| State | 2010 | 2005 | 2015 | ||||||||
| Census Data | Violations | TTHM | Violations | TTHM | |||||||
| Population | Income | Systems | Total | TTHM | [ppb] | Total | TTHM | [ppb] | % Change | ||
| CT | Connecticut | 3,574,097 | $64,032 | 2605 | 5879 | 10 | 31.1 | 3445 | 6 | 77 | 147.6% |
| DE | Delaware | 897,934 | $55,847 | 496 | 121 | 17 | 45 | 125 | 1 | 74 | 64.4% |
| ME | Maine | 1,328,361 | $45,815 | 1875 | 2411 | 88 | 10 | 1105 | 11 | 29 | 190.0% |
| MD | Maryland | 5,773,552 | $68,854 | 3559 | 736 | 8 | 13.6 | 1239 | 66 | 58 | 326.5% |
| MA | Massachusetts | 6,547,629 | $62,072 | 1712 | 180 | 1 | 14 | 2314 | 6 | 77 | 450.0% |
| NH | New Hampshire | 1,316,470 | $61,042 | 2483 | 1100 | 42 | 44 | 926 | 8 | 91 | 106.8% |
| NJ | New Jersey | 8,791,894 | $67,681 | 3950 | 2296 | 19 | 33 | 3018 | 8 | 72 | 118.2% |
| NY | New York | 19,378,102 | $54,148 | 8979 | 7189 | 474 | 38 | 5886 | NR | 69 | 81.6% |
| PA | Pennsylvania | 12,702,379 | $49,288 | 9298 | 13,734 | 76 | 52 | 19,031 | 43 | 71 | 36.5% |
| RI | Rhode Island | 1,052,567 | $52,254 | 490 | 88 | 3 | 34.2 | 164 | 6 | 78 | 128.1% |
| VT | Vermont | 625,741 | $49,406 | 1367 | 642 | 1 | 22 | 880 | 15 | 48 | 118.2% |