Ecological Risk-based Remediation, Sediment, and the CT RSRs

Transcription

1 Ecological Risk-based Remediation, Sediment, and the CT RSRs CBIA s 2014 Environmental & Energy Conference Nick Hastings Agenda Original 1996 RSRs Applicable Sites RCRA Corrective Action Sites Commissioner-determined 2007/8 Proposed Revisions Use of Benchmarks Erodable Soils Recent Wave 2 Discussion Document Key Issues Going Forward 1

2 Original 1996 RSRs 22a-133k-2(i): Additional Remediation of Soil (1) the Commissioner determines that (2) at any location at which polluted soil has there is a potential ecological risk he may eroded into a surface-water body, the require that an ecological risk assessment commissioner may require that the effect of be conducted in accordance with such polluted soil on aquatic life be EPA/630/R-92/001, February 1992, assessed and that remediation to protect or "Framework For Ecological Risk restore aquatic life and surface water quality Assessment and that additional remediation from the effects of such polluted soils be be conducted to mitigate any risks identified undertaken in such assessment Applicable Sites RCRA Corrective Action Sites EPA DEEP-lead LEP-delegated DEEP-determined 2

3 From 2007 Proposed RSR Revisions 2007/8 Proposed Revisions Use of Threshold ( no effect ) Benchmarks as Remediation Standards Draft defined Erodable Soils" as The upper two feet of soil within 100 feet of the banks of a waterbody and applied sediment remedial goals directly 3

4 2008 draft RSR Additional Remediation Language Ecological Risk Assessments Conducted in accordance with EPA guidance Scoping Level ERA (pathway analysis) Screening Level ERA (benchmark comparison) Site-specific ERA (risk-based remedial decision) Eco risk assessments methods approved in writing by the Commissioner DEP will have guidance document [Slide based on DEP October 20, 2008 presentation on Key Revisions Since October 2007] Recent Wave 2 Discussion Document Retained concept of erodable soils: Soils which can be carried to surface water through erosion (for instance contaminated soil on a riverbank) are included as sediment throughout this document. Added LEP Risk Assessment options intent is to expand self-implementing options 4

5 LEP Risk Assessment Option 1: provides a Middle Ground These sites do not warrant expensive field studies or toxicity tests EPA calls this a Refinement of COCs ; first step in a Site-specific ERA Program needs a way to further evaluate sites using existing site and literature data Many sites will have low exceedances of benchmarks 5

6 Option 1 (ERM-Q) Approach: PROs: Uses relationship to existing effect-level data (ERMs or PECs) to assess risk Desktop study avoids costly field studies or tests CONs: All COCs are treated together, which is not scientifically sound in many cases; effects not additive A total HQ of 0.5 may produce low cleanup levels LEP Risk Assessment Option 1: Toxicity Test Approach: PROs: Tests effects of actual site sediments Results may show less toxicity than predicted by literature benchmarks Results can be used to generate cleanup levels CONs: Tests are expensive ($800 - $2,000 each) Natural variability can obscure trends Results can be affected by non-site COCs, such as PAHs. 6

7 Roundtable Breakout Session Input Self-Implementing Options need to be truly self-implementing. Currently, many potential outcomes will trigger Commissioner approval. Self-implementing options should be as large a piece of the pie as possible. Establish guidance on how to determine background concentrations and when they can be used. Include language on incidental sources (i.e., parking lot runoff). What is the definition of sediment? Erodable soils? Sediment contained within storm water conveyances? Establish reasonable/acceptable low threshold numeric criteria Key Issues Going Forward Definition of Sediment including Erodable Soil and how standards would apply Background Determination and use in Riskbased remedial Decisions How Bioaccumulation will be handled and for which COCs (e.g. Hg, pesticides, PCBs, PAHs)? 7

8 Key Issues Going Forward cont. Need more self-implementing options and greater clarity in the form of guidance as companion to revisions Use of EPA and other states guidance to inform DEEP guidance More to Come Questions / Discussion 8