Community Water System · PWS OK1021691
Grand Lake PWA
Operator location Ochelata, Oklahoma - 40% of 362 violations are health-based (upper-third health share (> 23%)); groundwater source; 2,800 served per SDWIS.
- 2,800
- People served (this PWS) Middle third of systems
- 362
- EPA violations (this PWS) Upper third of systems
- 144
- Health-based (this PWS) Upper third by health-based share
- Untested
- UCMR5 (this PWS) No UCMR5 result
Grand Lake PWA standing, high SDWIS violation third
40% of 362 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 40% is upper-third health share (> 23%). Population rank #11,138 of 29,740 among systems serving 500+.
The verdict
Grand Lake PWA sits in the upper third of the sitemap cohort by violation count (362), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,800 (mid served population (≤ 3,309)). Health-based share is 40% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #11,138 of 29,740
- Population · /systems
- #177 of 558
- Population · OK
- 362
- Total EPA violations on record
- 40%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 1,327
- County
- Delaware
- School/Daycare
- No
- MCL Violations
- 118
- Monitoring Violations
- 197
- Treatment Tech Violations
- 26
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Total Haloacetic Acids (HAA5) | MCL | 70 | 2013 |
| CARBON, TOTAL | MR | 54 | 2009 |
| TTHM | MCL | 43 | 2013 |
| Surface Water Treatment Rule | MR | 30 | 2004 |
| CARBON, TOTAL | TT | 25 | 2014 |
| Coliform (TCR) | MR | 24 | 2010 |
| Consumer Confidence Rule | Other | 21 | 2023 |
| Chlorine | MR | 9 | 2018 |
| Interim Enhanced Surface Water Treatment Rule | MR | 8 | 2005 |
| Gross Alpha, Excl. Radon and U | MR | 8 | 2022 |
| Combined Radium (-226 and -228) | MR | 8 | 2022 |
| Gross Beta Particle Activity | MR | 8 | 2022 |
| Combined Uranium | MR | 8 | 2022 |
| Total Haloacetic Acids (HAA5) | MR | 7 | 2015 |
| TTHM | MR | 7 | 2015 |
| Lead and Copper Rule | MR | 7 | 2024 |
| Nitrate-Nitrite | MR | 6 | 2006 |
| Revised Total Coliform Rule | MON | 5 | 2018 |
| Combined Radium (-226 and -228) | MCL | 5 | 2024 |
| Arsenic | MR | 4 | 2007 |
| E. COLI | MR | 4 | 2020 |
| Surface Water Treatment Rule | TT | 1 | 1993 |
Violation Count vs. the National Corpus
Grand Lake PWA has 362 recorded EPA violations, 93% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 7% carry more. 40% of this system's own violations are health-based (144 of 362), and it ranks #11,138 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
362 Higher than most more violations than 93% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
How many violations vs. how serious, among peer systems
Grand Lake PWA plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.
Violation volume vs. health-based share
Health-based violations on Grand Lake PWA
144 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for OK1021691.
Sources: EPA SDWIS
Nationwide peers
362 violations · 2,800 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Grand Lake PWA
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Oklahoma compares on the same EPA violation measures. Oklahoma systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.