Human Health and Ecological Risk Assessment at Teck Cominco s Kimberley Operations:

Transcription

1 Human Health and Ecological Risk Assessment at Teck Cominco s Kimberley Operations: Overview of Regulatory Process and Preliminary Findings of the Problem Formulation Authors: C. Wilson, P.Eng., R.Wilson, M.Sc., DABT, N.Sandstrom, P.Eng. Morrow Environmental Consultants Inc. B.Dawson, P.Eng., Teck Cominco Metals Ltd. G.Mann, M.Sc., P.Allard, M.Sc., R.Baker, M.Sc., Azimuth Consulting Group

2 Introduction/Background of the Site Overview of Regulatory Framework and how it has changed since project began Objectives and Approach for the Human Health and Ecological Risk Assessment (HH/Eco RA) Preliminary Findings of the Problem Formulation Q/A PRESENTATION OUTLINE

3 Teck Cominco Kimberley Operations

4 INTRODUCTION/BACKGROUND Description of Site and Operations Sullivan ore body discovered 1892 Teck Cominco Metals Ltd. (and predecessors) operated underground Pb/Zn mine from 1909 until December 31, 2001 > 90 years of mining, milling, and industrial operations on > 1,000 ha of land owned by Teck Cominco Surrounds the City of Kimberley

5 TECK COMINCO KIMBERLEY, BC

6 INTRODUCTION/BACKGROUND: Environmental Initiatives 1968 gypsum impoundments, recycling water in Fertilizer Plant 1979 Drainage Water Treatment Plant capture and treatment of ARD (incl.seepage) 1980s and 1990s interception systems to capture ARD, waste rock dump relocations/recontouring Resulted in marked improvements to water courses e.g., Mark Creek

7 Graph 1: Conceptual Water Quality Trends in Mark Creek at the LMY (Station MY-16) Mg/L (total) Zinc 20 0 Iron 1910 Year Zinc Iron

8 REGULATORY FRAMEWORK Who has jurisdiction for environmental management during and post closure? What is the process for regulatory involvement? How has the process changed over time? What approach has Teck Cominco taken to negotiate the regulatory minefield?

9 REGULATORY FRAMEWORK Process for mine closure and reclamation legislated in BC by Ministry of Energy and Mines (MEM) and its predecessors Health, Safety and Reclamation Code Process for remediation of contaminated sites legislated in BC by Ministry of Water, Land & Air Protection (MWLAP) and its predecessors Waste Management Act, Contaminated Sites Regulation (CSR)

10 REGULATORY FRAMEWORK 1991 Teck Cominco Decommissioning and Closure Plan (revised in 2000) Implemented via Teck Cominco Reclamation Permit M-74 Long term management of ARD protection of watercourses reclamation of disturbed land public safety and health

11 REGULATORY FRAMEWORK Trigger into contaminated sites type process in 1995 (note: pre-csr) Demolition permit to demolish in place buildings associated with historical mine facilities in Lower Mine Yard Phased assessment/remediation of former facilities (focus non-mine contaminants) Results reported to MWLAP

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13 REGULATORY FRAMEWORK IF a mine site under a Reclamation Permit can also be defined as a contaminated site under the CSR, are there two processes to follow? Well, yes.

14 REGULATORY FRAMEWORK MWLAP expanded requirements for the Entire Site: Phased assessment/remediation at other areas of the site Mine-derived contaminants (metals, ARD) as well as non-mine contaminants included (soil, water) Testing the Closure Plan as a Remedial Action Plan will post-closure conditions meet remediation requirements under CSR?

15 REGULATORY FRAMEWORK Teck Cominco s strategy: Retain ownership of the site as dormant industrial land Minimize duplication by making use of data collected under Reclamation Permit Minimize fees payable to MWLAP under CSR Use existing public consultation process

16 REGULATORY FRAMEWORK Approach to Remediation Remediation as defined under CSR (not Reclamation as per Permit M-74) CSR offers Remedial Alternatives: clean up to generic/matrix numerical standards site specific numerical standards (including elevated background) risk based standards

17 REGULATORY FRAMEWORK Approach to Remediation The approach at Kimberley is a combined numerical standards-based approach and risk-based approach Consistent with the Closure Plan: Excavation to meet CSR land or water use standards where practical Where not feasible (e.g., ARD) evaluate risks posed by residual levels

18 REGULATORY FRAMEWORK The Problems Encountered Uniqueness of Site surrounds City of Kimberley CSR definition of contaminated site even if source doesn t originate on the site Requires site specific RA addressing particular land use (if different than property wide RA)

19 REGULATORY FRAMEWORK What s changed between then and now? Bill 32 (last May) under WMA Remediation of Mineral Exploration Sites and Mines core and non-core areas Limits powers of MWLAP at non-core areas of mine sites Reality check would this amendment have affected the approach at Kimberley?

20 OVERVIEW OF RISK ASSESSMENT: Application at Mine Sites in BC Common tool at contaminated sites Mine sites: naturally elevated mineralization Located adjacent to wild lands Development of Risk Assessment Guidance for Mine Sites in progress

21 OVERVIEW OF RISK ASSESSMENT: Main Elements of HH and Eco RA Figure 1.3-1: Generic risk assessment framework for the Kimberley Operations site. Communication and Risk Management Effects Assessment Problem Problem Formulation Formulation Analysis Phase Risk Risk Characterization Characterization Exposure Assessment Information Refinement

22 OVERVIEW OF RISK ASSESSMENT: Main Elements of HH and Eco RA Problem Formulation Nature of Contamination What receptors may be present What pathways likely relevant Develop Protection Goals Conceptual Model

23 OVERVIEW OF RISK ASSESSMENT: Main Elements of HH and Eco RA Problem Formulation Tool to allow stakeholders (Teck Cominco, regulators, non-government) to identify and achieve understanding on issues relevant to quantification of environmental risk In the context of Closure Plan (i.e., under post closure conditions)

24 PROBLEM FORMULATION: Focus on key risk issues! One does not swat a gnat while being charged by elephants - Alvin Winberg (1978)

25 OVERVIEW OF RISK ASSESSMENT: Hydrogeological/Geochemical Model Receiving Environment (St. Mary River) is key Comprehensive hydrogeological model flow pathways Geochemical model mechanisms of contaminant release Current loading estimates Future loading estimates

26 PRELIMINARY FINDINGS Problem Formulation Data Sets Data Sources: CSR assessments (soil, water) Permit sampling (e.g., receiving waters) Reclamation monitoring (soil, plant tissue) Reclamation research monitoring (soil, plant tissue) Reconnaissance sampling 2001 (gaps)

27 PRELIMINARY FINDINGS Problem Formulation Data Sets Soils Data: Sampling locations excluded areas planned for reclamation Sampling depth - < 1 m depth Contaminants metals (primarily As, Cd, Pb, Zn) Screened against CSR industrial land use standards

28 Tissue: PRELIMINARY FINDINGS Problem Formulation Data Sets Plants, soil invertebrates extensive data base on reclaimed impoundments; 2001 sampling in other areas Aquatic 2001 sampling (periphyton,benthic) Water: Extensive surface and groundwater data sets (monthly, quarterly, and/or annual sampling)

29 PRELIMINARY FINDINGS Problem Formulation HH Findings Potential exposures primarily based on concentrations measured at the site Fugitive dust and fish/wild game tissue concentrations model and/or measure 3 main conceptual models

30 Model #1 HHRA Conceptual Model for Trespassers at the Kimberley Operations Site Ingestion of Berries Dust Inhalation Incidental Surface Soil Ingestion Dermal Contact with Surface Soils CREEK Incidental Surface Water Ingestion Dermal Contact with Surface Water

31 Model #2 HHRA Conceptual Model for Maintenance Workers at the Kimberley Operations Site ` Dust Inhalation Incidental Surface Soil Ingestion Dermal Contact with Surface Soils CREEK

32 Model #3 HHRA Conceptual Model for Individuals Living Near the Kimberley Operations Site Deer / Elk Consumption Ingestion of Berries Dust Inhalation Fish Consumption CREEK Incidental Surface Water Ingestion Dermal Contact with Surface Water

33 PRELIMINARY FINDINGS Problem Formulation Terrestrial Receptors of Concern (ROCs) scientific and human value considerations ROCs plants, soil invertebrates, reptiles, mammals, birds Listed species higher level of protection Representative species (f00d chain model)

34 Conceptual model for terrestrial ERA open soils scenarios

35 PRELIMINARY FINDINGS Problem Formulation Terrestrial Contaminant uptake by plant roots and soil invertebrates localized effects at formerly active areas Mammals and birds limited risks for nonlisted species; moderate/high for listed (presence of listed species on the site requires confirmation)

36 PRELIMINARY FINDINGS Problem Formulation Aquatic Determination of primary vs. secondary receiving environments (latter not directly assessed) Loadings from the HGA ROCs plants, invertebrates, fish, birds, amphibians Laboratory toxicity testing - use of representative species plus field data collection (e.g., fish, benthic)

37 Conceptual model for Aquatic ERA

38 PRELIMINARY FINDINGS Problem Formulation Aquatic 2001 Benthic sampling no major differences among stations Aquatic plants/invert s Lab toxicity testing showed adverse effects from one area Fish toxicity testing showed no adverse effects (limited testing) Birds limited risks for non-listed; moderate/high for listed Mammals none depending primarily on fish

39 SUMMARY Parallel regulatory processes result in redundancy and additional time/cost Phased approach to assessment/remediation and input from stakeholders ensures transparent process Good site characterization critical Reclamation still in process PF results allow for risk management decisions to be made as reclamation proceeds