Holliston Water Department
EPA ID: MA2136000 · 15,713 people served · 1 ZIP code
Looking at the EPA enforcement file for Holliston Water Department, 2 violations are listed as unresolved — those findings cover the utility's service area of approximately 15,713 people and remain open in the federal compliance system, awaiting formal corrective action documentation.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Holliston Water Department Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Holliston Water Department serves a community with a median household income of $154,684 and an estimated 14,964 residents across its service area. Approximately 78% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Holliston Water Department's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in Middlesex County, Massachusetts rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 80th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Detected Contaminants
How Holliston Water Department compares to EPA limits
What This Means For You
Chlorite at 2 mg/L exceeds the EPA maximum of 1 mg/L. Anemia and nervous system effects in infants and children. Consider ferrous sulfate reduction filtration.
Stage 1 DBP Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Contaminant 1028 at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 1032 at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 2306 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. 5 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Chlorite was detected in this water system. ferrous sulfate reduction filtration can reduce exposure.
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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
Holliston Water Department (EPA ID: MA2136000) is a community water system in Massachusetts that serves approximately 15,713 people from groundwater sources.
This system serves ZIP code 01746 in Holliston.
Average Home Safety Score: C (59/100)
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 |
|---|---|---|---|
| October 1, 2024 | Stage 1 DBP Rule | Monitoring | Unresolved |
| April 1, 2023 | Stage 1 DBP Rule | Monitoring | Unresolved |
| April 1, 2023 | Contaminant 1028 | Monitoring | Resolved |
| April 1, 2023 | Chlorite | Monitoring | Resolved |
| January 1, 2023 | Contaminant 1032 | Monitoring | Resolved |
| January 1, 2023 | Chlorite | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Chlorite | Disinfection Byproducts | 2 | No |
| Stage 1 DBP Rule | Treatment Failure | 2 | No |
| Contaminant 1028 | Other Violation | 1 | No |
| Contaminant 1032 | Other Violation | 1 | No |
| Contaminant 2306 | Other Violation | 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 |
|---|---|---|---|
| 01746 | 0.0029 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High 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: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by MA or modeled from parcel and building-footprint data.
- 01746 — Holliston
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Holliston Water Department (MA2136000) on EPA.gov.
Frequently Asked Questions
Is Holliston Water Department water safe to drink?
Holliston Water Department has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Holliston Water Department serve?
Holliston Water Department serves approximately 15,713 people across 1 ZIP code in Massachusetts.
Where does Holliston Water Department get its water?
The primary water source is groundwater.
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 →
Lead Service Line Inventory
Utility-reported lead service line presence and tap-sample lead level under federal LCRI requirements:
Below federal action level (0.015 mg/L)
MassDEP reports utility-level presence flag and tap-sampling without per-line breakdown. Customers should inquire with the utility about service line material at a specific address.
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: MassDEP LCRR Service Line Inventory · Submitted 2024
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.
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
Holliston Water Department (EPA ID: MA2136000) — request the latest Consumer Confidence Report or ask about specific contaminants.