Impact Area Value Calculator


Project Footprint (PF) - hectares (ha)

The Project Footprint ("PF") may be slightly larger than the legal boundaries of the mine. This space is readily visible in active pits and impoundments, and includes subsidiary roads and other rights of way that are integral to the mine’s infrastructure, and other disturbances that would not exist but for the mine. Use an accurate mapped reference, or estimate.

Project Impact Footprint (PIF) - hectares (ha)

All mining activities affect the land and water beyond their permitted boundaries. To account for the “Project Impact Footprint “(“PIF”) we chose an area 4-times greater than the mine’s property or Project Footprint (“PF”). These areas may not feel the direct effect of excavations or tailings storage, but the peripheral area endures seepage, dust, noise, and general disturbance to the natural area that would not exist but for the presence of the mine or mining activity. Multiply your PF by 4.

Natural Area Value (NAV) - dollars ($) / hectare (ha)

The Natural Area Value (“NAV”) is obtained by calculating the per-hectare average price of a hectare of land in your jurisdiction. In British Columbia, this was obtained by calculating the per-hectare average of recent purchases made by B.C. Parks, the Greater Vancouver Regional District, and the complete record of purchases by the Capital Regional District, for parks and other green spaces shown in table IAV 1, on page 18 of the Summary. You may use your own value.

Company Profile (Co)
1 - High 2 - Average 3 - Low 4 - Poor

All companies behave differently. FMC's basic scale from 1- 4 is based on the record of Indigenous engagement and community relations in general; history of maintenance issues/inspection orders; and history, nature, and gravity of regulatory violations.

Dam Design (TSF)

Primary TSF or mean TSF dam design method. If this mining project has a TSF, enter the risk factor number for its design in this space. For a good explanation of different TSF dam designs see: ICMM

1 - Dry/Filtered 2 - Downstream 3 - Centerline 4 - Upstream

Many mines (such as Gibraltar, in B.C.), also incorporate different dam design methods in a single TSF, from the original design through subsequent raises. The Gibraltar TSF has 7 dams, begun as a combination “modified upstream” and “downstream”, with subsequent raises using the less reliable “upstream” method. In the Summary, we applied an average “3” (centreline) for the Gibraltar Mine TSF design overall risk factor Multiplier.

Liner Type (LT)
1 - Engineered 2 - Partial 3 - None

If your mine has a TSF it may or may not have a bottom liner, or layers of filtration to protect groundwater. These are made from different materials, some manmade, some natural. Use 1 for an engineered liner with 3 (or more) layers of fabric and/or filtration material); 2 for a partially engineered (1 or 2 layers) liner; and 3 if the TSF has no liner or filtration layers.

Precipitation Zone (PZ)
1 - Low 2 - Low/Med 3 - Medium 4 - Med/High 5 - High

For British Columbia FMC uses a scale of 1-5 from the University of British Columbia Department of Geography Fig.2 - "Continentality Effect: Distance from the Pacific Coast".

Seismic Zone (SZ)
1 - Low 2 - Low/Med 3 - Medium 4 - Med/High 5 - High

For British Columbia, FMC uses the Natural Resources Canada definitions.

Water Bodies (WB) - hectares (ha)

The portion of significant water bodies (rivers, lakes, wetlands) at risk of, or experiencing direct or indirect disturbance, discharge, or degradation within the Project Footprint, Project Impact Footprint, or downstream of the mine. Downstream calculations can run ad infinitum. This portion of the calculation is meant to reflect the sustained damage within a reasonable periphery of a mine. In some instances, this may cover may tens, or even hundreds of kilometres; in other case it may be confined within a smaller area. Calculate the average width of the river or stream by its length to obtain its area in hectares.