Interesting reading, as always, from Gordon Campbell, this time on Pike River.
From Campbell's piece
here, the prospectus document.
"Gas in the Brunner Seam is generally at low to moderate levels, giving Pike River confidence it can safely and efficiently mine this seam. The Mine Plan incorporates a high level of ventilation and other safety measures to guard against any seam gas and ventilation issues. In areas of low to moderate gas, the gas will flow under natural pressure and be vented into the Mine’s return air ventilation system. In the isolated areas, where seam gas contents are at greater levels, it may be necessary to drain the gas using a negative pressure pump from the tunnel entrance area and either exhaust the gas into the atmosphere or burn it in an enclosed flare….
Pike River has had studies undertaken that show that Pike River coal has a low inherent propensity to spontaneously combust meaning the coal itself has a low likelihood of self heating in normal atmospheric conditions. All quantities of ventilating air within the sections of the Mine will be sufficient to dilute gas emissions to levels below statutory permissible limits and maintain comfortable conditions for operating diesel powered equipment."
