WaterVerge

Is Rio Rico, AZ Tap Water Safe to Drink?

Graded C — but 1,4-Dioxane was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

18K residents served 1 water system PWSID: AZ0412011
Overall Score
62.1 / 100
Violations
14 active
Last Updated
May 2026
Source
Groundwater
#161 of 292 in Arizona Top 76% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
CGRADE
Water Quality Grade
62.1/100
waterverge.com
C 62.1/100

Rio Rico, AZ — Water Quality Report

Rio Rico's drinking water received a grade of C (62.1 out of 100), indicating fair water quality. The city's 1 water system serves approximately 17,960 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 8 PFAS compounds, with levels exceeding EPA maximum contaminant levels in the water supply.

The system has 421 violations on record, including 4 health-based violations. 14 remain unresolved.

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

What to know about Rio Rico's water

Rio Rico ranks #161 out of 292 cities in Arizona for water quality, placing it below average in the state.

Rio Rico 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.

Of particular concern: PFAS "forever chemical" levels exceed the 2024 EPA maximum contaminant levels. These synthetic compounds don't break down naturally and require specialized filtration such as reverse osmosis or granular activated carbon.

Hexavalent chromium (chromium-6) was detected at 1.00 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

Quality Breakdown

Water quality score

See methodology →
62.1 out of 100 Grade C
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
18.8/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
8.3/20
F
8 PFAS compounds detected.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Rio Rico, AZ water safe to drink?

Concerns Identified

Rio Rico's drinking water has significant quality concerns based on EPA testing data. With a grade of C (62.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 17,960 residents using groundwater (wells).

14
Active Violations
0.0 ppb
Lead (90th %ile)
8 compounds
PFAS Detected
4 events
Disaster History

Recent water quality updates for Rio Rico

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

PFAS
8 PFAS "forever chemical" compounds detected

PFAS levels exceed EPA maximum contaminant levels. Reverse osmosis or activated carbon filtration recommended.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Rio Rico's water quality assessment. Grade: C (62.1/100).

Violation
1 drinking water violation recorded

Contaminants: 2,4-D.

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
2 drinking water violations recorded

Contaminants: Total Haloacetic Acids (HAA5), TTHM.

Disaster
HURRICANE KATRINA EVACUATION

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

Key contaminant findings

Based on the most recent EPA sampling data for Rio Rico's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (8 compounds) Elevated
Detected: Highest: lithium at 20.2000 µg/L Limit: 0.004 µg/L (EPA MCL)

PFAS "forever chemicals" exceed EPA maximum contaminant levels. Reverse osmosis or granular activated carbon filtration strongly recommended.

PFAS "forever chemicals" detected

UCMR 5 testing found 8 PFAS compounds in Rio Rico's water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.

Compound Level EPA MCL Status
lithium 20.2000 µg/L 0.004 µg/L Within Limit
PFOS 0.0409 µg/L 0.004 µg/L Over MCL
PFBS 0.0200 µg/L 0.004 µg/L Within Limit
PFHxS 0.0109 µg/L 0.004 µg/L Within Limit

Violation history

Rio Rico's water system has 421 total violations on record, including 4 health-based violations. 14 remain unresolved. 4 violations were issued in the last 5 years.

MRRPTOtherMCL
Most recent violations:
Jul 2025 2,4-D Resolved
Aug 2024 Revised Total Coliform Rule Open
Jan 2023 Total Haloacetic Acids (HAA5) Resolved
Jan 2023 TTHM Resolved
Oct 2017 Total Haloacetic Acids (HAA5) Resolved

Flood & environmental risk

Cochise County has experienced 4 federally declared disasters since 1970. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Ramsey Canyon, Garden Canyon, San Pedro, San Pedro River, Huachuca Canyon.

HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3241
SEVERE STORMS, TORNADOES & FLOODING
Flood FEMA DR-977
SEVERE STORMS & FLOODING
Flood FEMA DR-691

Where does Rio Rico's water come from?

Rio Rico's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 17,960 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Ramsey Canyon (river), Garden Canyon (river), San Pedro (river), San Pedro River (river), Huachuca Canyon (river).

What Rio Rico residents can do

Install a water filter

Recommended: Reverse osmosis system. This addresses the specific contaminants found in Rio Rico'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.

Monitor alerts during storms

Rio Rico'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
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
20.2000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
1.3 µg/L
EPA MCL: 60 µg/L · 2% of limit
Within LimitUCMR 4 DataHAA6Br: 1.5 µg/LHAA9: 2.0 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
1.00 µg/L
CA MCL (no federal MCL): 10 µg/L · 10% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
720.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 48% of limit
DetectedUCMR 3 Data
1,4-Dioxane
Organic
Over HA
0.45 µg/L
EPA Health Advisory: 0.35 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
Manganese
Inorganic
Detected
8.1 µg/L
EPA Secondary MCL: 50 µg/L · 16% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
4.80 µg/L
EPA Short-term HA: 21 µg/L · 23% of limit
DetectedUCMR 3 Data
Molybdenum
Inorganic
Detected
2.30 µg/L
EPA Lifetime HA: 40 µg/L · 6% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Detected
20.2 µg/L
State screening level: 60 µg/L · 34% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
8
Detected
2
Exceed EPA MCL
12.72
Hazard Index
PFOS max: 0.0409 µg/L PFOA max: 0.0100 µg/L
Compliance Record

Violation summary

421
Total violations
4
Health-based
14
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

421 Total
14 Active
4 Health-based
407 Resolved
Violations by category
Volatile Organic Chemicals
227
Synthetic Organic Chemicals
63
Stage 1 Disinfectants and Disinfection Byproducts Rule
54
Inorganic Chemicals
22
Nitrate Rule
18
Aug 2024 Active
Revised Total Coliform Rule
Reporting
Reporting 0
Jul 2015 Active
Consumer Confidence Rule
Other Violation 0
Jul 2014 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2014 Active
Consumer Confidence Rule
Other Violation 0
Jul 2013 Active
Consumer Confidence Rule
Other Violation 0
Oct 2011 Active
Consumer Confidence Rule
Other Violation 0
Jul 2011 Active
Consumer Confidence Rule
Other Violation 0
Oct 2010 Active
Consumer Confidence Rule
Other Violation 0
Jul 2010 Active
Consumer Confidence Rule
Other Violation 0
Jul 2009 Active
Consumer Confidence Rule
Other Violation 0
Jul 2007 Active
Consumer Confidence Rule
Other Violation 0
Oct 2006 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2002 Active
Consumer Confidence Rule
Other Violation 0
Active
Compliance Violation
Monitoring 0
Jul 2025 Resolved
2,4-D
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2025
Jan 2023 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2023
Jan 2023 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2023
Oct 2017 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2018
Oct 2017 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2018
Jan 2016 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2016
Showing 20 of 421 violations
Industrial pollution

Top industrial polluters within 10 miles of Rio Rico

Industrial polluters nearby

Reported releases to surface water by facilities near Rio Rico, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
CALPORTLAND CO RIO RICO PLANT
Nonmetallic Mineral Product · TAIHEIYO CEMENT USA INC
RIO RICO, AZ85648
2.3 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Drought conditions

D1 — moderate drought

Santa Cruz County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.

27.3%
Months in D2+ (last 30y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

4
Declared disasters
Sep 2005
Most recent
Flood
Most common type

Cochise County has experienced 4 federally declared disasters since 1970. 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
Oct 1983
SEVERE STORMS & FLOODING
Flood FEMA #691
Sep 1970
HEAVY RAINS & FLASH
Flood FEMA #294

Recommended water filters

Based on contaminants detected in Rio Rico's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
PFAS compounds exceed EPA maximum contaminant levels

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 20.200 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA 0.007 HI µg/L PFAS Detected
PFBS 0.020 HI µg/L PFAS Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA 0.004 HI µg/L PFAS Detected
PFHxS 0.011 HI µg/L PFAS Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA 0.010 0.004 µg/L PFAS Over MCL
PFOS 0.041 0.004 µg/L PFAS Over MCL
PFPeA 0.003 HI µg/L PFAS Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 4.4 ppb from 2003 (4.4 ppb) to 2024 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Private
Population Served
17,960
Water Systems
1
Water Source

Where Rio Rico's water comes from

Groundwater

Rio Rico'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 private ownership and serves approximately 17,960 people through 1 water system.

Local Hydrology

Water bodies near Rio Rico

Rio Rico is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Ramsey Canyon
river
Garden Canyon
river
San Pedro
river
San Pedro River
river
Huachuca Canyon
river
Infrastructure

Water systems serving Rio Rico

System Name PWSID Population Source
LIBERTY WATER RIO RICO AZ0412011 17,960 GW
Regional Comparison

How Rio Rico compares

Full Arizona rankings →

Rio Rico's score of 62.1/100 is above the average of 42/100 among major Arizona cities. It outscores 10 of 10 nearby cities.

Rio Rico (this city)
62.1
Phoenix
37.5
Tucson
38.1
Mesa
40.6
Chandler
40.5
Gilbert
34.8
Arizona avg
42
City Profile

About Rio Rico, AZ

Wikipedia →

Sierra Vista is a city in Cochise County, Arizona, United States. According to the 2020 Census, the population of the city is 45,308, and is the 27th most populous city in Arizona. The city is part of the Sierra Vista-Douglas Metropolitan Area, with a 2010 population of 131,346. Fort Huachuca, a U.S. Army post, has been incorporated and is located in the northwest part of the city. Sierra Vista is bordered by the cities of Huachuca City and Whetstone to the north and Sierra Vista Southeast to the South.

Economic Profile
$62,537
Median Income
$190,415
Median Home Value
$1,004/mo
Median Rent
7.7%
Unemployment
Community
33.8
Median Age
131
People / sq mi
23.7%
College Educated
81.8%
Homeownership
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Frequently asked questions

Is Rio Rico, AZ tap water safe to drink?

Rio Rico's water quality earned a grade of C (62.1/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #161 out of 292 cities tested in Arizona.

What contaminants are in Rio Rico's water?

Lead was measured at 0.0 ppb (90th percentile). 8 PFAS compounds were detected. 421 violations are on record.

How is Rio Rico'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 Rio Rico?

PFAS compounds exceed EPA limits — a reverse osmosis or activated carbon filter is recommended.

Where does Rio Rico's water come from?

Rio Rico's water is sourced from Groundwater. The city has 1 water system serving approximately 17,960 residents.

What health violations has Rio Rico's water system had?

Rio Rico has 4 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. 14 violations remain unresolved.

Is Rio Rico's groundwater at risk of contamination?

Rio Rico 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 421 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.

Why does Rio Rico have so many PFAS compounds in its water?

8 different PFAS "forever chemical" compounds were detected in Rio Rico's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. Some levels exceed the 2024 EPA maximum contaminant levels — a reverse osmosis or NSF-certified activated carbon filter is strongly recommended.

How does Rio Rico's water compare to other cities?

Rio Rico ranks #161 out of 292 cities in Arizona (better than 45% of state cities) and #11911 out of 15744 cities nationally (24th percentile). The grade of C reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.