Science Response 2012/039

Sufficiency Review of the Draft lake productivity information submitted in relation to the new prosperity gold-copper mine project

Context

Taseko Mines Limited has proposed the development and operation of a gold and copper mine (New Prosperity Mine), located on the Fraser plateau, approximately 125 km southwest of Williams Lake, British Columbia. The project consists of an open pit mine with a 20 year estimated operating life, and would employ conventional copper porphyry floatation processing. Development of the mine would involve new construction of an open pit, an onsite mill and support infrastructure, a 125km power transmission line, a 2.8km mine access road, a tailings storage facility and ore and waste rock storage areas.

The proposed mine would be located within the Fish Creek watershed, which hosts several fish-bearing creeks and lakes, including Fish Lake, that are likely to be impacted by the development. A previous project submission to CEAA occurred in 2009-2010, but was deemed by a federal review panel and the Government of Canada to have significant adverse environmental affects, and was not approved for development. The current New Prosperity project is a modification of the former development proposal, and the subject of an ongoing Canadian Environmental Assessment Act (CEAA) review (CEAA Registry 11-05-63928).

In June, 2012, Fisheries and Oceans Canada’s Pacific Region Ecosystem Management Branch requested Pacific Region Science Branch to conduct an initial review of the draft New Prosperity Gold-Copper Mine Project Environmental Impact Statement (draft EIS; submitted June 4, 2012) for information adequacy and completeness necessary to the proper evaluation of potential effects of mining activities the productivity of Fish Lake.

Specifically,

1. Is the information referenced both sufficient and recent enough for Science to model or assess future productivity of Fish Lake and its tributaries? 
2. If not, what other information would be reasonable to request to infer future productivity?
3. Is there enough information to make reasonably informed inferences, or to identify risks associated with data gaps?
4. Are the methods used to assess the potential effects on future productivity of Fish Lake appropriate and executed properly.

A review of the Draft EIS revealed several shortcomings in the modeling approaches and characterization of Fish Lake before, during and after mining operations.  In particular, fish productivity models assuming phosphorus limitation of Fish Lake may be of questionable application, and the future effects of climate change, lake eutrophication, and recirculation of lake outflow water to inflows on the thermal regimes and the productivity of Fish Lake have not been fully considered.

This Science Special Response is from the June 26, 2012 Science Special Response review process considering the sufficiency of the lake productivity information submitted in relation to the New Prosperity Gold-Copper Mine project.

Complete document (PDF, 184 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.