Blog Entry

Taseko Gets an Incomplete: 50 Substantial Deficiencies Found in Environmental Impact Statement

Yesterday the federal review panel examining the New Prosperity Gold Copper Mine Project issued a notice to the proponent, Taseko Mines, that the company's environmental impact statement (EIS) is deficient in fifty different ways. This determination follows a scathing review of an earlier draft in July and an initial indication at the end of November that the Panel was not satisfied with how Taseko dealt with cumulative environmental effects.

Taseko rushed to get this application filed after a previous version of the project was rejected by the federal government following a similar review process. One of the most controversial aspects of the previous proposal, but certainly not the only one, was the plan to drain Teztan Biny or Fish Lake - a culturally important and ecologically productive lake full of rainbow trout. 

A keystone of Taseko's re-submission is their claim that they can now economically and technically prevent significant negative effects to Teztan Biny, while maintaining access to it for First Nations and recreational purposes. This while the lake is within an industrial mining site sandwiched between a 500m deep open pit, and a 36 storey tailings impoundment. Seems improbable to us and according to various reviewers and the Panel, Taseko has failed to provide enough information to support the claim.

Ten of the fifty deficiencies identified by the Panel relate to the prediction of impacts on Fish Lake. Here's one that stuck out to me (apologies for the long quote but it's really worth reading):

As part of site investigations for the original Prosperity Mine Project, the Proponent conducted a pump test in 1994 on wells immediately north of Fish Lake for the purpose of evaluating the use of wells for pit dewatering (Appendix, p. 7). The test yielded estimates of hydraulic conductivity in hydrogeologic units between the proposed pit and Fish Lake that were considered unrealistically high, possibly due to problems with the testing procedure (Appendix, Table C-5). Results from the test were therefore considered unreliable and discounted. Since that time, it appears that the Proponent has not undertaken any further site investigation work aimed at confirming the original pump test results or at better characterizing groundwater interactions between the proposed open pit and Fish Lake. Currently, for pre-development conditions, the Proponent estimates groundwater baseflow discharge to Fish Lake at 446-493 m3/day and lakebed seepage at 0 m3/day (Table, p.642). The Panel notes that NRCan considers these estimates to be very low.

The Panel acknowledges that NRCan and the Proponent’s consultant (BGC) have previously recommended the Proponent undertake further site investigations adjacent to Fish Lake aimed at better characterizing hydraulic conductivities in the area and thereby improving confidence in predictions of pit dewatering effects on groundwater interactions with Fish Lake (Appendix, p.14).

So to translate some of the technical jargon, the only available field data on groundwater flows between the would-be open pit and Teztan Biny come from one well that showed such a high flow rate Taseko didn't want to believe the numbers. A high flow rate indicates a major risk of draining water into the pit that would otherwise be headed to the lake or that's already in the lake. Rather than using the measured field data, Taseko used estimates that Natural Resources Canada considers to be "very low" and would underestimate the risks. 

The Panel asks Taseko to explain this but not to do any new field work, which on one hand is disappointing but also understandable given the pressure they are under to conclude their review and the Tsilhqot'in National Government's concerns about allowing additional work in their territory for a project they staunchly oppose.

The other deficiencies flagged by the Panel reference a cornucopia of serious flaws in the EIS that were pointed out by government agencies (see our summary here), the Tsilhqot'in, and other reviewers, including one of MiningWatch's comments about the inadequate assessment of accidents and malfunctions.

It's now up to Taseko to respond to the deficiencies. As they do that the clock counting down the panel's 1-year time limit is paused. If the recent past is any indication Taseko will respond in relatively short order with a defensive, bordering on belligerent, attitude and marginal improvements in the information presented. From there the panel will decide to ask for further information or prepare for the hearings. Either way, MiningWatch will continue to monitor and provide critical input into the process.