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|Aquatic Life
      Human Health
      Biocriteria
      Nutrients
      Microbial
        (Pathogen)
						Criteria
          Table
        Rulemakings, Withdrawals, and Other Federal Register Notices                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | Aquatic Life
      Human Health
      Biocriteria
      Nutrients
      Microbial
        (Pathogen)
						Criteria
          Table
        Rulemakings, Withdrawals, and Other Federal Register Notices |                                                                                              | Aquatic Life
			
			
			 

      Ammonia

            Fact Sheet: 1999 Update

            United States 

                    Environmental Protection

                    Agency

                  Office of Water

                    4305

                  EPA-823-F-99-013

                    December 1999*The U.S. Environmental Protection Agency (EPA) is publishing 

              a 1999 Update of Ambient Water Quality Criteria for Ammonia (1999 

              Ammonia Update). The 1999 Ammonia Update contains EPA's most recent 

              freshwater aquatic life criteria for ammonia, superseding all previous 

              EPA recommended freshwater criteria for ammonia. The 1999 Ammonia 

              Update pertains only to fresh waters. It does not change or supersede 

              the EPA's aquatic life criterion for ammonia in salt water, published 

              in Ambient Water Quality Criteria for Ammonia (Saltwater) in 1989.*

            **Background**

            Under the Clean Water Act, EPA is required to publish and periodically 

              update ambient water quality criteria. These criteria reflect the 

              latest scientific knowledge on the effects of water pollutants on 

              public health and welfare, aquatic life, and recreation. These criteria 

              guide states, territories, and authorized tribes in developing water 

              quality standards and ultimately provide a basis for controlling 

              discharges or releases of pollutants into our nation's waterways.

            Ambient water quality criteria are based solely on data and scientific 

              judgments on the relationship between pollutant concentrations and 

              the effects on aquatic life, human health, and the environment. 

              These criteria do not reflect consideration of economic impacts 

              or the technological feasibility of reducing chemical concentrations 

              in ambient water.

            **1999 Ammonia Update**

            The 1999 Update of Water Quality Criteria for Ammonia incorporates 

              comments received from the 1998 Update. The 1999 Update contains 

              EPA's most recent freshwater aquatic life criteria for ammonia and 

              supersedes all previous freshwater aquatic life ammonia criteria. 

              The new criteria reflect recent research and data since 1984, and 

              are a revision of several elements in the 1984 Criteria, including 

              the pH and temperature relationship of the acute and chronic criteria 

              and the averaging period of the chronic criterion. As a result of 

              these revisions, the acute criterion for ammonia is now dependent 

              on pH and fish species, and the chronic criterion is dependent on 

              pH and temperature. At lower temperatures, the dependency of the 

              chronic criterion is also dependent on 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 temperature 

              decreases, and a 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.

            **Additional Information**

            EPA is issuing a *Federal Register* notice of availability 
              for the 1999 Update, which summarizes changes in the 1999 Update 
              and describes EPA's recommendations for implementing the criteria. 
              The full text of the *Federal Register* notice is available 
              at http://www.epa.gov/waterscience/standards/ammonia/ 
              on the Internet. For additional information, contact Office of Science 
              and Technology, U.S. EPA, 1200 Pennsylvania Avenue NW, Washington 
              DC, 20460. | Ammonia

            Fact Sheet: 1999 Update

            United States 

                    Environmental Protection

                    Agency

                  Office of Water

                    4305

                  EPA-823-F-99-013

                    December 1999*The U.S. Environmental Protection Agency (EPA) is publishing 

              a 1999 Update of Ambient Water Quality Criteria for Ammonia (1999 

              Ammonia Update). The 1999 Ammonia Update contains EPA's most recent 

              freshwater aquatic life criteria for ammonia, superseding all previous 

              EPA recommended freshwater criteria for ammonia. The 1999 Ammonia 

              Update pertains only to fresh waters. It does not change or supersede 

              the EPA's aquatic life criterion for ammonia in salt water, published 

              in Ambient Water Quality Criteria for Ammonia (Saltwater) in 1989.*

            **Background**

            Under the Clean Water Act, EPA is required to publish and periodically 

              update ambient water quality criteria. These criteria reflect the 

              latest scientific knowledge on the effects of water pollutants on 

              public health and welfare, aquatic life, and recreation. These criteria 

              guide states, territories, and authorized tribes in developing water 

              quality standards and ultimately provide a basis for controlling 

              discharges or releases of pollutants into our nation's waterways.

            Ambient water quality criteria are based solely on data and scientific 

              judgments on the relationship between pollutant concentrations and 

              the effects on aquatic life, human health, and the environment. 

              These criteria do not reflect consideration of economic impacts 

              or the technological feasibility of reducing chemical concentrations 

              in ambient water.

            **1999 Ammonia Update**

            The 1999 Update of Water Quality Criteria for Ammonia incorporates 

              comments received from the 1998 Update. The 1999 Update contains 

              EPA's most recent freshwater aquatic life criteria for ammonia and 

              supersedes all previous freshwater aquatic life ammonia criteria. 

              The new criteria reflect recent research and data since 1984, and 

              are a revision of several elements in the 1984 Criteria, including 

              the pH and temperature relationship of the acute and chronic criteria 

              and the averaging period of the chronic criterion. As a result of 

              these revisions, the acute criterion for ammonia is now dependent 

              on pH and fish species, and the chronic criterion is dependent on 

              pH and temperature. At lower temperatures, the dependency of the 

              chronic criterion is also dependent on 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 temperature 

              decreases, and a 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.

            **Additional Information**

            EPA is issuing a *Federal Register* notice of availability 
              for the 1999 Update, which summarizes changes in the 1999 Update 
              and describes EPA's recommendations for implementing the criteria. 
              The full text of the *Federal Register* notice is available 
              at http://www.epa.gov/waterscience/standards/ammonia/ 
              on the Internet. For additional information, contact Office of Science 
              and Technology, U.S. EPA, 1200 Pennsylvania Avenue NW, Washington 
              DC, 20460. |  | United States 

                    Environmental Protection

                    Agency | Office of Water

                    4305 | EPA-823-F-99-013

                    December 1999 | 
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | -------------------------------------------------------------------------------------------- | ------------------------------------------- | ----------------------------------------------------- | 
|Aquatic Life
      Human Health
      Biocriteria
      Nutrients
      Microbial
        (Pathogen)
						Criteria
          Table
        Rulemakings, Withdrawals, and Other Federal Register Notices                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Ammonia

            Fact Sheet: 1999 Update

            United States 

                    Environmental Protection

                    Agency

                  Office of Water

                    4305

                  EPA-823-F-99-013

                    December 1999*The U.S. Environmental Protection Agency (EPA) is publishing 

              a 1999 Update of Ambient Water Quality Criteria for Ammonia (1999 

              Ammonia Update). The 1999 Ammonia Update contains EPA's most recent 

              freshwater aquatic life criteria for ammonia, superseding all previous 

              EPA recommended freshwater criteria for ammonia. The 1999 Ammonia 

              Update pertains only to fresh waters. It does not change or supersede 

              the EPA's aquatic life criterion for ammonia in salt water, published 

              in Ambient Water Quality Criteria for Ammonia (Saltwater) in 1989.*

            **Background**

            Under the Clean Water Act, EPA is required to publish and periodically 

              update ambient water quality criteria. These criteria reflect the 

              latest scientific knowledge on the effects of water pollutants on 

              public health and welfare, aquatic life, and recreation. These criteria 

              guide states, territories, and authorized tribes in developing water 

              quality standards and ultimately provide a basis for controlling 

              discharges or releases of pollutants into our nation's waterways.

            Ambient water quality criteria are based solely on data and scientific 

              judgments on the relationship between pollutant concentrations and 

              the effects on aquatic life, human health, and the environment. 

              These criteria do not reflect consideration of economic impacts 

              or the technological feasibility of reducing chemical concentrations 

              in ambient water.

            **1999 Ammonia Update**

            The 1999 Update of Water Quality Criteria for Ammonia incorporates 

              comments received from the 1998 Update. The 1999 Update contains 

              EPA's most recent freshwater aquatic life criteria for ammonia and 

              supersedes all previous freshwater aquatic life ammonia criteria. 

              The new criteria reflect recent research and data since 1984, and 

              are a revision of several elements in the 1984 Criteria, including 

              the pH and temperature relationship of the acute and chronic criteria 

              and the averaging period of the chronic criterion. As a result of 

              these revisions, the acute criterion for ammonia is now dependent 

              on pH and fish species, and the chronic criterion is dependent on 

              pH and temperature. At lower temperatures, the dependency of the 

              chronic criterion is also dependent on 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 temperature 

              decreases, and a 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.

            **Additional Information**

            EPA is issuing a *Federal Register* notice of availability 
              for the 1999 Update, which summarizes changes in the 1999 Update 
              and describes EPA's recommendations for implementing the criteria. 
              The full text of the *Federal Register* notice is available 
              at http://www.epa.gov/waterscience/standards/ammonia/ 
              on the Internet. For additional information, contact Office of Science 
              and Technology, U.S. EPA, 1200 Pennsylvania Avenue NW, Washington 
              DC, 20460. |                                                                                                                                                                                                                  | United States 

                    Environmental Protection

                    Agency | Office of Water

                    4305                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | EPA-823-F-99-013

                    December 1999                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|United States 

                    Environmental Protection

                    Agency                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | Office of Water

                    4305                                                                                                                                                                      | EPA-823-F-99-013

                    December 1999                                       
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

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