Canada's largest coal company is challenging a new Montana water quality standard that aims to limit concentrations of toxic runoff from the company's mines in British Columbia as it travels across the international border into the Kootenai River and Lake Koocanusa. Teck Resources Ltd. this month filed a petition with the state Board of Environmental Review, part of the Department of Environmental Quality, which last year adopted a stringent site-specific water quality standard for the trace element selenium, a byproduct of coal mining that's been found at high levels in fish tissue and egg samples on both sides of the border.