ตัวกรองผลการค้นหา
Secondary standards
แปลว่า(Environmental Engineering) Recommended drinking water quality standards which relate to aesthetics and/or health. These standards are recommended, not required. See primary standards.
Primary standards
แปลว่า(Environmental Engineering) Required drinking water quality standards related directly to human health. These standards are required and enforceable by the U.S. EPA. See secondary standards.