Lago Del Oro Water Company
EPA ID: AZ0411117 · 18,132 people served · 4 ZIP codes
Lago Del Oro Water Company's current EPA file includes 71 unresolved violations — every outstanding finding is documented in federal records for this utility, which supplies water to approximately 18,132 residents across its service territory.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Lago Del Oro Water Company Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Lago Del Oro Water Company serves a community with a median household income of $95,838 and an estimated 41,722 residents across its service area.
Environmental Justice Note: 39% 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?
Lago Del Oro Water Company'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 Pima County, Arizona 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 Lago Del Oro Water Company compares to EPA limits
What This Means For You
Atrazine at 2 mg/L exceeds the EPA maximum of 0.003 mg/L. Endocrine disruption, cardiovascular & reproductive effects. Consider granular activated carbon (GAC) filtration.
Lead at 8 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.
Haloacetic Acids (HAA5) at 11 mg/L exceeds the EPA maximum of 0.06 mg/L. Cancer risk; reproductive & developmental effects. Consider granular activated carbon (GAC) filtration.
Total Trihalomethanes (TTHM) at 9 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Consumer Confidence Report Rule at 44 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. 4 detections recorded.
Atrazine 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 Arizona
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
Lago Del Oro Water Company (EPA ID: AZ0411117) is a community water system in Arizona that serves approximately 18,132 people from groundwater sources.
This system provides water to 4 ZIP codes across 3 communities.
Average Home Safety Score: C (62/100)
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 |
|---|---|---|---|
| September 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| September 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| September 1, 2025 | E. coli | Monitoring | Unresolved |
| August 19, 2025 | Contaminant 0700 | Health-based | Unresolved |
| August 7, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| August 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| August 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| August 1, 2025 | E. coli | Monitoring | Unresolved |
| August 1, 2025 | Fecal Coliform | Monitoring | Unresolved |
| July 1, 2025 | Radium-228 | Monitoring | Unresolved |
| July 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| July 1, 2025 | Surface Water Treatment Rule | Monitoring | Unresolved |
| July 1, 2025 | Barium | Monitoring | Unresolved |
| July 1, 2025 | E. coli | Monitoring | Unresolved |
| July 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| July 1, 2025 | Fecal Coliform | Monitoring | Unresolved |
| January 1, 2023 | Total Trihalomethanes (TTHM) | 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 | 44 | Yes |
| Lead and Copper Rule | Treatment Failure | 27 | No |
| Revised Total Coliform Rule | Microbiological | 21 | No |
| Stage 1 DBP Rule | Treatment Failure | 17 | No |
| E. coli | Microbiological | 15 | No |
| Fecal Coliform | Microbiological | 14 | Yes |
| Barium | Inorganic | 12 | Yes |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 11 | Yes |
| Stage 2 DBP Rule | Treatment Failure | 10 | Yes |
| Surface Water Treatment Rule | Treatment Failure | 10 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 9 | No |
| Lead | Inorganic | 8 | Yes |
| Total Organic Carbon | Disinfection Byproducts | 4 | No |
| Contaminant 0700 | Other Violation | 4 | Yes |
| Gross Alpha | Radionuclides | 3 | No |
Health Risk Details
Haloacetic Acids (HAA5) (EPA limit: 0.06 mg/L)
Cancer risk; reproductive & developmental effects At-risk groups: pregnant women, infants, long-term consumers of chlorinated municipal water.
Removal methods: granular activated carbon (GAC), carbon block filter, reverse osmosis. Find the right filter →
Lead (EPA limit: 0.015 mg/L (action level))
Brain damage in children, kidney & blood pressure in adults At-risk groups: infants, children under 6, pregnant women.
Removal methods: reverse osmosis, distillation, certified carbon block filter (NSF/ANSI 53). Find the right filter →
Fluoride (EPA limit: 4 mg/L (secondary standard: 2.0 mg/L))
Tooth & bone damage at high levels At-risk groups: children under 8 during tooth development, elderly with compromised bone density, people with kidney disease.
Removal methods: reverse osmosis, activated alumina, distillation. Find the right filter →
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
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 1 additional ZIP 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 Lago Del Oro Water Company (AZ0411117) on EPA.gov.
Frequently Asked Questions
Is Lago Del Oro Water Company water safe to drink?
Lago Del Oro Water Company has recorded 29 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 Lago Del Oro Water Company serve?
Lago Del Oro Water Company serves approximately 18,132 people across 4 ZIP codes in Arizona.
Where does Lago Del Oro Water Company 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 →
PFAS Substances Detected in This System
This water system's Consumer Confidence Report disclosed the following PFAS compounds. Levels are from the utility's most recent reporting cycle.
In April 2024, EPA finalized the first National Primary Drinking Water Regulation for six PFAS. Public water systems have until 2029 to comply. EPA — PFAS regulation overview →
Source: Consumer Confidence Report disclosed by Lago Del Oro Water Company (AZ0411117).
ZipCheckup is not affiliated with this water utility. PFAS detection data is sourced from public Consumer Confidence Reports filed by the utility itself.
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.
Lago Del Oro Water Company (AZ0411117)
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.
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
Lago Del Oro Water Company (EPA ID: AZ0411117) — request the latest Consumer Confidence Report or ask about specific contaminants.