Watco Water
What EPA’s and CDC’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 1,039 people
- Connections
- 390
- Water source
- Groundwater
- Based in
- Bourden Ranch Estates, AZ
- County
- Navajo
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and CDC’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. 1 health-based violation since 2016.
What was found
Nitrate and arsenic: Arizona’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.
Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from Sept. 17, 2012 to Oct. 3, 2018. Newer results are in the utility’s annual water quality report.
Below EPA’s limits3
Nitrate
Comes from the source
0.47ppm
Highest yearly average, 2020 to 2023
2023 average: 0.41 ppm
Averaged by year, the highest was 0.47 ppm, in 2021, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.41 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.51 ppm, in 2015.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Fluoride
Forms or is added in treatment
0.15ppm
Highest yearly average, 2012 to 2018
Averaged by year, the highest was 0.15 ppm, in 2018, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Chromium (total)
Comes from the source
2.5ppb
Highest yearly average, 2012 to 2018
2018, one sample: 1.2 ppb
Averaged by year, the highest was 2.5 ppb, in 2012, below EPA’s legal limit of 100 ppb. Its highest single sample was 3.1 ppb. In 2018, the latest year on file, its one sample was 1.2 ppb.
What handles it
- NSF/ANSI 58 look for “Chromium (Hexavalent) Reduction”
- NSF/ANSI 53 look for “Chromium Reduction”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Lead
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Revised Total Coliform Rule | Coliform or E. coli results required a detailed review of the system, and it or its fixes were not done on time.EPA: Treatment Technique, Level 2 Assessment (RTCR) | Nov. 6, 2022 | — | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 11 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate and arsenic results here are Arizona’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Watco Water’s own annual report, which it must send you every year, has newer results for those and the contaminants this page does not show.
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.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; CDC’s yearly averages for Arizona cover 2020 to 2023; EPA’s compliance samples are from Sept. 17, 2012 to Oct. 3, 2018.
Testing your own tap
The 2 labs Arizona certifies closest to the area Watco Water serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Sacred Water Testing LLC
Show Low, AZ · under a mile
Mohave Environmental Labs
Holbrook, AZ · about 43 miles
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages Arizona supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Arizona’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Arizona Department of Health Services, Arizona certified commercial drinking water laboratories, read Oct. 17, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID AZ0409049. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and CDC’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportWatco Water must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded