Notes on Applicable State and Federal Laws (ARARs)
            
            
Quick Links:Potable Ground WaterSurface Water - Protection of Human HealthSurface Water - Protection of the Environment Potable Ground Water Potable Ground ARARs are concentrations established under applicable state and federal laws that must be considered when establishing cleanup levels for potable ground water [see WAC 173-340-720(3)(b)(ii), (4)(b)(i), and (5)(b)(i)] are accessible in the CLARC Information System using the CLARC Database Search tool. These concentrations are defined as "maximum contaminant levels" or "MCLs". For hazardous substances for which sufficiently protective, health-based concentrations have been established under applicable state and federal laws, the most stringent of those concentrations is used. A concentration established under applicable state and federal laws is sufficiently protective if the excess cancer risk does not exceed 1 in 100,000 (1 x 10-5) and the hazard quotient does not exceed one (1). If the concentra- tion is not sufficiently protective, then either the concentration must be adjusted down- ward in accordance with WAC 173-340-720(7)(b) or a protective concentration must be calculated using the equations provided in the regulation. For hazardous substances for which health-based concentrations have not been estab- lished under applicable state and federal laws, a protective concentration must be cal- culated using the equations provided in the regulation. Surface Water Protection of Human Health Surface Water ARARs Ambient Water Quality Criteria for Protection of Human Health are concentrations established under applicable state and federal laws that must be considered when establishing cleanup levels for surface water. See WAC 173-340-730(2)(b)(i), (3)(b)(i), and (4)(b)(i) are accessible in the CLARC Information System using the CLARC Database Search tool. These concentrations are defined as "ambient water quality criteria". The source for each of the values published in the table is listed in the table. For hazardous substances for which sufficiently protective, health-based concentrations have been established under applicable state and federal laws, the most stringent of those concentrations is used. See WAC 173-340-730(3)(b)(iii), (4)(b)(iii). A concen- tration established under applicable state and federal laws is sufficiently protective if the excess cancer risk does not exceed 1 in 100,000 (1 x 10-5) and the hazard quotient does not exceed one (1). If the concentration is not sufficiently protective, then either the con- centration must be adjusted downward in accordance with WAC 173-340-730(5)(b) or a protective concentration must be calculated using the equations provided in the regulation. For hazardous substances for which health-based concentrations have not been esta- blished under applicable state and federal laws, a protective concentration must be cal- culated using the equations provided in the regulation. See WAC173-340-730(3)(b)(iii), (4)(b)(iii). Surface Water Protection of the Environment Surface Water ARARs Ambient Water Quality Criteria for Protection of Aquatic life are concentrations established under applicable state and federal laws that must be considered when establishing cleanup levels for surface water [see WAC 173-340-730(2)(b)(i), (3)(b)(i), and (4)(b)(i)] are accessible in the CLARC Information System using the CLARC Database Search tool. These concentrations are defined as "ambient water quality criteria". The source for each of the values published in the table is listed in the table. For hazardous substances for which environmental effects-based concentrations have been established under applicable state and federal laws, the most stringent of those concentrations is used. See WAC173-340-730(3)(b)(iii), (4)(b)(iii). For hazardous substances for which environmental effects-based concentrations have not been established under applicable state and federal laws, a protective concentration must be established. Protective concentrations are defined as concentrations that do not re- sult in adverse effects on the protection and propagation of fish, aquatic life, and wildlife. See WAC 173-340-730(3)(b)(iii), (4)(b)(iii). Whole effluent toxicity (WET) testing may be used to demonstrate that a concentration is protective of fish and aquatic life. Other methods may need to be used to demonstrate that a concentration is protective of wildlife, if this is a concern at the site.