Head-to-head water quality
Boston, MA vs Herndon, VA
Side-by-side water quality comparison: Boston (Grade B) vs Herndon (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
Boston
Herndon
Better
Violations subscore / 45
42.8
36.2
Boston
Lead/Copper subscore / 20
6.0
20.0
Herndon
Contaminant subscore / 20
19.0
10.3
Boston
Compliance subscore / 10
5.0
5.0
Tie
Source subscore / 5
4.0
4.0
Tie
Lead & copper at the tap
Lead and Copper Rule (LCR) 90th-percentile readings — the value that 10% of sampled homes exceed.
Factor
Boston
Herndon
Better
Lead 90th-percentile (latest) · EPA action level: 15 µg/L
0.0 µg/L
0.0 µg/L
Herndon
Copper 90th-percentile (latest) · EPA action level: 1.3 mg/L
—
—
—
PFAS — "forever chemicals"
UCMR 5 testing, 2023–2025. Federal MCLs: PFOA + PFOS = 4 ng/L; HFPO-DA = 10 ng/L.
Factor
Boston
Herndon
Better
PFAS analytes detected
0 of 30
8 of 30
Boston
PFAS exceeds federal MCL
No
Yes
Boston
PFAS hazard index · Sum of (max/MCL) across detected analytes; > 1 indicates exceedance
—
3.27
Herndon
Violation history
SDWA enforcement actions — fewer is better.
Factor
Boston
Herndon
Better
Violations (last 5 years)
0
2
Boston
Health-based violations (total)
5
14
Boston
Unresolved violations
3
7
Boston
Other contaminants tested
UCMR rounds 1–4 + UCMR 5 lithium. Maxima where data exists; "—" means not tested.
Factor
Boston
Herndon
Better
Chromium-6 (max)
—
0.28 µg/L
Herndon
HAA5 (avg)
15.35 µg/L
18.70 µg/L
Boston
Manganese (max)
10.90 µg/L
3.10 µg/L
Herndon
Strontium (max)
39.40 µg/L
200.00 µg/L
Boston
NDMA (max)
3.88 ng/L
—
Boston
Vanadium (max)
—
0.84 µg/L
Herndon
Chlorate (max)
220.00 µg/L
400.00 µg/L
Boston
Molybdenum (max)
—
1.70 µg/L
Herndon
Industrial proximity
Superfund National Priorities List + Toxic Release Inventory facilities within 10 miles of the city centroid.
Factor
Boston
Herndon
Better
Superfund sites within 10 mi
1
1
Tie
TRI lbs to surface water within 10 mi (2023)
55
676
Boston
System size & source
Factor
Boston
Herndon
Population served
3.3M
1.1M
—
Water source
Surface water
Surface water
—
Number of water systems
2
4
—
See the full reports
Frequently asked
Which has better water — Boston or Herndon?
Boston, MA scores higher (76.8 vs 75.5) on WaterVerge's 100-point methodology, earning a Grade B compared to Herndon's Grade B. 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.