WaterVerge

Is Upper Cov Wells, Lower Cov Wells, Sikul, AZ Tap Water Safe to Drink?

Graded A, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

538 residents served 1 water system PWSID: 090400006
Overall Score
91.7 / 100
Violations
2 active
Last Updated
May 2026
Source
Groundwater
#43 of 292 in Arizona Top 10% nationally
Native American
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
91.7/100
waterverge.com
A 91.7/100

Upper Cov Wells, Lower Cov Wells, Sikul, AZ — Water Quality Report

Upper Cov Wells, Lower Cov Wells, Sikul's drinking water received a grade of A (91.7 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 538 residents using groundwater.

Lead levels were measured at 0.5 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 16 violations on record, including 3 health-based violations. 2 remain unresolved.

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

What to know about Upper Cov Wells, Lower Cov Wells, Sikul's water

Upper Cov Wells, Lower Cov Wells, Sikul ranks #43 out of 292 cities in Arizona for water quality, placing it above average in the state.

Upper Cov Wells, Lower Cov Wells, Sikul 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, Upper Cov Wells, Lower Cov Wells, Sikul may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

Quality Breakdown

Water quality score

See methodology →
91.7 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
41.7/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.5 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Upper Cov Wells, Lower Cov Wells, Sikul, AZ water safe to drink?

Use Caution

Upper Cov Wells, Lower Cov Wells, Sikul's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (91.7/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 538 residents using groundwater (wells).

2
Active Violations
0.5 ppb
Lead (90th %ile)
9 events
Disaster History

Recent water quality updates for Upper Cov Wells, Lower Cov Wells, Sikul

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Upper Cov Wells, Lower Cov Wells, Sikul's water quality assessment. Grade: A (91.7/100).

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: Nitrate.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3241). Hurricane event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Disaster
SEVERE STORMS, TORNADOES & FLOODING

Federal disaster declaration (FEMA DR-977). Flood event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Upper Cov Wells, Lower Cov Wells, Sikul's water supply.

Lead Within Limits
Detected: 0.5 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Upper Cov Wells, Lower Cov Wells, Sikul's water system has 16 total violations on record, including 3 health-based violations. 2 remain unresolved. 1 violation was issued in the last 5 years.

MRMCL
Most recent violations:
Jul 2025 Lead and Copper Rule Open
Jan 2006 Nitrate Resolved
Feb 2005 Coliform (TCR) Resolved
Jan 2005 Nitrate Resolved
Jan 2004 Dalapon Resolved

Flood & environmental risk

Pima County has experienced 9 federally declared disasters since 1966. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.

HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3241
SEVERE STORMS, TORNADOES & FLOODING
Flood FEMA DR-977
SEVERE STORMS & FLOODING
Flood FEMA DR-884

Where does Upper Cov Wells, Lower Cov Wells, Sikul's water come from?

Upper Cov Wells, Lower Cov Wells, Sikul's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 538 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Upper Cov Wells, Lower Cov Wells, Sikul residents can do

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.

Monitor alerts during storms

Upper Cov Wells, Lower Cov Wells, Sikul's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

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
0.5 ppb
EPA Action Level: 15 ppb · 3% of limit
Safe Level
Compliance Record

Violation summary

16
Total violations
3
Health-based
2
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

16 Total
2 Active
3 Health-based
14 Resolved
Violations by category
Synthetic Organic Chemicals
7
Nitrate Rule
3
Total Coliform Rule
3
Lead and Copper Rule
1
Radionuclides and Revised Rad Rule
1
Jul 2025 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Jan 2006 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2006
Feb 2005 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Feb 2005
Jan 2005 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2005
Jan 2004 Resolved
Dalapon
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
Picloram
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
2,3,7,8-TCDD
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
2,4-D
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
2,4,5-TP
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
Pentachlorophenol
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Jan 2004 Resolved
Dinoseb
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Oct 2003 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Oct 2003
Aug 2000 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Aug 2000
Environmental Risk

Flood & disaster history

9
Declared disasters
Sep 2005
Most recent
Flood
Most common type

Pima County has experienced 9 federally declared disasters since 1966. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3241
Jan 1993
SEVERE STORMS, TORNADOES & FLOODING
Flood FEMA #977
Dec 1990
SEVERE STORMS & FLOODING
Flood FEMA #884
Oct 1983
SEVERE STORMS & FLOODING
Flood FEMA #691
Dec 1978
SEVERE STORMS & FLOODING
Flood FEMA #570
Mar 1978
SEVERE STORMS & FLOODING
Flood FEMA #551

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.5 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 decreased by 8.5 ppb from 1993 (9.0 ppb) to 2026 (0.5 ppb).
Contaminant Rankings

See how Upper Cov Wells, Lower Cov Wells, Sikul compares by contaminant

Explore where Upper Cov Wells, Lower Cov Wells, Sikul ranks among all Arizona cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Native American
Population Served
538
Water Systems
1
Water Source

Where Upper Cov Wells, Lower Cov Wells, Sikul's water comes from

Groundwater

Upper Cov Wells, Lower Cov Wells, Sikul'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 538 people through 1 water system.

Infrastructure

Water systems serving Upper Cov Wells, Lower Cov Wells, Sikul

System Name PWSID Population Source
Covered Wells Regional 090400006 538 GW
Regional Comparison

How Upper Cov Wells, Lower Cov Wells, Sikul compares

Full Arizona rankings →

Upper Cov Wells, Lower Cov Wells, Sikul's score of 91.7/100 is above the average of 42/100 among major Arizona cities. It outscores 10 of 10 nearby cities.

Upper Cov Wells, Lower Cov Wells, Sikul (this city)
91.7
Phoenix
37.5
Tucson
38.1
Mesa
40.6
Chandler
40.5
Gilbert
34.8
Arizona avg
42
City Profile

About Upper Cov Wells, Lower Cov Wells, Sikul, AZ

Wikipedia →

Sells is an unincorporated community and census-designated place (CDP) in Pima County, Arizona, United States. The population was 2,799 at the 2000 census. It is the capital of the Tohono O'odham Nation and the home of several tribal businesses, such as Tohono O'Odham Ki:Ki Association. It was originally named Indian Oasis by cattle-ranchers/businessmen brothers Joseph and Louis Ménager in 1912. The Ménager brothers also built and ran the Indian Oasis Mercantile Store. The settlement took its present English name in 1918 to honor Indian Commissioner Cato Sells. The O'odham name means "tortoise got wedged".

Economic Profile
$44,038
Median Income
$53,719
Median Home Value
$474/mo
Median Rent
15.5%
Unemployment
Community
24.8
Median Age
101
People / sq mi
3.7%
College Educated
62.6%
Homeownership
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Frequently asked questions

Is Upper Cov Wells, Lower Cov Wells, Sikul, AZ tap water safe to drink?

Upper Cov Wells, Lower Cov Wells, Sikul's water quality earned a grade of A (91.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #43 out of 292 cities tested in Arizona.

What contaminants are in Upper Cov Wells, Lower Cov Wells, Sikul's water?

Lead was measured at 0.5 ppb (90th percentile). 16 violations are on record.

How is Upper Cov Wells, Lower Cov Wells, Sikul'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 Upper Cov Wells, Lower Cov Wells, Sikul?

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

Where does Upper Cov Wells, Lower Cov Wells, Sikul's water come from?

Upper Cov Wells, Lower Cov Wells, Sikul's water is sourced from Groundwater. The city has 1 water system serving approximately 538 residents.

What health violations has Upper Cov Wells, Lower Cov Wells, Sikul's water system had?

Upper Cov Wells, Lower Cov Wells, Sikul has 3 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.

Is Upper Cov Wells, Lower Cov Wells, Sikul's groundwater at risk of contamination?

Upper Cov Wells, Lower Cov Wells, Sikul 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 16 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 Upper Cov Wells, Lower Cov Wells, Sikul's water compare to other cities?

Upper Cov Wells, Lower Cov Wells, Sikul ranks #43 out of 292 cities in Arizona (better than 85% of state cities) and #1559 out of 15744 cities nationally (90th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Upper Cov Wells, Lower Cov Wells, Sikul's small water system affect quality?

Upper Cov Wells, Lower Cov Wells, Sikul's system serves approximately 538 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 16 violations on record.