Methane extraction threatens rivers, report says
Study suggests plan poses risk to three major salmon streams at once, could cause extensive damage to environment
MARK HUME
theglobeandmail.com
May 15, 2008
VANCOUVER -- A new report released by the Pembina Institute raises fears about the possible impact of coal-bed methane extraction on three major salmon rivers in northwestern British Columbia.
The institute says commercial coal-bed methane development has never taken place in a salmon watershed before, and it describes as "an irresponsible experiment" a provincial plan allowing Shell Canada Ltd. into the headwaters of the Stikine, Skeena and Nass rivers.
Shell has been granted tenure to drill on 412,000 hectares of land about 150 kilometres northwest of Smithers, where the Klappan and Groundhog coalfields are thought to contain eight trillion cubic feet of methane.
Shell's project is in the early stages. Three exploratory wells were drilled in 2004 before work was curtailed due to native blockades and a flood that washed out a road.
Shell is planning to resume work this fall after improving access over the winter so that drill rigs could drive to the area. The company has promised to protect the environment and to work with native groups to safeguard traditional activities, but there have been warnings that Tahltan protesters could put up more blockades soon.
The Pembina Institute study is sure to increase tensions because it concludes that coal-bed methane extraction in the area, known as "the sacred headwaters" because three salmon rivers are born there, could lead to extensive environmental damage.
"Land disturbance could lead to increased runoff, increased erosion and increased sediment loads in stream.
"Stream turbidity would affect overall salmon health, and increased sediment deposition could damage spawning grounds," states a draft copy of the report, which is to be released in its final form today.
The Pembina Institute calculated that if 1,000 wells were drilled in the tenure (a mid-range estimate) then about 16 square kilometres of land - an area covering 2,700 football fields - would be cleared for well pads, roads and pipelines.
Because the area is laced with small streams it would be impossible to prevent erosion and the flow of sediments into salmon bearing waters, the report says.
In addition, water extraction during methane drilling could reduce aquifers to such low levels that groundwater flows to streams and lakes would drop.
"This phenomenon is extremely complex and difficult to predict, but the impacts could be highly significant for salmon," the report concludes.
"Groundwater is essential to maintaining flow and wetted areas in some streams, and can also act as a buffer against daily and seasonal temperature fluctuations. A reduction in groundwater upwelling could lead to impacts such as more eggs freezing in winter, fry hatching too late to feed adequately, and lower winter survival for juvenile fish."
The study projects that over 20 years, enough water to fill 200,000 Olympic swimming pools will be pumped out of coal seams to facilitate methane removal.
Drawdowns on water tables would extend several kilometres beyond well fields, and water levels would not be restored until several years after methane extraction ended, the study states.
It warns that in addition to affecting stream flows, the water extracted from coal seams could lead to increased pollution.
"Disposal of groundwater produced by CBM [coal-bed methane] wells is often associated with significant environmental impacts because it can be highly saline. Arsenic, ammonia, boron, iron, manganese, radium fluoride and high sodium absorption ratios have also been observed in CBM water."
The Pembina Institute warns of "key information gaps" concerning the geology, ecology and hydrology of the area, and says more research is needed to determine the full extents of environmental risk.
"Given the sensitivity of salmon to disturbance in their critical habitats, it is fully possible that impacts cannot be mitigated within acceptable limits. This can only be confirmed with additional research."
The report was done for the Pembina Institute by GW Solutions, a Vancouver Island-based consulting firm with an expertise in the management of aquifers and watersheds.
The Pembina Institute is an independent think tank concerned with public policy. |
