Inspiration Mining Corporation would like to announce that it intends to proceed with the dewatering of the existing ramp to the Langmuir No. 1 mine.
The Corporation intends to dewater the Ramp in order to commence an advanced exploration program in the higher grade mineralization ore body which occurs in the Langmuir No. 1 mine. The dewatering process requires a permit to take water application to the Ministry of the Environment. The PTTW is required to ensure safe working conditions and to supply process water for the mining operations. To support its application, the Corporation retained AMEC Earth & Environmental, a division of AMEC Americas Limited, to undertake a hydrogeological study.
The Ramp was used by the property's former owner, Timmins Nickel, to extract over 100,000 tonnes of ore with an average of 2.2% nickel. Langmuir No. 1 mine is an underground mine which is only accessible through the use of the Ramp, which extends to a length of 1,650 feet. Upon the cessation of operations by Timmins Nickel, the Langmuir No. 1 mine and the Ramp were allowed to be filled with ground and rain water.
The results of the AMEC study were issued on September 3, 2008. That study was quite extensive and had to be based on a large number of factors, including surface water drainage, nature of the overburden and bedrock, groundwater chemistry, the details, underground water flow, and a multitude of environmental factors. The preparation of also required consideration not only all historical data for the area as well as the baseline environmental report by BZ Environmental. Details not otherwise available were developed through additional DDH drilling by AMEC to provide information.
In addition, a numerical 3D steady-state groundwater flow (MODFLOW) model was developed to estimate seepage into the underground workings at the Langmuir No.1 mine site and to access the zone-of-influence associated with the long-term mine dewatering operations. The model is based on the previously developed groundwater flow model for the McWatters Mine Site located at a distance of about 2 km to the south of the Langmuir No.1 Mine site.
Model simulations, conducted for the Langmuir No 1 mine site by AMEC, showed that:
- Long-term groundwater seepage into the increased (by about 25%) existing underground mine workings is expected to be about 150 m,
- Zone-of-influence, defined by the 0.3 m drawdown contour, is predicted to not exceed about 2 km from the mine site,
- Reduction of the groundwater flow contribution to the unnamed creek, originating at a distance of about 750 m to the south-east of the mine site, is predicted to be 50 m, and
- Total groundwater flow contribution to Night Hawk Lake and its tributaries is predicted to be reduced by about 65 m due to the dewatering of the Langmuir No.1 Mine.
Based on the above, AMEC concluded in its report that dewatering of the underground workings at the Langmuir No. 1 mine site may have a relatively limited impact on the nearby surface water features. However, impact on other surface water features, located further away from the mine site, is expected to be non-measurable or negligible.