Arsenic, Iron and Manganese Rulemaking

DEQ reviewed Oregon's water quality criteria for arsenic, iron and manganese established to protect human health. The changes account for the presence of naturally-occurring earth metals, which include arsenic, iron and manganese, in Oregon waters and continue to protect human health. Without these changes, DEQ and regulated parties could be required to expend resources that will not result in health benefits.

• Arsenic Rulemaking
• Iron and Manganese Rulemaking
• Contact

Arsenic Rulemaking

The Environmental Quality Commission (EQC) revised Oregon’s water quality criteria for arsenic on April 21, 2011. EPA approved the criteria on October 17, 2011, making the revised criteria effective under the Clean Water Act. The revised criteria protect human health and account for the presence of arsenic in Oregon waters due to natural sources.

The new arsenic criteria are shown on Table 40 and the arsenic reduction policy is in OAR 340-041-0033.  

DEQ proposed revised arsenic criteria for public comment in Aug.-Sept. of 2010 and held two public hearings. DEQ re-opened public comment Feb. 1-23, 2011 to invite further comment on revised proposed numeric criteria. Please see the rulemaking documents below for additional information.

Rulemaking Documents

• EQC Staff Report PDF
• Issue Paper: Water Quality Standards Review and Recommendations: Arsenic PDF
• Proposed Rulemaking Announcement PDF
• Proposed Toxic Pollutants Water Quality Standards Rule (OAR 340-041-0033) (including the proposed arsenic reduction policy) PDF
• Proposed Table 20 (showing revised numeric arsenic criteria) PDF
• Summary of Public Comment and DEQ's Response PDF
• Fiscal Addendum PDF
• Statement of Need and Fiscal and Economic Impact PFD
• Land Use Evaluation Statement PDF

Iron and Manganese Rulemaking

The Environmental Quality Commission revised Oregon’s water quality criteria for iron and manganese at their meeting on Dec. 9, 2010. EPA approved the criteria in June 2011, making the revised criteria effective under the Clean Water Act. The rule amendment withdrew the “water and fish ingestion” criteria for iron and manganese and withdrew the “fish consumption only” criterion for manganese as it applies to freshwaters. The “fish consumption only” criterion for manganese remains in place as it applies to saltwater in order to protect for the consumption of oysters and other marine mollusks.

• Table 40 PDF
• EPA’s Iron and Manganese Approval Letter to DEQ (June 9, 2011) PDF
• EPA's Technical Support Document (June 9, 2011) PDF

The new criteria may be found in Table 40 (link above) and additional background information may be found in the Iron and Manganese Issue Paper.

Contact Information

For questions about these rulemakings, please contact:

Debra Sturdevant
DEQ Water Quality Division
Phone: (503) 229-6691, E-mail