. 2023 Sep 22;34(1):3–22. doi: 10.1038/s41370-023-00597-z

Table 2.

US public water systems (PWSs) by water source quarter 4, 2022^a.

	Source water type	Number of systems	Population served (millions)
Community water systems^b	Groundwater	37,936	91
Community water systems^b	Surface water	11,714	229
Noncommunity water systems^c	Groundwater	98,689	17.3
Noncommunity water systems^c	Surface water	3038	2.2
Total all PWSs	Groundwater	136,625	108
	Surface water	14,752	231
	All sources	151,377	339

^aEPA. Safe Drinking Water Information System, GPRA [Government Performance and Responsibility Act] Inventory Report, 2022 Q4 [Quarter 4], available online at https://obipublic.epa.gov/analytics/saw.dll?PortalPages&PortalPath=/shared/SFDW/_portal/Public (visited February 22, 2023). Note that due to rounding, the total percentages may not add up to precisely 100%.

^bCommunity Water System: serves the same 15 or more service connections or an average of at least 25 or more people for at least 60 days a year.

^cNoncommunity Water System: serves at least 15 service connections or an average of at least 25 people for at least 60 days a year, but the population changes. Examples: campgrounds, restaurants, etc.