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

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

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

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

5. 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.

6. 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)

7. 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

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

9. 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.

10. 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)

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

12. 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.

13. Porewater
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