More than half of homes in three New England states rely on septic tanks
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More than half the homes in Maine, Vermont, and New Hampshire rely on septic tanks, according to new data from the U.S. Census Bureau. The 2025 American Community Survey, which asked about wastewater for the first time, found 55.0 percent of Maine's housing units on septic, 54.4 percent of Vermont's, and 50.1 percent of New Hampshire's.
Nationally, about 118 million homes, or 79.6 percent, connect to a public sewer. Another 28.5 million, or 19.2 percent, use a septic tank, and about 1.7 million use something else. The bureau said wastewater has been "one of the most frequently requested housing data points by a wide range of federal partners, trade associations and local governments." Before this, the bureau said, the American Housing Survey was the only source.
After northern New England, septic systems are most common across the South, along with Montana and Alaska. Alabama is fourth at 37.4 percent, followed by West Virginia and Mississippi at 35.5 percent each and Montana at 35.2 percent. Twelve states are above 30 percent.
By raw numbers, North Carolina has the most homes on septic, about 1.78 million. Florida has 1.71 million, Texas 1.68 million, and New York 1.52 million.
The District of Columbia, with 0.4 percent, is nearly all sewer. Among states, Utah is lowest at 6.1 percent, followed by Nevada at 6.8 percent and California at 7.2 percent. Hawaii and Alaska stand out in another way: 8.7 percent and 7.0 percent of their homes use a system that is neither a public sewer nor a septic tank, the highest shares in the country. The bureau's analysis found public sewers are more common where housing is newer.
The kind of home matters a lot. About half of mobile homes, 49.9 percent, use septic tanks, compared with 26.0 percent of detached single-family houses. Owners are far more likely than renters to have one: 25.4 percent of owner-occupied homes use septic, compared with 6.9 percent of rented homes.
| Rank | State | Share of homes on septic | Homes on septic | Share on public sewer |
|---|---|---|---|---|
| 1 | Maine | 55.0% | 424,675 | 42.8% |
| 2 | Vermont | 54.4% | 188,468 | 43.8% |
| 3 | New Hampshire | 50.1% | 331,643 | 49.0% |
| 4 | Alabama | 37.4% | 898,934 | 61.6% |
| T5 | West Virginia | 35.5% | 309,939 | 62.4% |
| T5 | Mississippi | 35.5% | 485,671 | 61.2% |
| 7 | Montana | 35.2% | 191,416 | 63.4% |
| 8 | North Carolina | 34.4% | 1,777,948 | 64.7% |
| 9 | Kentucky | 33.3% | 689,995 | 65.4% |
| 10 | Alaska | 32.4% | 107,054 | 60.6% |
| 11 | Tennessee | 32.3% | 1,064,296 | 66.8% |
| 12 | Arkansas | 31.6% | 453,414 | 67.2% |
| 13 | Georgia | 29.7% | 1,404,175 | 69.1% |
| 14 | South Carolina | 29.1% | 751,315 | 70.0% |
| 15 | Michigan | 26.8% | 1,256,249 | 72.3% |
| 16 | Wisconsin | 26.1% | 740,929 | 72.2% |
| 17 | Connecticut | 25.5% | 396,759 | 73.9% |
| 18 | Oklahoma | 24.7% | 448,132 | 74.0% |
| 19 | Wyoming | 24.5% | 69,435 | 74.2% |
| 20 | Idaho | 24.1% | 204,700 | 74.8% |
| 21 | Virginia | 23.4% | 884,063 | 75.5% |
| 22 | Washington | 23.2% | 795,791 | 76.2% |
| 23 | Indiana | 22.6% | 688,773 | 76.6% |
| 24 | New Mexico | 22.2% | 218,007 | 76.5% |
| 25 | Massachusetts | 21.9% | 671,338 | 77.2% |
| 26 | Rhode Island | 21.7% | 106,105 | 76.5% |
| T27 | South Dakota | 21.5% | 92,309 | 77.5% |
| T27 | Minnesota | 21.5% | 561,327 | 77.6% |
| 29 | Louisiana | 21.4% | 462,445 | 75.9% |
| 30 | Missouri | 19.0% | 545,411 | 77.9% |
| 31 | North Dakota | 18.6% | 71,396 | 80.8% |
| 32 | Pennsylvania | 18.3% | 1,077,801 | 80.3% |
| 33 | Iowa | 17.9% | 261,907 | 81.4% |
| 34 | Ohio | 17.7% | 951,077 | 81.4% |
| T35 | New York | 17.4% | 1,520,693 | 81.0% |
| T35 | Oregon | 17.4% | 331,699 | 82.0% |
| T35 | Delaware | 17.4% | 83,947 | 81.5% |
| 38 | Florida | 15.8% | 1,709,219 | 83.3% |
| 39 | Maryland | 15.3% | 400,987 | 83.6% |
| 40 | Texas | 13.1% | 1,683,293 | 85.9% |
| 41 | Kansas | 13.0% | 171,966 | 84.1% |
| 42 | Nebraska | 12.7% | 112,763 | 85.6% |
| 43 | Arizona | 11.3% | 382,264 | 87.9% |
| T44 | Hawaii | 11.0% | 63,373 | 80.3% |
| T44 | Illinois | 11.0% | 604,072 | 88.1% |
| 46 | Colorado | 10.4% | 280,449 | 89.1% |
| 47 | New Jersey | 8.8% | 336,823 | 90.5% |
| 48 | California | 7.2% | 1,073,659 | 92.3% |
| 49 | Nevada | 6.8% | 94,125 | 92.6% |
| 50 | Utah | 6.1% | 79,229 | 93.5% |
| 51 | District of Columbia | 0.4% | 1,526 | 98.5% |
The figures cover all housing units, including vacant ones. Our septic rankings use occupied homes only, so their numbers differ slightly. The question was one of several new ones on the 2025 survey, along with electric vehicles and solar panels.
Sources
U.S. Census Bureau, American Community Survey 1-year estimates, 2025, table B25150 (sewer type by units in structure) and table B25149 (tenure by sewer). Evan Brassell, "Sewers or Septic Systems? How U.S. States Treat Wastewater," U.S. Census Bureau, October 29, 2026. KY3, November 4, 2026.
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Which state has the most septic tanks?
North Carolina has the most homes on septic tanks, about 1.78 million, according to the 2025 American Community Survey. Maine has the highest share, with 55.0 percent of its housing units on septic, followed by Vermont at 54.4 percent.
How many homes in the US use septic tanks?
About 28.5 million U.S. homes, or 19.2 percent, used a septic tank in 2025, according to the Census Bureau. About 118 million homes, or 79.6 percent, connected to a public sewer, and about 1.7 million used something else.
Which states have the fewest septic tanks?
Utah has the lowest share of any state, with 6.1 percent of homes on septic, followed by Nevada at 6.8 percent and California at 7.2 percent. In the District of Columbia, the share is 0.4 percent.
