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Official EPA SDWIS Verified ReportWater Quality & Testing GuideHistorical Record: No Recorded SDWIS Violations

ZIP Code 93668 Water Quality & Testing Report

Tranquillity, CA · Fresno County County · Updated for 2026

Sahajul HaqueCompiled & verified by Sahajul Haque from official EPA SDWIS records
Public Health & Medical Notice: Drinking water quality data on this page reflects historical compliance records submitted under the Safe Drinking Water Act. This information does not constitute medical advice or a real-time safety guarantee. If you are pregnant, nursing, preparing infant formula, or immunocompromised, consult a healthcare provider. Boiling water kills biological pathogens, but does NOT remove chemical contaminants like lead, arsenic, or PFAS.
Quick EPA Verified Answer

Is Tap Water Safe to Drink in ZIP 93668 (Tranquillity, CA)?

Caution / Filtration Recommended: Tap water in ZIP code 93668 (Tranquillity, CA) has compliance concerns, earning an EPA Safety Grade of C (67/100) due to 1 health violation(s) and 0 ppb lead. While treated by Tranquillity Irrigation District, residents are advised to use an NSF/ANSI 53 certified water filter for drinking and cooking.

Safety Score
C

Water Safety Grade

Fair — Some compliance concerns

Health Violations

1

Total Violations

3

Lead Risk

High

Contaminants

1

⚠

Active Water Quality Issues Detected

EPA records show 3 unresolved violations. Contact Tranquillity Irrigation District for current status.

About Tap Water in ZIP Code 93668

Tap water in ZIP code 93668 (Tranquillity, CA) is distributed by Tranquillity Irrigation District (EPA ID: CA1010030), serving approximately 807 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of C with a composite quality score of 67/100.

Water System

Tranquillity Irrigation District

EPA ID: CA1010030

Water Source

Ground Water

Population Served

807 residents

County

Fresno County County, California

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Lead Levels in ZIP 93668

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Data Not Available

Lead testing data was not found in EPA records for ZIP code 93668. Contact Tranquillity Irrigation District to request lead testing results.

Lead exposure risk in 93668 is rated High. EPA models estimate a 61% exposure probability based on housing and infrastructure age.

Lead Exposure Risk Rating
High
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

61%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Water Hardness & Mineral Content

Grains per gallon (GPG) & Parts per million (PPM / mg/L)

Classification: Hard9.7 GPG · 166 mg/L

Water in ZIP 93668 is Hard (166 mg/L / 9.7 GPG). Residents may notice white mineral spots on glassware, reduced soap efficiency, and mineral scale on faucets and showerheads.

Recommendation: An ion-exchange water softener or descaler is recommended to prolong the life of water heaters, dishwashers, and plumbing.
Hardness (GPG)

Grains per gallon

9.7 GPG
Hardness (PPM / mg/L)

Parts per million CaCO3

166 mg/L
Appliance Scaling Risk
High / Severe

Official EPA SDWIS Database Entry

Utility: Tranquillity Irrigation District · PWSID: CA1010030

Verify on EPA.gov
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Violation History

Past 5 years — EPA SDWIS data

Tranquillity Irrigation District has recorded 1 health-based violation out of 3 total violations over the past 5 years. 3 violations remain unresolved in EPA tracking records.

Total Violations (5 yr)
3
Health-Based Violations
1
Unresolved Violations
3
Boil Water Advisories
0
Compliance Risk
High

Regulatory compliance risk for this utility is rated High based on past reporting and enforcement records.

⚗️

Contaminants Detected

Contaminants with health-based violations on record

EPA records identify 1 contaminant with health-based violations in the past 5 years: Stage 2 DBP Rule.

Stage 2 DBP Rule

⚖ Enforcement Actions

EPA or state regulators have issued 2 enforcement actions to address compliance lapses.
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Water Source & Environmental Factors

Ground Water

This system draws water from underground aquifers. Groundwater is naturally filtered through soil and rock, but can still contain naturally occurring minerals like arsenic, radium, or nitrates.

Water Source Type
Ground Water
EPA Radon Zone

Moderate potential

Zone 2
Energy Burden

% of household income spent on energy — indicator of older infrastructure

5.91%

EPA Radon Zone 2 — moderate radon potential. The EPA recommends testing your home regardless of zone designation.

Water Quality Testing in ZIP 93668

Tap Water & Well Testing Recommendations

Residents in ZIP code 93668 served by Tranquillity Irrigation District can test tap water or private well systems to verify water purity. Testing detects hidden contaminants before they impact family health.

Tap Water Testing Steps

  • 1.Conduct a certified lead check if your home was constructed before 1986.
  • 2.Use certified lab testing kits rather than uncalibrated test strips for regulated compliance.
  • 3.Sample water from both your kitchen faucet and water heater to compare line purity.

Private Well Testing Steps

  • •Test for Coliform bacteria and Nitrates annually.
  • •Test for heavy metals, radon, and PFAS every 3 years.
  • •Send samples to a state-certified drinking water laboratory recognized by California State Water Resources Control Board.
Certified Lab Testing: Always use an EPA-certified drinking water laboratory in CA for formal legal or real estate compliance testing.

🛡 What Should You Do? — ZIP 93668 Recommendations

  • ⚠ Use a certified NSF/ANSI 53 filter for drinking and cooking water if you have young children
  • ⚠ Never give unfiltered tap water to infants in formula — use certified bottled or filtered water
  • ⚠ Request a copy of the Consumer Confidence Report to see what was detected and when
  • ⚠ Call the EPA Safe Drinking Water Hotline: 1-800-426-4791

Recommended Water Treatment Systems:

🏺

NSF 53 Lead Pitcher Filter

Specifically certified to reduce lead and copper at the tap.

Lead Filter Guide →
⚗️

NSF 58 Under-Sink RO System

Advanced filtration for PFAS, fluoride, nitrates, and organic chemicals.

RO System Guide →

Frequently Asked Questions — ZIP 93668 Water Quality

Is tap water safe to drink in ZIP code 93668?+
Tap water in 93668 (Tranquillity, CA) meets major standards but has a grade of C due to minor past violations. Vulnerable populations may want to use a certified filter as a precaution.
How do I get my water tested in ZIP 93668 (Tranquillity, CA)?+
To test water quality in ZIP 93668, you can order a certified drinking water test kit or send water samples to an EPA/NELAP certified laboratory in CA. Certified testing checks for lead, coliform bacteria, nitrates, hardness, and PFAS that standard test strips miss. Contact California State Water Resources Control Board for a list of certified regional labs.
How hard is the tap water in 93668?+
Tap water in 93668 is classified as Hard with an estimated mineral hardness of 166 mg/L (9.7 GPG). An ion-exchange water softener or descaler is recommended to prolong the life of water heaters, dishwashers, and plumbing.
Should I test private well water in 93668?+
Yes. Unlike municipal systems, private wells in 93668 are not regulated by the EPA or local utilities. Private well owners should test their water annually for coliform bacteria and nitrates, and every 3 to 5 years for heavy metals (lead, arsenic) and volatile organic compounds.
What is the lead level in 93668 tap water?+
Lead level data is not available in EPA records for 93668. Contact your utility for details.
Is there an active boil water notice in 93668?+
There are currently no active boil water advisories on record for 93668. Water treatment systems are operating within normal parameters.
Who provides tap water to 93668?+
Tap water in ZIP code 93668 is provided by Tranquillity Irrigation District (EPA ID: CA1010030), serving approximately 807 residents.
What water filter should I use in 93668?+
Based on water metrics for 93668, we recommend Reverse Osmosis (PFAS & Lead). Look for certifications such as NSF/ANSI 58 (Reverse Osmosis), NSF/ANSI 53 (Lead & VOCs), NSF/ANSI P473 (PFAS/PFOS).

Data Sources & Methodology

Water quality data for ZIP code 93668 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by Tranquillity Irrigation District. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →