PROPOSED CHANGES TO REVISE WATER STANDARDS IN SCHEDULE 6 OF CSR. Heather Osachoff, MSc, PhD, RPBio Risk Assessment Officer May 20, 2015

Transcription

1 PROPOSED CHANGES TO REVISE WATER STANDARDS IN SCHEDULE 6 OF CSR Heather Osachoff, MSc, PhD, RPBio Risk Assessment Officer May 20, 2015

2 WHAT IS HAPPENING? Contaminated Sites Regulation (CSR): Contains standards for the protection of human health and the environment. In 2015/2016, the Land Remediation Section of the Ministry of Environment (MOE) is preparing updates and/or changes to the Environmental Management Act (EMA) and the Contaminated Sites Regulation (CSR). Specific, relevant changes include: Updating standards for all matrices listed in the Schedules of the CSR (soil, sediment, vapour, water). This presentation focuses on the proposed updates to the water standards.

3 WATER STANDARDS IN CSR Two Relevant Schedules: (1) Schedule 6, Generic Water Standards Aquatic Life (AW) Irrigation Water (IW) Livestock Water (LW) Drinking Water (DW)

4 SCHEDULE 6 STANDARDS Sources: (1) Adopted (circa 1996) from BC MOE, Canadian Council of Ministers of the Environment (CCME), or Health Canada. AW standard = 10 x BC MOE Water Quality Guideline (WQG) IW, LW, DW standards not altered (2) Recently, generic numerical DW standards derived for Al, Fe, Mn using: Health Canada drinking water guideline derivation equations, US EPA toxicity reference values (TRVs), and Health Canada characteristics for the Canadian general population adult body weight and water ingestion rate values. toxicologically-based derivations

5 AW STANDARD (AQUATIC LIFE) History of 10-fold Factor: (1) The Contaminated sites Soil Standards Taskforce (CSST) responded to recommendations from the Eco-Workshop held earlier in Considerations were given to: no factor, a 10-fold factor, or a 20-fold factor. (2) In March of 1996, an Expert Panel reviewed the CS standards at a Review Workshop and a dilution factor was desired by the Expert Panel. (3) In September of 1996, BC MOE released responses to the Expert Panel review of March 1996: BC Environment is considering incorporating a dilution factor in the Schedule 6 aquatic life standards, by multiplying the proposed draft 3 standards by 10. The rationale behind this is that for most sites, it is expected that groundwater will not totally constitute the water used directly by aquatic life, and that a minimum of 10:1 dilution will occur at most sites where groundwater is an issue.

6 WATER STANDARDS IN CSR Two Relevant Schedules: (2) Schedule 10, Generic Numerical Soil and Water Standards Drinking Water (DW)

7 SCHEDULE 10 STANDARDS Source: US EPA Regional Screening Levels

8 3 PROPOSED CHANGES

9 WATER SCHEDULE Proposed changes: (1) Repeal existing CSR Schedules 6 and 10 and move existing Schedule 6 and 10 substances into a proposed new single schedule that consolidates water standards.

10 WATER SCHEDULE Proposed changes: (1) Repeal existing CSR Schedules 6 and 10 and move existing Schedule 6 and 10 substances into a proposed new single schedule that consolidates water standards. For Schedule 10, this would be all substances with DW standards and this process would include an update of standards using recent US EPA Regional Screening Levels.

11 WATER SCHEDULE Proposed changes: (1) Repeal existing CSR Schedules 6 and 10 and move existing Schedule 6 and 10 substances into a proposed new single schedule that consolidates water standards. For Schedule 10, this would be all substances with DW standards and this process would include an update of standards using recent US EPA Regional Screening Levels. List the substances in the new water schedule by alphabetical name (IUPAC naming), maintaining consistency with other CSR schedules.

12 WATER SCHEDULE Proposed changes: (1) Repeal existing CSR Schedules 6 and 10 and move existing Schedule 6 and 10 substances into a proposed new single schedule that consolidates water standards. For Schedule 10, this would be all substances with DW standards and this process would include an update of standards using recent US EPA Regional Screening Levels. List the substances in the new water schedule by alphabetical name (IUPAC naming), maintaining consistency with other CSR schedules. Retain 10-fold factor for calculation of AW standards.

13 WATER SCHEDULE Proposed changes: (2) Where sufficient toxicological data exists or another jurisdiction has an available standard, subject to time and resources, derive or adopt aquatic life (AW) and/or drinking water (DW) standards for use in the proposed new single schedule of CSR water standards. Where such updates are not possible, the standard values will remain as they are currently listed.

14 WATER SCHEDULE Proposed changes: (2) Where sufficient toxicological data exists or another jurisdiction has an available standard, subject to time and resources, derive or adopt aquatic life (AW) and/or drinking water (DW) standards for use in the proposed new single schedule of CSR water standards. Where such updates are not possible, the standard values will remain as they are currently listed.

15 WATER SCHEDULE Proposed changes: (2) Where sufficient toxicological data exists or another jurisdiction has an available standard, subject to time and resources, derive or adopt aquatic life (AW) and/or drinking water (DW) standards for use in the proposed new single schedule of CSR water standards. Where such updates are not possible, the standard values will remain as they are currently listed. Priority: derive > adopt.

16 WATER SCHEDULE Proposed changes: (2) Where sufficient toxicological data exists or another jurisdiction has an available standard, subject to time and resources, derive or adopt aquatic life (AW) and/or drinking water (DW) standards for use in the proposed new single schedule of CSR water standards. Where such updates are not possible, the standard values will remain as they are currently listed. Priority: derive > adopt. Priority: DW > AW. Deferred to next update: remaining DW and AW not updated in Stage 10 amendments; IW and LW.

17 WATER SCHEDULE Proposed changes: (3) Where sufficient toxicological data exists or another jurisdiction has an available standard, derive or adopt standards for new and emerging contaminants of concern, including the following substances or families: perfluorinated compounds estrogen hormones antimicrobials alkylphenols and alcohol ethoxylates current use pesticides polybrominated diphenyl ethers (PBDEs), and hardness Priority: derive > adopt Priority: DW > AW

18 NOTES Derivation Details: For DW, will follow previous derivation of Fe, Al, Mn: Health Canada calculations and receptor characteristics. Maintain 10-5 or 1/100,000 risk level. Emphasis is on toxicologically-based derivations and adoptions (transparent, scientifically credible, etc.). Examples of how this thinking could affect standards: Consideration being given to replacing taste and odour based standards with toxicologically-based standards. Consideration being given to using information regarding additional exposure routes (e.g.) inhalation from showering can be an important route for some substances and could be used in the derivation of a DW standard.

19 DERIVATION SOURCES Hierarchy (follows Technical Guidance 7): United States (US) Environmental Protection Agency (EPA) (e.g. for toxicity reference values (TRVs)). Health Canada. BC MOE approved or working Water Quality Guidelines for the protection of aquatic life, irrigation, livestock or drinking water. CCME approved or interim Water Quality Guidelines for the protection of aquatic life, irrigation, livestock or drinking water. Federal Environmental Quality Guidelines (Environment Canada under CEPA, 1999) The World Health Organization (WHO) water criteria. Canadian provincial government agencies (e.g., Ontario MOE). States in the US (e.g., State of California or Minnesota). European Union agencies (e.g. REACH). Nations in the British commonwealth (e.g., Australia, Britain).

20 DERIVATION EXAMPLE

21 EXAMPLES Updating an existing substance: TCE (Trichloroethylene), Schedule 6 DW = 5 µg/l Parameter Health Canada DW Standard US EPA US EPA Carcinogenicity Dose Total Daily Intake (1) mg/kg/d Reference Dose (2) mg/kg/d Oral Slope Factor (2) (mg/kg/d) -1 Ingestion rate 4 L/d 1.5 L/d - Calculated DW Standard 5.2 µg/l 4.7 µg/l 23 µg/l adult 2 µg/l toddler DW Standard (1) Health Canada PQRA Part II 5 µg/l (MAC) 5 µg/l (for 1/100,000 risk) (2) US EPA IRIS database:

22 ADOPTION EXAMPLE

23 EXAMPLES Adding a new substance: 17α-ethinylestradiol (EE2; synthetic hormone) BC WQG for EE2 released in 2012 Propose to: adopt and set AW standard as 10 x (30 d mean of 0.5 ng/l EE2) = AW of 5 ng/l EE2

24 SUMMARY Major Proposed Changes: Combine Schedules 6 and 10 into a new water schedule. Update Schedule 10 values based on most recent US EPA Regional Screening Levels. Update Schedule 6 standards by derivation or adoption using a hierarchy of sources for toxicological information and/or standards. Retain 10 fold factor for calculating AW standards. Derive or adopt standards for emerging substances (PFOS, EE2, NP/NPEO, etc.). Focus on: (1) DW standards, (2) AW standards; defer IW and LW.

25 THANK YOU HEATHER OSACHOFF