Water Quality in Calera, OK: 18 Violations — Grade C
Grade C · Score 66/100 · 1 water system · Updated 2026-05-03
Calera's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
According to EPA filings, Calera, OK has 18 water compliance violations on record — sourced from SDWIS, the federal database that tracks reportable events for every registered public water system in the state.
Water Quality by ZIP Code in Calera
Water quality varies across Calera's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 74730 | C | 66 | 18 | 10 | View report → |
Violation Trend
EPA violations recorded for water systems serving Calera.
Water Quality Overview
Calera, Oklahoma receives a water quality grade of C with an overall score of 66 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Calera have accumulated 18 EPA violations, including 10 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 2,815 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Calera's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Calera water systems is 0.0008 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Water Systems Serving Calera
Calera is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 2,815 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 Calera. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Calera
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 Calera Water Systems
The following contaminants have been detected or caused violations across Calera's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 7 | 1 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 3 | 1 | Yes |
| Revised Total Coliform Rule | Microbiological | N/A | 2 | 1 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 2 | 1 | Yes |
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 Calera:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 3 | 3 |
| 2022 | 8 | 8 |
| 2023 | 3 | 3 |
| 2024 | 1 | 1 |
Violations have decreased from 3 in 2021 to 1 in 2024, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Calera. Recent actions:
| Date | Action Type |
|---|---|
| 2025-07-11 | State Informal Action |
| 2024-07-16 | State Order Extension |
| 2024-05-01 | State Informal Action |
| 2023-11-06 | State Order Extension |
| 2023-10-19 | State Informal Action |
| 2023-10-19 | State Informal Enforcement |
| 2023-10-17 | State Informal Action |
| 2023-09-22 | State Informal Action |
| 2023-09-22 | State Informal Enforcement |
| 2023-08-30 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-07-11.
Calera vs. Nearby Oklahoma Cities
How Calera's water quality compares to similar cities in Oklahoma:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Calera | C | 18 | 1 | 2,815 |
| Watonga | A | 8 | 1 | 2,816 |
| Stroud | A | 8 | 1 | 2,811 |
| Roland | B | 1 | 1 | 2,842 |
Common Questions About Calera Water
These are the most common questions residents search for about water quality in Calera, Oklahoma:
Is Calera water hard or soft? Water hardness varies by source. Calera's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Calera tap water? Calera's water receives a grade of C (66/100). There are 10 health-based violations — consider filtration.
What is the best water filter for Calera? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Calera vs. Oklahoma Average
Understanding how Calera compares to the broader Oklahoma 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 Calera.
ZIP Codes in Calera
Calera spans 1 ZIP code. The ZIP with the lowest water quality score is 74730. 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.