Municipal wastewater treatment : evaluating improvements in national water quality

1. Introduction 1 Background 2 Study Approach 4 The First Leg: An Examination of BOD Loadings Before and After the CWA 5 The Second Leg: An Examination of “Worst-Case” DO in Waterways 6 Below Point Sources Before and After the CWA The Third Leg: Case Study Assessments of Water Quality 12 The Target Audience for this Book 13 References 13 2. An Examination of BOD Loadings Before and After the CWA 17 A. History of Water Supply and Its Effects on Public Health 17 Impacts on Water Supply Users and “The Great Sanitary Awakening” 19 Impacts on Water Resources Users 21 B. Evolution of Wastewater Treatment 23 Primary Treatment 23 Dissolved Oxygen as an Indicator of Water Quality 23 Secondary Treatment 25 Biochemical Oxygen Demand (BOD) as a Measure of Organic Wasteload Strength 26 C. The Federal Role in Implementing Secondary Treatment in the Nation’s POTWs 27 The Federal Role in Secondary Treatment Before the Clean Water Act 27The Federal Role in Secondary Treatment After the Clean Water Act 33 D. Nationwide Trends in BOD Loading from POTWs 42 Types of BOD Reported in this Trends Analysis 43 Trends in POTW Inventory 48 Trends in Population and Influent Wastewater Flow to POTWs 50 Trends in Influent BOD Loading to POTWs 52 Trends in Effluent BOD Loading from POTWs 57 Trends in BOD Removal Efficiency 63 Future Trends in BOD Effluent Loading 64 E. BOD5 Loadings from Point and Nonpoint Sources 70 Pollutant Loading from Sources Other than POTWs 71 BOD5 Loads from the National Water Pollution Control Assessment Model (NWPCAM) 76 Comparison of Point and Nonpoint Sources of BOD5 at the National Level 85 F. Investment Costs for Water Pollution Control Infrastructure 85 The Construction Grants Program 85 Other Investment Costs for Water Pollution Control Infrastructure 90 Future Infrastructure Needs 93 G. Summary, Conclusions, and Future Trends 95 Key Points of the Background Sections 95 Key Points of the BOD Loading Analysis Sections 96 Key Points of the Investment Costs Section 98 Conclusions and Future Trends 98 References 100 3. An Examination of “Worst-Case” DO in Waterways Below Point Sources Before and After the CWA 105 A. Background 106 Sources of DO Data 107 “Worst Case” Conditions as a Screening Tool 107 The Role of Spatial Scale in this Analysis 119 B. Data Mining 119 Step 1—Data Selection Rules 119 Step 2—Data Aggregation Rules from a Temporal Perspective 120 Step 3—Calculation of the Worst-Case DO Summary Statistic Rules 121 Step 4—Spatial Assessment Rules 122 Step 5—Data Aggregation Rules from a Spatial Perspective 125Step 6—Development of the Paired Data Sets (at Each Spatial Scale) 126 C. Comparison of Worst-Case DO in Waterways Below Point Source Discharges Before and After the CWA at Three Spatial Scales 126 Before and After DO at Reach Scale 127 Before and After DO at Catalog Unit Scale 130 Comparison of the Change in Signal Between the Reach and Catalog Unit Scales Using the Upper White River Basin (Indiana) as an Example 154 Before and After DO at Major River Basin Scale 162 D. Summary and Conclusions 171 Key Points of the Background Section 172 Key Points of the Data Mining Section 173 Key Points of the Comparison Analysis Section 174 Conclusions 176 References 179 4. Case Study Assessments of Water Quality 181 A. Background 181 B. Selection of Case Study Waterways 183 C. Before and After CWA 184 D. Policy Scenarios for Municipal Effluent Discharges 189 E. Discussion and Conclusions 194 References 195 5. Connecticut River Case Study 199 Background 199 Physical Setting and Hydrology 200 Population, Water, and Land Use Trends 203 Historical Water Quality Issues 204 Legislative and Regulatory History 205 Impacts of Wastewater Treatment 206 Pollutant Loading and Water Quality Trends 206 Recreational and Living Resources Trends 207 Summary and Conclusions 210 References 2116. Hudson-Raritan Estuary Case Study 213 Background 213 Physical Setting and Hydrology 215 Population, Water, and Land Use Trends 215 Historical Water Quality Issues 220 Legislative and Regulatory History 223 Impacts of Wastewater Treatment 225 Pollutant Loading and Water Quality Trends 225 Recreational and Living Resources Trends 242 Summary and Conclusions 248 References 249 7. Delaware Estuary Case Study 255 Physical Setting and Hydrology 256 Population, Water, and Land Use Trends 259 Historical Water Quality Issues 261 Legislative and Regulatory History 262 Impacts of Wastewater Treatment 263 Pollutant Loading and Water Quality Trends 263 Evaluation of Water Quality Benefits Following Treatment Plant Upgrade 270 Recreational and Living Resources Trends 273 Summary and Conclusions 279 References 281 8. Potomac Estuary Case Study 285 Physical Setting and Hydrology 286 Population, Water, and Land Use Trends 288 Historical Water Quality Issues 290 Legislative and Regulatory History 290 Impacts of Wastewater Treatment 291 Pollutant Loading and Water Quality Trends 291 Evaluation of Water Quality Benefits Following Treatment Plant Upgrades 294 Recreational and Living Resources Trends 298Summary and Conclusions 308 References 309 9. James River Estuary Case Study 311 Physical Setting and Hydrology 311 Population Trends 314 Historical Water Quality Issues 315 Legislative and Regulatory History 316 Impacts of Wastewater Treatment 317 Pollutant Loading and Water Quality Trends 317 Evaluation of Water Quality Benefits Following Treatment Plant Upgrades 321 Recreational and Living Resources Trends 324 Summary and Conclusions 325 References 325 10. Upper Chattahoochee River Case Study 327 Physical Setting and Hydrology 328 Population, Water, and Land Use Trends 331 Historical Water Quality Issues 333 Legislative and Regulatory History 335 Impacts of Wastewater Treatment 336 Pollutant Loading and Water Quality Trends 336 Recreational and Living Resources Trends 340 Summary and Conclusions 342 References 342 11. Ohio River Case Study 345 Physical Setting and Hydrology 346 Population, Water, and Land Use Trends 347 Historical Water Quality Issues 350 Legislative and Regulatory History 350 Impacts of Wastewater Treatment 352 Pollutant Loading and Water Quality Trends 352Recreational and Living Resources Trends 356 Summary and Conclusions 358 References 358 12. Upper Mississippi River Case Study 361 Physical Setting and Hydrology 362 Population, Water, and Land Use Trends 366 Historical Water Quality Issues 367 Legislative and Regulatory History 372 Impacts of Wastewater Treatment 373 Pollutant Loading and Water Quality Trends 373 Evaluation of Water Quality Benefits Following Treatment Plant Upgrades 383 Recreational and Living Resources Trends 386 Summary and Conclusions 390 References 393 13. Willamette River Case Study 399 Physical Setting and Hydrology 400 Population, Water, and Land Use Trends 403 Historical Water Quality Issues 404 Legislative and Regulatory History 405 Impacts of Wastewater Treatment 406 Pollutant Loading and Water Quality Trends 406 Recreational and Living Resources Trends 408 Summary and Conclusions 410 References 412 Appendix A. United States Waterways Identified with Water Pollution Problems Before the 1972 Clean Water Act 415 Appendix B. National Municipal Wastewater Inventory and Infrastructure, 1940–2016 449 Appendix C. National Public and Private Sector Investment in Water Pollution Control 501Appendix D. Before and After CWA Changes in Tenth Percentile Dissolved Oxygen and Ninetieth Percentile BOD5 at the Catalog Unit Level 507 Appendix E. Before and After CWA Changes in Tenth Percentile Dissolved Oxygen at the RF1 Reach Level 523 Appendix F. Hydrologic Conditions of the 48 Contiguous States, Summer (July–September) from 1961 through 1995 537 Appendix G. Municipal and Industrial Wastewater Loads by Major River Basin Before and After the Clean Water Act: 1950, 1973, and ca. 1995 583 Appendix H. Municipal and Industrial Water Withdrawals by Major River Basin: 1940–1995 593