EDMONTON - Environmentalists are heading to court Tuesday to fight regulatory approval of Imperial Oil's $7-billion Kearl oilsands project, saying plans to soften its impact are unproven and the  job of managing its cumulative effects was given to an association that has "a track record of failure.''

Kearl, the third massive oilsands project approved by Alberta's Energy and Utilities Board in early 2006, was opposed during public hearings by environmentalists, area aboriginals and the local municipality of Wood Buffalo.

The approval came with a long list conditions. The board also said the cumulative effects of Kearl and the other projects should be monitored by and subject to the findings of the Cumulative Environmental Management Association, composed of a wide variety of stakeholders.

"The Kearl project was approved in spite of (the association's) continued failure to identify precautionary, science-based ecological thresholds for the Athabasca Oil Sands Region,'' says a release from Ecojustice, one of the groups bringing the lawsuit against Imperial, which also names several federal departments.

"In the absence of defined ecological thresholds a true assessment of the environmental impacts associated with the proposed projects cannot occur.''

The association, created in 1999, has been ineffective, said Ecojustice.

"(It) is a multi-stakeholder committee with a track record of failure, limited consensus as to its goals and no power to implement its recommendations.''

Among other concerns, Ecojustice also says Imperial's land reclamation strategy is based too heavily on computer modelling without any practical results to back up its projections.

However, Imperial says the association's failure to reach consensus on limits to growth hasn't stopped the provincial government from passing environmental regulations in the area when required.

In documents filed with the court, Imperial also points to mountains of evidence and testimony that the board took into consideration before making its determination.

"The panel heard and considered considerable evidence with respect to environmental effects and cumulative environmental effects and proposed mitigation of these effects,'' said an affidavit from Mark Little of Imperial.

The case will be heard in Federal Court in Edmonton.