The mine waste at the Naranjo facility would be confined by an earth-core rockfill dam with a height of 157 meters (one of the largest earth-core rockfill dams in the world) with the tailings on the downstream side next to the dam and the waste rock on the upstream side. [...] Although, according to the GISTM, the minimization of the permanent aboveground storage of tailings is one of the two purposes of a multiple accounts analysis, the EIS does not include any serious consideration of the alternative of backfill of mine waste into the exhausted open pits or quarries. [...] For the avoidance of groundwater contamination, the site for an aboveground tailings facility that is preferred in the EIS cannot be regarded as ideal since the EIS expresses concerns regarding the high permeability of the foundation, the potential for excessive seepage from the tailings storage facility, and the need for mitigative measures. [...] According to the analysis of the consequences of dam failure in the EIS, the spilled tailings will flow northward along the Maguaca River to the confluence with the Yuna River and then continue flowing northward along the Yuna River. [...] Finally, although the El Llagal and Naranjo facilities would be only 840 meters apart and in the same watershed in the headwaters of the Maguaca River, the analysis of the consequences of dam failure did not consider the consequences of the simultaneous failure of both tailings storage facilities, although such an outcome is certainly credible considering that the same earthquake or precipitation.
- Pages
- 65
- Published in
- Canada
