Nassau County, New York
SDWIS compliance plate
Sheet NY059 · Nassau County 44 sys · 7,471 viol · #36/3254
VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-HIGH · SRC-GW · SYS-MID · BOOK-FULL
- VIOL-SEVERE 97.7% flagged
- HEALTH-LOW 2.8% health
- RANK-TOP #36/3254
- PHOTO-FINISH ±0.1 pp
- PFAS-HIGH 60.6% detect
- SRC-GW GW lead 100%
- SYS-MID 44 systems
- BOOK-FULL 7/7 fields
Nearest flagged-rate peer: Oswego County ( -0.1 pp flagged-rate)
According to EPA SDWIS county population served used on /counties, Nassau County ranks #36 of 3,254 counties by people served, and #3 of 58 counties in New York. See methodology · corpus placement.
Nassau County standing, mid-flagged corpus third
Flagged-system rate 97.7% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 2.8% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 60.6% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #36 of 3,254 · #3 of 58 in New York.
Flagged-rate neighbourhood around Nassau County
Lowest/highest poles plus in-state counties nearest Nassau County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.
Water Systems
| System Name | Population | Violations | PFAS |
|---|---|---|---|
| Liberty Utilities New York - Lynbrook | 220,000 | 19 | Detected |
| Liberty Utilities New York - Merrick | 135,000 | 249 | Clean |
| WA of Western Nassau | 120,000 | 25 | Detected |
| Town of Hempstead Water Department | 110,000 | 2 | Detected |
| Jericho WD | 58,000 | 373 | Detected |
| Hempstead (V) | 56,000 | 237 | Detected |
| Hicksville WD | 48,000 | 9 | Detected |
| Freeport (V) | 45,000 | 5 | Clean |
| South Farmingdale WD | 44,700 | 1 | Clean |
| Manhasset Lakeville WD | 43,000 | 1,476 | Detected |
| Massapequa WD | 43,000 | 346 | Clean |
| Long Beach City | 35,000 | 21 | Clean |
| Plainview WD | 34,000 | 236 | Detected |
| Port Washington WD | 34,000 | 582 | Detected |
| Bethpage WD | 33,000 | 9 | Detected |
| West Hempstead WD | 32,031 | 327 | Clean |
| Jones Beach State Park | 30,799 | 17 | - |
| Glen Cove City | 28,000 | 534 | Detected |
| Rockville Centre (V) | 24,700 | 131 | Clean |
| Garden City (V) | 23,272 | 96 | Detected |
| Mineola (V) | 20,600 | 82 | Detected |
| Westbury WD | 20,500 | 34 | Detected |
| Franklin Square WD | 20,000 | 127 | Clean |
| Garden City Park WD | 18,000 | 16 | Detected |
| Roslyn WD | 17,000 | 95 | Detected |
| Albertson WD | 13,500 | 1,243 | Detected |
| Liberty Utilities New York - Sea Cliff | 13,400 | 9 | Clean |
| Carle Place WD | 9,005 | 248 | Clean |
| Farmingdale (V) | 8,744 | 8 | Clean |
| Oyster Bay WD | 8,700 | 12 | Detected |
| Locust Valley WD | 7,500 | 6 | Detected |
| Williston Park (V) | 7,287 | 14 | Detected |
| Bayville (V) | 6,700 | 76 | Clean |
| Old Westbury (V) | 4,700 | 9 | Clean |
| Sands Point (V) | 2,900 | 0 | - |
| East Williston (V) | 2,556 | 9 | - |
| Tobay Beach | 2,420 | 247 | - |
| Lido-Point Lookout WD | 2,000 | 16 | - |
| Plandome (V) | 1,600 | 20 | - |
| Cathedral Gardens WD | 1,500 | 76 | - |
| Glenwood WD | 1,000 | 1 | - |
| Liberty Utilities New York - Mill Neck | 280 | 18 | - |
| Seawanhaka Yacht Club | 60 | 298 | - |
| Beaver Dam Winter Sports | 35 | 112 | - |
Compare beyond New York
Mid-flagged peers for Nassau County
Cross-state counties nearest Nassau County on flagged-system share (97.7%) and cumulative violation count (7,471). In-state neighbours stay on the compliance plate above.
Similar flagged-system rate
Nearest cross-state counties by % of SDWIS systems with at least one violation on record.
Similar violation load
Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).
Read our methodology · Check your water system - how this data is sourced, computed, and verified.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.