Porewater: NJDEP Site Remediation Program regulatory perspective SETAC - Hudson Delaware Chapter 2015 Fall Workshop October 7, 2015 Princeton, NJ Greg Neumann - NJDEP

NJDEP Regulations NJDEP Technical Requirements for Site Remediation – NJAC 7:26E Minimum regulatory requirements Ecological Evaluation Technical Guidance (February, 2015)

Ecological Evaluation Technical Guidance Sections relevant to Porewater: Section 5 Ecological Evaluation (EE) Section 6 Ecological Risk Assessment Risk Characterization – quantify ecological risk Section 6.2.2.3 Sediment Porewater sampling Section 6.4.6 PAHs – USEPA White Paper (2009) SPME – 3 Tiered approach assess risk to benthic community. Appendix F Sediment Porewater Sampling Techniques

Porewater – Why? Bioavailability Arsenic Arsenic Sed. Chemistry 45 ppm 340 ppb Pore Water 100 ppb

Bioavailability/Porewater Bulk sediment chemistry results are not accurate predictors of sediment toxicity. Measure solid phase. Porewater concentrations more accurately predict benthic toxicity by measuring bioavailable fraction Site-specific sediment characteristics influence porewater concentrations (i.e. TOC, AVS, DOC, pH, Eh) Porewater results represent the bioavailable fraction of sediment contamination.

Porewater Sampling Most appropriate during risk characterization stage of ERA Predominately used to evaluate risk to benthic community. GW Surface Water discharges Utilized in a Weight of Evidence approach Sediment toxicity tests Tissue sampling PBTs (PCB/DDT)

Porewater Sampling Post-Remedial Monitoring Baseline Conditions Conventional and Amended Sediment Caps In-situ Treatment – activated carbon, apatite, organophylic clay, ZVI Remedies effective due to sorptive capacity – longevity GW remedy to protect SW Baseline Conditions

Porewater Sampling Devices Trident Probe Ultra Seep System Piezometers Peeper Rigid polyethylene Push-Point Sampler Diffusion Gradient Thin Films

Porewater Sampling Considerations Sampling medium must be capable of detecting site Contaminants Of Concern Deployment time – must be able to achieve equilibrium Performance Reference Compounds In-situ vs. Ex-Situ Data generated must be in line with Data Quality Objectives.

Future Needs Current guidance primarily focuses on the sampling techniques and design factors related to pore water sampling (characterization of risk) Future guidance is needed that clearly documents how porewater sampling results can be used to develop sediment clean-up goals. Much of the porewater info. is housed in literature/research based publications. This info. has to be brought forward and presented in more primary based guidance documents (EPA/SETAC/ITRC Publications)

Future Needs Standardization of sampling devices and protocols. Additional studies to link PW results to benthic toxicity.

NJDEP & Porewater NJDEP Regulations and Guidance support the use of Porewater sampling!! Porewater sampling can effectively be used to better quantify ecologic risk. Porewater sampling can be employed during the risk characterization stage of an ERA and during Post-Remedial Monitoring. Porewater sampling can represent an important line of evidence in an overall weight of evidence approach.

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