EPA gives green light to Oregon's Water Quality Assessment
The U.S. Environmental Protection Agency granted final approval of Oregon’s 2018/2020 Integrated Report on November 12, 2020. A fundamental piece of the state’s water quality program, the report provides the most current assessment of water quality data throughout the state. The Oregon Department of Environmental Quality uses the report to make decisions about Oregon’s water quality. It is accessible through both an online searchable database and a web-based map tool that is transparent and easy to use, available on DEQ’s website here.
“The Integrated Report is the cornerstone of the water quality program and provides the foundation for many other water quality regulatory programs. It is an important component of the Clean Water Act framework and provides valuable information on the status of Oregon’s waterways,” DEQ Water Quality Division Administrator Justin Green said.
DEQ submitted the final 2018/2020 Integrated Report to EPA for approval in April 2020. Following requests for additional information on several proposed listings and delistings, DEQ resubmitted the report in October. EPA’s final approval means the 2018/2020 Integrated Report is now in effect.
In 2016, DEQ initiated significant improvements on how it develops and publishes its Integrated Report. DEQ staff reconstructed the framework and foundation to streamline and improve its water quality assessment. In mid-2018, DEQ held its first statewide request for water quality data since the 2004/2006 Integrated Report, and DEQ analyzed over 6.5 million rows of data for the 2018/2020 Integrated Report.
One major improvement is the method by which waterbody segments are delineated, assessed and reported. Because waterbodies change as they flow from headwaters to the mouth, DEQ splits up the waterbody into multiple pieces, or assessment units. These fixed assessment units improve the integrity and quality of assessment process, allow DEQ to more easily summarize information related to water quality in Oregon and track water quality changes over time.
Key findings of the 2018/2020 Integrated Report assessment continue to indicate the most widespread causes of impairments are temperature, dissolved oxygen, and E. coli.
• In 2018/2020, DEQ assessed 2,871 units for one or more parameters, representing 146,057 river miles. This represents 41% of Oregon’s mapped assessment units.
• Forty four percent of Oregon’s river miles are impaired; this is an increase from 33 percent in 2012.
• Impairment of the Fish and Aquatic Life use is the most commonly unsupported use. This is largely driven by non-attainment of the temperature criteria.
The draft Integrated Report 2018/2020 was open for public comment for a total of 99 days from Sept. 30, 2019, through Jan. 6, 2020. Staff provided six informational sessions across the state and recorded an online webinar to provide an overview of the information contained in the Integrated Report and demonstrate the functionality of the new tools.
Oregon’s 2018/2020 Integrated Report on Surface Water Quality and List of Water Quality Limited Waters is available on DEQ’s website: https://www.oregon.gov/deq/wq/Pages/epaApprovedIR.aspx
Media contact: Contacts: Jennifer Flynt, public affairs specialist, flynt.jennifer@deq.state.or.us, 503.730.5924
Read all DEQ news releases online here.
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