Lago del Oro Water Company water quality report, rewritten
- Serves
- 18,132
- Connections
- 6,915
- Water source
- Groundwater
- Based in
- Catalina, AZ
- County
- Pinal
- Owner
- Private
The ZIP code it serves
PWSID AZ0411117 · EPA data
Read this first
- Lithium (above EPA’s health benchmark) was found in 13 of 26 samples, highest 20 ppb. Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.
No health-based violations on file since 2016. EPA lists 30 monitoring or reporting violations, which are paperwork and testing lapses rather than water quality findings.
What was found
Highlighted: above the health goal, or EPA’s health benchmark where there is no goal. Circled: above the legal limit in at least one sample, or the action level. Every scale puts that line at its middle.
PFAS and lithium: EPA UCMR 5, samples taken from Oct. 9, 2024 to April 22, 2026. Each blue tick on a scale is one sample where it was found.
Lithium (above EPA’s health benchmark)
Comes from the source
20ppb
Highest of 26 samples; found in 13
Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.
What handles it
No certification claim covers this compound yet.
Also found, with no federal limit
EPA measured these PFAS to learn how often they occur. None has a legal limit or a health goal yet.
| Compound | Highest sample | Found in | Certification claim |
|---|---|---|---|
| PFPeA | 6.5 ppt | 2 of 26 | None covers it |
| PFHxA | 4.1 ppt | 2 of 26 | None covers it |
Tested and not found
Below EPA’s minimum reporting level in every sample taken from Oct. 9, 2024 to April 22, 2026. Not found means not measured above that level, which is not the same as zero.
All 28 compounds tested and not found
- 11Cl-PF3OUdS
- 4:2 FTS
- 6:2 FTS
- 8:2 FTS
- 9Cl-PF3ONS
- ADONA
- HFPO-DA (GenX)
- Lead
- NEtFOSAA
- NFDHA
- NMeFOSAA
- PFBA
- PFBS
- PFDA
- PFDoA
- PFEESA
- PFHpA
- PFHpS
- PFHxS
- PFMBA
- PFMPA
- PFNA
- PFOA
- PFOS
- PFPeS
- PFTA
- PFTrDA
- PFUnA
Violations since 2016
No health-based violations on file with EPA since 2016. There are 30 monitoring or reporting violations: a sample missed, late or not reported.
What this report cannot tell you
- Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in Lago del Oro Water Company’s own annual report, which it must send you every year.
- Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
- Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from Oct. 9, 2024 to April 22, 2026.
Other Arizona utilities
- City of Phoenix1.7 million
- City of Tucson732,906
- City of Mesa466,000
- Town of Gilbert247,600
- City of Chandler247,328
- City of Scottsdale241,361
- City of Glendale234,766
- City of Peoria187,676
- City of Tempe165,000
- Arizona Water Co - Pinal Valley134,432
- Epcor - Agua Fria127,718
- City of Yuma103,264
Sources
- EPA UCMR 5 occurrence data, file of Aug. 27, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q2
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
What to do next
Read up on Lithium
What each one does to health, where it comes from, and the certification claim that addresses it.
About LithiumGet the utility’s own report
Lago del Oro Water Company must send you a water quality report every year. It lists nitrate, arsenic and byproduct levels this page cannot.
How to read itTest your own tap for lead
Your service line, solder and fixtures decide the lead at your faucet, not the utility’s average.
Lead in your water: what to doDecide if you want a filter at all
A filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.
NSF/ANSI standards, decoded