| <Agency Code> | <Agency Desc> | <Agency Type> | <Agency Type Desc> |
|---|---|---|---|
| 1401 | Superior Silica Sands, LLC | J | PRIVATE |
| 1400 | U.S. Silica Company | J | PRIVATE |
| 1399 | Western Gas Resources | J | PRIVATE |
| 1398 | Taylor Frac, LLC | J | PRIVATE |
| 1397 | Smart Sand, LLC | J | PRIVATE |
| 1396 | Chippewa Sand Company, LLC | J | PRIVATE |
| 1395 | Consci LTD | J | PRIVATE |
| 1394 | Pima County Regional Wastewater Reclamation Department | F | STATE AGENCY |
| 1393 | University of Texas School of Public Health | K | INSTITUTION |
| 1392 | Northwest Clean Air Agency | J | PRIVATE |
| 1391 | Devon Energy | J | PRIVATE |
| 1390 | Tata Chemicals | J | PRIVATE |
| 1389 | Colorado State University | J | PRIVATE |
| 1388 | Sinclair Refinery, Sinclair | J | PRIVATE |
| 1387 | Enefit | Z | OTHER |
| 1386 | CGI Federal | J | PRIVATE |
| 1384 | North Central Texas Council of Governments | Z | OTHER |
| 1383 | Orsat | P | EPA REGION |
| 1382 | Columbia Analytical Services | P | EPA REGION |
| 1381 | US EPA - Region 9 Superfund | P | EPA REGION |
| 1380 | Colorado Bureau of Land Management | S | GEMS |
| 1379 | Williams Field Service Company | J | PRIVATE |
| 1378 | Short Elliott Hendrickson (SEH, Inc.) | J | PRIVATE |
| 1377 | EOG Resources | J | PRIVATE |
| 1376 | Mountain Studies Institute | Z | OTHER |
| 1375 | PSGC (Prairie State Generating Company, LLC), IL | J | PRIVATE |
| 1373 | Shell Engineering & Assoc., MO | J | PRIVATE |
| 1372 | Encana, WY | J | PRIVATE |
| 1371 | Washington University in St. Louis | K | INSTITUTION |
| 1370 | US Geological Survey | N | FED NONMILITARY |
| 1369 | US Army Corps of Engineers | L | MILITARY |
| 1368 | EPA HQ - OECA | N | FED NONMILITARY |
| 1367 | Black Butte Coal Company | J | PRIVATE |
| 1366 | Wyoming Bureau of Land Management | F | STATE AGENCY |
| 1365 | Solvay | J | PRIVATE |
| 1364 | Black hills Power | J | PRIVATE |
| 1363 | Mountain Cement | J | PRIVATE |
| 1362 | EE-MS, Environmental Engineering Measurement | J | PRIVATE |
| 1361 | ARA, Atmospheric Research and Analysis | J | PRIVATE |
| 1360 | City of Frisco | L | MILITARY |
| 1359 | Crocker Nuclear Laboratory, University of California | C | EPA HQ EFFECTS |
| 1358 | City of Aspen, CO | H | CITY AGENCY |
| 1357 | Freeport McMoRan Miami, Inc. | J | PRIVATE |
| 1356 | Environmental Standards, Inc., PA | J | PRIVATE |
| 1355 | Severn Trent Laboratories, Knoxville, TN | J | PRIVATE |
| 1354 | PACE Analytical Services, Inc., MN | J | PRIVATE |
| 1353 | DATA CHEM Laboratories, Inc., OH | J | PRIVATE |
| 1352 | Kohler, WI | J | PRIVATE |
| 1351 | Golder Associates, Inc. | J | PRIVATE |
| 1350 | Arch Coal Company, WY | J | PRIVATE |
| 1349 | WY Refining Company, WY | J | PRIVATE |
| 1348 | Pacificorp, WY | J | PRIVATE |
| 1347 | Anadarko, WY | J | PRIVATE |
| 1346 | New York City Department of Health and Mental Hygiene | J | PRIVATE |
| 1345 | Mactec, Inc | J | PRIVATE |
| 1344 | USEPA - Clean Air Markets Division | A | EPA HQ ATM |
| 1343 | Wisconsin Department of Administration(DOA) | F | STATE AGENCY |
| 1342 | LaCrosse County, WI | G | COUNTY AGENCY |
| 1341 | Metal Tek Inc., WI | J | PRIVATE |
| 1340 | Didion Milling, Inc., WI | J | PRIVATE |
| 1339 | Citation Corp., WI | J | PRIVATE |
| 1338 | New Jersey Meadowlands Commission | F | STATE AGENCY |
| 1337 | Port of Los Angeles | H | CITY AGENCY |
| 1336 | Graymont Western US, Inc. | J | PRIVATE |
| 1335 | Ohio University, Athens, OH | K | INSTITUTION |
| 1334 | Chester LabNet. | J | PRIVATE |
| 1333 | Aspen Consulting & Testing | J | PRIVATE |
| 1332 | Hydrometrics | J | PRIVATE |
| 1331 | Meteorological Solutions, Inc. | J | PRIVATE |
| 1330 | Fishbak, Thompson & Carr & Huber, MI | J | PRIVATE |
| 1329 | Environmental Analytical Services Inc., CA | J | PRIVATE |
| 1328 | Florida Department of Environmental Protection (FDEP) | F | STATE AGENCY |
| 1327 | Benton Clean Air Authority, WA | I | DISTRICT AGENCY |
| 1326 | Center for Lab Science RJ Lee Grp Inc/Columbia Basin Col. | K | INSTITUTION |
| 1325 | Vectren Corporation | J | PRIVATE |
| 1324 | Duke Energy | J | PRIVATE |
| 1323 | University of Cincinnati | K | INSTITUTION |
| 1322 | US EPA ORD | A | EPA HQ ATM |
| 1321 | US EPA OEI | A | EPA HQ ATM |
| 1319 | Florida Sugar Cane League | J | PRIVATE |
| 1318 | EXCEL Management Systems, Inc. | J | PRIVATE |
| 1317 | APPTIS, Inc. | J | PRIVATE |
| 1316 | ICF International | J | PRIVATE |
| 1315 | Computer Science Corporation | J | PRIVATE |
| 1314 | Lockheed Martin Information Technology | J | PRIVATE |
| 1313 | Tahoe Regional Planning Agency | I | DISTRICT AGENCY |
| 1312 | RJ Lee Group, Center for Laboratory Sciences Pasco, WA | J | PRIVATE |
| 1311 | Loyola University Chicago | K | INSTITUTION |
| 1310 | County of Suffolk (NY) Division of Environmental Quality | G | COUNTY AGENCY |
| 1309 | South Alabama Regional Planning Commission | I | DISTRICT AGENCY |
| 1308 | Great Smoky Mtn NP | N | FED NONMILITARY |
| 1307 | Capitol Area Council of Governments, TX | I | DISTRICT AGENCY |
| 1306 | Weston Solutions, TX | J | PRIVATE |
| 1305 | Dios Dado Environmental Ltd., Selma, TX | J | PRIVATE |
| 1304 | CIRA, Colorado State University | K | INSTITUTION |
| 1303 | Direccion General De Ecoligia Gobierno del Estado de Baja California | Z | OTHER |
| 1302 | Maricopa Association of Governments | G | COUNTY AGENCY |
| 1301 | South East Texas Regional Planning Commission (SETRPC) | I | DISTRICT AGENCY |
| 1300 | Air ToxicsLimited, CA | J | PRIVATE |
| 1299 | URSCorp, TX | J | PRIVATE |
| 1298 | MARAMA | J | PRIVATE |
| 1297 | NESCAUM | J | PRIVATE |
| 1296 | Independent Contractor | J | PRIVATE |
| 1295 | Universidad Autonoma De Baja, CA | K | INSTITUTION |
| 1294 | Sierra Research, CA | J | PRIVATE |
| 1293 | Mid-American Energy, IA | J | PRIVATE |
| 1292 | Springfield City Utilities, MO | H | CITY AGENCY |
| 1290 | Doe Run Herculaneum | J | PRIVATE |
| 1289 | Doe Run Glover | J | PRIVATE |
| 1288 | Doe Run Buick | J | PRIVATE |
| 1287 | Planetgov User Support | J | PRIVATE |
| 1269 | Naval Surface Warfare Center, Crane Division, IN | L | MILITARY |
| 1268 | RR Donnley, IN | J | PRIVATE |
| 1267 | Center For Disease Control | N | FED NONMILITARY |
| 1266 | Quality Data Systems, Inc. | J | PRIVATE |
| 1265 | Hanson Aggregates Midwest, Inc., OH | J | PRIVATE |
| 1264 | Glacier Vandervell, Inc., OH | J | PRIVATE |
| 1263 | D. A. B. Industries, Inc., OH | J | PRIVATE |
| 1261 | US EPA Ann Arbor Lab | C | EPA HQ EFFECTS |
| 1260 | Northern Arizona University | K | INSTITUTION |
| 1259 | Hamilton County Department Of Environmental Services | G | COUNTY AGENCY |
| 1258 | Logistics Management Institute | J | PRIVATE |
| 1257 | International Truck & Engine Corp., WI | J | PRIVATE |
| 1256 | Ohio EPA Central Office | F | STATE AGENCY |
| 1255 | Saskpower | J | PRIVATE |
| 1252 | Missouri Dept Of Natural Resources | F | STATE AGENCY |
| 1251 | ECR Incorporated | J | PRIVATE |
| 1250 | URS Corporation | J | PRIVATE |
| 1247 | Monroe County, WI | G | COUNTY AGENCY |
| 1246 | Washington State University | K | INSTITUTION |
| 1245 | NYU - School Of Medicine | K | INSTITUTION |
| 1244 | ABT Associates, Inc. | J | PRIVATE |
| 1243 | Environ | J | PRIVATE |
| 1242 | E.H. Pechan | J | PRIVATE |
| 1240 | Versar, Inc., Esm Operations | J | PRIVATE |
| 1239 | Hovensa L. L. C. | J | PRIVATE |
| 1238 | Environment Canada | J | PRIVATE |
| 1237 | Procter And Gamble Paper Products Company | J | PRIVATE |
| 1236 | Stillwater Mining Company | J | PRIVATE |
| 1233 | Cenex Harvest States - Superior, WI | J | PRIVATE |
| 1229 | Goodyear Tire Obion County, TN | J | PRIVATE |
| 1228 | The Southern Company | J | PRIVATE |
| 1227 | Gainesville Regional Utilities | J | PRIVATE |
| 1226 | FDEP Ambient Monitoring Section | F | STATE AGENCY |
| 1225 | Collier County Pollution Control Department | G | COUNTY AGENCY |
| 1224 | Ambient Air Services, Inc. | J | PRIVATE |
| 1223 | Alachua County Environmental Protection Department | G | COUNTY AGENCY |
| 1222 | Veeland Farm Services | J | PRIVATE |
| 1221 | Atmospheric Analysis & Consulting Inc. Ventura, CA | J | PRIVATE |
| 1220 | Parsons Engineering Science, Inc. | J | PRIVATE |
| 1217 | Research Triangle Institute RTP, NC | J | PRIVATE |
| 1216 | Hammond Pb | J | PRIVATE |
| 1215 | Lone Star Industries | J | PRIVATE |
| 1214 | Grain Processors | J | PRIVATE |
| 1213 | John'S Manville | J | PRIVATE |
| 1212 | Toyota | J | PRIVATE |
| 1211 | A K Steel | J | PRIVATE |
| 1210 | Martins Ferry Health Department | H | CITY AGENCY |
| 1209 | Jackson, MS Department Of Health | H | CITY AGENCY |
| 1208 | Environmental Engineering | J | PRIVATE |
| 1207 | Desert Research Institute | J | PRIVATE |
| 1206 | Dynecol, Inc | J | PRIVATE |
| 1205 | Duval Health Improvement Authority | G | COUNTY AGENCY |
| 1204 | Durham County Air Pollution Control Agency | G | COUNTY AGENCY |
| 1203 | Ziegler Company | J | PRIVATE |
| 1202 | Yuma County Department Of Health | G | COUNTY AGENCY |
| 1201 | Yuba County APCD | I | DISTRICT AGENCY |
| 1200 | Youngstown Department Of Public Works | H | CITY AGENCY |
| 1199 | York Research Consultants | J | PRIVATE |
| 1198 | Yolo-Solano APCD | I | DISTRICT AGENCY |
| 1197 | Yellowstone Energy Ltd Partnership | J | PRIVATE |
| 1196 | Yellowstone County Air Pollution Control Agency | G | COUNTY AGENCY |
| 1195 | Yakima County Clean Air Authority | I | DISTRICT AGENCY |
| 1194 | Xontech, Inc | J | PRIVATE |
| 1193 | Wythe County Bureau Of Sport Fisheries And Wildlife | G | COUNTY AGENCY |
| 1192 | Wyoming Valley Survey | I | DISTRICT AGENCY |
| 1191 | Wyoming Regional Program Director | F | STATE AGENCY |
| 1190 | Wyoming Department Of Public Health | F | STATE AGENCY |
| 1189 | Wyoming Department Of Health And Social Services | F | STATE AGENCY |
| 1188 | Wyoming Air Quality Division, Dept Of Environmental Quality | F | STATE AGENCY |
| 1187 | Wyodale Resources | J | PRIVATE |
| 1186 | WW Engineering And Science | J | PRIVATE |
| 1185 | World Color Press, Inc | J | PRIVATE |
| 1184 | Woodward Clyde Consultants | J | PRIVATE |
| 1183 | Woodville Lime And Chemical | J | PRIVATE |
| 1182 | Wood County & Parkersburg County Health Department | G | COUNTY AGENCY |
| 1181 | Wm J Kennedy And Son Company | J | PRIVATE |
| 1180 | Wisconsin Winnebago Business Committee | Z | OTHER |
| 1179 | Wisconsin Tissue Mills | J | PRIVATE |
| 1178 | Wisconsin Public Service Corporation | J | PRIVATE |
| 1177 | Wisconsin Power And Light Company | J | PRIVATE |
| 1176 | Wisconsin Electric Power Company | J | PRIVATE |
| 1175 | Wisconsin Dept Of Natural Resources, Air Monitoring Section | F | STATE AGENCY |
| 1174 | Wisconsin Department Of Transportation | F | STATE AGENCY |
| 1173 | Winona Department Of Health | H | CITY AGENCY |
| 1172 | Wilner Wood Products, South Paris | J | PRIVATE |
| 1171 | Will County Health Department | G | COUNTY AGENCY |
| 1170 | Wicomico County Health Department | G | COUNTY AGENCY |
| 1169 | Wichita Sedgwick County Department Of Community Health | G | COUNTY AGENCY |
| 1168 | WI State Lab Of Hygiene - Occupational Health Laboratory | F | STATE AGENCY |
| 1167 | WI State Lab Of Hygiene - Environmental Science Section | F | STATE AGENCY |
| 1166 | White Pine Copper Company | J | PRIVATE |
| 1165 | White Earth Reservation | I | DISTRICT AGENCY |
| 1164 | Whirlpool Corporation | J | PRIVATE |
| 1163 | Wheeling Air Pollution Control Department | H | CITY AGENCY |
| 1162 | Weyerhaeuser Company | J | PRIVATE |
| 1161 | WESTVACO | J | PRIVATE |
| 1160 | Weston Consultants | J | PRIVATE |
| 1159 | Westmoreland Resources | J | PRIVATE |
| 1158 | Westinghouse Environmental Services Department | J | PRIVATE |
| 1157 | Westfield River Paper Company, Inc | J | PRIVATE |
| 1156 | Western Kraft Paper Group | J | PRIVATE |
| 1155 | Western Gas Processors | J | PRIVATE |
| 1154 | Western Environmental Services | J | PRIVATE |
| 1153 | Western Energy Company | J | PRIVATE |
| 1152 | West Virginia State Department Of Health | F | STATE AGENCY |
| 1151 | West Virginia Northern Panhandle Regional Office | F | STATE AGENCY |
| 1150 | West Virginia Air Pollution Control Commission | F | STATE AGENCY |
| 1149 | West Central Wisconsin Biosolids | J | PRIVATE |
| 1148 | Wellesley College | K | INSTITUTION |
| 1147 | Weld County Health Department | G | COUNTY AGENCY |
| 1146 | Weber County Health Department | G | COUNTY AGENCY |
| 1145 | Weaver Construction Company | J | PRIVATE |
| 1144 | Wayne Disposal, Inc | J | PRIVATE |
| 1143 | Wayne County Air Pollution Control Division | G | COUNTY AGENCY |
| 1142 | Wausau Paper Mills | J | PRIVATE |
| 1141 | WAUPACA Foundry | J | PRIVATE |
| 1140 | Waste Technologies Industries | J | PRIVATE |
| 1139 | Waste Management Of Wisconsin, Inc | J | PRIVATE |
| 1138 | Washoe County District Health Department | G | COUNTY AGENCY |
| 1137 | Washington State Department Of Health | F | STATE AGENCY |
| 1136 | Washington State Department Of Ecology | F | STATE AGENCY |
| 1135 | Washington Parish Health Unit | G | COUNTY AGENCY |
| 1134 | Wasco-Sherman Health Department | G | COUNTY AGENCY |
| 1133 | Warzyn Engineering, Inc | J | PRIVATE |
| 1132 | Warren Petroleum | J | PRIVATE |
| 1131 | Walker County Health Dept Health Effects Research Laboratory | G | COUNTY AGENCY |
| 1130 | W. H. Hunt Trust Estate | J | PRIVATE |
| 1129 | W W Engineering And Science | J | PRIVATE |
| 1128 | Volusia County Environmental Management Department | G | COUNTY AGENCY |
| 1127 | Virginia Department of Environmental Quality | F | STATE AGENCY |
| 1126 | Virginia Polytechnic Institute | K | INSTITUTION |
| 1125 | Virginia Division Of Consolidated Laboratories | F | STATE AGENCY |
| 1124 | Virgin Islands Department Of Planning & Natural Resources | F | STATE AGENCY |
| 1123 | Village Of Mccock Environmental Board | H | CITY AGENCY |
| 1122 | Village Of Bedford Park Air Pollution Control Commission | H | CITY AGENCY |
| 1121 | Vigo County Division Of Air Pollution Control | G | COUNTY AGENCY |
| 1120 | Vicksburg Fire Department | H | CITY AGENCY |
| 1119 | Vermont Agency Of Environmental Conservation | F | STATE AGENCY |
| 1118 | Ventura County APCD | I | DISTRICT AGENCY |
| 1117 | Ventron Corporation | J | PRIVATE |
| 1116 | Vandenberg AFB | J | PRIVATE |
| 1115 | Ute Research Laboratory | K | INSTITUTION |
| 1113 | Utah Department Of Environmental Quality | F | STATE AGENCY |
| 1112 | USM Corporation | J | PRIVATE |
| 1111 | USG Interior Products | J | PRIVATE |
| 1110 | US Forest Service | N | FED NONMILITARY |
| 1109 | US EPA/OAQPS/AAMG | A | EPA HQ ATM |
| 1108 | US EPA/OAQPS | A | EPA HQ ATM |
| 1107 | US EPS/Human Studies Lab/Health Effects Research Div | C | EPA HQ EFFECTS |
| 1106 | US EPA National Exposure Research Lab | A | EPA HQ ATM |
| 1105 | US EPA - Region 10 | P | EPA REGION |
| 1104 | US EPA - Region 9 | P | EPA REGION |
| 1103 | US EPA - Region 8 | P | EPA REGION |
| 1102 | US EPA - Region 7 | P | EPA REGION |
| 1101 | US EPA - Region 6 | P | EPA REGION |
| 1100 | US EPA - Region 5 | P | EPA REGION |
| 1099 | US EPA - Region 4 | P | EPA REGION |
| 1098 | US EPA - Region 3 | P | EPA REGION |
| 1097 | US EPA - Region 2 | P | EPA REGION |
| 1096 | US EPA - Region 1 | P | EPA REGION |
| 1095 | US EPA - Meteorological Laboratory - RAPS | B | EPA HQ MET |
| 1094 | US EPA - Great Lakes National Program Office | P | EPA REGION |
| 1093 | US Department Of Interior (USGS-BLM) | N | FED NONMILITARY |
| 1092 | Upjohn | J | PRIVATE |
| 1091 | Unocal | J | PRIVATE |
| 1090 | University Of Minnesota | K | INSTITUTION |
| 1089 | University Of Michigan, School Of Public Health | K | INSTITUTION |
| 1088 | University Of Medicine And Dentistry Of New Jersey | K | INSTITUTION |
| 1087 | University Of Massachusetts | K | INSTITUTION |
| 1086 | University Of Maryland | K | INSTITUTION |
| 1085 | University Of Maine, State Agricultural Experimental | K | INSTITUTION |
| 1084 | University Of Iowa | J | PRIVATE |
| 1083 | University Of Florida Air Pollution Research Laboratory | K | INSTITUTION |
| 1082 | University Of California-Riverside | K | INSTITUTION |
| 1081 | University Of Arizona, Department Of Civil Engineering | K | INSTITUTION |
| 1080 | University Hygenic Laboratory | F | STATE AGENCY |
| 1079 | University College Of Pharmacy, Washington | K | INSTITUTION |
| 1078 | United States Veterans Administration | N | FED NONMILITARY |
| 1077 | United States Quarantine Station | N | FED NONMILITARY |
| 1076 | United States Fish And Wildlife Service | N | FED NONMILITARY |
| 1075 | United States Customs | N | FED NONMILITARY |
| 1074 | United States Coast Guard | L | MILITARY |
| 1073 | United States Bureau Of Reclamation | N | FED NONMILITARY |
| 1072 | United States Atomic Energy Commission | N | FED NONMILITARY |
| 1071 | United States Army | L | MILITARY |
| 1070 | United State Fluorspar Corporation | J | PRIVATE |
| 1069 | United Power Association, Elk River | J | PRIVATE |
| 1068 | United Power Association | J | PRIVATE |
| 1067 | United Illuminating | J | PRIVATE |
| 1066 | Union Carbide | J | PRIVATE |
| 1065 | Union Camp | J | PRIVATE |
| 1064 | Unifour Air Pollution Control Program | G | COUNTY AGENCY |
| 1063 | U S State Department | N | FED NONMILITARY |
| 1062 | U P Generating Company | J | PRIVATE |
| 1061 | Tuolumne County APCD | I | DISTRICT AGENCY |
| 1060 | Tulsa City-County Health Department | G | COUNTY AGENCY |
| 1059 | Tulare County APCD | I | DISTRICT AGENCY |
| 1058 | Tucson Electric Power Company | J | PRIVATE |
| 1057 | TS Monitoring | J | PRIVATE |
| 1056 | Triton Coal | J | PRIVATE |
| 1055 | Tri-County, IL Health Department | G | COUNTY AGENCY |
| 1054 | Tri-County, Co Health Department | G | COUNTY AGENCY |
| 1053 | Tri-County District Health Service | I | DISTRICT AGENCY |
| 1052 | Tri-County Air Pollution Authority | I | DISTRICT AGENCY |
| 1051 | Tri-Borough Air Resources Management District | I | DISTRICT AGENCY |
| 1050 | Trenton Engineering Department | H | CITY AGENCY |
| 1049 | Trenton Bureau Of Adult And Occupational Health | H | CITY AGENCY |
| 1048 | TRC Environmental Consultants, Inc | J | PRIVATE |
| 1047 | Tracer Technologies | J | PRIVATE |
| 1046 | Town Of Vail Envrionmental Health | H | CITY AGENCY |
| 1045 | Total Leonard | J | PRIVATE |
| 1044 | Topeka And Shawnee County Health Department | G | COUNTY AGENCY |
| 1043 | Tonto Hills Observatory | J | PRIVATE |
| 1042 | Tondu Interests | J | PRIVATE |
| 1041 | Timken | J | PRIVATE |
| 1040 | Ticonderoga Jr-Sr High School | K | INSTITUTION |
| 1039 | Thunder Basin Coal Company | J | PRIVATE |
| 1038 | The Otis Elevator Company | J | PRIVATE |
| 1037 | The Canter Oil Company | J | PRIVATE |
| 1036 | The Ansul Company | J | PRIVATE |
| 1035 | Texas Commission On Environmental Quality | F | STATE AGENCY |
| 1034 | Texas Gulf Chemical Company | J | PRIVATE |
| 1032 | Texarkana-Bowie County Health Department | G | COUNTY AGENCY |
| 1031 | Texaco | J | PRIVATE |
| 1030 | Terre Haute Department Of Smoke Supervision And Inspection | H | CITY AGENCY |
| 1029 | Tennessee Valley Authority | N | FED NONMILITARY |
| 1028 | Tennessee River Pulp And Paper Company | J | PRIVATE |
| 1027 | Tennessee Luttrell Lime | J | PRIVATE |
| 1026 | Tennessee Eastman Company | J | PRIVATE |
| 1025 | Tennessee Division Of Air Pollution Control | F | STATE AGENCY |
| 1024 | Tenneco | J | PRIVATE |
| 1023 | Tell City Hall | H | CITY AGENCY |
| 1022 | Tehama County APCD | I | DISTRICT AGENCY |
| 1021 | Tazewell County Health Department | G | COUNTY AGENCY |
| 1020 | Target Corporation | J | PRIVATE |
| 1019 | Superior Services, Inc | J | PRIVATE |
| 1018 | Sylvania Silica | J | PRIVATE |
| 1017 | Swanson Environmental, Inc | J | PRIVATE |
| 1016 | Sutter County APCD | I | DISTRICT AGENCY |
| 1015 | Superior Testing Laboratory | J | PRIVATE |
| 1014 | Superior National Forest | I | DISTRICT AGENCY |
| 1013 | Superior Mining, Portage | J | PRIVATE |
| 1012 | Superior Environmental Services, Inc | J | PRIVATE |
| 1011 | Sunedco | J | PRIVATE |
| 1010 | Sullivan County Health Department | G | COUNTY AGENCY |
| 1009 | Stone Container Corporation | J | PRIVATE |
| 1007 | Steubenville Air Pollution Department | H | CITY AGENCY |
| 1006 | Steel Dynamics | J | PRIVATE |
| 1005 | Stauffer Chemical Company | J | PRIVATE |
| 1004 | Statler Industries | J | PRIVATE |
| 1003 | State Of New York Department Of Health | F | STATE AGENCY |
| 1002 | State Of Maryland Air Management Administration | F | STATE AGENCY |
| 1001 | State Of Louisiana | F | STATE AGENCY |
| 1000 | State Of Delaware | F | STATE AGENCY |
| 0999 | Stanislaus County APCD | I | DISTRICT AGENCY |
| 0998 | Standard Oil Company | J | PRIVATE |
| 0997 | St Tammany Parish Health Unit | G | COUNTY AGENCY |
| 0996 | St Regis Paper Company, Champion, Bucksport | J | PRIVATE |
| 0995 | St Petersburg Department Of Pollution Control | H | CITY AGENCY |
| 0994 | St Paul Smoke Abatement Board, Dept Of Public Utilities | H | CITY AGENCY |
| 0993 | St Paul Air Pollution Control Agency | H | CITY AGENCY |
| 0992 | St Louis County Health Department Air Pollution Control | G | COUNTY AGENCY |
| 0991 | St Louis County Health Department | G | COUNTY AGENCY |
| 0990 | St Louis City Division Of Air Pollution Control | H | CITY AGENCY |
| 0989 | St Joseph County Health Department | G | COUNTY AGENCY |
| 0988 | St Croix Meadows Greyhound Racetrack | J | PRIVATE |
| 0987 | St Cloud Air Pollution Control Agency | H | CITY AGENCY |
| 0986 | Springfield-Greene County Air Pollution Control Authority | H | CITY AGENCY |
| 0985 | Springfield Health Department | H | CITY AGENCY |
| 0984 | Springfield Department Of Public Health And Safety | H | CITY AGENCY |
| 0983 | Spring Creek Coal Company | J | PRIVATE |
| 0982 | Spokane County Air Pollution Control Authority | I | DISTRICT AGENCY |
| 0981 | Spartanburg County Pollution Control Authority | G | COUNTY AGENCY |
| 0980 | Sparta Manufacturing Company | J | PRIVATE |
| 0979 | Southwestern Ohio Air Pollution Control Agency | F | STATE AGENCY |
| 0978 | Southwest Air Pollution Control Authority | I | DISTRICT AGENCY |
| 0976 | Southern Services, Inc | J | PRIVATE |
| 0975 | Southern Indiana Gas And Electric Company | J | PRIVATE |
| 0974 | South Dakota School Of Mines And Technology | J | PRIVATE |
| 0973 | South Dakota Dept Environmental Protection Air Quality Prog | F | STATE AGENCY |
| 0972 | South Coast Air Quality Management District | I | DISTRICT AGENCY |
| 0971 | South Carolina Department Health And Environmental Control | F | STATE AGENCY |
| 0970 | South Bend Department Of Engineering | H | CITY AGENCY |
| 0969 | Sonoma Technology | J | PRIVATE |
| 0968 | Snohomish County Health Department | G | COUNTY AGENCY |
| 0967 | Siskiyou County APCD | I | DISTRICT AGENCY |
| 0966 | Sirrine Environmental Consultants | J | PRIVATE |
| 0965 | Sioux Falls Health Department | H | CITY AGENCY |
| 0964 | Silver Valley Laboratory | J | PRIVATE |
| 0963 | Sigeco | J | PRIVATE |
| 0961 | Shell | J | PRIVATE |
| 0960 | Shasta County APCD | I | DISTRICT AGENCY |
| 0959 | Semarnap | A | EPA HQ ATM |
| 0958 | Sea Ray | J | PRIVATE |
| 0957 | Scott Paper Company, Winslow | J | PRIVATE |
| 0956 | Scoot Graphics, Inc | J | PRIVATE |
| 0955 | Science Applications International Corporation | J | PRIVATE |
| 0954 | Scholte And Koogler Environmental Consultants | J | PRIVATE |
| 0953 | Savage Zinc Incinc Company | J | PRIVATE |
| 0952 | Saturn Corporation | J | PRIVATE |
| 0951 | Sarasota County Environmental Services | G | COUNTY AGENCY |
| 0950 | Santurce Department Of Health Air Pollution Control Program | I | DISTRICT AGENCY |
| 0949 | Santa Clara County Health Department | I | DISTRICT AGENCY |
| 0948 | Santa Barbara County APCD | I | DISTRICT AGENCY |
| 0947 | San Marcos-Hays County Health Department | G | COUNTY AGENCY |
| 0946 | San Luis Obispo County APCD | I | DISTRICT AGENCY |
| 0945 | San Joaquin Valley Unified Air Pollution Control District | I | DISTRICT AGENCY |
| 0944 | San Joaquin County APCD | I | DISTRICT AGENCY |
| 0943 | San Francisco Health Department | H | CITY AGENCY |
| 0942 | San Diego County Air Pollution Control District | I | DISTRICT AGENCY |
| 0941 | San Antonio Metropolitan Health District | I | DISTRICT AGENCY |
| 0940 | Salinas Department Of Health | H | CITY AGENCY |
| 0939 | Saginaw Valley State University | K | INSTITUTION |
| 0938 | Saginaw Malleable Iron Plant | J | PRIVATE |
| 0937 | Saginaw Health Department, Sanitation Division | H | CITY AGENCY |
| 0936 | Sacramento County APCD | I | DISTRICT AGENCY |
| 0935 | S. D. Warren Company | J | PRIVATE |
| 0934 | Rogers Group | J | PRIVATE |
| 0933 | Rust/Sec Donohue Environment & Infastructure | J | PRIVATE |
| 0932 | Rust Engineering Company | J | PRIVATE |
| 0931 | Russell County Health Department | G | COUNTY AGENCY |
| 0930 | RTP Environmental Associates | J | PRIVATE |
| 0929 | Rowe Yankee Atomic Power Plant | J | PRIVATE |
| 0928 | Rowan County Health Department | G | COUNTY AGENCY |
| 0927 | Rowan County Air Pollution Control Agency | G | COUNTY AGENCY |
| 0926 | Ross Metals Incorporated | J | PRIVATE |
| 0925 | Rosebud Operating Services, Inc | J | PRIVATE |
| 0924 | Rosebud Energy | J | PRIVATE |
| 0923 | Rocky Mountain Arsenol (US Army) | L | MILITARY |
| 0922 | Rocky Mountain Energy Company | J | PRIVATE |
| 0921 | Horsehead Corp | J | PRIVATE |
| 0920 | Rockingham County Health Department | G | COUNTY AGENCY |
| 0919 | Rockford Department Of Public Health | H | CITY AGENCY |
| 0918 | Rock Island Department Of Health | H | CITY AGENCY |
| 0917 | Rock Island County Department Of Health | G | COUNTY AGENCY |
| 0916 | Rock Hill City Health Department | H | CITY AGENCY |
| 0915 | Robert Ogilby Company | J | PRIVATE |
| 0914 | Roanoke County/City Of Salem Air Pollution Control | G | COUNTY AGENCY |
| 0913 | Roanoke County Health Department | G | COUNTY AGENCY |
| 0912 | RMT, Inc | J | PRIVATE |
| 0911 | Riverside County APCD | I | DISTRICT AGENCY |
| 0910 | Rio Arriba County | G | COUNTY AGENCY |
| 0909 | Richmond Power And Light | J | PRIVATE |
| 0908 | Rhone Poulenc | J | PRIVATE |
| 0907 | Rhode Island DEM And DOH | F | STATE AGENCY |
| 0906 | Resource Consultants Incorporated | J | PRIVATE |
| 0905 | Reserve Mining Company | J | PRIVATE |
| 0904 | Research Corporation Of New England | J | PRIVATE |
| 0903 | Regional Waste Systems, Portland | J | PRIVATE |
| 0902 | Reading Bureau Of Health | H | CITY AGENCY |
| 0901 | Rayovac Company | J | PRIVATE |
| 0900 | Ramp - Basin Electric | J | PRIVATE |
| 0899 | Radian Corporation | J | PRIVATE |
| 0898 | R-3, Inc | J | PRIVATE |
| 0897 | Qualitech | J | PRIVATE |
| 0896 | Quebecor | J | PRIVATE |
| 0895 | Quadri County Health Department | G | COUNTY AGENCY |
| 0894 | Pitkin County Department Of Health | G | COUNTY AGENCY |
| 0893 | Putnam County Health Department | G | COUNTY AGENCY |
| 0892 | Purdue University Civil Eng Department | K | INSTITUTION |
| 0891 | Pulaski County Health Department | G | COUNTY AGENCY |
| 0890 | Puget Sound Air Pollution Control Agency | I | DISTRICT AGENCY |
| 0889 | Puerto Rico Environmental Quality Board | F | STATE AGENCY |
| 0888 | Puerto Rico Department Of Health | F | STATE AGENCY |
| 0887 | Pueblo Health Department | H | CITY AGENCY |
| 0886 | Public Service Of Indiana | J | PRIVATE |
| 0885 | Prince William County Health Department | G | COUNTY AGENCY |
| 0884 | Prince George's County Health Department | G | COUNTY AGENCY |
| 0883 | PPG Ind, Inc | J | PRIVATE |
| 0882 | Powder River Coal Company | J | PRIVATE |
| 0881 | Potlatch Corporation | J | PRIVATE |
| 0880 | Portsmouth City Health Dept Division Air Pollution Control | H | CITY AGENCY |
| 0879 | Portsmouth City Health Department | H | CITY AGENCY |
| 0878 | Porter County Health Department | G | COUNTY AGENCY |
| 0877 | Port Arthur City Health Department | H | CITY AGENCY |
| 0876 | Popco | J | PRIVATE |
| 0875 | Ponce District Hospital | I | DISTRICT AGENCY |
| 0874 | Polk County Physical Planning | G | COUNTY AGENCY |
| 0873 | Polk County Environmental Services Department | G | COUNTY AGENCY |
| 0872 | Placer County APCD | I | DISTRICT AGENCY |
| 0871 | Placer Amex | J | PRIVATE |
| 0870 | Pittsburgh Plate Glass | J | PRIVATE |
| 0869 | Pioneer Valley Tsp Group | J | PRIVATE |
| 0868 | Pinellas County Health Department | G | COUNTY AGENCY |
| 0867 | Pinellas County Department Of Environmental Management | G | COUNTY AGENCY |
| 0866 | Pine State Power | J | PRIVATE |
| 0865 | Pinal County APCD | G | COUNTY AGENCY |
| 0864 | Pima County Health Department | G | COUNTY AGENCY |
| 0863 | Phillips Petroleum | J | PRIVATE |
| 0862 | Philadelphia Div Air Pollution Control And Env Sanitation | H | CITY AGENCY |
| 0861 | Philadelphia Air Management Services | H | CITY AGENCY |
| 0860 | Phelps Dodge Corporation | J | PRIVATE |
| 0859 | Pfizer Corporation | J | PRIVATE |
| 0858 | Perth Amboy City Hall | H | CITY AGENCY |
| 0857 | Pepco | J | PRIVATE |
| 0856 | Peoria Office Of Director Of Inspections | H | CITY AGENCY |
| 0855 | Penobscot Energy Recovery Company, Orrington | J | PRIVATE |
| 0854 | Pennsylvania State University (Penn State) | K | INSTITUTION |
| 0853 | Pennsylvania State Department Of Health | F | STATE AGENCY |
| 0852 | Pennsylvania State Department Of Forests And Waters | F | STATE AGENCY |
| 0851 | Pennsylvania Department Of Environmental Protection | F | STATE AGENCY |
| 0850 | Pennsylvania Bureau Of Air Quality | F | STATE AGENCY |
| 0849 | Penn-Dixie Industries, Inc | J | PRIVATE |
| 0847 | PEI Associates | J | PRIVATE |
| 0846 | Pegasus Gold Corporation | J | PRIVATE |
| 0845 | Peerless Cement | J | PRIVATE |
| 0844 | Pedco Environmental | J | PRIVATE |
| 0843 | Pedco And Battelle | J | PRIVATE |
| 0842 | Peavey Company | J | PRIVATE |
| 0841 | Peabody Coal Company | J | PRIVATE |
| 0840 | PBX | J | PRIVATE |
| 0839 | Payne And Dolan, Inc | J | PRIVATE |
| 0838 | Pasco County Health Department | G | COUNTY AGENCY |
| 0837 | Pasadena Health Department | H | CITY AGENCY |
| 0836 | Paoli Corporation | J | PRIVATE |
| 0835 | Panhandle Health District | I | DISTRICT AGENCY |
| 0834 | Panhandle Eastern Pipeline | J | PRIVATE |
| 0833 | Palm Beach County Health Department | G | COUNTY AGENCY |
| 0832 | Palisades High School | K | INSTITUTION |
| 0831 | Packaging Corporation Of America | J | PRIVATE |
| 0830 | Pacific Gas And Electric | J | PRIVATE |
| 0829 | Pacific Environmental Services | J | PRIVATE |
| 0828 | Pace Analytical, Inc | J | PRIVATE |
| 0827 | P.R. Environmental Quality Board | F | STATE AGENCY |
| 0826 | Oxychem Florida, Inc | J | PRIVATE |
| 0825 | OWR Grace | J | PRIVATE |
| 0824 | Owens-Corning Fiberglas Corporation | J | PRIVATE |
| 0823 | Oregon State University | K | INSTITUTION |
| 0822 | Oregon State Board Of Health | F | STATE AGENCY |
| 0821 | Oregon Department Of Environmental Quality | F | STATE AGENCY |
| 0820 | Orange County Environmental Protection Division | G | COUNTY AGENCY |
| 0819 | Orange City-County Health Department | G | COUNTY AGENCY |
| 0818 | Ontonagon WWTP | J | PRIVATE |
| 0816 | Omaha-Douglas County Health Department | H | CITY AGENCY |
| 0815 | Olympic Air Pollution Control Authority | I | DISTRICT AGENCY |
| 0814 | Olmstead County Health Department | G | COUNTY AGENCY |
| 0813 | Olin Corporation | J | PRIVATE |
| 0812 | Oklahoma Dept. Of Environmental Quality Air Quality Division | F | STATE AGENCY |
| 0811 | Oklahoma City-County Health Department | G | COUNTY AGENCY |
| 0810 | Ohio EPA, Southwest District Office | F | STATE AGENCY |
| 0809 | Ohio EPA, Southeast District Office | F | STATE AGENCY |
| 0808 | Ohio EPA, Northwest District Office | F | STATE AGENCY |
| 0807 | Ohio EPA, Northeast District Office | F | STATE AGENCY |
| 0806 | Ohio EPA, Division Of Environmental Services | F | STATE AGENCY |
| 0805 | Ohio EPA, Central District Office | F | STATE AGENCY |
| 0804 | Ohio Edison Company | J | PRIVATE |
| 0803 | Ohio Department Of Health | H | CITY AGENCY |
| 0801 | Office Of Director Of Public Works-Greensboro | H | CITY AGENCY |
| 0800 | O.M. Scott Company | J | PRIVATE |
| 0798 | NYSDEC Toxics Data Laboratory | F | STATE AGENCY |
| 0797 | NY State Lead Sampling Lab | F | STATE AGENCY |
| 0796 | NTIC Richfield Company | J | PRIVATE |
| 0795 | NTH, Consultants, Ltd | J | PRIVATE |
| 0794 | Northwest Air Pollution Authority | I | DISTRICT AGENCY |
| 0793 | Northrop Services | J | PRIVATE |
| 0792 | Northern States Power Company | J | PRIVATE |
| 0791 | Northern Sonoma County APCD | I | DISTRICT AGENCY |
| 0790 | Northern Sierra APCD | I | DISTRICT AGENCY |
| 0789 | Northern Laboratories | J | PRIVATE |
| 0788 | Northern Indiana Public Service Company | J | PRIVATE |
| 0786 | Northeast Utilities | J | PRIVATE |
| 0785 | Northeast Colorado Health Department | F | STATE AGENCY |
| 0784 | North Ohio Valley Air Authority | F | STATE AGENCY |
| 0783 | North Dakota State University | K | INSTITUTION |
| 0782 | North Dakota State Department Of Health | F | STATE AGENCY |
| 0781 | North Coast Unified Air Quality Management District | I | DISTRICT AGENCY |
| 0780 | North Central District Health Department | I | DISTRICT AGENCY |
| 0779 | North Carolina Western Regional Air Pollution Control Agency | I | DISTRICT AGENCY |
| 0778 | North Carolina State University | K | INSTITUTION |
| 0777 | North Carolina State Board Of Health | F | STATE AGENCY |
| 0776 | North Carolina Dept Of Environment And Natural Resources | F | STATE AGENCY |
| 0775 | North Carolina Department Of Water And Air Resources | F | STATE AGENCY |
| 0774 | North American Weather Consultants | J | PRIVATE |
| 0773 | North American Coal | J | PRIVATE |
| 0772 | Norfolk Health Department | H | CITY AGENCY |
| 0771 | Noranda, Inc | J | PRIVATE |
| 0770 | Niagara County Department Of Air Pollution Control | G | COUNTY AGENCY |
| 0769 | Newport News Department Of Public Works | H | CITY AGENCY |
| 0768 | New York State Department Of Environmental Conservation | F | STATE AGENCY |
| 0767 | New York Port Authority And Environmental Management | J | PRIVATE |
| 0766 | New Rochelle Department Of Public Health | H | CITY AGENCY |
| 0765 | New Mexico Environment Department | F | STATE AGENCY |
| 0764 | New Jersey State Department Of Environmental Protection | F | STATE AGENCY |
| 0763 | New Jersey Institute Of Technology | K | INSTITUTION |
| 0762 | New Hampshire Air Resources Agency | F | STATE AGENCY |
| 0761 | New England Power Company | J | PRIVATE |
| 0760 | New England Ethanol, Auburn | J | PRIVATE |
| 0759 | New Butte Mining Incorporated | J | PRIVATE |
| 0758 | New Albany And Floyd County Health Department | H | CITY AGENCY |
| 0757 | Nevada Division Of Environmental Protection | F | STATE AGENCY |
| 0756 | Network Environmental, Inc | J | PRIVATE |
| 0755 | Nekoosa Packaging Company | J | PRIVATE |
| 0754 | Needles City Hall | H | CITY AGENCY |
| 0753 | Nebraska Public Power Company | J | PRIVATE |
| 0752 | Nebraska Department Of Environmental Control | F | STATE AGENCY |
| 0751 | Ndo Utilities Commission | H | CITY AGENCY |
| 0750 | NC Dept Of Environment, Health And Natural Resources | F | STATE AGENCY |
| 0749 | Natural Resource Ecology Laboratory | J | PRIVATE |
| 0748 | Natural Gas Pipeline Company | J | PRIVATE |
| 0747 | National Weather Service | N | FED NONMILITARY |
| 0746 | National Southwire Aluminum Company | J | PRIVATE |
| 0745 | National Park Service | N | FED NONMILITARY |
| 0744 | National Oceanic And Atmospheric Administration/Umo | N | FED NONMILITARY |
| 0743 | National Lime And Stone Company | J | PRIVATE |
| 0742 | National Climatic Center, Us Department Of Commerce | N | FED NONMILITARY |
| 0741 | National Bureau Of Standards | N | FED NONMILITARY |
| 0740 | Natchez Fire Department | H | CITY AGENCY |
| 0739 | Nassau County Health Department | G | COUNTY AGENCY |
| 0738 | Nassau County Department Of Health | G | COUNTY AGENCY |
| 0737 | N G K Metals Reading, PA | J | PRIVATE |
| 0736 | Montgomery Watson | J | PRIVATE |
| 0735 | Muskegon County Health Department | G | COUNTY AGENCY |
| 0734 | Muscatine Power & Water Company | J | PRIVATE |
| 0733 | Murray & Trettle, Inc | J | PRIVATE |
| 0732 | Municipality Of Anchorage Air Pollution Control Agency | G | COUNTY AGENCY |
| 0731 | Mummy Mountain Observatory | J | PRIVATE |
| 0730 | Mt Dept Of Environmental Quality, Air Quality Division | F | STATE AGENCY |
| 0729 | Mountain, Inc | J | PRIVATE |
| 0728 | Morton Salt | J | PRIVATE |
| 0727 | Morton Grove Air Pollution Control Board | H | CITY AGENCY |
| 0726 | Morehouse Parish Health Unit | G | COUNTY AGENCY |
| 0725 | Montgomery County, MD Health Department | G | COUNTY AGENCY |
| 0724 | Montgomery County, OH Health Department | G | COUNTY AGENCY |
| 0723 | Montgomery County, AL Health Department | G | COUNTY AGENCY |
| 0722 | Montgomery County Department Of Public Health | G | COUNTY AGENCY |
| 0721 | Monterey Bay Unified APCD | I | DISTRICT AGENCY |
| 0720 | Montaup Electric Company | J | PRIVATE |
| 0719 | Montana Tunnels Mining, Inc | J | PRIVATE |
| 0718 | Montana Talc Company | J | PRIVATE |
| 0717 | Montana Resources | J | PRIVATE |
| 0716 | Montana Refining Company | J | PRIVATE |
| 0715 | Montana Power Company | J | PRIVATE |
| 0714 | Montana Department Of State Lands | F | STATE AGENCY |
| 0713 | Monsanto Industrial Chemicals Company | J | PRIVATE |
| 0712 | Monroe County Health Department | G | COUNTY AGENCY |
| 0711 | Monitor Sugar | J | PRIVATE |
| 0710 | Moline Health Department | H | CITY AGENCY |
| 0709 | Mojave Desert AQMD | I | DISTRICT AGENCY |
| 0708 | Modoc County APCD | I | DISTRICT AGENCY |
| 0707 | Mobile Coal Producing | J | PRIVATE |
| 0706 | Mobil Chemical Company | J | PRIVATE |
| 0705 | Mitre Corporation | J | PRIVATE |
| 0704 | Missoula City-County Health Department | G | COUNTY AGENCY |
| 0703 | Mississippi DEQ, Office Of Pollution | F | STATE AGENCY |
| 0702 | Mississippi Air And Water Pollution Control Commission | F | STATE AGENCY |
| 0701 | Minnesota Power And Light Company | J | PRIVATE |
| 0700 | Minnesota Pollution Control Agency, Division Of Air Quality | F | STATE AGENCY |
| 0699 | Minnesota Department Of Transportation | F | STATE AGENCY |
| 0698 | Minnesota Department Of Health | F | STATE AGENCY |
| 0697 | Minneapolis Air Pollution Control Division | H | CITY AGENCY |
| 0696 | Mingo Junction Air Pollution Department | H | CITY AGENCY |
| 0695 | Mineral Hill Mine | J | PRIVATE |
| 0694 | Mineral County Health Department | G | COUNTY AGENCY |
| 0693 | Midwest Energy Resources Company | J | PRIVATE |
| 0692 | Midland Cogeneration Venture | J | PRIVATE |
| 0691 | Mid Williamette Valley Air Pollution Authority | G | COUNTY AGENCY |
| 0690 | Michigan Tech University | K | INSTITUTION |
| 0689 | Michigan State Department Of Conservation | F | STATE AGENCY |
| 0688 | Michigan Standard Alloys | J | PRIVATE |
| 0687 | Michigan Recovery Systems | J | PRIVATE |
| 0686 | Michigan Disposal, Inc | J | PRIVATE |
| 0685 | Michigan Dept Of Environmental Quality-Air Quality Division | F | STATE AGENCY |
| 0684 | Michigan Department Of Public Health | F | STATE AGENCY |
| 0683 | Michigan City Air Pollution Control Division | H | CITY AGENCY |
| 0682 | Metropolitan Health Department/Nashville & Davidson County | L | MILITARY |
| 0681 | Metropolitan Airports Commission | H | CITY AGENCY |
| 0680 | Metronics Associates | J | PRIVATE |
| 0679 | Mesa County Health Department | G | COUNTY AGENCY |
| 0678 | Mercer County Health Department | G | COUNTY AGENCY |
| 0677 | Merced County APCD | I | DISTRICT AGENCY |
| 0675 | Mendocino County APCD | I | DISTRICT AGENCY |
| 0674 | Menasha | J | PRIVATE |
| 0673 | Memphis-Shelby County Health Department | G | COUNTY AGENCY |
| 0672 | Melvin Simon & Associates, Inc - Mall Of America | J | PRIVATE |
| 0671 | Medina County Joint Vocational School | J | PRIVATE |
| 0670 | Medical Area Total Energy Plant (MATEP) | J | PRIVATE |
| 0669 | Mecklenburg County Air Quality | G | COUNTY AGENCY |
| 0668 | Mead Paper Company | J | PRIVATE |
| 0667 | McVehil-Monnett Associates | J | PRIVATE |
| 0666 | McCracken County Health Department | G | COUNTY AGENCY |
| 0665 | Mauna Loa Observatory | J | PRIVATE |
| 0664 | Matagorda County Health Department | G | COUNTY AGENCY |
| 0663 | Master Metals | J | PRIVATE |
| 0662 | Massachusetts Port Authority | J | PRIVATE |
| 0661 | Massachusetts Muncipal Wholesale Electric Company | J | PRIVATE |
| 0660 | Mass Dept Environmental Protection-Div Air Quality Control | F | STATE AGENCY |
| 0659 | Maryland State Division Of Air Quality Control | F | STATE AGENCY |
| 0658 | Maryland State Division Of Air Monitoring | F | STATE AGENCY |
| 0657 | Maryland State Department Of Health | F | STATE AGENCY |
| 0656 | Maryland State Bureau Of Air Quality And Noise Control | F | STATE AGENCY |
| 0655 | Maryland Department Of The Environment | F | STATE AGENCY |
| 0654 | Maryland Air Quality Programs | F | STATE AGENCY |
| 0653 | Marvin Windows & Doors | J | PRIVATE |
| 0652 | Martin Marietta Cement/Dragon Cement/Thomaston | J | PRIVATE |
| 0651 | Martin Marietta And Ohio Lime Companies | J | PRIVATE |
| 0650 | Martin Marietta | J | PRIVATE |
| 0649 | Martin County Health Department | G | COUNTY AGENCY |
| 0648 | Marshall-Harrison County Health District | G | COUNTY AGENCY |
| 0647 | Marshall University, Department Of Chemistry | K | INSTITUTION |
| 0646 | Marquette Board Of Light And Power | J | PRIVATE |
| 0645 | Mariposa County APCD | I | DISTRICT AGENCY |
| 0644 | Marietta Board Of Health | H | CITY AGENCY |
| 0643 | Maricopa County Air Quality | G | COUNTY AGENCY |
| 0642 | Marathon Oil | J | PRIVATE |
| 0641 | Mansfield-Richland Health Department | H | CITY AGENCY |
| 0640 | Manitowoc Public Utilities | J | PRIVATE |
| 0639 | Manistique Pulp & Paper | J | PRIVATE |
| 0638 | Manatee County Environmental Management Department | G | COUNTY AGENCY |
| 0637 | Maine Technical Services | J | PRIVATE |
| 0635 | Maine D.E.P. Bureau Of Air Quality Control, Augusta | F | STATE AGENCY |
| 0634 | Mahoning-Trumbull Air Pollution Control Agency | H | CITY AGENCY |
| 0633 | Madison Paper Industries | J | PRIVATE |
| 0632 | Madison Department Of Public Health | H | CITY AGENCY |
| 0631 | Madison County Department Of Public Health | G | COUNTY AGENCY |
| 0630 | Madera County APCD | I | DISTRICT AGENCY |
| 0629 | Macomb County Health Department | G | COUNTY AGENCY |
| 0628 | Lafarge Lime Ohio Inc | J | PRIVATE |
| 0627 | Lynchburg Water Department | H | CITY AGENCY |
| 0626 | Luzenzac America, Inc | J | PRIVATE |
| 0625 | Lubbock City-County Health Department | G | COUNTY AGENCY |
| 0624 | Lowa Public Service Company | J | PRIVATE |
| 0623 | Louisiana Pacific | J | PRIVATE |
| 0622 | Loudoun County Health Department | G | COUNTY AGENCY |
| 0621 | Los Angeles County APCD | I | DISTRICT AGENCY |
| 0620 | Lorain Department Of Public Service | H | CITY AGENCY |
| 0619 | Lorain Air Air Pollution Control Agency | J | PRIVATE |
| 0618 | Long Island Lighting Company | J | PRIVATE |
| 0617 | Long Beach Department Of Public Health | H | CITY AGENCY |
| 0616 | Lomac, Inc (Bofors Lakeway) | J | PRIVATE |
| 0615 | Loeb Industries | J | PRIVATE |
| 0614 | Livonia Bureau Of Inspections | H | CITY AGENCY |
| 0613 | Linn County Health Department | G | COUNTY AGENCY |
| 0612 | Lincoln-Mesa County Health Department | G | COUNTY AGENCY |
| 0611 | Lincoln-Lancaster County Health Department | G | COUNTY AGENCY |
| 0610 | Lincoln Pulp And Paper Company, Lincoln | J | PRIVATE |
| 0609 | Lincoln County Health Department | G | COUNTY AGENCY |
| 0608 | Lewis And Clark County Health Department | G | COUNTY AGENCY |
| 0607 | Lehigh Valley Air Pollution Control District | I | DISTRICT AGENCY |
| 0606 | Lehigh Portland Cement | J | PRIVATE |
| 0605 | Lassen County APCD | I | DISTRICT AGENCY |
| 0604 | Las Animas-Huerfand District Health Department | I | DISTRICT AGENCY |
| 0603 | Larimer County Health Department | G | COUNTY AGENCY |
| 0602 | Laredo-Webb County Health Department | G | COUNTY AGENCY |
| 0601 | Lansing Car Assembly | J | PRIVATE |
| 0600 | Lansing Board Of Water And Light | J | PRIVATE |
| 0599 | Lansing Air Pollution Control Board | H | CITY AGENCY |
| 0598 | Lane Regional Air Pollution Authority | I | DISTRICT AGENCY |
| 0597 | Land Reclamation Company | J | PRIVATE |
| 0596 | Lancaster Labs, Inc | J | PRIVATE |
| 0595 | Lake County Health Department Division Air Pollution Control | G | COUNTY AGENCY |
| 0594 | Lake County Consolidated Air Quality Monitoring Work Group | G | COUNTY AGENCY |
| 0593 | Lake County APCD | I | DISTRICT AGENCY |
| 0592 | Lake Charles Technical Air Committee | J | PRIVATE |
| 0591 | Lafarge Corporation | J | PRIVATE |
| 0590 | Lackawanna Valley Survey | G | COUNTY AGENCY |
| 0588 | Missouri Laboratory Services Program | F | STATE AGENCY |
| 0587 | La Crosse Health Department | H | CITY AGENCY |
| 0586 | L. F. C. Power Systems | J | PRIVATE |
| 0584 | Kentucky Division For Air Quality | F | STATE AGENCY |
| 0583 | Koch Refining Company | J | PRIVATE |
| 0582 | Koch Hydrocarbon | J | PRIVATE |
| 0581 | Knox County Department Of Air Pollution Control | G | COUNTY AGENCY |
| 0580 | Knife River Coal | J | PRIVATE |
| 0579 | Kings County APCD | I | DISTRICT AGENCY |
| 0578 | Kimberly Clark Corporation | J | PRIVATE |
| 0577 | Kiewit Mining Company | J | PRIVATE |
| 0576 | Kerr - McGee | J | PRIVATE |
| 0575 | Kern County APCD | I | DISTRICT AGENCY |
| 0574 | Kenvirons, Inc | J | PRIVATE |
| 0573 | Kentucky Utilities | J | PRIVATE |
| 0572 | Kentucky Power Company | J | PRIVATE |
| 0571 | Kentucky Electric Steel Company | J | PRIVATE |
| 0570 | Kent County Landfill | G | COUNTY AGENCY |
| 0569 | Kenosha Health Department | H | CITY AGENCY |
| 0568 | Kennecott Minerals Company | J | PRIVATE |
| 0567 | Kendall Company | J | PRIVATE |
| 0566 | Kemron Environmental Services | J | PRIVATE |
| 0565 | Keci Television | J | PRIVATE |
| 0564 | Kantus | J | PRIVATE |
| 0563 | Kansas Department Of Health And Environment | F | STATE AGENCY |
| 0562 | Kansas City, KS And Wyandotte County Health Department | G | COUNTY AGENCY |
| 0561 | Kansas City Health Department, Air Quality Section | H | CITY AGENCY |
| 0560 | Kansas City Air Quality Division, Missouri | H | CITY AGENCY |
| 0559 | Kalamazoo City-County Health Department | H | CITY AGENCY |
| 0558 | JPI Transportation Products, Inc | J | PRIVATE |
| 0557 | Johnstown Fire Department | H | CITY AGENCY |
| 0556 | Johnson County Health Department | G | COUNTY AGENCY |
| 0555 | Johns Hopkins University | K | INSTITUTION |
| 0554 | John Brown Incorporated | J | PRIVATE |
| 0553 | Jersey City Board Of Health | H | CITY AGENCY |
| 0552 | Jefferson County, TX Health Department | G | COUNTY AGENCY |
| 0551 | Jefferson County, CO Health Department | G | COUNTY AGENCY |
| 0550 | Jefferson County, AL Department Of Health | G | COUNTY AGENCY |
| 0549 | Jefferson County, KY Air Pollution Control District | G | COUNTY AGENCY |
| 0548 | Janesville Department Of Public Works | H | CITY AGENCY |
| 0547 | James W Gelhaus Townsend, MT | J | PRIVATE |
| 0546 | James River Paper Corporation | J | PRIVATE |
| 0545 | Jacksonville Department Health And Rehabilitation Services | H | CITY AGENCY |
| 0544 | City of Jacksonville Environmental Quality Division | H | CITY AGENCY |
| 0543 | Jacksonville Air Pollution Control Activity | H | CITY AGENCY |
| 0542 | Jackson Department Of Public Health | H | CITY AGENCY |
| 0541 | Jackson, KY Department Of Health | H | CITY AGENCY |
| 0540 | Jackson County Iron Company | J | PRIVATE |
| 0539 | Jackson City Planning Office, Colorado Department Of Health | H | CITY AGENCY |
| 0538 | J.R. Simplot Company | J | PRIVATE |
| 0537 | J.M. Huber Corporation, Easton | J | PRIVATE |
| 0536 | J.E. Baker Company | J | PRIVATE |
| 0534 | Ironton City Health Department | H | CITY AGENCY |
| 0533 | Ironton Air Pollution Control Agency | H | CITY AGENCY |
| 0532 | Iowa State Department Of Health | F | STATE AGENCY |
| 0531 | Iowa Power And Light Company | J | PRIVATE |
| 0530 | Iowa Department Of Natural Resources | F | STATE AGENCY |
| 0529 | Interpoll Laboratories, Inc | J | PRIVATE |
| 0528 | International Paper Company | J | PRIVATE |
| 0527 | Inter-Mountain Laboratory Sheridan, WY | J | PRIVATE |
| 0526 | Inland Mining Company | J | PRIVATE |
| 0525 | Indianapolis State Police | H | CITY AGENCY |
| 0524 | Indianapolis Power And Light Company | J | PRIVATE |
| 0523 | Indianapolis Office of Environmental Services | H | CITY AGENCY |
| 0522 | Indiana University Of Pennsylvania | K | INSTITUTION |
| 0521 | Indiana State Department Of Conservation | F | STATE AGENCY |
| 0520 | Indiana Depart Of Environ Management/Office Of Air Quality | F | STATE AGENCY |
| 0519 | Indiana & Michigan Electric Company | J | PRIVATE |
| 0518 | Imperial County APCD | I | DISTRICT AGENCY |
| 0517 | Imore Gas Gaw And Electric Company | J | PRIVATE |
| 0516 | Immigration And Custom Building | N | FED NONMILITARY |
| 0514 | Illinois State Water Survey | F | STATE AGENCY |
| 0513 | Illinois Environmental Protection Agency | F | STATE AGENCY |
| 0512 | Illinois Department Of Public Health | F | STATE AGENCY |
| 0511 | Idaho Department Of Health And Welfare-Environment Division | F | STATE AGENCY |
| 0510 | Idaho Air Quality Bureau | F | STATE AGENCY |
| 0509 | I/N Tek | J | PRIVATE |
| 0508 | Holtrachem Manufacturing Company | J | PRIVATE |
| 0506 | Humboldt County APCD | I | DISTRICT AGENCY |
| 0505 | Hudson Municipal Air Pollution Commission | G | COUNTY AGENCY |
| 0504 | Howard County Health Department | G | COUNTY AGENCY |
| 0503 | Houston Lighting And Power | J | PRIVATE |
| 0502 | Horsehead Resource Development Company | J | PRIVATE |
| 0501 | Hoosier Energy | J | PRIVATE |
| 0500 | Hooker Chemical Company | J | PRIVATE |
| 0499 | Honda Of America, Inc | J | PRIVATE |
| 0498 | Homestake Mining Company | J | PRIVATE |
| 0497 | Homestake Copper Company | J | PRIVATE |
| 0496 | Holyoke Gas And Electric | J | PRIVATE |
| 0495 | Hollingsworth And Vase Company | J | PRIVATE |
| 0494 | Holland Board Of Public Works | J | PRIVATE |
| 0493 | Hoerner-Waldorf Corporation | J | PRIVATE |
| 0492 | Hillsborough County Health Department | G | COUNTY AGENCY |
| 0491 | Hillsborough County Environmental Protection Commission | G | COUNTY AGENCY |
| 0490 | Hibbing Taconite | J | PRIVATE |
| 0489 | Hess Oil, Virgin Islands Corporation | J | PRIVATE |
| 0488 | Hernando County Planning Department | G | COUNTY AGENCY |
| 0487 | Hercules | J | PRIVATE |
| 0486 | Henry-Martinsville Health District | I | DISTRICT AGENCY |
| 0485 | Henderson County Health Department | G | COUNTY AGENCY |
| 0484 | Hechimovich Sanitary Landfill, Inc | J | PRIVATE |
| 0483 | Hazleton Dept Environmental Resources, Bureau Air Pollution | H | CITY AGENCY |
| 0482 | Hawaiian Electric Company | J | PRIVATE |
| 0481 | Hawaii State Department Of Health | F | STATE AGENCY |
| 0480 | Haverhill Paperboard | J | PRIVATE |
| 0479 | Hatteras Naval Facility, United States Navy | L | MILITARY |
| 0478 | Harvard School Of Public Health, Department Of Physiology | K | INSTITUTION |
| 0477 | Hardy Salt | J | PRIVATE |
| 0476 | Hanna Mining Company | J | PRIVATE |
| 0475 | Hancock County Health Department | G | COUNTY AGENCY |
| 0474 | Hampton Health Department | H | CITY AGENCY |
| 0473 | Hammond Health Department | H | CITY AGENCY |
| 0472 | Hammond Division Of Air Pollution Control | H | CITY AGENCY |
| 0471 | Hamilton County Southwest Ohio Air Pollution Control | G | COUNTY AGENCY |
| 0470 | Gulf Coast Research Lab Institutions Of Higher Learning | J | PRIVATE |
| 0469 | Guilford County Health Department | G | COUNTY AGENCY |
| 0468 | Guam Power Authority | J | PRIVATE |
| 0467 | Guam Environmental Protection Agency | F | STATE AGENCY |
| 0466 | GRI | J | PRIVATE |
| 0465 | Greenville County Health Department | G | COUNTY AGENCY |
| 0464 | Greenlee County | G | COUNTY AGENCY |
| 0463 | Greede Industries | J | PRIVATE |
| 0462 | Greater Detroit Resource Recovery Authority | J | PRIVATE |
| 0461 | Greater Anchorage Area Borough Health Department | I | DISTRICT AGENCY |
| 0460 | Great Northern Paper Company, Millinocket | J | PRIVATE |
| 0459 | Great Falls City-County Health Department | G | COUNTY AGENCY |
| 0458 | Great Basin Unified APCD | I | DISTRICT AGENCY |
| 0457 | Grayson County Health Department | G | COUNTY AGENCY |
| 0456 | Grand Rapids Department Of Air Pollution | H | CITY AGENCY |
| 0455 | Grand Haven Board Of Water And Light | J | PRIVATE |
| 0454 | Grand Forks Health Department | H | CITY AGENCY |
| 0453 | Gopher Smelting And Refining | J | PRIVATE |
| 0452 | Golden Sunlight Mines, Inc | J | PRIVATE |
| 0451 | Gold Field Mining Corporation | J | PRIVATE |
| 0450 | Gmad - Lake Orion | J | PRIVATE |
| 0449 | GM Central Foundry | J | PRIVATE |
| 0448 | Glenn County APCD | I | DISTRICT AGENCY |
| 0447 | Glendale Department Of Public Service | H | CITY AGENCY |
| 0446 | Glen Cove Department Of Public Works | H | CITY AGENCY |
| 0445 | Glassboro State College, Science Department | K | INSTITUTION |
| 0444 | Glacier National Park | N | FED NONMILITARY |
| 0443 | Glacier Daido America | J | PRIVATE |
| 0442 | Gillen Company | J | PRIVATE |
| 0441 | Geraghty & Miller, Inc | J | PRIVATE |
| 0440 | Georgia Pacific Company, Woodland | J | PRIVATE |
| 0439 | Georgia Dept Of Natural Resources Air Quality Evaluation | F | STATE AGENCY |
| 0438 | Georgia Department Of Public Health | F | STATE AGENCY |
| 0437 | Georgia Air Protection Branch Ambient Monitoring Program | F | STATE AGENCY |
| 0436 | Georesearch, Inc | J | PRIVATE |
| 0435 | Geomet Technologies, Inc | J | PRIVATE |
| 0434 | Geneva Steel | J | PRIVATE |
| 0433 | Geneva Lakes Environmental Agency | Z | OTHER |
| 0432 | General Smelting And Refining | J | PRIVATE |
| 0431 | General Portland Cement Company | J | PRIVATE |
| 0430 | General Motors | J | PRIVATE |
| 0429 | General Mills | J | PRIVATE |
| 0428 | General Foods, Post Division | J | PRIVATE |
| 0427 | General Electric | J | PRIVATE |
| 0426 | General Chemical Corporation | J | PRIVATE |
| 0425 | GCA, Technology Division | J | PRIVATE |
| 0424 | Gaston County Health Department | G | COUNTY AGENCY |
| 0423 | Gaston County Air Pollution Agency | G | COUNTY AGENCY |
| 0422 | Gary Fire Department | H | CITY AGENCY |
| 0421 | Gary Division Of Air Pollution Control | H | CITY AGENCY |
| 0420 | Galveston City-County Health Department | G | COUNTY AGENCY |
| 0419 | Gainesville Air Pollution Research Laboratory | H | CITY AGENCY |
| 0418 | Florida Dep Of Environmental Protection Lab, Tallahassee | F | STATE AGENCY |
| 0417 | Fulton County Health Department | G | COUNTY AGENCY |
| 0416 | Ft Union Coal Company | J | PRIVATE |
| 0414 | Fresno County APCD | I | DISTRICT AGENCY |
| 0413 | Frederick County Health Department | G | COUNTY AGENCY |
| 0412 | Fraser Paper Company, Madawaska | J | PRIVATE |
| 0411 | Franklin County Marine Laboratory | G | COUNTY AGENCY |
| 0410 | France Stone Company | J | PRIVATE |
| 0409 | Foth And Van Dyke | J | PRIVATE |
| 0408 | Fort Worth Health Department | H | CITY AGENCY |
| 0407 | Fort Wayne Board Of Health | H | CITY AGENCY |
| 0404 | Forsyth County Health Department | G | COUNTY AGENCY |
| 0403 | Forsyth County Environmental Affairs Department | G | COUNTY AGENCY |
| 0402 | Ford Motors | J | PRIVATE |
| 0401 | FMC Corporation | J | PRIVATE |
| 0400 | Fluid Management, Inc | J | PRIVATE |
| 0399 | Florida State Board Of Health | F | STATE AGENCY |
| 0398 | Florida Power Corporation | J | PRIVATE |
| 0397 | Florida Power And Light | J | PRIVATE |
| 0396 | Florida Dept of Environmental Protection, Central District | F | STATE AGENCY |
| 0395 | Florida Dept of Environmental Protection, Southwest District | F | STATE AGENCY |
| 0394 | Florida Dept of Environmental Protection, Southeast District | F | STATE AGENCY |
| 0393 | Florida Dept of Environmental Protection, South District | F | STATE AGENCY |
| 0392 | Florida Dept of Environmental Protection, Northwest District | F | STATE AGENCY |
| 0391 | Florida Dept of Environmental Protection, Northeast District | F | STATE AGENCY |
| 0390 | Florida Dept of Environmental Protection Northeast District Branch Office | F | STATE AGENCY |
| 0389 | Florida Department Of Air And Water Pollution Control | F | STATE AGENCY |
| 0388 | Flint Department Of Public Works And Utilities | H | CITY AGENCY |
| 0387 | Flint Air Pollution Control Division | H | CITY AGENCY |
| 0386 | Flathead County Health Department | G | COUNTY AGENCY |
| 0385 | Flambeau Mining Corporation | J | PRIVATE |
| 0384 | Fitchburg Paper Company | J | PRIVATE |
| 0383 | Federal Government | N | FED NONMILITARY |
| 0382 | Feather River Air Quality Management District | I | DISTRICT AGENCY |
| 0381 | Farrell City Hall | H | CITY AGENCY |
| 0380 | Fargo Health Department | H | CITY AGENCY |
| 0379 | Fairfax County Health Department, Environmental Health Div. | G | COUNTY AGENCY |
| 0378 | Fairbanks North Star Borough Environmental Services | G | COUNTY AGENCY |
| 0377 | Exxon Minerals Company | J | PRIVATE |
| 0376 | Exxon | J | PRIVATE |
| 0375 | Exide Corporation | J | PRIVATE |
| 0374 | Ewing Paper Mills | J | PRIVATE |
| 0373 | Everglades National Park | N | FED NONMILITARY |
| 0372 | Evansville Division Of Air Pollution Control | H | CITY AGENCY |
| 0371 | Etowah County Health Department | G | COUNTY AGENCY |
| 0370 | Espey, Huston, And Associates, Inc | J | PRIVATE |
| 0369 | Erie County Health Department | G | COUNTY AGENCY |
| 0368 | Erie County Dept Of Health Division Of Environmental Control | G | COUNTY AGENCY |
| 0367 | Erie County Department Of Environmental Control | G | COUNTY AGENCY |
| 0366 | Erie Bureau Of Engineers Licenses And Smoke Abatement | H | CITY AGENCY |
| 0365 | Eri/University Of Connecticut | K | INSTITUTION |
| 0364 | ERCE | J | PRIVATE |
| 0363 | ER & T Commonwealth Edison | J | PRIVATE |
| 0362 | EPA New Mexico IPA | F | STATE AGENCY |
| 0361 | Environmental Monitoring Company (Emc) | J | PRIVATE |
| 0360 | Enviroplan | J | PRIVATE |
| 0359 | Environmental Waste Control | J | PRIVATE |
| 0358 | Environmental Testing | J | PRIVATE |
| 0357 | Environmental System Corporation | J | PRIVATE |
| 0356 | Environmental Science And Engineering | J | PRIVATE |
| 0355 | Environmental Science & Engineering, Inc (Ese) | J | PRIVATE |
| 0354 | Environmental Research Foundation | J | PRIVATE |
| 0353 | Environmental Research & Technology, Inc (ERT) | J | PRIVATE |
| 0352 | Environmental Health Services | J | PRIVATE |
| 0351 | Environmental Health Laboratories-Philadelphia | J | PRIVATE |
| 0350 | District Dept of Environment, Air Quality Div - DDOE/AQD | I | DISTRICT AGENCY |
| 0349 | Environmental Consulting Services, Inc | J | PRIVATE |
| 0348 | Enviro-Chem | J | PRIVATE |