled SESOIL concentrations, a map of the delineated ground water plume (with concentration isopleths) showing AT123D ground water sources and the concentrations and dimensions used in the model for each source, the SEVIEW project map, results from the most current version of the SEVIEW model software of the SESOIL CLIMATE report, the SESOIL HYDROLOGIC CYCLE report, the SESOIL PROFILE AND LOAD REPORT, the SESOIL POLLUTANT CYCLE report, an AT123D Point of Compliance Report at the downgradient edge of the Area of Concern at the centerline of the plume at the surface of the water table, and an AT123D Point of Compliance Report at the maximum extent of the plume at the centerline of the plume at the surface of the water table. For each AT123D Point of Compliance Report, the numerical concentration of the contaminant at the last time step (end of the CEA time period) shall be shown in an EXCEL window pasted on to the report. The project file (.prj file) from the SEVIEW project shall also be submitted; and
ii. A description and basis of how the SESOIL/AT123D input parameters were determined, including all related tables, figures, and laboratory results.
8. Except for the existing CEA and the remedial action permit, the Department shall not require the use of any additional institutional control, engineering control, or a remedial action permit, pursuant to N.J.A.C. 7:26C-7for an ARS based on site-specific SESOIL/AT123D modeling.
9. An alternative software package equivalent to SEVIEW that has been authorized by the Department may be used as a substitute for SEVIEW in application of III(c) of this appendix.
(d) A site-specific soil organic carbon content (foc) in the Soil Water Partition Equation, found at N.J.A.C. 7:26D Appendix 4 as follows:
1. Collect and analyze samples for determining foc in accordance with the appropriate Department guidance.
2. Input the appropriate foc value(s) in the Department's foc calculator located on the Department's website to determine the site-specific foc value.
3. Input the site-specific foc value into the Soil-Water Partition Equation calculator located on the Department's website in order to determine the alternative remediation standard.
4. Provide the following to the Department in addition to the applicable form found on the Department's website with the applicable remedial phase report:
i. The resultant ARS and the modified input parameters used in the Department's foc and soil-water partition calculators; and
ii. A description and basis of how the soil organic carbon content was selected, including all related tables, figures, and laboratory results.
(e) The Synthetic Precipitation Leaching Procedure (SPLP) ARS options contained in technical guidance issued by the Department, except when combining with a site-specific DAF as provided in III(a) of this appendix. The procedure shall be as follows:
1. Collect samples and implement the SPLP procedure in accordance with the appropriate Department guidance.
2. Input the appropriate values into the Department's SPLP calculator located on the Department's website.
3. Provide the following to the Department in addition to the applicable form found on the Department's website with the applicable remedial phase report:
i. The resultant ARS and the modified input parameters used in the Department's SPLP calculator; and
ii. A description and basis of how the samples were selected, including all related laboratory results.
(f) Site-specific data for immobile contaminants only when:
1. The contaminant exhibits a very low mobility in soil as defined by a high soil organic carbon-water partition coefficient (Koc) or a high soil-water partition coefficient (Kd), factors that increase a contaminant's mobility are not present, and a clean zone of two feet or greater exists between the contamination and the water table, as described in appropriate Department guidance.
2. The procedure shall be as follows:
i. Collect and analyze soil samples in accordance with the appropriate Department guidance; and
ii. Provide a description and basis of how the samples were used to demonstrate compliance with the migration to ground water exposure pathway, including all related tables, figures, and laboratory results, to the Department, in addition to the applicable form found on the Department's website with the applicable remedial phase report.
3. If compliance with the migration to ground water exposure pathway is determined by the site-specific conditions in III(f)1 of this appendix only, then the numeric standards in this chapter shall not apply, but the pathway will be deemed to have been satisfactorily addressed on a narrative basis.
(g) Site-specific data for metals, semi-volatile contaminants, and volatile contaminants only when:
1. The highest concentrations of remaining contamination are located at the water table and no ground water impact above the ground water remediation standard is observed as demonstrated by ground water sampling, as described in appropriate Department guidance.
2. The procedure shall be as follows:
i. Collect and analyze soil and ground water samples in accordance with the appropriate Department guidance; and
ii. Provide a description and basis of how the samples were used to demonstrate compliance with the migration to ground water exposure pathway, including all related tables, figures, and laboratory results, to the Department, in addition to the applicable form from the Department's website with the applicable remedial phase report.
3. If compliance with the migration to ground water exposure pathway is determined by the site-specific conditions in III(g) of this appendix only, then the numeric standards in this chapter shall not apply, but the pathway will be deemed to have been satisfactorily addressed on a narrative basis.
N.J. Admin. Code Tit. 7, ch. 26D, app 8