Wastewater infrastructure connects households, industry and communities to treatment, conveyance and reuse systems. The figures below distinguish reported treatment from safe treatment, facility counts from populations served, and capital needs from actual spending.
Key Wastewater Infrastructure Statistics
The most useful wastewater infrastructure statistics span global reporting, U.S. systems, investment categories and treatment outcomes:
- In 2022, 107 countries reported at least some wastewater statistics, representing 73% of the world’s population.
- In 2022, 76% of reported total wastewater received some level of treatment across 73 countries covering 42% of the global population.
- In 2022, 60% of reported total wastewater was safely treated to at least secondary level across 42 countries covering 12% of the global population.
- In 2022, 17,544 publicly owned treatment works served 270.4 million people in the United States and territories.
- On January 1, 2022, reported publicly owned treatment works served 82% of the U.S. population.
- In 2022, 6,705 U.S. treatment plants provided advanced treatment.
- From the 2022 needs horizon, total U.S. clean-water infrastructure needs were estimated at $630.1 billion in January 2022 dollars.
- For the 2022 needs horizon, wastewater infrastructure represented about 55% of total reported U.S. needs.
- For the 2022 needs horizon, conveyance-system repair needs were estimated at $110.1 billion in the United States and territories.
- From 2012 to 2022, advanced-treatment needs rose 36%, from $61.5 billion to $83.6 billion in the United States and territories.
- From 2012 to 2022, combined sewer overflow correction needs fell 39%, from $59.5 billion to $36.5 billion in the United States and territories.
- For the 2022 needs horizon, New York and California each reported more than $50 billion in total needs.
- For the 2022 needs horizon, the six states reporting more than $25 billion each together represented 42% of nationwide total needs.
- In 2022, 38% of industrial wastewater was reported as treated in 22 countries representing 8% of the global population.
- In 2022, 42% of household wastewater was not safely treated before discharge in the UN-Water global estimate.
- In 2022, an estimated 113 billion cubic metres of household wastewater was released with inadequate or no treatment globally.
- In 2022, 55 U.S. states and territories reported conveyance-system needs, with American Samoa the exception.
Contents
- Global wastewater infrastructure coverage and data reach
- U.S. wastewater infrastructure scale and treatment plants
- Wastewater infrastructure investment needs
- Wastewater infrastructure trends
- State and per-capita wastewater infrastructure statistics
- Industrial and household wastewater treatment data
- Wastewater infrastructure outcomes and measurement limits
Global Wastewater Infrastructure Statistics: Coverage and Data Reach
UN-Water’s Progress on Wastewater Treatment – 2024 Update reports 2022 data, but the global picture is constrained by uneven national reporting. Coverage measures how much information was available, not necessarily how much wastewater was treated worldwide.
- In 2022, 107 countries reported at least some wastewater statistics, covering 73% of the world’s population.
- Some-level treatment was calculated for 73 countries covering 42% of the global population, and 76% of reported total wastewater received some treatment.
- Safe treatment, defined here as at least secondary treatment, was calculated for 42 countries covering 12% of the global population; 60% of reported total wastewater in those countries was safely treated.
- National-level total-wastewater treatment reporting covered only 20% of the world’s population in 2015, while industrial-treatment reporting covered 5%.
UN-Water also reports that 91 of 95 countries with treated-wastewater statistics for 2022 included urban treatment-plant data. Among the 107 countries reporting any wastewater statistics, 91 included some urban flows treated, while 49 reported industrial wastewater generated and 27 reported industrial wastewater treated.
| Global measure | Reported result | Period and scope |
|---|---|---|
| Countries reporting any wastewater statistics | 107; 73% of world population | 2022, global reporting countries |
| Countries with calculable some-level treatment | 73; 42% of global population | 2022, reporting countries |
| Reported wastewater receiving some treatment | 76% | 2022, 73-country calculation |
| Countries with calculable safe treatment | 42; 12% of global population | 2022, reporting countries |
| Reported wastewater safely treated | 60% | 2022, 42-country calculation |
Reported 2022 wastewater treated totaled 220 billion m³, while reported wastewater generated totaled 187 billion m³. UN-Water cautions that these aggregates use inconsistent country coverage and definitions, and says the apparent change from 32% in the 2021 report to 76% in the 2024 report mainly reflects improved data collection rather than a comparable treatment increase.
Source: Progress on Wastewater Treatment – 2024 Update.
U.S. Wastewater Infrastructure Scale and Treatment Plants
The U.S. Environmental Protection Agency’s 2022 Clean Watersheds Needs Survey provides a facility and population snapshot for the United States and territories. On January 1, 2022, the survey listed 17,544 publicly owned treatment works serving 270.4 million people.
- EPA estimated that the reported population served equaled 82% of the U.S. population, excluding people served by decentralized systems.
- Of the 17,544 reported plants, 6,705 provided advanced treatment in 2022.
- The 2022 CWNS was EPA’s 17th survey since the Clean Water Act was enacted in 1972.
- EPA’s map omitted 192 treatment plants because coordinates were missing; map omission did not mean omission from the survey.
These figures describe reported centralized systems and the CWNS classification of advanced treatment. They should not be read as a complete count of every decentralized wastewater installation.
Source: 2022 Clean Watersheds Needs Survey Report to Congress and Clean Watersheds Needs Survey.
Wastewater Infrastructure Investment Needs by Category
EPA’s 2022 CWNS estimates are capital needs generally projected over the subsequent 20 years and expressed in January 2022 dollars. They are reported needs, not audited expenditures, completed projects, funding gaps or amounts already spent.
| Category | 2022 reported need | Share of total needs |
|---|---|---|
| Secondary treatment | $66.6 billion | 10.6% |
| Advanced treatment | $83.6 billion | 13.3% |
| Conveyance repair | $110.1 billion | 17.5% |
| New conveyance | $41.0 billion | 6.5% |
| Combined sewer overflow correction | $36.5 billion | 5.8% |
| Water reuse | $7.7 billion | 1.2% |
| Decentralized treatment systems | $74.7 billion | 11.9% |
| Desalination | $0.2 billion | Less than 0.1% |
Total reported clean-water infrastructure needs were $630.1 billion, with wastewater infrastructure representing about 55%. EPA’s wastewater grouping includes treatment, conveyance, combined sewer overflow correction, reuse and desalination; decentralized systems are also reported as a distinct need category.
The 2022 wastewater-treatment subtotal for Categories I and II was $150.2 billion, compared with $126.4 billion in 2012. Across Categories I–V, the subtotal was $337.8 billion in 2022 versus $304.7 billion in 2012.
Source: 2022 Clean Watersheds Needs Survey Report to Congress.
Wastewater Infrastructure Trends in Treatment, Overflows and Reuse
Reported needs increased 73% from the previous CWNS, but comparable categories increased 37% from 2012 to 2022. The broader increase reflects the 2022 expansion to nonpoint-source and decentralized categories, so cross-year comparisons require care.
- Secondary-treatment needs rose 3%, from $64.9 billion in 2012 to $66.6 billion in 2022.
- Advanced-treatment needs rose 36%, from $61.5 billion in 2012 to $83.6 billion in 2022.
- Combined sewer overflow needs fell 39%, from $59.5 billion in 2012 to $36.5 billion in 2022.
- Conveyance repair and new-system needs rose 27%, from $118.7 billion in 2012 to $151.1 billion in 2022.
- Water-reuse needs rose 3%, from $7.5 billion in 2012 to $7.7 billion in 2022.
- Decentralized-treatment needs rose 172%, from $27.4 billion in 2012 to $74.7 billion in 2022, although the category’s scope and reporting treatment changed.
A historical EPA comparison reported that the population receiving less-than-secondary treatment fell from almost 60 million to 4.1 million. The 2012 CWNS release does not state the exact start year for that comparison, so the figures should be treated as the release’s historical comparison rather than a precisely dated time series.
Source: 2022 Clean Watersheds Needs Survey Report to Congress and EPA Survey Shows $271 Billion Needed for Nation’s Wastewater Infrastructure.
State and Per-Capita Wastewater Infrastructure Statistics
State-reported needs are concentrated in a small number of jurisdictions, while per-capita rankings highlight different places because the denominator is the CWNS served/population basis.
- New York and California each reported more than $50 billion in total needs for the 2022 needs horizon.
- Florida, Virginia, Louisiana and Georgia each reported more than $25 billion.
- The six states above together reported 42% of nationwide total needs, while 28 states each reported less than 1%.
- The highest total per-capita needs were $7,203 in Northern Mariana Islands, $6,182 in West Virginia, $5,799 in New Mexico, $5,776 in Louisiana and $5,303 in Virginia.
Advanced-treatment needs were highest in Florida at $13.9 billion, followed by California at $10.8 billion. The largest advanced-treatment per-capita needs were Utah at $1,070, Colorado at $976, Iowa at $973, Georgia at $661 and Florida at $644.
Conveyance needs were highest in New York at $18.9 billion, California at $15.0 billion, Florida at $10.6 billion, Ohio at $9.8 billion and North Carolina at $7.3 billion. Across the United States and territories, 66% of reported conveyance needs, or $99.8 billion, were documented in capital-improvement plans; documentation does not mean project completion.
Source: 2022 Clean Watersheds Needs Survey Report to Congress.
Industrial and Household Wastewater Treatment Data
Industrial and household measures use different populations and reporting coverage, so they should not be compared as identical denominators. UN-Water’s household component of SDG 6.3.1 includes sewage and faecal sludge treated on-site or off-site, not only flows carried through sewers.
- In 2022, 38% of industrial wastewater was reported as treated in 22 countries with treatment data, representing 8% of the global population.
- In those reporting countries, 27% of industrial wastewater was reported as safely treated, meaning at least secondary treatment.
- In 2022, the global estimate found that 42% of household wastewater was not safely treated before discharge.
- An estimated 113 billion m³ of household wastewater was released with inadequate or no treatment in 2022.
The industrial results are therefore highly limited in geographic coverage, while the household estimate is based on available SDG 6.3.1 reporting and definitions. Neither should be presented as a fully global facility-level treatment census.
Source: Progress on Wastewater Treatment – 2024 Update.
Wastewater Infrastructure Outcomes, Gaps and Measurement Limits
Earlier EPA material provides historical context but should not be treated as independently verified current data. The 2012 CWNS reported $197.8 billion for publicly owned wastewater pipes and treatment facilities, $48.0 billion for combined sewer overflow correction, $19.2 billion for stormwater management and $6.1 billion for recycled-water treatment and distribution, all as historical capital needs for the United States on January 1, 2012.
The same EPA release stated that the Clean Water State Revolving Fund had provided more than $105 billion in low-interest loans since 1987 by the 2016 release. That is cumulative program financing through the stated release period, not total wastewater infrastructure spending.
The 2022 survey also shows how reporting scope affects interpretation:
- Fifty states reported advanced-treatment needs, while six states or territories did not; a missing reported need does not mean a jurisdiction had no advanced-treatment plants.
- Thirty-five states reported combined-sewer-overflow correction needs; this is not a count of overflow events.
- Fifty-five states and territories reported conveyance-system needs, with American Samoa the exception; CWNS uses “states” to include territories and the District of Columbia.
The main measurement limits are consistent across the dataset: global aggregates do not cover the entire world, U.S. needs are estimates rather than expenditures, decentralized and centralized populations are treated differently, and expanded survey categories complicate historical comparisons.
Source: EPA Survey Shows $271 Billion Needed for Nation’s Wastewater Infrastructure and 2022 Clean Watersheds Needs Survey Report to Congress.