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

ZIP Code 75021 Water Quality & Testing Report

Denison, TX · Grayson 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 75021 (Denison, TX)?

Yes, tap water in ZIP code 75021 (Denison, TX) is safe to drink under EPA Safe Drinking Water Act standards. Supplied by City of Denison, the area earns an EPA Safety Grade of A (94/100) with 0 health violations, 1.8 ppb lead, and very hard (189 mg/L / 11.1 GPG) water.

Safety Score
A

Water Safety Grade

Excellent — Meets all EPA standards

Health Violations

0

Total Violations

2

Lead Risk

Moderate

Contaminants

0

⚠

Active Water Quality Issues Detected

EPA records show 0 unresolved violation. Contact City of Denison for current status.

About Tap Water in ZIP Code 75021

Tap water in ZIP code 75021 (Denison, TX) is distributed by City of Denison (EPA ID: TX0910003), serving approximately 27,500 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of A with a composite quality score of 94/100.

Water System

City of Denison

EPA ID: TX0910003

Water Source

Surface Water

Population Served

27,500 residents

County

Grayson County County, Texas

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Lead Levels in ZIP 75021

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

Lead Level: 1.8 ppb — Very Low

The 90th percentile lead level in 75021 is 1.8 ppb. This meets the EPA action level of 15 ppb. Health experts recommend a target of 0 ppb for optimal safety.

Lead exposure risk in 75021 is rated Moderate. EPA models estimate a 45% exposure probability based on housing and infrastructure age.

Lead Level (90th percentile)
1.80 ppb (0.0018 mg/L)
Lead Exposure Risk Rating
Moderate
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

45%
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: Very Hard11.1 GPG · 189 mg/L

Water in ZIP 75021 is Very Hard (189 mg/L / 11.1 GPG). High concentrations of dissolved limestone minerals cause severe mineral buildup, stiff laundry, dry skin, and premature water heater wear.

Recommendation: A whole-home water softener system is strongly recommended to protect plumbing and home appliances.
Hardness (GPG)

Grains per gallon

11.1 GPG
Hardness (PPM / mg/L)

Parts per million CaCO3

189 mg/L
Appliance Scaling Risk
High / Severe

Official EPA SDWIS Database Entry

Utility: City of Denison · PWSID: TX0910003

Verify on EPA.gov
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Violation History

Past 5 years — EPA SDWIS data

City of Denison has recorded 2 violations, but none are health-based (e.g., administrative or monitoring infractions).

Total Violations (5 yr)
2
Health-Based Violations
0
Unresolved Violations
0
Boil Water Advisories
0
Compliance Risk
Moderate

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

⚗️

Contaminants Detected

Contaminants with health-based violations on record

No health-based contaminant violations are on record for ZIP code 75021 under the Safe Drinking Water Act.

⚖ Enforcement Actions

EPA or state regulators have issued 10 enforcement actions to address compliance lapses.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
EPA Radon Zone

Lower potential

Zone 3
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$1
Energy Burden

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

1.92%

EPA Radon Zone 3 — lower radon potential, though the EPA still recommends testing all homes.

Water Quality Testing in ZIP 75021

Tap Water & Well Testing Recommendations

Residents in ZIP code 75021 served by City of Denison 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 Texas Commission on Environmental Quality (TCEQ).
Certified Lab Testing: Always use an EPA-certified drinking water laboratory in TX for formal legal or real estate compliance testing.

🛡 What Should You Do? — ZIP 75021 Recommendations

  • ✓ Run cold water for 30 seconds each morning before use — especially if pipes are old
  • ✓ Request your annual Consumer Confidence Report from City of Denison
  • ✓ If your home was built before 1986, consider testing your own tap for lead
  • ✓ Use a pitcher filter (NSF/ANSI 42 certified) for improved taste

Recommended Taste & Safety Filter:

🚰

NSF/ANSI 53 Certified Pitcher Filter

Best for removing aesthetic chlorine, odors, and low-level heavy metals.

Filter Selection Guide →

Frequently Asked Questions — ZIP 75021 Water Quality

Is tap water safe to drink in ZIP code 75021?+
Yes — tap water in 75021 (Denison, TX) meets EPA standards with a water safety grade of A. No health-based violations are on record in the past 5 years.
How do I get my water tested in ZIP 75021 (Denison, TX)?+
To test water quality in ZIP 75021, you can order a certified drinking water test kit or send water samples to an EPA/NELAP certified laboratory in TX. Certified testing checks for lead, coliform bacteria, nitrates, hardness, and PFAS that standard test strips miss. Contact Texas Commission on Environmental Quality (TCEQ) for a list of certified regional labs.
How hard is the tap water in 75021?+
Tap water in 75021 is classified as Very Hard with an estimated mineral hardness of 189 mg/L (11.1 GPG). A whole-home water softener system is strongly recommended to protect plumbing and home appliances.
Should I test private well water in 75021?+
Yes. Unlike municipal systems, private wells in 75021 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 75021 tap water?+
The 90th percentile lead level in 75021 is 1.8 ppb. The EPA action level is 15 ppb. This is below the EPA action level.
Is there an active boil water notice in 75021?+
There are currently no active boil water advisories on record for 75021. Water treatment systems are operating within normal parameters.
Who provides tap water to 75021?+
Tap water in ZIP code 75021 is provided by City of Denison (EPA ID: TX0910003), serving approximately 27,500 residents.
What water filter should I use in 75021?+
Based on water metrics for 75021, we recommend None / Standard Pitcher. Look for certifications such as NSF/ANSI 42 (Chlorine, Taste & Odor).

Data Sources & Methodology

Water quality data for ZIP code 75021 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 City of Denison. 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 →