Estero Municipal Improvement District
EPA ID: CA4110021 · 36,556 people served · 1 ZIP code
ZipCheckup's reading of EPA SDWIS for Estero Municipal Improvement District (CA4110021): 1 EPA violation in the last five years. Although 1 violation appeared on Estero Municipal Improvement District's record, all have been remedied - currently compliant, 36,556 served.
Data: EPA SDWIS
Service Area Map
Coverage area for Estero Municipal Improvement District Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Estero Municipal Improvement District serves a community with a median household income of $182,417 and an estimated 35,950 residents across its service area. Approximately 75% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Estero Municipal Improvement District'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.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites.
Infrastructure Risk
Detected Contaminants
How Estero Municipal Improvement District compares to EPA limits
What This Means For You
Haloacetic Acids (HAA5) at 1 mg/L exceeds the EPA maximum of 0.06 mg/L. Cancer risk; reproductive & developmental effects. Consider granular activated carbon (GAC) filtration.
Haloacetic Acids (HAA5) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
Similar-sized systems in California
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
Estero Municipal Improvement District (EPA ID: CA4110021) is a community water system in California that serves approximately 36,556 people from surface water sources.
This system serves ZIP code 94404 in San Mateo.
Violation History
Status breakdown for accepted records with record years 2021-2026: 1 resolved, 0 archived, 0 addressed, and 0 unaddressed. Under this source contract, current noncompliance is the sum of addressed and unaddressed records. Archived and resolved records are excluded from current noncompliance.
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| July 1, 2022 | Haloacetic Acids (HAA5) | Non-health-based | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1 | No |
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
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: 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 CA or modeled from parcel and building-footprint data.
- 94404 - San Mateo
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Estero Municipal Improvement District (CA4110021) on EPA.gov.
Frequently Asked Questions
Is Estero Municipal Improvement District water safe to drink?
The accepted 2026Q2 ECHO snapshot shows no current noncompliance for Estero Municipal Improvement District; its 1 accepted 2021-2026 record are resolved or archived. Historical compliance status does not establish conditions at a specific tap.
How many people does Estero Municipal Improvement District serve?
Estero Municipal Improvement District serves approximately 36,556 people across 1 ZIP code in California.
Where does Estero Municipal Improvement District get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
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 →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Estero Municipal Improvement District (CA): 1 EPA Violation. https://zipcheckup.com/water-system/ca4110021/
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url = {https://zipcheckup.com/water-system/ca4110021/}
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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
Estero Municipal Improvement District (EPA ID: CA4110021) - request the latest Consumer Confidence Report or ask about specific contaminants.