CHEMICAL PROFILES|National Media Quality Standards

CWA-AWQC: The Clean Water Act requires EPA to establish ambient water quality criteria (AWQC), which serve as the scientific foundation for state surface water quality standards. Separate AWQC are derived to protect aquatic life and human health. EPA's Criteria Table lists aquatic life, human health, and nutrient criteria for 158 pollutants. 15 criteria were revised in December 2003 and are available at http://epa.gov/waterscience/humanhealth/15table-fs.htm#crit. More detailed ambient water quality criteria documents can be obtained from EPA's Office of Water at http://www.epa.gov/waterscience/pc/ambient2.html. Scorecard reports EPA's AWQC for Human Health for consumption of water plus aquatic organisms.

EPA-DWEL: Drinking Water Equivalent Levels are used by EPA as a guideline for evaluating drinking water quality. They are not enforceable legal standards. DWELs define a lifetime exposure concentration protective of adverse, non-cancer health effects, assuming that all exposure to a contaminant is from drinking water. EPA, Office of Water. 2004 Edition of the Drinking Water Standards and Health Advisories. http://www.epa.gov/ost/drinking/standards/dwstandards.pdf.

EPA-HA: Health Advisories are used by EPA as a guideline for evaluating drinking water quality. They are not enforceable legal standards. HAs define the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effect over various exposure durations (one-day to lifetime), with a margin of safety. EPA, Office of Water. 2004 Edition of the Drinking Water Standards and Health Advisories. http://www.epa.gov/ost/drinking/standards/dwstandards.pdf.

NAAQS: The Clean Air Act requires EPA to establish national ambient air quality standards. EPA, Office of Air Quality Planning and Standards. http://www.epa.gov/air/criteria.html.

SDWA-DRAFT: The Safe Drinking Water Act requires EPA to establish maximum contaminant levels for public drinking water. Some MCLs are only draft values and have not been formally proposed or adopted as regulations. Draft MCLs are not enforceable legal standards. EPA, Office of Water. 2004 Edition of the Drinking Water Standards and Health Advisories. http://www.epa.gov/ost/drinking/standards/dwstandards.pdf.

SDWA-MCL: The Safe Drinking Water Act requires EPA to establish maximum contaminant levels for public drinking water. EPA, Office of Water. 2004 Edition of the Drinking Water Standards and Health Advisories. http://www.epa.gov/ost/drinking/standards/dwstandards.pdf.

SDWA-SMCL: Secondary maximum contaminant levels are used by EPA as a guideline for evaluating drinking water quality. They are not enforceable legal standards. SMCLs define acceptable levels of contaminants based on taste, odor, color and certain other non-aesthetic effects of drinking water. EEPA, Office of Water. 2004 Edition of the Drinking Water Standards and Health Advisories. http://www.epa.gov/ost/drinking/standards/dwstandards.pdf.