Lake Hemet Mwd
EPA ID: CA3310022 · 52,913 people served · 5 ZIP codes
Dating back across the full five-year EPA tracking window, Lake Hemet Mwd encountered 3 violations, each subsequently remedied and closed — today the utility meets all federal drinking water requirements for the 52,913 residents in its service area and holds no open enforcement actions.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Lake Hemet Mwd Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Lake Hemet Mwd serves a community with a median household income of $61,579 and an estimated 171,028 residents across its service area. Approximately 57% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 44% 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?
Lake Hemet Mwd'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 Riverside County, California 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 Lake Hemet Mwd compares to EPA limits
What This Means For You
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Total Coliform at 1 presence exceeds the EPA maximum of presence.
Consumer Confidence Report Rule at 1 mg/L exceeds the EPA maximum of mg/L.
Total Trihalomethanes (TTHM) was detected in this water system. granular activated carbon (GAC) 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
Lake Hemet Mwd (EPA ID: CA3310022) is a community water system in California that serves approximately 52,913 people from groundwater sources.
This system provides water to 5 ZIP codes across 2 communities.
Average Home Safety Score: B (80/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| Total Coliform | Microbiological | 1 | No |
| Consumer Confidence Report Rule | Reporting Failure | 1 | Yes |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 92543 | 0.0008 mg/L | No | N/A |
| 92544 | 0.0008 mg/L | No | N/A |
| 92546 | 0.0008 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: 3 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 2 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.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Lake Hemet Mwd (CA3310022) on EPA.gov.
Frequently Asked Questions
Is Lake Hemet Mwd water safe to drink?
Lake Hemet Mwd has recorded 1 health-based violation 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 Lake Hemet Mwd serve?
Lake Hemet Mwd serves approximately 52,913 people across 5 ZIP codes in California.
Where does Lake Hemet Mwd 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.
- #34 / 50 Highest Exposure Burden (California)
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
Lake Hemet Mwd (EPA ID: CA3310022) — request the latest Consumer Confidence Report or ask about specific contaminants.