Public water system record
CS El Prado Water Company
Serves Yuma and El Prado Estates, Yuma County, AZ · 404 people served
Federal records show 27 health-based violations and 34 monitoring/reporting issues for CS El Prado Water Company in the last ten years. The most serious issue in this window was a Arsenic violation that EPA lists as archived, not resolved.
System profile
Source water
Groundwater
ZIP
63131
EPA system ID
AZ0414442
- Health-based violations, last 10 years
- 27
- Resolved
- 21
- Unresolved
- 0
- Archived by EPA
- 6
- Any acute record
- Yes
- Monitoring issues, last 10 years
- 34
Key facts
- CS El Prado Water Company draws water from 1 well.
- Highest measured level in the last 10 years: Arsenic, 0.026 mg/L, federal limit 0.01 mg/L (2.6 times the limit), 2019.
- Most recent formal enforcement: compliance order (no penalty) by Arizona, September 2024.
- Record on file since 1980, with 21 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 114 unknown out of 158 service lines.
Check whether CS El Prado Water Company serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Arsenic
Contaminant limit exceeded
Measured 0.025 mg/L, federal limit 0.01 mg/L (2.5 times the limit)
|
330 | Jul 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.024 mg/L, federal limit 0.01 mg/L (2.4 times the limit)
|
330 | Apr 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
|
330 | Jan 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
|
330 | Oct 1, 2024 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.014 mg/L, federal limit 0.01 mg/L (1.4 times the limit)
|
330 | Jul 1, 2024 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Apr 1, 2024 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Revised Total Coliform Rule
Contaminant limit exceeded
|
110 | Mar 1, 2024 | Resolved | Yes |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
330 | Oct 1, 2022 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
330 | Jul 1, 2022 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.015 mg/L, federal limit 0.01 mg/L (1.5 times the limit)
|
330 | Apr 1, 2022 | Resolved | No |
|
Groundwater Rule
Treatment technique failure
|
140 | Mar 10, 2022 | Resolved | No |
|
Groundwater Rule
Treatment technique failure
|
140 | Mar 10, 2022 | Resolved | No |
|
Groundwater Rule
Treatment technique failure
|
140 | Mar 10, 2022 | Resolved | No |
|
Groundwater Rule
Treatment technique failure
|
140 | Mar 2, 2022 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.014 mg/L, federal limit 0.01 mg/L (1.4 times the limit)
|
330 | Jan 1, 2022 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Oct 1, 2021 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
330 | Jul 1, 2021 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
330 | Apr 1, 2021 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Jan 1, 2021 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
330 | Oct 1, 2020 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.016 mg/L, federal limit 0.01 mg/L (1.6 times the limit)
|
330 | Jul 10, 2019 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit)
|
330 | Apr 1, 2019 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.026 mg/L, federal limit 0.01 mg/L (2.6 times the limit)
|
330 | Jan 1, 2019 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit)
|
330 | Oct 1, 2018 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.022 mg/L, federal limit 0.01 mg/L (2.2 times the limit)
|
330 | Jul 1, 2018 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
|
330 | Apr 1, 2018 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Jan 1, 2018 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Arsenic
Monitoring and reporting
|
Oct 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Public Notice
OTHER
|
Aug 17, 2025 | Resolved |
|
Public Notice
OTHER
|
Jun 7, 2025 | Resolved |
|
Arsenic
Monitoring and reporting
|
Jan 1, 2025 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2024 | Resolved |
|
Arsenic
Monitoring and reporting
|
Apr 1, 2024 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Jan 1, 2024 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 13, 2022 | Resolved |
|
Public Notice
OTHER
|
Feb 14, 2022 | Resolved |
|
Public Notice
OTHER
|
Jan 28, 2022 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2021 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2021 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Dec 1, 2020 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Nov 1, 2020 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2020 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Jul 1, 2020 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2020 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Mar 1, 2020 | Resolved |
|
Public Notice
OTHER
|
Apr 13, 2019 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Oct 1, 2018 | Resolved |
|
Arsenic
Monitoring and reporting
|
Jan 1, 2018 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Nov 3, 2017 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2017 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2017 | Resolved |
|
Arsenic
Monitoring and reporting
|
Apr 1, 2017 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Jan 1, 2017 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Dec 1, 2016 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Oct 1, 2016 | Resolved |
|
Arsenic
Monitoring and reporting
|
Oct 1, 2016 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Oct 1, 2016 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2016 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Oct 1, 2015 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2015 | Resolved |
Full record since 1980
EPA's records for CS El Prado Water Company go back to 1980. Before October 19, 2016 they list 21 health-based violations (21 resolved) and 100 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1980s | 0 | 1 |
| 1990s | 0 | 50 |
| 2000s | 4 | 18 |
| 2010 to October 18, 2016 | 17 | 31 |
| October 19, 2016 to 2019 | 7 | 9 |
| 2020s | 20 | 19 |
Most recent health-based violation before October 19, 2016: Arsenic, began July 2016, Resolved.
Show all 21 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Arsenic
Contaminant limit exceeded
Measured 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
|
Jul 1, 2016 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.024 mg/L, federal limit 0.01 mg/L (2.4 times the limit)
|
Apr 1, 2016 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.015 mg/L, federal limit 0.01 mg/L (1.5 times the limit)
|
Jan 1, 2016 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.016 mg/L, federal limit 0.01 mg/L (1.6 times the limit)
|
Oct 1, 2015 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.018 mg/L, federal limit 0.01 mg/L (1.8 times the limit)
|
Oct 1, 2012 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Sep 1, 2012 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.027 mg/L, federal limit 0.01 mg/L (2.7 times the limit)
|
Jul 1, 2012 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit)
|
Apr 1, 2012 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.025 mg/L, federal limit 0.01 mg/L (2.5 times the limit)
|
Jan 1, 2012 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.024 mg/L, federal limit 0.01 mg/L (2.4 times the limit)
|
Oct 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.02 mg/L, federal limit 0.01 mg/L (2 times the limit)
|
Jul 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.022 mg/L, federal limit 0.01 mg/L (2.2 times the limit)
|
Apr 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.016 mg/L, federal limit 0.01 mg/L (1.6 times the limit)
|
Jan 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.015 mg/L, federal limit 0.01 mg/L (1.5 times the limit)
|
Oct 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Jul 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Apr 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jan 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.015 mg/L, federal limit 0.01 mg/L (1.5 times the limit)
|
Jan 1, 2009 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
|
Oct 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
|
Apr 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.034 mg/L, federal limit 0.01 mg/L (3.4 times the limit)
|
Oct 1, 2007 | Resolved |
Enforcement actions
Arizona regulators took 3 formal enforcement actions against CS El Prado Water Company between 2012 and 2024. The most recent was a compliance order (no penalty) in September 2024.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Sep 24, 2024 | Arizona | Compliance order (no penalty) | 9 violations (6 health-based): Arsenic |
| Jun 17, 2022 | Arizona | Compliance order (no penalty) | 25 violations (25 health-based): Arsenic |
| Nov 20, 2012 | Arizona | Compliance order (no penalty) | 37 violations (33 health-based): Arsenic |
What the violations mean
Arsenic
22 incidentsArsenic exceeded the federal limit
Long-term arsenic exposure is linked to cancer and cardiovascular effects
Groundwater Rule
4 incidentsThe system did not complete a treatment step or action that the Groundwater Rule requires (a treatment technique violation).
The utility had to notify customers about each of these violations.
Revised Total Coliform Rule
1 incidentThe system did not meet a requirement of the Revised Total Coliform Rule
Coliform and E. coli rules protect against bacteria in the distribution system
Where the water comes from
CS El Prado Water Company draws water from 1 well.
Annual water quality report
CS El Prado Water Company must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Systems serving 500 or fewer people may meet the rule by telling customers the report is available on request, so you may need to ask CS El Prado Water Company for a copy.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Arizona.
Certified drinking water labs by state EPA guidance for private wells