WaterVerge

Is Casamero Lake, Borrego Pass, Smith Lake, AZ Tap Water Safe to Drink?

Graded A, with 4 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

906 residents served 1 water system PWSID: NN3500256
Overall Score
91.9 / 100
Violations
4 active
Last Updated
May 2026
Source
Groundwater
#38 of 292 in Arizona Top 9% nationally
Native American
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
91.9/100
waterverge.com
A 91.9/100

Casamero Lake, Borrego Pass, Smith Lake, AZ — Water Quality Report

Casamero Lake, Borrego Pass, Smith Lake's drinking water received a grade of A (91.9 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 906 residents using groundwater.

Lead levels were measured at 2.5 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.

The system has 86 violations on record, including 2 health-based violations. 4 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Casamero Lake, Borrego Pass, Smith Lake's water

Casamero Lake, Borrego Pass, Smith Lake ranks #38 out of 292 cities in Arizona for water quality, placing it above average in the state.

Casamero Lake, Borrego Pass, Smith Lake relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

As a small community water system, Casamero Lake, Borrego Pass, Smith Lake may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

Quality Breakdown

Water quality score

See methodology →
91.9 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
39.9/45
B
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 2.5 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Casamero Lake, Borrego Pass, Smith Lake, AZ water safe to drink?

Concerns Identified

Casamero Lake, Borrego Pass, Smith Lake's drinking water has significant quality concerns based on EPA testing data. With a grade of A (91.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 906 residents using groundwater (wells).

4
Active Violations
2.5 ppb
Lead (90th %ile)

Recent water quality updates for Casamero Lake, Borrego Pass, Smith Lake

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Casamero Lake, Borrego Pass, Smith Lake's water quality assessment. Grade: A (91.9/100).

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
4 drinking water violations recorded

Contaminants: Diquat, Glyphosate, Endothall.

Violation
6 drinking water violations recorded

1 health-based. Contaminants: 2,3,7,8-TCDD, Glyphosate, Endothall.

Key contaminant findings

Based on the most recent EPA sampling data for Casamero Lake, Borrego Pass, Smith Lake's water supply.

Lead Within Limits
Detected: 2.5 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Casamero Lake, Borrego Pass, Smith Lake's water system has 86 total violations on record, including 2 health-based violations. 4 remain unresolved.

OtherMRMCL
Most recent violations:
Apr 2016 Revised Total Coliform Rule Open
Oct 2014 Diquat Resolved
Oct 2014 Glyphosate Resolved
Oct 2014 Endothall Resolved
Oct 2014 2,3,7,8-TCDD Resolved

Where does Casamero Lake, Borrego Pass, Smith Lake's water come from?

Casamero Lake, Borrego Pass, Smith Lake's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 906 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Casamero Lake, Borrego Pass, Smith Lake residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Casamero Lake, Borrego Pass, Smith Lake's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
2.5 ppb
EPA Action Level: 15 ppb · 17% of limit
Safe Level
Compliance Record

Violation summary

86
Total violations
2
Health-based
4
Active / unresolved
Apr 2016
Most recent violation
Compliance Record

Violations & advisories

86 Total
4 Active
2 Health-based
82 Resolved
Violations by category
Synthetic Organic Chemicals
50
Volatile Organic Chemicals
21
Total Coliform Rule
6
Radionuclides and Revised Rad Rule
3
Nitrate Rule
2
Apr 2016 Active
Revised Total Coliform Rule
Other Violation 0
Jul 2014 Active
Public Notice
Other Violation 0
Oct 2013 Active
Stage 2 Disinfectants and Disinfection Byproducts Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Oct 2014 Resolved
Diquat
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2014
Oct 2014 Resolved
Glyphosate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2014
Oct 2014 Resolved
Endothall
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2014
Oct 2014 Resolved
2,3,7,8-TCDD
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2014
Jul 2014 Resolved
2,3,7,8-TCDD
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2014
Jul 2014 Resolved
Glyphosate
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2014
Jul 2014 Resolved
Endothall
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2014
Jul 2014 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jul 2014
Jul 2014 Resolved
Diquat
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2014
Apr 2014 Resolved
Glyphosate
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 2014
Apr 2014 Resolved
Endothall
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 2014
Apr 2014 Resolved
2,3,7,8-TCDD
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 2014
Apr 2014 Resolved
Diquat
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 2014
Mar 2014 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2014
Jan 2014 Resolved
Glyphosate
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2014
Jan 2014 Resolved
Endothall
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2014
Showing 20 of 86 violations

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 2.5 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has increased by 0.5 ppb from 1993 (2.0 ppb) to 2022 (2.5 ppb).
Contaminant Rankings

See how Casamero Lake, Borrego Pass, Smith Lake compares by contaminant

Explore where Casamero Lake, Borrego Pass, Smith Lake ranks among all Arizona cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Native American
Population Served
906
Water Systems
1
Water Source

Where Casamero Lake, Borrego Pass, Smith Lake's water comes from

Groundwater

Casamero Lake, Borrego Pass, Smith Lake's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by native american ownership and serves approximately 906 people through 1 water system.

Infrastructure

Water systems serving Casamero Lake, Borrego Pass, Smith Lake

System Name PWSID Population Source
Casamero Lake-Smith Lake NTUA NN3500256 906 GW
Regional Comparison

How Casamero Lake, Borrego Pass, Smith Lake compares

Full Arizona rankings →

Casamero Lake, Borrego Pass, Smith Lake's score of 91.9/100 is above the average of 42/100 among major Arizona cities. It outscores 10 of 10 nearby cities.

Casamero Lake, Borrego Pass, Smith Lake (this city)
91.9
Phoenix
37.5
Tucson
38.1
Mesa
40.6
Chandler
40.5
Gilbert
34.8
Arizona avg
42
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Frequently asked questions

Is Casamero Lake, Borrego Pass, Smith Lake, AZ tap water safe to drink?

Casamero Lake, Borrego Pass, Smith Lake's water quality earned a grade of A (91.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #38 out of 292 cities tested in Arizona.

What contaminants are in Casamero Lake, Borrego Pass, Smith Lake's water?

Lead was measured at 2.5 ppb (90th percentile). 86 violations are on record.

How is Casamero Lake, Borrego Pass, Smith Lake's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Casamero Lake, Borrego Pass, Smith Lake?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Casamero Lake, Borrego Pass, Smith Lake's water come from?

Casamero Lake, Borrego Pass, Smith Lake's water is sourced from Groundwater. The city has 1 water system serving approximately 906 residents.

What health violations has Casamero Lake, Borrego Pass, Smith Lake's water system had?

Casamero Lake, Borrego Pass, Smith Lake has 2 health-based violations on record. The most recent violation was recorded in April 2016. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.

Is Casamero Lake, Borrego Pass, Smith Lake's groundwater at risk of contamination?

Casamero Lake, Borrego Pass, Smith Lake uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 86 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Casamero Lake, Borrego Pass, Smith Lake's water compare to other cities?

Casamero Lake, Borrego Pass, Smith Lake ranks #38 out of 292 cities in Arizona (better than 87% of state cities) and #1460 out of 15744 cities nationally (91th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Casamero Lake, Borrego Pass, Smith Lake's small water system affect quality?

Casamero Lake, Borrego Pass, Smith Lake's system serves approximately 906 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 86 violations on record.