Water Quality Data Screening: Benchmark Information

Summary information and links to the selected benchmarks used to evaluate EWEB’s water quality data.

1. U.S. Environmental Protection Agency Primary Maximum Contaminant Level

Benchmark Abbreviation: Primary MCL
Agency Website: http://water.epa.gov/drink/contaminants/index.cfm

2. Oregon Department of Environmental Quality Effective Human Health Water Quality Criteria for Toxic Pollutants

Benchmark Abbreviation: DEQ HHC
Agency Website: http://www.deq.state.or.us/wq/rules/div041/table40.pdf

3. U.S. Geological Survey Health-Based Screening Levels*

Benchmark Abbreviation: USGS HBSL
Agency Website: http://cida.usgs.gov/hbsl/apex/f?p=104:1:
*Note from the USGS website (see link above): Health-Based Screening Levels (HBSLs) are non-enforceable water-quality benchmarks that can be used to (1) supplement EPA MCLs and HHBPs, (2) determine whether contaminants found in surface-water or groundwater sources of drinking water may indicate a potential human-health concern, and (3) help prioritize monitoring efforts. HBSLs were developed by the USGS National Water-Quality Assessment (NAWQA) Program for contaminants that do not have USEPA MCLs or HHBPs.

HBSLs were updated in June 2014 in order to:
• Provide benchmarks, when possible, for 267 new contaminants analyzed by the NAWQA Program.
• Remove HBSLs for contaminants that have new USEPA chronic HHBPs.
• Be consistent with new USEPA policies, by calculating both Noncancer and Cancer HBSLs for some contaminants.

4. U.S. Environmental Protection Agency Regional Screening Level (USEPA RSL)

Benchmark Abbreviation: EPA RSL
Agency Website: https://semspub.epa.gov/work/03/2229071.pdf

5. U.S. Environmental Protection Agency Human Health Benchmarks for Pesticides

Benchmark Abbreviation: EPA HHBP
Agency Website: http://iaspub.epa.gov/apex/pesticides/f?p=HHBP:home

6. Oregon Department of Environmental Quality Water Quality Standard for E. Coli

Benchmark Abbreviation: OR Rec Max
Agency Website: http://www.oregon.gov/deq/RulesandRegulations/Documents/toxics1.pdf
*Note: On July 22, 1999, EPA approved Oregon’s applicable water quality standard for bacteria in freshwater as follows: 30-day log mean of 126 org/100 MPN/100 ml and a single sample maximum (SSM) of 406 org/100 MPN/100 ml for e. coli (OAR041-009). EWEB’s water quality data portal currently includes the ability to screen monitoring results for the SSM; however, a tool that allows the public to easily evaluate monitoring data using the 30-day log mean may be made available in the future for monitoring locations that have multiple results within a 30-day period.

7. Oregon Health Authority Public Health Division Advisory Guidelines for Harmful Algae Blooms

Benchmark Abbreviation: OHA
Agency Website: https://public.health.oregon.gov/HealthyEnvironments/Recreation/HarmfulAlgaeBlooms