Water Quality

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. The new criteria are shown on Table 40 and the associated policies are in OAR 340-041-0033.

Arsenic rulemaking

The Environmental Quality Commission 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.
 
Please see the rulemaking documents below for additional information.
 

Rulemaking documents

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.