Two environmental groups say logging operations on California€™s North Coast should be covered by state water pollution controls. Regional regulators decided last month to exempt timber operations from some permit requirements. But the Environmental Protection Information Center and the Humboldt Watershed Council filed suit in Santa Rosa this week to challenge the new policy. The environmental groups say that if loggers are exempted from the regulations, there could be damage to streams and fish populations. The regulators say logging operations were already covered by state Department of Forestry rules.