Public water system record
City of Williams
Serves Williams, Coconino County, AZ · 3,145 people served
Federal records show 6 health-based violations and 33 monitoring/reporting issues for City of Williams 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
- Health-based violations, last 10 years
- 6
- Resolved
- 5
- Unresolved
- 0
- Archived by EPA
- 1
- Any acute record
- Yes
- Monitoring issues, last 10 years
- 33
Key facts
- City of Williams draws water from 2 wells and 5 surface water intakes (4 of them for emergency, seasonal or other part-time use).
- Highest measured level in the last 10 years: Arsenic, 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit), 2025.
- Record on file since 1978, with 6 health-based violations before October 19, 2016.
Check whether City of Williams 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 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
|
330 | Oct 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | May 1, 2023 | Resolved | Yes |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Apr 1, 2023 | Resolved | Yes |
|
CARBON, TOTAL
Treatment technique failure
|
210 | Oct 1, 2022 | Resolved | No |
|
CARBON, TOTAL
Treatment technique failure
|
210 | Jul 1, 2022 | Resolved | No |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Jan 1, 2017 | Resolved | Yes |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Surface Water Treatment Rule
Monitoring and reporting
|
Dec 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Dec 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2025 | Resolved |
|
Chlorine
Monitoring and reporting
|
May 1, 2025 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Oct 2, 2023 | Resolved |
|
Public Notice
OTHER
|
Jan 31, 2023 | Resolved |
|
CARBON, TOTAL
Monitoring and reporting
|
Jan 1, 2023 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Oct 2, 2022 | Resolved |
|
CARBON, TOTAL
Monitoring and reporting
|
Oct 1, 2022 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Sep 1, 2022 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Sep 1, 2022 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Mar 1, 2022 | Resolved |
|
Chlorine
Monitoring and reporting
|
Jan 1, 2022 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Jan 1, 2022 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Oct 1, 2021 | Resolved |
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2021 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Sep 1, 2021 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Mar 1, 2021 | Resolved |
|
Public Notice
OTHER
|
Jan 31, 2020 | Resolved |
|
Public Notice
OTHER
|
Jan 31, 2020 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Jun 1, 2019 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Jun 1, 2019 | Resolved |
|
E. coli
Monitoring and reporting
|
Dec 9, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Nov 25, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Nov 11, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Oct 28, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Oct 14, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Aug 5, 2018 | Resolved |
|
E. coli
Monitoring and reporting
|
Jun 10, 2018 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Mar 1, 2018 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Mar 1, 2018 | Resolved |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Nov 1, 2016 | Resolved |
|
Chlorine
Monitoring and reporting
|
Oct 1, 2016 | Resolved |
Full record since 1978
EPA's records for City of Williams go back to 1978. Before October 19, 2016 they list 6 health-based violations (4 resolved, 2 archived by EPA without a recorded fix) and 195 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1970s | 0 | 6 |
| 1980s | 2 | 24 |
| 1990s | 0 | 48 |
| 2000s | 4 | 74 |
| 2010 to October 18, 2016 | 0 | 43 |
| October 19, 2016 to 2019 | 1 | 12 |
| 2020s | 5 | 20 |
Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began April 2006, Resolved.
Show all 6 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.104 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
|
Apr 1, 2006 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.104 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
|
Jan 1, 2006 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.104 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
|
Oct 1, 2005 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.104 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
|
Jul 1, 2005 | Resolved |
|
Gross Alpha, Excl. Radon and U
Contaminant limit exceeded
|
Jul 31, 1988 | Archived |
|
Gross Alpha, Excl. Radon and U
Contaminant limit exceeded
|
Jan 1, 1988 | Archived |
What the violations mean
Interim Enhanced Surface Water Treatment Rule
3 incidentsThe system did not meet a filtration or treatment requirement for surface water
Inadequate treatment of surface water can let pathogens such as Cryptosporidium and Giardia through
CARBON, TOTAL
2 incidentsThe system did not complete a treatment step or action that federal rules require for CARBON, TOTAL (a treatment technique violation).
The utility had to notify customers about each of these violations.
Arsenic
1 incidentArsenic exceeded the federal limit
Long-term arsenic exposure is linked to cancer and cardiovascular effects
Where the water comes from
City of Williams draws water from 2 wells and 5 surface water intakes (4 of them for emergency, seasonal or other part-time use). 1 smaller public system such as schools, businesses or campgrounds buys water from City of Williams.
Annual water quality report
City of Williams 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.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
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