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

ZIP Code 73446 Water Quality & Testing Report

Madill, OK · Marshall County County · Updated for 2026

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 73446 (Madill, OK)?

Yes, tap water in ZIP code 73446 (Madill, OK) is safe to drink under EPA Safe Drinking Water Act standards. Supplied by Marshall County Rural Water District #2, the area earns an EPA Safety Grade of B (70/100) with 24 health violations, 1.1 ppb lead, and hard (129 mg/L / 7.5 GPG) water.

Safety Score
B

Water Safety Grade

Good — Minor issues on record

Health Violations

24

Total Violations

29

Lead Risk

Moderate

Contaminants

2

⚠

Active Water Quality Issues Detected

EPA records show 26 unresolved violations. Contact Marshall County Rural Water District #2 for current status.

About Tap Water in ZIP Code 73446

Tap water in ZIP code 73446 (Madill, OK) is distributed by Marshall County Rural Water District #2 (EPA ID: OK1010848), serving approximately 17,587 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of B with a composite quality score of 70/100.

Water System

Marshall County Rural Water District #2

EPA ID: OK1010848

Water Source

Surface Water

Population Served

17,587 residents

County

Marshall County County, Oklahoma

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Lead Levels in ZIP 73446

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

Lead Level: 1.1 ppb — Very Low

The 90th percentile lead level in 73446 is 1.1 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 73446 is rated Moderate. EPA models estimate a 41% exposure probability based on housing and infrastructure age.

Lead Level (90th percentile)
1.10 ppb (0.0011 mg/L)
Lead Exposure Risk Rating
Moderate
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

41%
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: Hard7.5 GPG · 129 mg/L

Water in ZIP 73446 is Hard (129 mg/L / 7.5 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

7.5 GPG
Hardness (PPM / mg/L)

Parts per million CaCO3

129 mg/L
Appliance Scaling Risk
High / Severe

Official EPA SDWIS Database Entry

Utility: Marshall County Rural Water District #2 · PWSID: OK1010848

Verify on EPA.gov
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Violation History

Past 5 years — EPA SDWIS data

Marshall County Rural Water District #2 has recorded 24 health-based violations out of 29 total violations over the past 5 years. 26 violations remain unresolved in EPA tracking records.

Total Violations (5 yr)
29
Health-Based Violations
24
Unresolved Violations
26
Boil Water Advisories
0
Compliance Risk
Critical

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

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Contaminants Detected

Contaminants with health-based violations on record

EPA records identify 2 contaminants with health-based violations in the past 5 years: Haloacetic Acids (HAA5), Stage 2 DBP Rule.

Haloacetic Acids (HAA5)Stage 2 DBP Rule

⚖ 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

$0
Energy Burden

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

2.88%

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

Water Quality Testing in ZIP 73446

Tap Water & Well Testing Recommendations

Residents in ZIP code 73446 served by Marshall County Rural Water District #2 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 Oklahoma Department of Environmental Quality.
Certified Lab Testing: Always use an EPA-certified drinking water laboratory in OK for formal legal or real estate compliance testing.

🛡 What Should You Do? — ZIP 73446 Recommendations

  • ✓ Run cold water for 30 seconds each morning before use — especially if pipes are old
  • ✓ Request your annual Consumer Confidence Report from Marshall County Rural Water District #2
  • ✓ 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 73446 Water Quality

Is tap water safe to drink in ZIP code 73446?+
Yes — tap water in 73446 (Madill, OK) meets EPA standards with a water safety grade of B. No health-based violations are on record in the past 5 years.
How do I get my water tested in ZIP 73446 (Madill, OK)?+
To test water quality in ZIP 73446, you can order a certified drinking water test kit or send water samples to an EPA/NELAP certified laboratory in OK. Certified testing checks for lead, coliform bacteria, nitrates, hardness, and PFAS that standard test strips miss. Contact Oklahoma Department of Environmental Quality for a list of certified regional labs.
How hard is the tap water in 73446?+
Tap water in 73446 is classified as Hard with an estimated mineral hardness of 129 mg/L (7.5 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 73446?+
Yes. Unlike municipal systems, private wells in 73446 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 73446 tap water?+
The 90th percentile lead level in 73446 is 1.1 ppb. The EPA action level is 15 ppb. This is below the EPA action level.
Is there an active boil water notice in 73446?+
There are currently no active boil water advisories on record for 73446. Water treatment systems are operating within normal parameters.
Who provides tap water to 73446?+
Tap water in ZIP code 73446 is provided by Marshall County Rural Water District #2 (EPA ID: OK1010848), serving approximately 17,587 residents.
What water filter should I use in 73446?+
Based on water metrics for 73446, we recommend Reverse Osmosis (PFAS & Lead). Look for certifications such as NSF/ANSI 53 (Chemical Contaminants), NSF/ANSI 42 (Aesthetic Effects).

Data Sources & Methodology

Water quality data for ZIP code 73446 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 Marshall County Rural Water District #2. 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 →