Loudoun Water - Central System
EPA ID: VA6107350 · 334,808 people served · 20 ZIP codes
While 1 violation did appear in Loudoun Water - Central System's five-year monitoring record, none remain unresolved — the utility has returned to full compliance and continues to serve approximately 334,808 residents under all current EPA drinking water standards.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Loudoun Water - Central System Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Loudoun Water - Central System serves a community with a median household income of $168,035 and an estimated 438,213 residents across its service area.
🌊 Where Does Your Water Come From?
Loudoun Water - Central System's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 1% of homes in Loudoun County, Virginia rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Loudoun Water - Central System compares to EPA limits
What This Means For You
Stage 1 DBP Rule at 1 mg/L exceeds the EPA maximum of mg/L.
Surface Water Treatment Rule at 1 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 31 detections recorded. 6 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Comparable Water Systems
Similar-sized systems in Virginia
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
LOUDOUN WATER - CENTRAL SYSTEM (EPA ID: VA6107350) is a community water system in Virginia that serves approximately 334,808 people from surface water sources.
This system provides water to 20 ZIP codes across 9 communities.
Average Home Safety Score: C (67/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| July 1, 2025 | Surface Water Treatment Rule | Monitoring | Resolved |
| October 1, 2023 | Stage 1 DBP Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
| Surface Water Treatment Rule | Treatment Failure | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 20105 | 0.00149 mg/L | No | N/A |
| 20146 | 0.0005 mg/L | No | N/A |
| 20147 | 0.0005 mg/L | No | N/A |
| 20148 | 0.0005 mg/L | No | N/A |
| 20149 | 0.0005 mg/L | No | N/A |
| 22093 | 0.0005 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: 11 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 9 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
- 20101 — Dulles
- 20102 — Dulles
- 20103 — Dulles
- 20104 — Dulles
- 20105 — Aldie
- 20120 — Centreville
- 20146 — Ashburn
- 20147 — Ashburn
- 20148 — Ashburn
- 20149 — Ashburn
- 20152 — Chantilly
- 20160 — Lincoln
- 20164 — Sterling
- 20165 — Sterling
- 20166 — Sterling
- 20175 — Leesburg
- 20176 — Leesburg
- 20189 — Dulles
- 22066 — Great Falls
- 22093 — Ashburn
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Loudoun Water - Central System (VA6107350) on EPA.gov.
Frequently Asked Questions
Is Loudoun Water - Central System water safe to drink?
Loudoun Water - Central System has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Loudoun Water - Central System serve?
Loudoun Water - Central System serves approximately 334,808 people across 20 ZIP codes in Virginia.
Where does Loudoun Water - Central System get its water?
The primary water source is surface water.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from Loudoun Water — Central System Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: Loudoun Water — Central System Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Since the Loudoun Water system has two sources of water (Potomac River and Goose Creek), two source water assessment reports have been conducted by the Virginia Department of Health. Based on state criteria, both sources are considered to be highly susceptible to contamination.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Watershed exposure sources reported
Land-use and natural conditions identified in the utility's source-water assessment as potential contamination sources upstream of treatment.
Treatment classification and chemical list sourced from Loudoun Water — Central System Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Loudoun Water does not have any lead service lines within its system. Orthophosphate is added to the water to coat pipes and reduce lead leaching. Corrosion inhibitor is used by both Fairfax Water and Loudoun Water to slow dissolution of lead from household plumbing components.
Lead Service Line Replacement Tracker
This water utility's lead service line (LSL) replacement program is tracked from public Consumer Confidence Report filings. Email signup notifies subscribers when the utility files an updated replacement plan or progress milestone.
Loudoun Water — Central System
ZipCheckup is not affiliated with this water utility. LSL replacement-program data is sourced from public CCR filings published by the utility. Subscription notifications are based on automated parsing of subsequent CCR releases.
Learn more about Lead and Copper Rule replacement requirements →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Notable events and violations
This section summarizes events the utility chose to disclose in its most recent Consumer Confidence Report, plus any federal compliance violations the utility recorded against itself. Both lists are utility-authored — ZipCheckup does not audit, judge, or reorder them.
Notable events from the utility's CCR
These bullet entries are the utility's own narration of operational, regulatory, or infrastructure events during the reporting period.
- PFPeA (perfluoropentanoic acid) detected at trace level (avg 0.00068 ug/L) in distribution system under UCMR5; this compound has no established MCL.
- Loudoun Water does not have any lead service lines within its system.
- EPA announced final PFAS drinking water regulation April 10, 2024, establishing MCLs for PFOA, PFOS, PFNA, PFHxS, HFPO-DA, and PFBS hazard index.
ZipCheckup note: items above reflect what the utility published in its most recent CCR. Federal violation records are also tracked separately by the EPA Safe Drinking Water Information System (SDWIS) — the SDWIS record is the authoritative federal source for any specific regulatory action.
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Loudoun Water - Central System (EPA ID: VA6107350) — request the latest Consumer Confidence Report or ask about specific contaminants.