A state bill on the verge of becoming law would ban the use of drinking water to irrigate decorative grass, a mandate endorsed by Marin leaders who are already largely prepared for it. Assembly Bill 1572, which has made its way to Gov. Gavin Newsom’s desk, would involve the kind of grassy areas in street medians, business parks and city sidewalks. Decorative grass could still be irrigated with recycled water. The restrictions proposed under were first implemented by the state as temporary provisions during the recent three-year drought. The rules are set to expire in June. The bill would make these rules a permanent way of life in California. Violations would carry fines of $500.