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WaterSafeCheck

Merrillville, IN Tap Water Quality

Water safety reports for all 2 ZIP codes in Merrillville, Indiana

Average Score

74/100

Health Violations

2

ZIP Codes

2

High Lead Risk

0

of 2 ZIP codes

B

About Tap Water in Merrillville, IN

The drinking water in Merrillville, IN generally meets all federal health standards, earning a solid B grade with a composite safety score of 74/100 across 2 ZIP codes. While the primary water utility, Cuii - Indiana Water Service, maintains adequate compliance with EPA regulations, there have been minor or administrative violations on record. Overall, residents receive safe tap water that is actively monitored by Indiana Department of Environmental Management.

Over the past 5 years, Merrillville has recorded 2 health-based violations. While occasional violations can occur due to seasonal changes or temporary infrastructure issues, Cuii - Indiana Water Service is legally required to resolve these quickly and notify the public via their annual Consumer Confidence Report. The city's water supply, primarily drawn from surface water, is treated to address these specific contaminants.

Fortunately, the modeled risk for widespread lead exposure in Merrillville's municipal water is relatively low compared to national averages. However, because lead typically enters drinking water through the corrosion of older, individual home plumbing rather than the main supply lines, residents in homes built before 1986 should still exercise caution by running the tap before use.

Health-Based Contaminant Violations in Merrillville

EPA records indicate that the following contaminants have exceeded Safe Drinking Water Act Maximum Contaminant Levels (MCLs) in Merrillville water systems over the past 5 years.

Consumer Confidence Report Rule

Note: The presence of a past violation does not necessarily mean current water is unsafe. Utilities are required to take corrective action. Review your Consumer Confidence Report for the latest status.

Water Quality by ZIP Code — Merrillville, IN

Click any ZIP code for the full water quality report

B
46411

Merrillville, IN

Score: 78/1001 violation
C
46410

Merrillville, IN

Score: 69/1001 violation

Frequently Asked Questions — Merrillville Water Quality

Is tap water safe to drink in Merrillville, IN?+
Yes — tap water in Merrillville meets all federal EPA standards and earns a B grade. It is generally safe for healthy adults. As always, running your tap for 30 seconds before use and using a filter adds extra protection for vulnerable populations.
What is the water quality score for Merrillville?+
The average water quality score across 2 ZIP codes in Merrillville, IN is 74/100. Scores are derived from EPA violation history, lead levels, enforcement actions, and infrastructure risk indicators. Individual ZIP codes may vary — search your specific ZIP above for a personalized report.
Does Merrillville have lead in its tap water?+
Lead risk ratings in Merrillville are relatively low based on EPA monitoring data. However, lead in home plumbing is a separate concern — if your home was built before 1986, individual tap testing is recommended.
How do I get the water quality report for Merrillville?+
Each ZIP code in Merrillville has a full water quality report on this site — click any ZIP code below. You can also get the annual Consumer Confidence Report (CCR) from your local water utility. The CCR is required to be published every year by July 1 and contains actual contaminant measurements and violation history.
Where does Merrillville's tap water come from?+
Tap water in Merrillville, IN primarily comes from surface water. Surface water systems treat water from rivers, lakes, or reservoirs using filtration, sedimentation, and disinfection before it reaches your tap.

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