AUGUSTA, Maine (AP) – Maine’s environmental groups and residents are pushing back against proposed changes to the state’s mining regulations. The state’s Board of Environmental Protection is hearing public testimony on the suggested rules Thursday. The Natural Resources Council of Maine and others are urging the board to implement stricter limits on groundwater contamination and require mining companies to pay for the full share of cleanup costs. Supporters of the rules say environmental groups want to make them so stringent that they prevent all future mining operations in Maine. They say mining will bring significant economic benefits to Maine communities. The new rules were prompted by J.D. Irving Co.’s interest in getting permits to mine gold, silver, copper and other metals in Aroostook County’s Bald Mountain.