Water Quality Standards Revisions for Freshwater Ammonia 2014
Mark your calendars to hear more about these proposed revisions
Ammonia Webinar—September 10, 10–12 PDT
DEQ is initiating a rulemaking to address EPA’s Jan. 31, 2013 disapproval of ammonia criteria that DEQ adopted in 2004. Oregon’s adopted criteria were based on EPA’s 1999 recommended criteria, which did not take into consideration ammonia toxicity to certain kinds of freshwater mussels and snails. EPA has since updated its national recommendation for ammonia in response to new mussel and snail sensitivity data, and published final revised criteria in the Federal Register on August 12, 2013. As part of the rulemaking, DEQ is also proposing to correct an error to the basin-specific criterion for pH for the main stem Snake River, which DEQ inadvertently limited to a portion of the basin during a rule update in 2003. In addition, DEQ is proposing to correct or clarify portions of water quality standards that EPA recently disapproved.
DEQ is holding an ammonia webinar for the public to review DEQ’s proposed changes to Oregon’s freshwater criteria for ammonia. Check back here later for agenda, presentation and webinar logistics closer to the webinar date.
EPA’s Jan. 31, 2013 disapproval of Oregon’s ammonia criteria results in Oregon retaining its currently effective ammonia criteria that are based on EPA recommendations from 1985 (criteria last approved by EPA). These criteria are in Table 30 and are dependent on pH and temperature using the ammonia calculator located on the toxics website. Until Oregon adopts revised criteria for ammonia and EPA approves those revisions, the criteria in Table 30 remain effective for Clean Water Act purposes.
DEQ proposes to adopt revised ammonia criteria to protect freshwater mussels and snails. Current information indicates that freshwater mussels and snails are present in many watersheds across Oregon. DEQ’s proposed ammonia criteria follow EPA’s August 2013 recommendations. EPA’s criteria are expressed as Total Ammonia Nitrogen (TAN) and are dependent on the pH and temperature of the water. See EPA’s website for more information about its ammonia recommendations.
Prior to initiating this rulemaking, DEQ met with stakeholders to discuss EPA’s latest ammonia recommendations and its potential application to Oregon waterbodies. Feedback received indicated that generally, EPA’s recommendations are appropriate for Oregon and that DEQ should move forward quickly to adopt revisions. Given this input, DEQ did not form an advisory committee for this rulemaking. Members of the public will have an opportunity to provide comments on the rulemaking as part of the public comment process.
In addition to ammonia revisions, the proposed rule would correct an error made in 2003 for the basin-specific pH standard for the main stem Snake River. The current standard incorrectly applies the standard to river miles 260-335 of the Snake River. This rule revision would correct that error so to ensure that the pH standard applies throughout the main stem Snake River in Oregon. DEQ also is proposing to make clarifying comments, noting that EPA disapproved the statewide narrative natural conditions criterion at OAR 340-041-0007(2) and numeric natural conditions criterion under the temperature standard as a result of a court decision. Finally, DEQ is proposing to amend basin-specific standards for the Umatilla Basin and remove a term from the definitions section to be consistent with EPA’s partial disapproval of DEQ’s site-specific criteria and use designations for the West Division Main Canal that EPA adopted in 2012.
|Ammonia Rulemaking Schedule - Milestones and Timeframes|
||Sept. 10, 2014|
||Sept. 16 – Oct. 30, 2014|
|Public hearing (Portland)
||Oct. 15, 2014|
|Environmental Quality Commission adoption
||Jan. 7 – 8, 2015|
||May 2015 (estimated)|
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Stay informed about the ammonia rulemaking by clicking the green envelope at the top left corner of this page to be added to DEQ’s mailing list for water quality standards rulemaking. Information related to the ammonia rulemaking will also be added to this website as it becomes available.