City of Caldwell water quality report, rewritten
- Serves
- 74,000
- Connections
- 25,000
- Water source
- Groundwater
- Based in
- Caldwell, ID
- County
- Canyon
- Owner
- Local government
PWSID ID31400132026 edition · EPA data
Read this first
- Lithium (above EPA’s health benchmark) was found in 11 of 17 samples, highest 16 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 94 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.
Lithium (above EPA’s health benchmark)
Comes from the source
16ppb
Highest of 17 samples; found in 11
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.
EPA UCMR 5, samples taken from April 24, 2023 to Aug. 11, 2025. Each blue tick is one sample where it was found.
Tested and not found
Below EPA’s minimum reporting level in every sample taken from April 24, 2023 to Aug. 11, 2025. Not found means not measured above that level, which is not the same as zero.
All 30 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
- PFHxA
- PFHxS
- PFMBA
- PFMPA
- PFNA
- PFOA
- PFOS
- PFPeA
- PFPeS
- PFTA
- PFTrDA
- PFUnA
Violations since 2016
No health-based violations on file with EPA since 2016. There are 94 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 City of Caldwell’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 April 24, 2023 to Aug. 11, 2025.
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
City of Caldwell 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
Other Idaho utilities
- Veolia Water Idaho264,978
- Meridian Water Dept147,340
- City of Nampa100,200
- City of Idaho Falls69,450
- City of Pocatello58,231
- City of Twin Falls56,121
- City of Coeur D Alene54,115
- City of Rexburg40,695
- City of Kuna32,038
- Moscow Water Dept26,000
- Falls Water Company Inc22,650
- City of Post Falls20,285
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.