&EPA United States Environmental Protection Agency Office of Water Regulations and Standards Washington, DC 20460 September 1980 Water Nitrogen-Ammonia/ Nitrate/Nitrite Water Quality Standards Criteria Summaries A Compilation of State/Federal Criteria ------- NITROGEN - AMMONIA/NITRATE/NITRITE Water Quality Standards Criteria Summaries A Compilation of State/Federal Criteria September 1980 U. S. Environmental Protection Agency Office of Water Regulations and Standards Washington, D. C. 20460 ------- NATIONAL SUMMARY OF STATE WATER QUALITY STANDARDS NITRATES/NITRITES/AMMONIA SEPTEMBER, 1980 PREPARED FOR UNITED STATES ENVIRONMENTAL PROTECTION AGENCY CRITERIA AND STANDARDS DIVISION 401 M STREET, S. W. WASHINGTON, D. C. 20460 PREPARED BY NALESNIK ASSOCIATES INCORPORATED 505 ELEVENTH STREET, S. E. WASHINGTON, D. C. 20003 Contract Number 68-01-6058 Project Number WA-80-A055 ------- INTRODUCTION This digest is compiled to provide general information to the public as well as to Federal, State, and local officials. It contains excerpts from the individual Federal-State water quality standards establishing pollutant specific criteria for interstate surface waters. The water quality standards program is implemented by the U. S. Environmental Protection Agency where responsibility for providing water quality recommendations, approving State-adopted standards for interstate waters, evaluating adherence to the standards, and overseeing enforcement of standards compliance, has been mandated by Congress. Standards, a nationwide strategy for surface water quality management, contain three major elements: the use (recreation, drinking water, fish and wildlife propagation, industrial, or agricultural) to be made of the navigable water; criteria to protect these uses; and an antidegradation statement to protect existing high quality waters, from degradation by the addition of pollutants. Water quality criteria (numerical or narrative specifications) for physical, chemical, temperature, and biological constituents are stated in the July 1976 U. S. Environmental Protection Agency publication Quality Criteria for Water (QCW), available from the Government Printing Office, Washington, D. C. The 1976 QCW, commonly referred to as the "Red Book," is the most current compilation of scientific information used by the Agency as a basis for assessing water quality. This publication is subject to periodic updating and revisions in light of new scientific and technical information. Criteria for ammonia, nitrate or nitrite nitrogen in State water quality standards are the subject of this digest. Ammonia in most waters is a biological degradation product of nitrogenous organic matter. When dissolved in water, ammonia will react with the water to form ammonium ions. Ammonium can also be released from proteinaceous organic matter and urea, or synthesized from nitrogen fixation. Nitrate is formed from the complete oxidation of ammonium by certain micro organisms in which nitrite is an intermediate product. In well oxygenated waters nitrite is readily oxidized to nitrate. The rationale for establishing water quality criteria for these three common molecular forms of nitrogen are: (1) ammonia toxicity to aquatic life is well documented and its toxicity is directly dependent on the pH of the water in which it is dissolved; (2) growing plants assimilate nitrate and ammonium ions into plant proteins; and (3) both nitrate and nitrite nitrogen are toxic to aquatic life where specific concentrations of either are reached in a waterbody. ------- To prevent the nuisance and toxic effects of any of the nitrogen forms, the 1976 Quality Criteria for Water recommends the following criteria: 0.02 mg/1 (as un-ionized ammonia) for freshwater aquatic life. Concentrations of total ammonia (NH, + NH^ ) which contain an un- ionized ammonia concentration of 0.020 mg/1 wH«(mg/l) Temper- pH Value ature (°C) 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 0«»* 10... 15... 20... 3o!" 25. 7.9 2.5 0.81 0.27 0.099 0.045 0.028 0.022 10 mg/1 nitrate nitrogen (N) for domestic water supply (health). Since water quality standards experience revisions and upgrading from time to time, following procedures set forth in the Clean Water Act, individual entries in this digest may be superseded. As these revisions are accomplished and allowing for the States to revise their standards accordingly, this digest will be updated and reissued. Because this publication is not intended for use other than as a general information resource, to obtain the latest information and for special purposes and applications, the reader needs to refer to the current approved water quality standards. These can be obtained from the State water pollution control agencies or the EPA or Regional Offices. Individual State-adopted criteria follow: 160. 110. 73. 50. 35. 51. 34. 23. 16. 11. 16. 11. 7.3 5.1 3.5 5.1 3.4 2.3 1.6 1.1 1.6 1.1 0.75 0.52 0.37 0.53 0.36 0.25 0.18 0.13 0.18 0.13 0.093 0.070 0.055 0.071 0.054 0.043 0.036 0.031 0.036 0.031 0.027 0.025 0.024 11 ------- REFERENCES California Water Quality Standards by River Basins, c.a. 1975 For more detailed information on selected basins, sub-basins and stretches of streams and coastal areas refer to California State Water Quality Standards. B Delaware Water Quality Standards, March 25, 1979 C Idaho Water Quality Standards, c.a. September, 1979 Missouri Water Quality Standards, c.a. February, 1978 p American Samoa Water Quality Standards, Revised July, 1973 F Territory of Guam Water Quality Standards, Sept. 1975 G Trust Territory of the Pacific Islands Water Quality Standards, October 21, 1973 H Virgin Islands Water Quality Standards, Aug. 1973 ENVIRONMENT REPORTER, The Bureau of National Affairs, Inc. Washington, D. C. 20037 1 Pages 701:0501-0509, February 16, 1979 2 Pages 706:1004-1008, July 20, 1979 3 Pages 711:0542-0544, August 5, 1977 4 Pages 716:0603, March 26, 1976 5 Pages 726:1005, 1011-1013, March 7, 1980 Basic Water Quality Standards adopted May 22, 1979, have not yet been submitted to EPA for formal approval. 6 Pages 731:1002-1009, September 8, 1978 7 Pages 746:1008-1014, October 19, 1979 8 Pages 751:0504-0505, January 25, 1980 9 Pages 765:0512-0515, January 30, 1976 10 Page 761:0503-0504, 1973 iii ------- 11 Page 766:0504-0509, October 5, 1979 12 Pages 771:0502-0504, September 29, 1978 13 Pages 776:0504-0506, April 10, 1979 14 Pages 781:0501-0502, May 18, 1979 15 Pages 786:0501-0502, August 29, 1975 16 Page 791:0583, May 26, 1978 17 Pages 796:0103-0108, February 16, 1979 18 Pages 801:1001-1002, Sept. 29, 1978 19 Page 806:1003, March 30, 1979 20 Page 811:1043, 1974 21 Pages 816:0602-0607, 0642-0648, 1974 99 Pages 821:0502-0505, June 30, 1978 23 Pages 831:0501-0510, February 21, 1975 f)A Z4 Page 836:0502, June 30, 1978 25 Pages 841:0507-0537, December 7, 1979 26 Pages 846:0501-0508, November 17, 1978 27 Pages 851:1001-1023, December 15, 1978 28 Pages 856:1001-1002, July 18, 1978 29 Pages 861:1002-1007, August 11, 1979 30 Pages 866:1004-1009, December 28, 1979 31 Pages 871:0501-0506, November 25, 1977 32 Pages 876:1001-1043, May 26, 1978 09 Pages 881:1001-1007, September 21, 1979 34 Pages 886:0513-0524, August 29, 1975 oe Pages 891:1001-1129, November 16, 1979 IV ------- 36 Pages 901:0501-0505, November 3, 1978 07 Pages 906:0501-0506, October 13, 1978 OQ Pages 911:0501-0507, June 22, 1979 39 Pages 916:0541-0544, April 14, 1978 4(1 Pages 921:1001-1003, August 13, 1976 41 Pages 926:0541-0563, January 26, 1979 49 Pages 931:0501-0508, May 26, 1978 43 Pages 936:1001-1003, June 27, 1975 44 Pages 941:1001-1005, May 26, 1978 45 Pages 946:0501-0520, July 14, 1978 46 Pages 951:1002-1003, April 28, 1978 47 Pages 956:1001-1007, January 11, 1980 48 Page 741:1002, November 23, 1979 4Q Pages 896:0301-0310, March 31, 1978 ------- NITRATES/NITRITES/AMMONIA State Alabama Alaska Arizona** Criteria Values in mg/1 Not specified Not specified A. The mean annual total nitrate concen- trations of the following waters shall not exceed the values given below nor shall the total nitrate concentrations of more than 10 percent of the samples in any year exceed the 90 percent values given below. Unless otherwise specified, indi- cated values also apply to tributaries to the named waters. Total nitrates as NO3 mg/1 4 Mean annual 7 90 pet-value 5 Mean annual 5 Mean annual 7 90 pet-value 5 Mean annual 7 90 pet-value B. The above standards are intended to protect the beneficial uses of the named waters. Because regulation of nitrates and phosphates alone may not be adequate to protect waters from eutrophication, no substance shall be added to any surface water which produces aquatic growth to the extent that such growths create a public nuisance or interference with bene- ficial uses of the water defined and desig- nated in Reg. 6-2-6.5. Designated Stream Use All All Colorado River from Utah border to Willow Beach (main stem) Colorado River from Willow Beach to Parker Dam (main stem) Colorado River from Parker Dam to Imperial Dam (main stem) Colorado River from Imperial Dam to Morelos Dam (main stem) -1- ------- State Arkansas Criteria Values in mg/1 Not specified Nutrients - The naturally occurring nitro- gen/phosphorus ratio shall not be signifi- cantly altered due to municipal, indus- trial, agricultural or other waste dis- charges, nor shall total phosphorus exceed 100 ugA in streams or 50 ug/1 in lakes and reservoirs due to any such discharges. Designated Stream Use All Calif orniaA Colorado' Nitrates + total nitrites 10 100 Ammonia - not specified Un-ionized ammonia - some basins Note: See California State Water Standards for specific rivers, basins and coastal waters. Ammonia (as N) 0.02 (un-ionized) 0.06 (un-ionized) 0.5 Nitrate (as N) 1001 10 Nitrite (as N) 0.05 0.5 10l 1.0 In order to provide a reasonable margin of safety to allow for unusual situations such as extremely high water ingestion or nitrite formation in slurries, the NO,-N plus NO2~N content in drinking waters Tor livestock and poultry should be limited to 100 ppm or less, and the NO^-N content alone be limited to 10 ppm or less. All Livestock watering (Basin 3) All Cold water biota Warm water biota Domestic water supply Agriculture Domestic water supply Cold water biota Warm water biota Agriculture Domestic water supply -2- ------- State Connecticut D Delaware Criteria Values in mg/1 Not specified Ammonia - N 0.4 Total nitrogen 3.0 Designated Stream Use All Public water supply Public water supply Florida7 Nitrate - 10.0 as N or that concentration determined in Nutrients below Nitrite - Not specified Ammonia (un-ionized) 0.02 Nutrients - In no case shall nutrient con- centrations of a body of water be altered so as to cause an imbalance in natural populations of aquatic flora and fauna. Public water supply All Public water supply, shell- fish, recreation Public water supply, shell- fish, recreation Q Georgia Not specified Q Hawaii Idaho10 Total nitrogen, not greater than 0.10 mg/1 Total nitrogen, not greater than 0.15 mg/1 Total nitrogen, not greater than 0.20 mg/1 Not specified Class AA Class A Class B All Illinois11 Ammonia (as N) 1.5 mg/ Ammonia Nitrogen as N. (Storet No. 00610). No effluent from any source which discharges to the Illinois River, The DesPlaines River downstream of its con- fluence with the Chicago River System, or the Calumet River System, and whose untreated waste load is 50,000 or more population equivalents shall contain more than 2.5 mg/1 of ammonia nitrogen as N - All waters except secondary contact and indigenous aquatic life and Lake Michigan Secondary contact and indigenous aquatic life waters -3- ------- State Criteria Values in mg/1 Designated Stream Use Illinois (con't) Indiana ^ during the months of April through October, or 4 mg/1 at other times, after December 31, 1977. Sources discharging to any of the above waters and whose untreated waste load cannot be computed on a population equivalent basis compar- able to that used for municipal waste treatment plants and whose ammonia nit- rogen discharge exceeds 100 pounds per day shall not discharge an efffluent of more than 3.0 mg/1 of ammonia nitrogen after December 31, 1974. 0.02 mg/1 10.0 mg/1 Nitrate-Nitrogen 1.0 mg/1 Nitrite-Nitrogen The bioassay criterion for toxic sub- stances of 1/10 x 96 hr TLM applies to ammonia in all waters except those listed in the specific standards as follows: Unionized Ammonia 0.03 mg/1 - Monthly Ave. 0.1 mg/1 - Daily Max. 0.02 mg/1 Monthly Ave. 0.05 mg/1 - Daily Max. 1.5 mg/1 total Ammonia Nitrogen 0.02 mg/1 Unionized Ammonia All Lake Michigan Waters Public and Food Processing water supply Public and Food Processing water supply Inner Harbor, Gary Harbor, Burns Harbor Lake Michigan Grand Calumet River and Indiana Harbor Ship Canal Wolf Lake and Wolf Lake Harbor Ammonia Toxic Substances: The concentration of toxic substances shall not exceed those values listed in the United States Environ- mental Protection Agency Administrator's Quality Criteria for Water 1976 for the protection of sensitive aquatic life. (For Ammonia this value is 0.02 mg/1 NH3) Toxic Substances: Not to exceed one- tenth of the 96-hour median tolerance limit of salmonid fishes or the natural Natural Spawning and Rearing or Imprinting Areas for Salmonid Fishes Migration Routes Salmonid Fishes for -4- ------- State Criteria Values in mg/1 Designated Stream Use Indiana (con't) Iowa 13 biota obtained from continuous flow bio- assays where the dilution water and toxi- cant are continuously renewed, except that other lower application factors may be used in specific cases when justified on the basis of available evidence. Nitrates and Nitrites: Plant Nutrients: Free from substances attributable to municipal, industrial, agri- cultural or other sources in concen- trations or combinations which will cause or contribute to the growth of aquatic plants or algae in such degree as to create a nuisance, be unsightly or deleterious, or be harmful to salmonid fishes or the natural biota. (Stream Pollution Control Board of the State of Indiana; SPC 12R, Sec.B; filed May 26, 1978, 3:30 PM 1 IR 100) Plant Nutrients: Free from substances attributable to municipal, industrial, agri- cultural or other sources in concen- trations or combinations which will cause or contribute to the growth of aquatic plants or algae in such degree as to create a nuisance, be unsightly or deleterious, or be harmful to salmonid fishes or the natural biota. Ammonia (N) 5 (Nov 1 - March 31) 2 (April 1 - Oct. 31) 2.5 (Nov.l - March 31) 1.0 (April 1 - Oct. 31) Nitrate (NO^) 45 Nitrite - Not specified Natural Spawning and Rearing or Imprinting Areas for Salmonid Fishes Migration Routes Salmonid Fishes for Warm water fish and aqua- tic life, secondary recrea- tion Cold water fish and aqua- tic life, secondary recrea- tion. Public water supply All Kansas 14 Ammonia: Man-made sources shall not cause the undissociated ammonium hydro- xide concentration of waters of the state to exceed 0.15 mg/1 as N. All -5- ------- State Kansas (con't) Kentucky 15 Louisiana 16 17 Maine1 Maryland 18 Massachusetts 19 Criteria Values in mg/1 Nitrites - Not specified Ammonia 0.05 Not specified Nutrients - the naturally occurring nitro- gen phosphorous ratio shall be maintained. Not specified Not specified The state recognizes that certain waters of the State are eutrophic or are approaching eutrophic conditions. All dis- charges to waters which are eutrophic or potentially eutrophic, when so identified by the State, shall be treated as necessary to reduce eutrophic effects. The State shall require that wastewaters, containing nutrients which cause or may cause eutro- phication be given advanced waste treat- ment prior to discharge, or be disposed of by spray irrigation on land, or by other practicable procedures which will avoid direct discharge to surface waters. Nitrate: 10 The discharge of nutrients, primarily phosphorus or nitrogen, to waters of the Commonwealth will be limited or prohi- bited by the Division as necessary to prevent excessive eutrophication of such waters. There shall be no new or increased discharges of nutrients into lakes and ponds, or tributaries thereto. Existing discharges containing nutrients which encourage eutrophication or growth of weeds or algae shall be treated. Acti- vities which may result in non-point dis- charges of nutrients shall be conducted in Designated Stream Use All All All All All Public water supply -6- ------- State Criteria Values in mg/1 Designated Stream Use Massachusetts (con't) accordance with the best management practices reasonably determined by the Division to be necessary to preclude or minimize such discharges of nutrients. Michigan 20 Not specified Nutrients originating from domestic, industrial, municipal or domestic animal sources shall be limited to the extent necessary to prevent stimulation of growths of aquatic rooted, attached and floating plants, fungi or bacteria which are or may become injurious to the desig- nated uses of the waters of the state. (1) Toxicity of undefined toxic substances not specifically included in subrules (2) i'id (3) shall be determined by develop- ment of 96-hour TLM's or other appro- priate effect and points obtained by continuous flow or in situ bioassays using suitable test organisms. Concentrations of undefined toxic substances in the waters of the State shall not exceed safe concentrations as determined by applying an application factor, based on knowledge of the behavior of the toxic substances and the organisms to be protected in the environment, to the TLM or other appro- priate effect end point. (2) For all waters of the State, unless on the basis of recent information, a more restrictive limitation is required to protect a designated use, concentrations of defined toxic substances, including heavy metals, shall be limited by application of the toxic substances, recommendations contained in the chapter on Freshwater Organisms, "Report of the National Technical Advisory Committee to the Secretary of the Interior, Water Quality Criteria, 1968," or by application of any toxic effluent standard, limitation or prohi- bition promulgated by the Administrator of the United States Environmental Protection Agency pursuant to section 307(a) of the United States Public Law 92-500, whichever is more restrictive. All All -7- ------- State Criteria Values in mg/1 Designated Stream Use Michigan (con't) (3) In addition to the standards prescribed in subrules (1) and (2), waters of the State used for public water supply shall, at the point of water intake, not exceed the permissible inorganic and organic chemicals criteria for raw public water supply in "Report of the National Technical Advisory Committee to the Secretary of the Interior, Water Quality Criteria, 1968," except that chlorides shall be limited to the same extent as prescribed by rule 1051(2). Minnesota 21 Nitrates (NOj) 45.0 0.2 Ammonia (N) 1.0 1.5 Unspecified toxic substances - none at levels hamful either directly or indirectly. Domestic water supply Classes A, B, and C Fisheries and recreation (Class A) Fisheries and recreation (Class B) Fisheries and recreation (Class C) Agriculture and wildlife (Class B) 22 Mississippi Not specified All Missouri 0.1 Ammonia nitrogen 0.02 10.0 Nitrate nitrogen Aquatic life Coldwater fishery Drinking water supply Montana 23 Not specified All Nebraska 24 Ammonia as N- Seasonal limits assigned to each designated stream segment with limits ranging from 1 to 6 mg/L. All Nevada25 Nitrates (NOJ 0.8 - 7.66 Single Value .07-5.0 Annual average Variable Variable -8- ------- State Criteria Values in mg/1 Designated Stream Use Nevada (con't) Nitrates (NOJ 1.0 - 5.0 Single Value .09 - 1.5 Annual Average Single value and annual average varies for each basin. See Water Pollution Rules, Table 1 thru 55 for specific rivers, lakes, and streams. 26 New Hampshire Not specified New Jersey 27 Ammonia or ammonium compounds: None, either alone or in combination with other substances, in such concentrations as to affect humans or be detrimental to the natural aquatic biota, produce undesirable aquatic life, or which would render the waters unsuitable for the desi- gnated uses. Where sources of public water supply is potential use, none which would cause standards for drinking water to be exceeded after appropriate treatment. Nitrate Nitrogen 2.0 3.0 Variable Variable All All All uses in FW-central Pine Barrens All uses in FW-lower Mullica and Wading Rivers Central Pine Barrens. New Mexico 28 Not specified Surface waters shall be free of nitrogen and other dissolved gasses at levels above 110% saturation when supersaturation is attributable to municipal, industrial or other discharges. All New York 29 Nitrates: Not specified Nitrites: Not specified Ammonia or ammonium compounds: 2.0 as NH3 at pH of 8.0 or above All All Water supply source for drinking, culinary or food processing; fish life -9- ------- State North Carolina 30 Criteria Values in mg/1 10.0 Nitrate nitrogen Designated Stream Use Drinking water supply (treatment plus disin- fection) North Dakota 31 Ohio32 Nitrates: 1.0 - 1.5 (depending upon type of drinking water treatment process utilized) NO3 as N: 0.375 (goal) Ammonia: 0.1 - 13.0 depending upon tem- perature and pH The concentration of un-ionized ammonia (NH3) shall not exceed 0.05 mgA, un- ionized ammonia shall be determined for values for total ammonia N, pH and tem- perature and the following equation: Un-ionized ammonia = l.^itotal ammo- nia-N)/ 1 + 10 tp a " pti; where pk = 0.0902 + 2730/273.2 + T) and T = Tempe- rature in degrees C Nitrate-N plus Nitrite-N: 10.0 Nitrite-N: 1.0 Nitrate-N: 10.0 Nitrates plus nitrites: 100.0 Ammonia as Nitrogen 0.2 - 13.0 mg/1 depending on temperature and pH 0.1 - 6.5 mg/1 depending on temperature and pH 1.5 - 12.8 mg/1 depending on temperature and pH 0.2 - 13.0 mg/1 depending on temperature and pH except as indicated for specific streams Nitrate - N; 10.0 mg/1 Nitrates plus nitrites: 100.0 mg/1 All All lake uses All except Ohio River uses All Ohio River uses All Ohio River uses All Ohio River uses Public water supply Agricultural water supply Warm water habitat Lake Erie, exceptional warm water and cold water habitat Seasonal habitat limited habitat warm water warm water Lake Erie and public water supply Lake Erie and agricultural water supply -10- ------- State Ohio (con't) Criteria Values in mg/1 Ammonia not greater than 12.0 mg/1 from 12/1/74 to 6/30/76; nor greater than 8.0 mg/1 from 7/1/76 to 1/1/79 Toxic substances less than 1/10 x 96 hr TLM (Applies to Ammonia) Designated Stream Use Lower Cuyahoga River Mahoning River Oklahoma 33 Nitrates as N: 10.0 Drinking water supply Oregon 34 Not specified All 35 Pennsylvania Nitrite plus Nitrate: 10.0 (as nitrogen) Ammonia nitrogen: 0.5 - 1.5 Note: See Drainage lists A through E of Pennsylvania Water Quality Standards for applicable uses and streams All Rhode Island 36 0<7 South Carolina Not specified Chemical constituents narrative: bio- assays shall be performed as required- Chemical constituents narrative: the limit prescribed by the USEPA will be used where not superseded by more strin- gent state requirements. Not specified All Fisheries (fresh water) Public drinking water supplies (fresh water) All South Dakota 38 10.0 Nitrates 50.0 0.02 un-ionized Ammonia (as N) 0.04 un-ionized ammonia (as N) 0.05 Domestic water supply Wildlife propagation Domestic water supply, cold water fish Warm water fish (perma- nent and semi-permanent) Warm water fish (marginal) -11- ------- State South Dakota (con't) Tennessee 39 Criteria Values in mg/1 Nitrites: Not specified Not specified Designated Stream Use All All Texas 40 Not specified All Utah 41 NH, as N 0.02 (un-ionized) NO3 as N 0.02 Aquatic life Aquatic life, recreation and aesthetics Vermont 42 There shall be no discharge of wastes to Class A waters that do not meet or exceed the technical and other require- ments for such waters nor shall there be any discharge of wastes containing any form of nutrients which would encourage eutrophication or growth of weeds or algae. There shall be no new or increased dis- charge of wastes after May 27, 1971 containing any form of nutrients which would encourage eutrophication or growth of weeds and algae in any lake, pond or reservoir. Any discharge of wastes existing prior to May 27, 1971 containing soluble or other nutrients which would encourage eutrophication or growth of weeds and algae in any lake, pond, or reservoir shall receive the highest practical degree of treatment currently available to remove such nutrients. All Virginia 44 Washington West Virginia45 Nitrates plus nitrites: 10.0 (as N) Not specified 45.0 Nitrates Public water supply All All Wisconsin 46 NH, - N 3.0 mg/1 during warm temperature 6.0 mg/1 during cold temperatures Intermediate aquatic life waters -12- ------- State 47 Wyoming American Samoa Criteria Values in mg/1 0.02 Ammonia as (N) The naturally occurring atomic ratio of NO,-N to PO.-P in a body of water will be maintained. Similarly, the ratio of inorganic phosphorus (orthophosphate) to total phosphorus (the sum of inorganic phosphorus, dissolved organic phosphorus, and particulate (phosphorus) will be main- tained in the ratio and amount as it occurs in the receiving waters naturally. Designated Stream Use All cold water fisheries All District of Columbia Ammonia - 0.02 mg/1 as unionized ammonia Nitrates/Nitrites - 10 mg/1 max. as nitrate (N) All waters Domestic water supply Guam Puerto Rico 49 Total nitrogen shall not exceed 0.40 mg/1 Total nitrogen shall not exceed 0.75 mg/1 Total nitrogen shall not exceed 1.5 mg/1 10.0 N: rate plus Nitrite (as N) 5.0 Nitrogen (NO2, NO3, NH3 G Trust Territories 0.01 Ammonia (N) Virgin Islands H The naturally occurring ratio of the concentrations of nitrogen to phosphorus will be maintained in all waters. Not specified AA A, 2b-I, 2b-II, C 2a-I, 2a-II All surface waters All coastal waters Drinking water supply All All -13- »U.S. GOVERNMENT PRINTING OFFICE: 1980- 341-O82/107 ------- |