Public water system record
Willow Lake
Serves Willow Lake, Clark County, SD · 255 people served
Federal records show 1 health-based violation and no monitoring/reporting issues for Willow Lake in the last ten years. The most serious issue in this window was a resolved Stage 1 Disinfection Byproducts Rule violation.
System profile
- Health-based violations, last 10 years
- 1
- Resolved
- 1
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 0
Key facts
- Willow Lake buys its water from Clark Rural Water System.
- Record on file since 1976, with 11 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 154 service lines.
Check whether Willow Lake 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 |
|---|---|---|---|---|
|
Stage 1 Disinfection Byproducts Rule
Treatment technique failure
|
210 | Nov 23, 2020 | Resolved | No |
Full record since 1976
EPA's records for Willow Lake go back to 1976. Before October 19, 2016 they list 11 health-based violations (11 resolved) and 8 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1970s | 0 | 2 |
| 1990s | 7 | 6 |
| 2000s | 2 | 0 |
| 2010 to October 18, 2016 | 2 | 0 |
| 2020s | 1 | 0 |
Most recent health-based violation before October 19, 2016: Stage 1 Disinfection Byproducts Rule, began February 2015, Resolved.
Show all 11 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Stage 1 Disinfection Byproducts Rule
Treatment technique failure
|
Feb 1, 2015 | Resolved |
|
Stage 1 Disinfection Byproducts Rule
Treatment technique failure
|
Feb 1, 2011 | Resolved |
|
Stage 1 Disinfection Byproducts Rule
Treatment technique failure
|
Feb 23, 2006 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jul 1, 2001 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Dec 1, 1999 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Sep 1, 1997 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Aug 1, 1994 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Nov 1, 1993 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Aug 1, 1992 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Dec 1, 1991 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Oct 1, 1991 | Resolved |
What the violations mean
Stage 1 Disinfection Byproducts Rule
1 incidentThe system did not meet a treatment requirement of the Stage 1 Disinfectants and Disinfection Byproducts Rule
Byproducts form when disinfectants react with natural material in water. Long-term exposure above federal limits may increase cancer risk
Where the water comes from
Willow Lake buys its water from Clark Rural Water System. It lists no wells or intakes of its own.
Buys water from
- Clark Rural Water System Clark, SD
Annual water quality report
Willow Lake 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 Willow Lake 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 South Dakota.
Certified drinking water labs by state EPA guidance for private wells