48 States by State

38,762 community water systems across 47 reporting states, serving 296,867,185 people, each carried at its most recent reported result in the three years from August 9, 2023 to August 9, 2026. The percentage on each state is coverage — systems with a current nitrate result as a share of that state’s active community water systems. Where it is low, the page says so rather than filling the gap in.

Enough reporting to describe

37 states report widely enough to read a pattern

Each state page carries NitrateSmart’s five-band distribution, a county map of the higher results, the named systems behind them, and what the evidence does and does not support.

Alabama99% of 500 systems · 494 reporting Arizona99% of 749 systems · 742 reporting California85% of 2,816 systems · 2,405 reporting Colorado98% of 1,056 systems · 1,033 reporting Delaware100% of 207 systems · 207 reporting Florida95% of 1,591 systems · 1,509 reporting Georgia99% of 1,742 systems · 1,723 reporting Iowa98% of 1,078 systems · 1,060 reporting Idaho100% of 767 systems · 767 reporting Illinoisover 99% of 1,788 systems · 1,782 reporting Indiana97% of 770 systems · 745 reporting Kansas64% of 855 systems · 547 reporting Kentucky95% of 374 systems · 357 reporting Louisiana65% of 911 systems · 591 reporting Massachusetts88% of 526 systems · 465 reporting Maryland99% of 463 systems · 458 reporting Maine98% of 385 systems · 376 reporting Missouri99% of 1,431 systems · 1,420 reporting Mississippi99% of 1,012 systems · 1,004 reporting Montana96% of 798 systems · 766 reporting North Carolina99% of 1,982 systems · 1,971 reporting Nebraska100% of 583 systems · 583 reporting New Jersey99% of 555 systems · 548 reporting New Mexico100% of 558 systems · 558 reporting Ohio99% of 1,127 systems · 1,112 reporting Oklahoma97% of 889 systems · 863 reporting Oregon99% of 937 systems · 932 reporting Pennsylvania99% of 1,851 systems · 1,840 reporting South Carolina98% of 563 systems · 553 reporting Tennessee98% of 446 systems · 435 reporting Texas94% of 4,740 systems · 4,473 reporting Virginia97% of 1,059 systems · 1,031 reporting Vermont99% of 404 systems · 400 reporting Washington93% of 2,313 systems · 2,141 reporting Wisconsin98% of 1,022 systems · 1,001 reporting West Virginia99% of 417 systems · 414 reporting Wyoming99% of 323 systems · 319 reporting

Described, on a narrow base

6 states have a full page built on thin coverage

These pages carry the same distribution, map and evidence as the states above, but fewer than half the state’s systems report into them. The pattern shown is real for the systems that reported; whether it holds for the ones that did not is not something this site can tell you. Read the coverage figure first.

Connecticut13% of 475 systems · 61 reporting Minnesota14% of 967 systems · 135 reporting Nevada25% of 195 systems · 49 reporting New York19% of 2,247 systems · 424 reporting South Dakota40% of 463 systems · 183 reporting Utah23% of 505 systems · 117 reporting

Too thin for a statewide claim

4 states report too little to describe

These pages give the exact fraction that reports and say which direction the uncertainty runs. They are left unshaded on the national map, because colouring them would put a number on the map the reporting cannot support.

Michigan5% of 1,377 systems · 71 reporting North Dakota30% of 305 systems · 92 reporting New Hampshireunder 1% of 706 systems · 1 reporting Rhode Island4% of 89 systems · 4 reporting

Nothing gathered yet

1 state has no reporting here at all

A system with no result has not been shown to be low and has not been shown to be high. It has not been read.

Arkansas664 systems, none reporting yet

How to read a coverage figure

A quiet state can mean quiet water or thin reporting

The two look identical on a map and they are not the same thing. A state reporting on 99% of its systems and finding little has told you something. A state reporting on 5% and finding little has told you almost nothing. That is why coverage sits beside every state here instead of behind it, and why the thin states are left unshaded on the national map rather than coloured a reassuring pale value.

Coverage is expected to grow as more sources are gathered. Where it is incomplete, and why.