© 2014 ARCADIS 24 June 2015 1 Imagine the result

© 2014 ARCADIS 24 June 2015 2

Presentation Outline •  Site Description and Background •  Natural Environment •  Objectives •  Modified SLRA Approach •  SLHHRA Highlights •  SLERA Highlights •  Innovative Approaches to Sampling •  Value Added Approach to the Field Program •  Next Steps

© 2014 ARCADIS 24 June 2015 3

Site Description and Background •  80 km decommissioned railway built in 1964 to allow

mining of ore near Fort Resolution, NT. •  1964 to early 1990s, ~ 60 million tonnes of ore and lead/

zinc concentrate were transported along the rail bed between Hay River and the open pit Pine Point Mine.

•  The railway was decommissioned in 1996 with the removal of most infrastructure.

•  Multiple communities are present in the regional area. •  Current uses: uncontrolled borrow source, seasonal

camping and recreational activities (hunting, wild food foraging, ATVing, hiking, fishing).

© 2014 ARCADIS 24 June 2015 4

Pine Point Rail Bed, NT

•  Site is a linear transport corridor surrounded by wild lands.

•  Local area includes access roads to quarries near the rail bed, pit lakes, tailings piles associated with the former mining activities.

•  Site is accessible by gravel access roads or from the adjacent highway.

© 2014 ARCADIS 24 June 2015 5

Site Description and Background •  Historical assessment and closure

activities have primarily focused on the main mine footprint.

•  Potential environmental impacts r e l a t e d t o a n c i l l a r y m i n e infrastructure (e.g., the transport of lead/zinc ore along the associated rail line) were not assessed at the time of mine closure.

•  Remediation efforts focused on the former mine site and associated town site.

© 2014 ARCADIS 24 June 2015 6

Natural Environment

http://inotternews.com/?p=7232

https://vraley.wikispaces.com/Common+Nighthawk

•  Shallow bedrock and pockets of coarse grained beach sediments.

•  Naturally elevated regional soil concentrations of metals.

•  Distinct characteristics of fenland habitats and mixed forests on low-lying poorly drained soils, and drier upland sites.

•  Presence of federally listed, and culturally significant Species at Risk utilizing these habitats.

•  Utilization of local foraged wild foods to supplement local people’s diets.

© 2014 ARCADIS 24 June 2015 7

Natural Environment

•  Site crosses fish bearing rivers and creeks. •  Importance of surface runoff as a transport

pathway to surrounding fen systems, local creeks and rivers.

•  Local presence of regionally listed and culturally or commercially important fish species in rivers and streams which drain the Site.

© 2014 ARCADIS 24 June 2015 8

Objectives •  Identify driving risks to human and ecological

receptors. •  Scope future investigation for site areas and

media contaminants. •  Obtain sufficient understanding of the

environmental and physical conditions at the site to make an informed decision on the necessity of any remedial or risk management actions.

© 2014 ARCADIS 24 June 2015 9

Modified SLRA Approach •  Screening level risk assessment completed after the

Phase II Environmental Site Assessment (ESA) rather than after a Phase III ESA.

•  Refined the SLRA approach to focus on site-specific receptors, realistic exposure terms, and refining exposure pathways with site specific data.

•  Goal of the SLRA was to aid in scoping further site assessment and/or remedial and management actions by: •  Identification of contaminants, media, and rail bed areas

driving unacceptable risks to human and ecological receptors.

© 2014 ARCADIS 24 June 2015 10

Modified SLRA Approach – Conceptual Site Model

© 2014 ARCADIS 24 June 2015 11

Screening Level HHRA Highlights •  Local community members

(toddlers to adults) utilizing the local area for recreational activities.

•  E.g. hunting, wild foods foraging, camping, ATVing.

© 2014 ARCADIS 24 June 2015 12

Screening Level HHRA Highlights •  Exposure - seasonal and transient. •  Considered a “worst case week” exposure to non-

carcinogens under an “ATV transport scenario” and a “camping scenario”.

•  Considered seasonal and repeated access to the Site over a lifetime (multiple life stages) to evaluate potential risks to local community members from carcinogens.

•  Potential health risks driven by exposure to lead and cadmium in foraged foods, and ingestion of lead in soils in assumed play areas, and lead in fugitive dust.

© 2014 ARCADIS 24 June 2015 13

Screening Level ERA Highlights •  Terrestrial and aquatic plant and

invertebrate communities •  “At risk” and typical birds,

mammals and fish

•  Exposure pathways included – direct contact with media, as well as accumulation of metals in tissues (invertebrate and vegetation) representing food items for larger wildlife receptors.

© 2014 ARCADIS 24 June 2015 14

Screening Level ERA Highlights •  Various information sources were considered in the SLERA

•  Risk calculations based on chemistry data •  Presence/absence biological observations •  Sediment toxicity testing at Site and reference locations.

•  Plant and invertebrate community receptors unlikely to be affected by railbed soil metals given negligible habitat on the ballast and acceptable risks adjacent to the ballast.

•  Potential adverse effects to typical (e.g. shrew, grouse) and at risk (e.g. common nighthawk) terrestrial receptors with small home ranges, driven by ingestion of soil metals.

•  Potential localized adverse effects to benthic invertebrates and plant communities in discrete creosote treated abutement areas.

© 2014 ARCADIS 24 June 2015 15

Innovative Approaches •  Northern climate - dry, windy •  ATV- typical means of transport

in northern remote areas. •  Ballast material – negligible

organic material, and lead/zinc concentrate powder f rom historical transport in unlined rail cars.

•  Conducted site specific fugitive dust sampling during ATV transit along the railbed, using a SKC aluminum cyclone, filter cassette and pump system.

•  Collected site specific particulate concentrations (kg particulate/m3) and reported metals concentrations (mg contaminant/m3) in respirable dust (<10 µm).

•  Maximum measured concentrations were utilized in ATV user quantitative risk calculations.

© 2014 ARCADIS 24 June 2015 16

“Value Added” Approach to Field Program •  L i n e o f E v i d e n c e - B i o l o g i c a l

observations in terrestrial and aquatic habitats (e.g. rapid benthic invertebrate assessment protocol).

•  Line of Evidence - Conducted sediment toxicity tests

•  Conducted surveys with local residents and aboriginal people regarding site specific land uses, exposure durations and foraged food intakes.

•  Conducted vegetation sampling of targeted wild foods, as well as “forage and browse” species in co-ordination with surface soil sampling.

•  .

© 2014 ARCADIS 24 June 2015 17

Next Steps Modified SLRA approach supported and focused future assessment work to: •  Further assess contaminants (e.g. lead) and

media (e.g. soil, foraged foods, sediment) driving unacceptable risks to site-specific receptors.

•  Focus future assessment work, in some cases, to localized Site areas (e.g. abutments).

•  Refine the conceptual model exposure pathways (e.g. foraged food intake) for human and ecological receptors.

© 2014 ARCADIS 24 June 2015 18

Acknowledgments •  Project work was conducted for:

•  Project work was executed in collaboration with Columbia Environmental Consulting Ltd.

•  Key Staff: Susan Winch, Meagan Gourley, Charlotte Lessard, Barbara Hard, Steve Livingstone (Franz/ARCADIS), Summer Zawacky and Elliot Tonasket (Columbia)

•  Local knowledge contributed by: Mr. Arthur Beck (Fort Resolution Metis Council) and Mr. Al Browning (Hay River Metis Council).

© 2014 ARCADIS 24 June 2015 19 © 2014 ARCADIS 24 June 2015 19

Imagine the result

Thank you! Questions?