Water Quality in Grand Coteau, LA: 10 Violations — Grade B
Grade B · Score 70/100 · 1 water system · Updated 2026-05-03
Grand Coteau's water is mostly safe. Minor violations exist but are primarily monitoring-related.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Looking at EPA compliance data for Grand Coteau, LA, the record shows 10 violations — findings that span health-based exceedances, monitoring lapses, and enforcement events tied to local utilities in the SDWIS database.
Water Quality by ZIP Code in Grand Coteau
Water quality varies across Grand Coteau's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 70541 | B | 78 | 10 | 3 | View report → |
Violation Trend
EPA violations recorded for water systems serving Grand Coteau.
Water Quality Overview
Grand Coteau, Louisiana receives a water quality grade of B with an overall score of 70 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Grand Coteau have accumulated 10 EPA violations, including 3 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 1,650 people.
What Grade B Means
A grade of B indicates good compliance with EPA drinking water standards. While not perfect, Grand Coteau's water systems meet the vast majority of federal requirements. Minor violations may exist but typically relate to monitoring or reporting rather than health-based standards.
Lead Levels
The average 90th percentile lead level across Grand Coteau water systems is 0.0070 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 89% of homes built before 1986, Grand Coteau has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Grand Coteau is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Grand Coteau
Grand Coteau is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 1,650 people across 1 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Grand Coteau. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Grand Coteau
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Grand Coteau Water Systems
The following contaminants have been detected or caused violations across Grand Coteau's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | N/A | 3 | 1 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 2 | 1 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 2 | 1 | Yes |
| Lead and Copper Rule | Treatment Technique | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Grand Coteau:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 1 | 1 |
| 2024 | 1 | 1 |
| 2025 | 1 | 1 |
Violation counts have remained stable over the observed period.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Grand Coteau. Recent actions:
| Date | Action Type |
|---|---|
| 2025-05-06 | State Order Extension |
| 2025-04-24 | State Informal Action |
| 2025-04-16 | State Informal Action |
| 2025-03-27 | State Order Extension |
| 2025-03-10 | State Informal Action |
| 2025-03-07 | State Informal Action |
| 2025-03-07 | State Informal Action |
| 2025-03-07 | State Informal Enforcement |
| 2025-02-06 | State Informal Action |
| 2025-02-04 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-05-06.
Grand Coteau vs. Nearby Louisiana Cities
How Grand Coteau's water quality compares to similar cities in Louisiana:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Grand Coteau | B | 10 | 1 | 1,650 |
| Clayton | D | 23 | 2 | 1,623 |
| Montgomery | B | 9 | 2 | 1,698 |
| Loranger | B | 11 | 4 | 1,596 |
Common Questions About Grand Coteau Water
These are the most common questions residents search for about water quality in Grand Coteau, Louisiana:
Is Grand Coteau water hard or soft? Water hardness varies by source. Grand Coteau's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Grand Coteau tap water? Grand Coteau's water receives a grade of B (70/100). There are 3 health-based violations — consider filtration.
What is the best water filter for Grand Coteau? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Grand Coteau vs. Louisiana Average
Understanding how Grand Coteau compares to the broader Louisiana average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Grand Coteau.
ZIP Codes in Grand Coteau
Grand Coteau spans 1 ZIP code. The ZIP with the lowest water quality score is 70541. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.
Frequently Asked Questions
Your Water is Safe — Here's How to Keep It That Way
Grade B is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.