May 25, 2017May 22, 2017  · applicable interim generic criterion in Appendix Table 2 shall apply...

May 25, 2017

NJDEP Division of Water Monitoring and StandardsBureau of Environmental Analysis, Restoration and Standards

Ground Water Quality Standards Program

Welcome, Introductions Meeting Purpose and Recap Evaluation of Current GWQC and Potential

Updates Next Steps Discussion Wrap Up

NJDEP DWMS BEARS May 25, 20172

To discuss re-evaluation of and potential updates to the existing health-based ground water quality criteria for Class II ground water

To obtain feedback from stakeholders on potential updates to the health-based criteria that would inform the rulemaking process

To gather additional information about specific constituents from stakeholders with knowledge/expertise in the subject

NJDEP DWMS BEARS May 25, 20173

This is an informal, technical meeting to discuss information related to the derivation and potential update of numeric ground water quality criteria.

The information presented today is preliminary and for discussion purposes only and should not be considered as draft, proposed, or final criteria.

NJDEP DWMS BEARS May 25, 20174

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Class II Criteria: ◦ N.J.A.C. 7:9C-1.7(d): Ground water quality

criteria for Class II-A and Class II-B are the same

Three types of Class II Criteria:◦ Specific Criteria◦ Interim Specific Criteria◦ Interim Generic Criteria for SOCs

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N.J.A.C. 7:9C-1.7(c)1: Specific criteria for ground water quality in Class II-A areas are listed in Appendix Table 1.

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N.J.A.C. 7:9C-1.7(c)2: The Department may establish an interim specific criterion for a constituent not listed in Appendix Table 1.

Pending rule proposal would add all 23 to Appendix Table 1 (3 would be updated)

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N.J.A.C. 7:9C-1.7(c)6: For a Synthetic Organic Chemical not listed in Appendix Table 1, the applicable interim generic criterion in Appendix Table 2 shall apply until an interim specific criterion is developed or a specific criterion is promulgated in accordance with this subsection.

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Constituents evaluated for potential interim specific vs. interim generic criteria are identified with an asterisk (*) on the Department’s website Interim Criteria.

Interim generic criterion is applied when:◦ Insufficient toxicity information is available to

derive a specific or interim specific criterion◦ Sufficient information is available to determine

carcinogenicity and presence/absence of other SOCs

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http://www.state.nj.us/dep/wms/bears/gwqs_interim_criteria_table.htm

Establishes interim specific criteria, interim PQLs and interim specific GWQS

Identifies interim generic criteria applied to certain constituents based on DSREH evaluation.

Does not establish “new” interim generic criteria

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Constituent CASRN IGGWQC Date of Determination

Fact Sheet Technical Support

Documentsacenaphthylene 208-96-8 100 11/7/05 September

2004acetonitrile 75-05-8 100 2/11/08 February 2008

benzo(g,h,i)perylene 191-24-2 100 11/7/05 September 2004

4-chloro-3-methylphenol 59-50-7 100 11/7/05 September

2004chloroethane 75-00-3 5 2/11/08 February 2008

dimethyl phthalate 131-11-3 100 11/7/05 February 2004

n-heptane 142-82-5 100 2/11/08 February 2008

1-methylnaphthalene 90-12-0 5 11/25/15 October 2015 June 2015

n-propanol 71-23-8 100 2/11/08 February 20081,2,4-trimethylbenzene 95-63-6 100 11/25/15 October 2015 March 2013

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N.J.A.C. 7:9C-1.7(c)3: The Department shall establish ground water quality criteria [except interim generic criteria] as follows:◦ i. If the Department promulgates in the Safe Drinking

Water Act rules at N.J.A.C. 7:10 a maximum contaminant level (MCL) for a constituent, the health-based level used to establish the MCL shall be the specific ground water quality criterion for the constituent.

◦ ii. For all other constituents, the Department shall develop ground water quality criteria for Class II-A ground water based upon the weight of evidence available regarding each constituent’s carcinogenicity, toxicity, public welfare or organoleptic effects, as appropriate for the protection of potable water, pursuant to (c)4 below.

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Human health-based criteria are based on chronic (lifetime) exposure to contaminated ground water via the ingestion pathway Carcinogens: One in one million (10-6)

lifetime risk level Non-carcinogens: No adverse effect from

ingestion for a lifetime

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GWQS rules (N.J.A.C. 7:9C-1.7(c)4)establish formulas for deriving criteria

Formulas include toxicity factors and default exposure assumptions◦ Cancer slope factor and 10-6 risk level for

carcinogens◦ Reference dose (RfD) for non-carcinogens and

carcinogens with no slope factor◦ Default exposure assumptions for body weight

and daily water consumption

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N.J.A.C. 7:9C-1.7(c)4: The Department shall use the following equations, data sources and conventions at i through iii below to derive specific and interim specific ground water quality criteria:

Pending rule proposal would allow:◦ Alternative values instead of default values◦ Modified equations based on applicable USEPA guidance, generally

accepted scientific evidence and methodologies, and/or peer-reviewed sources of information

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Criterion (µg/L) =Upper Bound Lifetime Average Adult Conversion Excess Cancer Risk X Weight X Factor

Carcinogenic Slope X Assumed Daily Water Factor Consumption

Where:Excess Cancer Risk = 1 x 10-6

Average Adult Weight = 70 kgConversion factor = 1,000 µg/day (if needed to express

criterion in µg/L)Carcinogenic Slope Factor = USEPA IRIS (default) Daily Water Consumption = 2 L/day

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Criterion (µg/L) = Reference Average Adult Conversion Relative Source

Dose X Weight X Factor X Contribution Assumed Daily X Uncertainty

Water Consumption FactorWhere:Reference Dose = USEPA IRIS (default)Average Adult Weight = 70 kgConversion factor = 1,000 µg/day (if needed to express

criterion in µg/L)Relative Source Contribution = 20% (or 0.2)Daily Water Consumption = 2 L/dayUncertainty Factor = 10 for carcinogens with no slope factor;

1 for non-carcinogens

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September 2016 External Stakeholder Meeting◦ Presented potential sources of updated toxicity

factors: USEPA IRIS USEPA Updated Ambient Water Quality Criteria for the

Protection of Human Health (adopted 2015) USEPA Updated Exposure Factors Handbook (2011) DWQI Recommended health-based MCLs Stakeholder process for potential amendments to

Remediation Standards◦ Discussed potential updates to 42 out of 209

criteria

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Clarified scope of updates:209 Specific criteria on Appx. Table 1-15 based on secondary drinking water

uses; not human health based (2004GWQS B&B, Table B)

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- 3 reference Safe Drinking Water Act Regulations

- 5 not derived using formulas at N.J.A.C. 7:9C-1.7(c)4i and ii: Ammonia Asbestos Copper Lead Nitrate and Nitrite

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209-15 Table B- 3 Drinking Water Rule- 5 Other=186 human health-based criteria under review for possible updates

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The following sources were reviewed for potential updated toxicity factors:◦ NJ Drinking Water Quality Institute (DWQI)◦ USEPA Integrated Risk Information System (IRIS)◦ USEPA Provisional Peer-Reviewed Toxicity Values

(PPRTV)◦ USEPA updated Human Health Criteria (HHC) and

the sources used as their basis ◦ USEPA Office of Water (OW) criteria documents◦ Cal EPA Public Health Goals (PHGs)◦ Agency for Toxic Substances & Disease Registry

Minimum Risk Levels (ATSDR MRLs)

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Criteria are being evaluated for potential update based on the following:1. New or revised toxicity factors Change in value Change in type (e.g. RfD to Cancer Slope Factor)

2. Changes to default exposure values Assumed adult weight (70 kg 80 kg) Daily water consumption (2 L/day 2.4 L/day)

3. Changes related to rounding Two significant figures instead of one

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Based on sources consulted, there are no appropriate new toxicity factors for 132 constituents (see handout)

These 132 will be updated based on potential changes to default exposure assumptions and rounding to 2 significant figures but their derivation will not be re-evaluated at this time

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Based on sources consulted, potentially appropriate new toxicity factors were found for 54 constituents (see handout)

These toxicity factors will be evaluated further to determine whether they are an appropriate basis for update of the criteria.

Criteria will be recalculated based on updated toxicity factors determined to be appropriate AND using potential changes to default exposure assumptions and rounding to 2 significant figures.

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Interim generic criteria in Appendix Table 2 will also be re-evaluated based on:◦ Current scientific information◦ Cumulative impacts of SOCs

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1,2,3-Trimethylbenzene 1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene PFOA PFOS Indane

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Potential update from interim generic criterion based on IRIS assessment◦ 1,2,3-Trimethylbenzene◦ 1,2,4-Trimethylbenzene◦ 1,3,5-Trimethylbenzene

DWQI recommended HMCL◦ PFOA (published)◦ PFOS (under development)

Request for new remediation standard◦ Indane

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Calculate potential updates for 132 constituents (DWMS)

Assess new toxicity factors to determine if they are appropriate basis for updates of criteria for 54 constituents (DSREH)

Clarify basis and implementation of remaining 23 criteria on Appendix Table 1 (Rule Team)

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Schedule series of workgroup meetings to present results as completed. ◦ August, October, December?

Stakeholders share relevant information by July?

Plenary meeting with PQL workgroup to review outputs, potential new/updated ground water quality standards◦ Target date: January 2018?

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