City of Mountain Home
EPA ID: ID4200032 · 14,651 people served · 2 ZIP codes
With 7 unresolved EPA violations, City of Mountain Home is currently out of full compliance — approximately 14,651 people in its service area.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 2 (2024) to 2 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for City of Mountain Home Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The City of Mountain Home serves a community with a median household income of $56,940 and an estimated 24,217 residents across its service area. Approximately 67% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 100% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
City of Mountain Home'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 2% of homes in Elmore County, Idaho 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 City of Mountain Home compares to EPA limits
What This Means For You
Lead at 1 mg/L (action level) exceeds the EPA maximum of 0.015 mg/L (action level). Brain damage in children, kidney & blood pressure in adults. Consider reverse osmosis filtration.
Consumer Confidence Report Rule at 6 mg/L exceeds the EPA maximum of mg/L.
Revised Total Coliform Rule at 4 presence exceeds the EPA maximum of presence.
Total Coliform at 3 presence exceeds the EPA maximum of presence.
Stage 2 DBP Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Lead was detected in this water system. reverse osmosis filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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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
City of Mountain Home, (EPA ID: ID4200032) is a community water system in Idaho that serves approximately 14,651 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Average Home Safety Score: C (61/100)
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 |
|---|---|---|---|
| August 1, 2025 | Consumer Confidence Report Rule | Health-based | Unresolved |
| June 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| October 17, 2024 | Stage 2 DBP Rule | Health-based | Resolved |
| October 17, 2024 | Stage 2 DBP Rule | Monitoring | Resolved |
| October 1, 2024 | E. coli | Monitoring | Unresolved |
| October 1, 2024 | Fecal Coliform | Monitoring | Unresolved |
| September 30, 2024 | Total Coliform | Monitoring | Unresolved |
| July 22, 2024 | Total Coliform | Monitoring | Unresolved |
| June 1, 2024 | Total Coliform | Monitoring | Unresolved |
| January 1, 2024 | Total Organic Carbon | Monitoring | Unresolved |
| January 1, 2023 | Contaminant 1052 | Monitoring | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 6 | Yes |
| Revised Total Coliform Rule | Microbiological | 4 | No |
| Total Coliform | Microbiological | 3 | No |
| Stage 2 DBP Rule | Treatment Failure | 2 | Yes |
| Lead | Inorganic | 1 | No |
| Contaminant 1052 | Other Violation | 1 | No |
| Total Organic Carbon | Disinfection Byproducts | 1 | No |
| Combined Radium | Radionuclides | 1 | No |
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
| E. coli | Microbiological | 1 | No |
| Fecal Coliform | Microbiological | 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 |
|---|---|---|---|
| 83647 | 0.004 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 ID or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Mountain Home (ID4200032) on EPA.gov.
Frequently Asked Questions
Is City of Mountain Home water safe to drink?
City of Mountain Home has recorded 2 health-based violations in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does City of Mountain Home serve?
City of Mountain Home serves approximately 14,651 people across 2 ZIP codes in Idaho.
Where does City of Mountain Home get its water?
The primary water source is groundwater.
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 →
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.
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
City of Mountain Home (EPA ID: ID4200032) — request the latest Consumer Confidence Report or ask about specific contaminants.