Is Oyster Bay (T), NY Tap Water Safe to Drink?
Graded B- — but Copper, 1,4-Dioxane and 2 more were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
71/100
waterverge.com Oyster Bay (T), NY — Water Quality Report
Oyster Bay (T)'s drinking water received a grade of B- (71 out of 100), indicating fair water quality. The city's 10 water systems serve approximately 278,180 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 8 PFAS compounds in the water supply.
The system has 258 violations on record, including 14 health-based violations. 4 remain unresolved.
What to know about Oyster Bay (T)'s water
Oyster Bay (T) ranks #701 out of 855 cities in New York for water quality, placing it among the lowest-rated in the state.
Oyster Bay (T) relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.
Hexavalent chromium (chromium-6) was detected at 1.79 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
Water quality score
See methodology →Is Oyster Bay (T), NY water safe to drink?
Oyster Bay (T)'s drinking water has significant quality concerns based on EPA testing data. With a grade of B- (71/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 10 water systems serve approximately 278,180 residents using groundwater (wells).
Recent water quality updates for Oyster Bay (T)
A timeline of significant water quality events, violations, and data updates.
Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.
Latest EPA compliance and testing data incorporated into Oyster Bay (T)'s water quality assessment. Grade: B- (71/100).
Federal disaster declaration (FEMA DR-4755). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4615). Hurricane event — may have impacted local water infrastructure.
Contaminants: TTHM.
Contaminants: Total Haloacetic Acids (HAA5), TTHM.
Key contaminant findings
Based on the most recent EPA sampling data for Oyster Bay (T)'s water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.
PFAS "forever chemicals" detected
UCMR 5 testing found 8 PFAS compounds in Oyster Bay (T)'s water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.
Violation history
Oyster Bay (T)'s water system has 258 total violations on record, including 14 health-based violations. 4 remain unresolved.
Flood & environmental risk
Nassau County has experienced 10 federally declared disasters since 2005. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Mill Neck Creek, Cold Spring Brook, Massapequa Creek, Bellmore Creek, Bellmore Creek Tributary.
Where does Oyster Bay (T)'s water come from?
Oyster Bay (T)'s drinking water comes from groundwater (wells), supplied by 10 water systems serving approximately 278,180 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Mill Neck Creek (river), Cold Spring Brook (river), Massapequa Creek (river), Bellmore Creek (river), Bellmore Creek Tributary (river).
What Oyster Bay (T) residents can do
Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Oyster Bay (T)'s water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Oyster Bay (T)'s area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Drought conditions
D1 — moderate droughtNassau County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Nassau County has experienced 10 federally declared disasters since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Oyster Bay (T)'s water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.60 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | 0.010 | HI | µg/L | PFAS | Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | 0.067 | HI | µg/L | PFAS | Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | 0.004 | HI | µg/L | PFAS | Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | 0.005 | HI | µg/L | PFAS | Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | 0.018 | HI | µg/L | PFAS | Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | 0.004 | HI | µg/L | PFAS | Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | 0.030 | HI | µg/L | PFAS | Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | 0.037 | HI | µg/L | PFAS | Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.600 mg/L (2017)
EPA action level: 1.3 mg/L
See how Oyster Bay (T) compares by contaminant
Explore where Oyster Bay (T) ranks among all New York cities for specific contaminants.
Water source & infrastructure
Where Oyster Bay (T)'s water comes from
Oyster Bay (T)'s drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by public/private ownership and serves approximately 278,180 people through 10 water systems.
Water bodies near Oyster Bay (T)
Oyster Bay (T) is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Oyster Bay (T)
| System Name | PWSID | Population | Source |
|---|---|---|---|
| JERICHO WD | NY2902831 | 58,000 | GW |
| HICKSVILLE WD | NY2902829 | 48,000 | GW |
| SOUTH FARMINGDALE WD | NY2902854 | 44,700 | GW |
| MASSAPEQUA WD | NY2902837 | 43,000 | GW |
| PLAINVIEW WD | NY2902845 | 34,000 | GW |
| BETHPAGE WD | NY2902817 | 33,000 | GW |
| OYSTER BAY WD | NY2902844 | 8,700 | GW |
| LOCUST VALLEY WD | NY2902833 | 7,500 | GW |
| GLENWOOD WD | NY2902850 | 1,000 | GWP |
| LIBERTY UTILITIES NEW YORK - MILL NECK | NY2902838 | 280 | GW |
How Oyster Bay (T) compares
Full New York rankings →Oyster Bay (T)'s score of 71/100 is on par with the average of 74/100 among major New York cities. It outscores 3 of 10 nearby cities. 7 of 10 nearby cities score higher.
Nearby cities
View New York rankings →About Oyster Bay (T), NY
Wikipedia →Syosset is a hamlet and census-designated place (CDP) located within the Town of Oyster Bay in Nassau County, on the North Shore of Long Island, in New York, United States. The population was 19,259 at the time of the 2020 census.
Learn more about your water
Guides and resources related to Oyster Bay (T)'s water quality findings.
Explore water quality across Nassau
Frequently asked questions
Is Oyster Bay (T), NY tap water safe to drink?
Oyster Bay (T)'s water quality earned a grade of B- (71/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #701 out of 855 cities tested in New York.
What contaminants are in Oyster Bay (T)'s water?
Lead was measured at 0.0 ppb (90th percentile). 8 PFAS compounds were detected. 258 violations are on record.
How is Oyster Bay (T)'s water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Oyster Bay (T)?
PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.
Where does Oyster Bay (T)'s water come from?
Oyster Bay (T)'s water is sourced from Groundwater. The city has 10 water systems serving approximately 278,180 residents.
What health violations has Oyster Bay (T)'s water system had?
Oyster Bay (T) has 14 health-based violations on record. The most recent violation was recorded in January 2019. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.
Is Oyster Bay (T)'s groundwater at risk of contamination?
Oyster Bay (T) uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 258 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
Why does Oyster Bay (T) have so many PFAS compounds in its water?
8 different PFAS "forever chemical" compounds were detected in Oyster Bay (T)'s water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. While detected, current levels are within EPA limits. An activated carbon filter can further reduce exposure.
How does Oyster Bay (T)'s water compare to other cities?
Oyster Bay (T) ranks #701 out of 855 cities in New York (better than 18% of state cities) and #10626 out of 15744 cities nationally (33th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.