Water Quality Report · Updated May 12, 2026
SUFFOLK COUNTY WATER AUTHORITY
SUFFOLK COUNTY WATER AUTHORITY delivers tap water graded D (62/100) by TapWaterSafety.org. The utility serves approximately 1,100,000 residents in SMITHTOWN (T), New York using groundwater. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. For questions, the utility can be reached at 631-563-0258.
Is SMITHTOWN (T) tap water safe to drink?
SUFFOLK COUNTY WATER AUTHORITY delivers tap water that earns a grade of D (62/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including pfas contamination.
The utility serves 1,100,000 residents in SMITHTOWN (T) and 8 other communities, drawing from groundwater.
Public testing data identifies 8 contaminants in this water above EWG's health-based guidelines, including: Perfluorohexane sulfonate (PFHXS), Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Chromium (hexavalent), 1,2,3-Trichloropropane, Haloacetic acids (HAA5), Perfluorononanoic acid (PFNA), Perfluorooctanoic acid (PFOA). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for SMITHTOWN (T) residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for SUFFOLK COUNTY WATER AUTHORITY.
PFAS contamination
Severe concernPerfluorononanoic acid (PFNA), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 0.227 ppt, 227x above the EWG health guideline of 0.001 ppt.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 8.3 ppb, 55x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 1.33 ppb, 22x above the EWG health guideline of 0.06 ppb.
Contact SUFFOLK COUNTY WATER AUTHORITY
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for SMITHTOWN (T)
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 62/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.227 ppt | 0.001 | 10.0 | — | — | — | — | 227× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
8.3 ppb | 0.15 | 80.0 | 100 | — | — | — | 55× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
1.33 ppb | 0.06 | — | — | — | — | — | 22× over |
| Chromium (hexavalent) Heavy metal |
0.414 ppb | 0.02 | — | — | — | — | — | 21× over |
| 1,2,3-Trichloropropane Other |
0.0126 ppb | 0.0007 | — | — | — | — | — | 18× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
1.15 ppb | 0.1 | 60.0 | 60 | — | — | — | 11× over |
| Perfluorononanoic acid (PFNA) PFAS |
0.024 ppt | 0.006 | 10.0 | — | — | — | — | 4.0× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.234 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 2.6× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.2 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.218 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Chlorate Disinfection byproduct |
57.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| 6:2 Fluorotelomer Sulfonic Acid (6:2 FTSA) Other |
0.09 ppt | 1.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
7.29 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| 1,1-Dichloroethane Volatile organic compound |
0.142 ppb | 3.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.206 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.935 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Cobalt Other |
0.0581 ppb | 70.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.747 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.14 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
0.0028 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.057 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0505 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.049 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.00778 ppb | — | — | — | — | — | — | Below guideline |
| Germanium Other |
0.0162 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
SUFFOLK COUNTY WATER AUTHORITY service area
This water system serves 9 communities in Suffolk County, New York. Click any city for its dedicated tap water quality page.
Find the right filter for SMITHTOWN (T) water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.