Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO

ZipCheckup tracks EPA drinking-water compliance for 923 public water systems serving 410 ZIP codes in Louisiana. The state record shows 4,598 EPA violations, 3,088 health-based.

City Water Quality Map: Louisiana

Each circle represents a city. Size indicates population, color indicates water quality grade. Tap a circle for details.

A B C D F Circle size = population

Cities with Most Violations in Louisiana

#	City	Grade	Violations	Systems	Population
1	Ferriday		143	5	9,382	Details →
2	Many		116	5	8,818	Details →
3	Vidalia		112	3	5,754	Details →
4	Zwolle		97	3	5,042	Details →
5	Noble		97	3	1,562	Details →
6	Coushatta		85	5	7,366	Details →
7	Slidell		79	12	94,837	Details →
8	Bernice		79	2	2,621	Details →
9	Shreveport		74	14	209,795	Details →
10	Ville Platte		74	5	18,939	Details →

Most Common Contaminants in Louisiana

Contaminant	Category	Violations	ZIPs Affected	Health Risk
Groundwater Rule	Treatment Technique	1,421	176	Yes
Total Trihalomethanes (TTHM)	Disinfection Byproducts	1,051	107	Yes
Public Notice Rule	Reporting	489	148	No
Lead and Copper Rule	Treatment Technique	439	179	Yes
Consumer Confidence Rule	Reporting	388	164	No
Interim Enhanced Surface Water Treatment Rule	Treatment Technique	376	64	Yes
Lead and Copper Rule Revisions	Treatment Technique	312	141	Yes
Haloacetic Acids (HAA5)	Disinfection Byproducts	307	49	Yes
Surface Water Treatment Rule	Treatment Technique	94	22	Yes
Total organic carbon	Disinfection Byproducts	81	23	Yes

Water Quality Overview

Louisiana has 923 community water systems represented across 410 directly mapped ZIP records. The associated city records cover approximately 4,519,358 people. The available records contain 4,598 EPA violations, including 3,088 health-based violations.

Health-based violations account for 67% of all violations in Louisiana. These violations indicate contaminant levels that may pose direct risks to human health, as opposed to monitoring or reporting failures.

Violation Breakdown

Violation Type	Count	Percentage
Health-based	3,088	67.2%
Monitoring/Reporting	1,510	32.8%
Total	4,598	100%

Health-based violations are MCL, MRDL (disinfectant) and treatment-technique violations. Monitoring violations indicate failures to test or report - these do not necessarily mean unsafe water, but they mean the water was not properly verified.

Cities with Most Violations

The following cities in Louisiana have the highest number of EPA violations:

Violation counts are cumulative across all water systems serving each city. Higher counts may reflect larger systems with more monitoring requirements, not necessarily worse water quality.

Violation Trend Over Time

Year-by-year EPA violations recorded across all water systems in Louisiana:

Health-based violations have decreased from 309 in 2021 to 132 in 2026, suggesting improving compliance across Louisiana.

Most Common Contaminants

The following contaminants have caused the most violations across Louisiana water systems:

How to Check Your Water in Louisiana

1. Enter your ZIP code on ZipCheckup for detailed water-system data including contaminant levels and violation history; the separate Home Safety Score is a multi-source index

2. Request your CCR - every water utility must provide an annual Consumer Confidence Report

3. Get a home test - certified kits ($20-$50) or professional lab tests ($150-$400)

4. Consider filtration - NSF-certified filters can address specific contaminants found in your area

EPA Enforcement

The EPA and state regulators have taken enforcement actions against water systems in Louisiana. Enforcement actions range from compliance assistance to formal orders and penalties.

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Enforcement: EPA ECHO

Updated daily.

What are EPA violations?

Health-based violations are EPA violations of a Maximum Contaminant Level (MCL), a Maximum Residual Disinfectant Level (MRDL) or a required treatment technique - the enforceable standards designed to protect human health. Louisiana has 3,088 such violations across its water systems. Not all violations cause illness; review each violation type and duration to understand possible health implications.

Understanding water quality grades

ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grades summarize ZipCheckup's scoring inputs; review the underlying records for specific issues. Grades are calculated per ZIP code and aggregated at the city, county, and state level.

Frequently Asked Questions

Is the tap water safe to drink in Louisiana?

Records for 923 community water systems mapped to ZIPs in Louisiana show 4,598 reported violations, including 3,088 health-based. Water quality varies by city and ZIP code - check your specific location for detailed results.

How many violations are on record for water systems serving Louisiana?

Louisiana has 4,598 EPA violations on record across 410 ZIP codes; 3,088 are classified as health-based violations. The remainder are monitoring or reporting violations.

Which city in Louisiana has the worst water quality?

Ferriday, LA has the most recorded EPA violations (143) among the cities with mapped water systems in Louisiana in our data. Check your water supplier's report and test your tap water for the most accurate picture of your local water quality.

Which city in Louisiana has the best water quality?

Violation records vary by water system across Louisiana. Check individual city reports for details.

What contaminants are found in Louisiana drinking water?

EPA regulates over 90 drinking-water contaminants nationally; water systems in Louisiana monitor those applicable to each system, which can include lead, copper, nitrate, disinfection byproducts, and bacteria. The most common violations vary by region - check your ZIP code for contaminant-specific data.