Public water system record
Lyon-Sioux RWS-Big Sioux
Serves an area of Lyon County, IA that includes Rock Rapids and Larchwood · 1,530 people served
Federal records show no health-based violations and 2 monitoring/reporting issues for Lyon-Sioux RWS-Big Sioux in the last ten years.
System profile
- Health-based violations, last 10 years
- 0
- Resolved
- 0
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 2
Key facts
- Lyon-Sioux RWS-Big Sioux draws water from 9 wells.
- Most recent formal enforcement: signed compliance agreement by Iowa, November 2006.
- Record on file since 1989, with 0 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 570 service lines.
Check whether Lyon-Sioux RWS-Big Sioux 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.
None since October 2016.
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Nitrite
Monitoring and reporting
|
Oct 1, 2019 | Resolved |
|
Combined Radium (-226 and -228)
Monitoring and reporting
|
Jul 1, 2012 | Resolved |
Full record since 1989
EPA's records for Lyon-Sioux RWS-Big Sioux go back to 1989. Before October 19, 2016 they list no health-based violations and 14 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1980s | 0 | 1 |
| 2000s | 0 | 11 |
| 2010 to October 18, 2016 | 0 | 2 |
| October 19, 2016 to 2019 | 0 | 1 |
Enforcement actions
Iowa regulators took 1 formal enforcement action against Lyon-Sioux RWS-Big Sioux in 2006. The most recent was a signed compliance agreement in November 2006.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Nov 6, 2006 | Iowa | Signed compliance agreement | 1 violation: Lead and Copper Rule |
Where the water comes from
Lyon-Sioux RWS-Big Sioux draws water from 9 wells. It also buys water from Rock Rapids Municipal Water Works. 5 other community water systems buy water from Lyon-Sioux RWS-Big Sioux.
Buys water from
- Rock Rapids Municipal Water Works Rock Rapids, IA
Community systems that buy water from it
- Larchwood Water Supply Larchwood, IA
- Lester Water Supply Lester, IA
- Lyon-Sioux RWS-Doon Rock Rapids, IA
- Lyon-Sioux RWS-Rock Rapids Rock Rapids, IA
- Rock Rapids Municipal Water Works Rock Rapids, IA
Annual water quality report
Lyon-Sioux RWS-Big Sioux 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 Iowa.
Certified drinking water labs by state EPA guidance for private wells