Member Pipeline - Regulatory - Alert (RA 00-1)
To:
Members & Affiliates, Water Quality Committee
From:
National Office
Date:
January 3, 2000
Subject:
Freshwater Ammonia Criteria Revisions
Reference:
RA 00-1
On December 22, 1999 the U.S. Environmental Protection Agency (EPA) announced the publication and availability of the “1999 Update of Ambient Water Quality Criteria for Ammonia.” The Update contains EPA's recommended ammonia criteria for the protection of freshwater aquatic life. These criteria are EPA's current recommendations for States, Territories, and authorized Tribes to use as guidance in adopting water quality standards. The 1999 Update incorporates revisions made in response to comment on the 1998 Update, and supercedes all previous freshwater ammonia criteria.
The new criteria reflect revision of several elements in the 1984 criteria resulting in an acute criterion for ammonia that is now dependent on pH and fish species and a chronic criterion dependent on pH and temperature. At lower temperatures, the dependency of the chronic criterion is also dependent upon the presence or absence of early life stages of fish. The temperature dependency in the 1999 Update results in a gradual increase in the criterion as the temperature decreases, and criterion that is more stringent, at temperatures below 15°C, when early life stages of fish are expected to be present. EPA's recommendations in the 1999 Update represent a change from both the 1984 chronic criterion, which was dependent mainly on pH, and from the 1998 Update, in which the chronic criterion was dependent on pH and the presence of early life stages of fish.
Attached, please find an EPA fact sheet further summarizing the changes and the December 22, 1999 Federal Register notice announcing the availability of the criteria document. A copy of the full 153 page document, “1999 Update of Ambient Water Quality Criteria for Ammonia” (EPA-822-R-99-014) may be obtained from the U.S. EPA by contacting the National Service Center for Environmental Publications (NSCEP) at 800/490-9198. The document is also available on the Internet at: http://www.epa.gov/ost/standards/ammonia/.
If you have any additional questions, please contact Mark Hoeke at AMSA 202/833-9106.
Attachments:
EPA Fact Sheet — 1999 Update of Ambient Water Quality Criteria for Ammonia - Technical Version Federal Register Notice of Availability — 1999 Update of Ambient Water Quality Criteria for Ammonia For this downloadable file, you must have the Acrobat Reader. If you don't have the Acrobat Reader, click on the icon below to download a copy. After you download and install a copy, return to this page and click on the link above for the downloadable file.
