Head-to-head water quality
Smithtown (T), NY vs Oakland, CA
Side-by-side water quality comparison: Smithtown (T) (Grade C) vs Oakland (Grade B). Lead, PFAS, violations, and source-water contamination
Score breakdown
Each factor is shown as raw points (out of the maximum). Higher = better.
Factor
Smithtown (T)
Oakland
Better
Violations subscore / 45
19.0
35.1
Oakland
Lead/Copper subscore / 20
20.0
16.0
Smithtown (T)
Contaminant subscore / 20
8.8
14.8
Oakland
Compliance subscore / 10
8.0
8.0
Tie
Source subscore / 5
5.0
4.0
Smithtown (T)
Lead & copper at the tap
Lead and Copper Rule (LCR) 90th-percentile readings — the value that 10% of sampled homes exceed.
Factor
Smithtown (T)
Oakland
Better
Lead 90th-percentile (latest) · EPA action level: 15 µg/L
0.0 µg/L
0.0 µg/L
Smithtown (T)
Copper 90th-percentile (latest) · EPA action level: 1.3 mg/L
—
1.8 mg/L
Oakland
PFAS — "forever chemicals"
UCMR 5 testing, 2023–2025. Federal MCLs: PFOA + PFOS = 4 ng/L; HFPO-DA = 10 ng/L.
Factor
Smithtown (T)
Oakland
Better
PFAS analytes detected
10 of 30
1 of 30
Oakland
PFAS exceeds federal MCL
Yes
No
Oakland
PFAS hazard index · Sum of (max/MCL) across detected analytes; > 1 indicates exceedance
5.97
—
Smithtown (T)
Violation history
SDWA enforcement actions — fewer is better.
Factor
Smithtown (T)
Oakland
Better
Violations (last 5 years)
31
2
Oakland
Health-based violations (total)
3
13
Smithtown (T)
Unresolved violations
10
6
Oakland
Other contaminants tested
UCMR rounds 1–4 + UCMR 5 lithium. Maxima where data exists; "—" means not tested.
Factor
Smithtown (T)
Oakland
Better
Chromium-6 (max)
5.59 µg/L
0.22 µg/L
Oakland
HAA5 (avg)
1.63 µg/L
34.22 µg/L
Smithtown (T)
Manganese (max)
176.80 µg/L
12.70 µg/L
Oakland
Strontium (max)
169.00 µg/L
320.00 µg/L
Smithtown (T)
1,4-Dioxane (max)
4.34 µg/L
—
Smithtown (T)
NDMA (max)
13.43 ng/L
3.30 ng/L
Oakland
Perchlorate (max)
12.10 µg/L
—
Smithtown (T)
Vanadium (max)
6.97 µg/L
2.40 µg/L
Oakland
Chlorate (max)
386.00 µg/L
480.00 µg/L
Smithtown (T)
Molybdenum (max)
1.18 µg/L
1.20 µg/L
Smithtown (T)
Industrial proximity
Superfund National Priorities List + Toxic Release Inventory facilities within 10 miles of the city centroid.
Factor
Smithtown (T)
Oakland
Better
Superfund sites within 10 mi
0
3
Smithtown (T)
TRI lbs to surface water within 10 mi (2023)
0
45
Smithtown (T)
System size & source
Factor
Smithtown (T)
Oakland
Population served
1.1M
1.4M
—
Water source
Groundwater
Surface water
—
Number of water systems
4
5
—
See the full reports
Frequently asked
Which has better water — Smithtown (T) or Oakland?
Oakland, CA scores higher (77.9 vs 60.9) on WaterVerge's 100-point methodology, earning a Grade B compared to Smithtown (T)'s Grade C. The score combines violation history, lead and copper levels, contaminant testing, monitoring compliance, and source-water type.
How is the WaterVerge water quality score calculated?
The grade combines five subscores: violation history (45 pts, weighted by recency and health-based severity), lead/copper 90th-percentile vs EPA action levels (20 pts), contaminant testing including PFAS, chromium-6, HAA5, NDMA, perchlorate, and Superfund/TRI proximity (20 pts), monitoring compliance (10 pts), and water-source-type risk (5 pts). Full methodology at /about/methodology.
Where does this water quality data come from?
From the EPA's public records: the SDWIS bulk download (violations + system info), UCMR rounds 1–5 (unregulated contaminant testing including PFAS, chromium-6, HAA5, NDMA, perchlorate, vanadium, lithium), the EPA Toxic Release Inventory (industrial polluters), the Superfund National Priorities List, the USGS Powell Domestic-Well Database (private-well chemistry), and the CDC Community Water Fluoridation system. Data is refreshed quarterly.