Water Quality Report · Updated October 07, 2026
LOUDOUN WATER - CENTRAL SYSTEM
LOUDOUN WATER - CENTRAL SYSTEM delivers tap water graded C (72/100) by TapWaterSafety.org. The utility serves approximately 334,808 residents in ASHBURN, Virginia using surface water. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline. For questions, the utility can be reached at 571-291-7844.
Is ASHBURN tap water safe to drink?
LOUDOUN WATER - CENTRAL SYSTEM delivers tap water that earns a grade of C (72/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 334,808 residents in ASHBURN, drawing from surface water.
Public testing data identifies 13 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Bromodichloromethane, Trichloroacetic acid, Chloroform, Dichloroacetic acid, Dibromochloromethane, Dibromoacetic acid, Nitrate and nitrite, Chromium (hexavalent), Radium, combined (-226 and -228), Bromate. 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.
EPA compliance record
Official U.S. EPA records for LOUDOUN WATER - CENTRAL SYSTEM (system ID VA6107350) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Lead and Copper Rule | Missed testing or reporting | 10/01/2023 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for ASHBURN residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for LOUDOUN WATER - CENTRAL SYSTEM.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 15.3 ppb, 255x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 28.5 ppb, 190x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 14.2 ppb, 142x above the EWG health guideline of 0.1 ppb.
Contact LOUDOUN WATER - CENTRAL SYSTEM
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 ASHBURN
Filters matched to the specific contaminants in this water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
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 72/100 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 |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
15.3 ppb | 0.06 | — | — | — | — | — | 255× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
28.5 ppb | 0.15 | 80.0 | 100 | — | — | — | 190× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
14.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 142× over |
| Bromodichloromethane Disinfection byproduct |
6.8 ppb | 0.06 | — | — | — | — | — | 113× over |
| Trichloroacetic acid Disinfection byproduct |
5.67 ppb | 0.1 | — | — | — | — | — | 57× over |
| Chloroform Disinfection byproduct |
18.2 ppb | 0.4 | — | — | — | — | — | 45× over |
| Dichloroacetic acid Disinfection byproduct |
7.75 ppb | 0.2 | — | — | — | — | — | 39× over |
| Dibromochloromethane Disinfection byproduct |
3.3 ppb | 0.1 | — | — | — | — | — | 33× over |
| Dibromoacetic acid Disinfection byproduct |
0.495 ppb | 0.03 | — | — | — | — | — | 17× over |
| Nitrate and nitrite Inorganic |
1.36 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 9.7× over |
| Chromium (hexavalent) Heavy metal |
0.116 ppb | 0.02 | — | — | — | — | — | 5.8× over |
| Radium, combined (-226 and -228) Radiological |
0.23 pCi/L | 0.05 | 5.0 | — | — | — | — | 4.6× over |
| Bromate Disinfection byproduct |
0.351 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 3.5× over |
| Bromoform Disinfection byproduct |
0.259 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
95.0 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
43.3 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Barium Heavy metal |
40.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
2.13 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.146 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.286 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.359 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.425 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.116 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
0.3 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.635 ppm | — | 4.0 | 1.5 | 1.5 | — | — | 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.
LOUDOUN WATER - CENTRAL SYSTEM service area
This water system serves 1 community in Loudoun County, Virginia. Click any city for its dedicated tap water quality page.
Find the right filter for ASHBURN water
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