bacteria EQC staff report 0816ItemI

DETP/19/30265

''Thursday, July 25, 2019 at 11:43:44 AM (GMT+07:00) Goldstein, Meyer:'' Rule Caption: Water Quality Standards for Bacteria Adm. Order No.: DEQ 9-2016 Filed with Sec. of State: 8-18-2016 Certified to be Effective: 8-18-16 Notice Publication Date: 4-1-2016 Rules Amended: 340-041-0009, 340-041-0101, 340-041-0220, 340-041-0230, 340-041-0300, 340-041-0320 Subject: The proposed rule amendments will: Revise Oregon’s water quality standards for bacteria in order to protect people who consume shellfish and recreate in coastal waters from illness due to fecal contamination of the water; Adopt the United States Environmental Protection Agency’s 2012 Recommended Water Quality Criteria for coastal waters for enterococcus bacteria including: - A 90-day geometric mean of 35 enterococcus organisms per 100 mL; and - A limit of 130 enterococcus organisms per 100 mL that cannot be exceeded more than ten percent of the time in any 90-day period. Clearly identify that E. coli criteria protect contact recreation in freshwaters, enterococcus criteria protect contact recreation in coastal waters and fecal coliform criteria protect shellfish harvesting; Establish water quality standards designated use maps and modify designated use tables for coastal basins to show where shellfish harvesting is a designated use and the boundary between coastal contact recreation use and freshwater contact recreation use for purposes of applying the correct water quality criteria to protect those uses; Change the averaging period for the E. coli standard for freshwaters from 30 days to 90 days and change the averaging methodology from “log mean” to “geometric mean;” Require that wastewater effluent from fecal sources discharged to waters designated for coastal water contact recreation meet the applicable criteria on a monthly basis; Include an implementation provision that would require a minimum of five samples to calculate the geometric mean criteria for E. coli and enterococcus, as well as the 90th percentile value for enterococcus.; and Incorporate plain language into the amended rules consistent with the Oregon Administrative Procedures Act.