Is LYON-SIOUX RWS-BIG SIOUX required to publish a Consumer Confidence Report?

Yes. LYON-SIOUX RWS-BIG SIOUX is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.

When is LYON-SIOUX RWS-BIG SIOUX’s next Consumer Confidence Report due?

LYON-SIOUX RWS-BIG SIOUX’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.

What is a Consumer Confidence Report?

A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

ROCK RAPIDS, IA · Lyon County

LYON-SIOUX RWS-BIG SIOUX Water System

Consumer Confidence Report status

LYON-SIOUX RWS-BIG SIOUX must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.

As of August 1, 2026, EPA's federal records show no open violations for LYON-SIOUX RWS-BIG SIOUX.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace Iowa’s official records. Always confirm current status with Iowa before making decisions based on this information.

System facts

System ID (PWSID): IA6000755
System type: Community Water System
Population served: 1,530
Service connections: 612
Ownership: privately owned
Water source: groundwater (wells)

LYON-SIOUX RWS-BIG SIOUX is one of 403 community water systems in Iowa in the 501 to 3,300 people size category, serving 1,530 people from groundwater.

As of August 1, 2026, its federal record holds 6 entries between 1989 and 2012, all of which EPA lists as closed. Nothing has been added since 2012.

All 6 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves inorganic chemicals and the Radionuclides and Revised Rad Rule.

Violation history

Monitoring, Regular
—
Combined Radium (-226 and -228)
July 1, 2012 – June 30, 2021
Resolved
Monitoring, Regular
—
Antimony, Total
January 1, 2005 – December 31, 2013
Resolved
Monitoring, Regular
—
Cadmium
January 1, 2005 – December 31, 2013
Resolved
Monitoring, Regular
—
Mercury
January 1, 2005 – December 31, 2013
Resolved
Monitoring, Regular
—
Nitrate
January 1, 2000 – March 31, 2000
Resolved
Monitoring, Regular
—
Nitrate
October 1, 1989 – December 31, 1989
Resolved

Resolved addressed and confirmed by the state

Period	Violation	Contaminant / rule	Health-based	Status
July 1, 2012 – June 30, 2021	Monitoring, Regular	Combined Radium (-226 and -228)	—	Resolved
January 1, 2005 – December 31, 2013	Monitoring, Regular	Antimony, Total	—	Resolved
January 1, 2005 – December 31, 2013	Monitoring, Regular	Cadmium	—	Resolved
January 1, 2005 – December 31, 2013	Monitoring, Regular	Mercury	—	Resolved
January 1, 2000 – March 31, 2000	Monitoring, Regular	Nitrate	—	Resolved
October 1, 1989 – December 31, 1989	Monitoring, Regular	Nitrate	—	Resolved

Resolved addressed and confirmed by the state

Enforcement actions

August 8, 2022State Public Notification received1 linked violation
August 30, 2021State Compliance achieved1 linked violation
August 19, 2021State Formal Notice of Violation issued3 linked violations
October 30, 2020State Public Notification received1 linked violation
October 21, 2020State Public Notification requested1 linked violation
October 21, 2020State Formal Notice of Violation issued1 linked violation
October 13, 2020State Compliance achieved1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification receivedgeneral compliance action — not tied to a specific violation on record
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
April 8, 2014State Public Notification received1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achievedgeneral compliance action — not tied to a specific violation on record
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
March 13, 2014State Compliance achieved1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Public Notification requested1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
February 18, 2014State Formal Notice of Violation issued1 linked violation
May 8, 2000State Public Notification received2 linked violations
April 18, 2000State Formal Notice of Violation issued1 linked violation
April 18, 2000State Public Notification requested1 linked violation
August 24, 1990State Formal Notice of Violation issued1 linked violation
January 23, 1990State Compliance achieved1 linked violation
January 23, 1990State Compliance achieved1 linked violation
December 11, 1989State Formal Notice of Violation issuedgeneral compliance action — not tied to a specific violation on record
December 11, 1989State Formal Notice of Violation issued1 linked violation
October 9, 1989State Compliance achievedgeneral compliance action — not tied to a specific violation on record

Common questions

Is LYON-SIOUX RWS-BIG SIOUX required to publish a Consumer Confidence Report?: Yes. LYON-SIOUX RWS-BIG SIOUX is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is LYON-SIOUX RWS-BIG SIOUX’s next Consumer Confidence Report due?: LYON-SIOUX RWS-BIG SIOUX’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does LYON-SIOUX RWS-BIG SIOUX have any open drinking water violations on record?: As of August 1, 2026, EPA's federal records show no open violations for LYON-SIOUX RWS-BIG SIOUX.
What is a Consumer Confidence Report?: A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

Contact

LYON-SIOUX RURAL WATER SYSTEM

712-472-3755

ROCK RAPIDS, IA 51246