MASON CITY, IA · Cerro Gordo County

MASON CITY WATER DEPARTMENT Water System

Current status

No open violations on record as of July 4, 2026.

This system's next federally required Consumer Confidence Report is due July 1, 2027, under the EPA's revised reporting rule.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 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): IA1750048
System type: Community Water System
Population served: 27,338
Service connections: 19,000
Ownership: local government
Water source: groundwater (wells)

Violation history

Monitoring, Routine (RTCR)
—
Revised Total Coliform Rule
June 1, 2024 – June 30, 2024
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
August 1, 2012 – August 31, 2012
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
June 1, 2008 – June 30, 2008
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2004 – June 28, 2006
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Radium (-226 and -228)
July 1, 2004 – September 30, 2004
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
March 1, 2004 – March 31, 2004
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Radium (-226 and -228)
July 1, 2003 – September 30, 2003
Resolved
Monitoring, Regular
—
Nitrate
April 1, 2003 – March 31, 2004
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Radium (-226 and -228)
April 1, 2003 – March 31, 2004
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
January 1, 2003 – January 31, 2003
Resolved
Notification, Public
—
Combined Radium (-226 and -228)
January 1, 2001 – March 31, 2001
Resolved
Maximum Contaminant Level Violation, Single Sample
Health-based
Combined Radium (-226 and -228)
January 1, 2000 – December 31, 2000
Archived
Monitoring, Regular
—
1,1-Dichloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
CHLOROBENZENE
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Styrene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Trichloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
2,4-D
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Dalapon
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
o-Dichlorobenzene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Dinoseb
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
2,4,5-TP
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
CHLOROBENZENE
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Styrene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Tetrachloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
1,2,4-Trichlorobenzene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Vinyl chloride
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Xylenes, Total
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
2,4,5-TP
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Di(2-ethylhexyl) adipate
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
1,2-Dichloroethane
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
cis-1,2-Dichloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
trans-1,2-Dichloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Styrene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
1,1,2-Trichloroethane
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
LASSO
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Picloram
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
2,4,5-TP
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Carbon tetrachloride
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
p-Dichlorobenzene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
cis-1,2-Dichloroethylene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Ethylbenzene
January 1, 1995 – December 31, 1999
Resolved
Monitoring, Regular
—
Combined Radium (-226 and -228)
July 1, 1989 – September 30, 1989
Resolved
Monitoring, Regular
—
Combined Radium (-226 and -228)
April 1, 1989 – June 30, 1989
Resolved
Monitoring, Regular
—
Nitrate
July 1, 1988 – June 30, 1991
Resolved
Notification, Public
—
Combined Radium (-226 and -228)
July 1, 1986 – September 30, 1986
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Radium (-226 and -228)
October 1, 1985 – September 30, 1986
Archived
Maximum Contaminant Level Violation, Average
Health-based
Combined Radium (-226 and -228)
April 1, 1985 – September 30, 1985
Archived
Notification, Public
—
Combined Radium (-226 and -228)
October 1, 1982 – September 30, 1986
Resolved
Maximum Contaminant Level Violation, Single Sample
Health-based
Combined Radium (-226 and -228)
April 1, 1980 – March 31, 1984
Resolved

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Period	Violation	Contaminant / rule	Health-based	Status
June 1, 2024 – June 30, 2024	Monitoring, Routine (RTCR)	Revised Total Coliform Rule	—	Resolved
August 1, 2012 – August 31, 2012	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
June 1, 2008 – June 30, 2008	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
July 1, 2004 – June 28, 2006	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
July 1, 2004 – September 30, 2004	Maximum Contaminant Level Violation, Average	Combined Radium (-226 and -228)	Health-based	Resolved
March 1, 2004 – March 31, 2004	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
July 1, 2003 – September 30, 2003	Maximum Contaminant Level Violation, Average	Combined Radium (-226 and -228)	Health-based	Resolved
April 1, 2003 – March 31, 2004	Monitoring, Regular	Nitrate	—	Resolved
April 1, 2003 – March 31, 2004	Maximum Contaminant Level Violation, Average	Combined Radium (-226 and -228)	Health-based	Resolved
January 1, 2003 – January 31, 2003	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
January 1, 2001 – March 31, 2001	Notification, Public	Combined Radium (-226 and -228)	—	Resolved
January 1, 2000 – December 31, 2000	Maximum Contaminant Level Violation, Single Sample	Combined Radium (-226 and -228)	Health-based	Archived
January 1, 1995 – December 31, 1999	Monitoring, Regular	1,1-Dichloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	CHLOROBENZENE	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Styrene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Trichloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	2,4-D	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Dalapon	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	o-Dichlorobenzene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Dinoseb	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	2,4,5-TP	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	CHLOROBENZENE	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Styrene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Tetrachloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	1,2,4-Trichlorobenzene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Vinyl chloride	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Xylenes, Total	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	2,4,5-TP	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Di(2-ethylhexyl) adipate	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	1,2-Dichloroethane	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	cis-1,2-Dichloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	trans-1,2-Dichloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Styrene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	1,1,2-Trichloroethane	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	LASSO	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Picloram	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	2,4,5-TP	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Carbon tetrachloride	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	p-Dichlorobenzene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	cis-1,2-Dichloroethylene	—	Resolved
January 1, 1995 – December 31, 1999	Monitoring, Regular	Ethylbenzene	—	Resolved
July 1, 1989 – September 30, 1989	Monitoring, Regular	Combined Radium (-226 and -228)	—	Resolved
April 1, 1989 – June 30, 1989	Monitoring, Regular	Combined Radium (-226 and -228)	—	Resolved
July 1, 1988 – June 30, 1991	Monitoring, Regular	Nitrate	—	Resolved
July 1, 1986 – September 30, 1986	Notification, Public	Combined Radium (-226 and -228)	—	Resolved
October 1, 1985 – September 30, 1986	Maximum Contaminant Level Violation, Average	Combined Radium (-226 and -228)	Health-based	Archived
April 1, 1985 – September 30, 1985	Maximum Contaminant Level Violation, Average	Combined Radium (-226 and -228)	Health-based	Archived
October 1, 1982 – September 30, 1986	Notification, Public	Combined Radium (-226 and -228)	—	Resolved
April 1, 1980 – March 31, 1984	Maximum Contaminant Level Violation, Single Sample	Combined Radium (-226 and -228)	Health-based	Resolved

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Enforcement actions

October 17, 2024State Compliance achieved1 linked violation
July 18, 2024State Public Notification requested1 linked violation
July 18, 2024State Formal Notice of Violation issued1 linked violation
July 8, 2024State Compliance achieved1 linked violation
September 18, 2012State Compliance achieved2 linked violations
September 11, 2012State Public Notification received1 linked violation
August 24, 2012State Formal Notice of Violation issued1 linked violation
August 24, 2012State Public Notification requested4 linked violations
August 22, 2012State Violation/Reminder Notice1 linked violation
June 28, 2006State Formal Notice of Violation issued1 linked violation
June 28, 2006State Compliance achieved1 linked violation
June 28, 2006State Public Notification received1 linked violation
June 28, 2006State Public Notification requested1 linked violation
June 28, 2006State Compliance achieved1 linked violation
June 28, 2006State Formal Notice of Violation issued1 linked violation
June 28, 2006State Public Notification requested2 linked violations
June 28, 2006State Compliance achieved2 linked violations
June 28, 2006State Compliance achieved2 linked violations
June 28, 2006State Public Notification requested3 linked violations
June 28, 2006State Public Notification received3 linked violations
June 28, 2006State Public Notification received4 linked violations
February 24, 2006State Compliance achieved1 linked violation
February 24, 2006State Compliance achieved1 linked violation
February 24, 2006State Compliance achieved3 linked violations
February 24, 2006State Compliance achieved1 linked violation
February 24, 2006State Compliance achieved1 linked violation
February 24, 2006State Compliance achieved1 linked violation
February 24, 2006State Compliance achieved2 linked violations
December 20, 2005State Compliance achieved2 linked violations
July 27, 2005State Formal Notice of Violation issued1 linked violation
July 27, 2005State Public Notification requested1 linked violation
April 21, 2005State Compliance achieved3 linked violations
April 21, 2005State Public Notification requested4 linked violations
April 11, 2005State Compliance achieved3 linked violations
April 11, 2005State Compliance achieved4 linked violations
March 31, 2005State Compliance achieved2 linked violations
February 11, 2005State Compliance achieved1 linked violation
February 11, 2005State Compliance achieved3 linked violations
February 11, 2005State Compliance achieved4 linked violations
September 14, 2004State Public Notification received1 linked violation
September 14, 2004State Public Notification received2 linked violations
August 6, 2004State Public Notification requested1 linked violation
June 28, 2004State Public Notification requested2 linked violations
March 3, 2004State Formal Notice of Violation issued2 linked violations
February 2, 2004State Public Notification requested2 linked violations
February 2, 2004State Formal Notice of Violation issued1 linked violation
February 2, 2004State Public Notification requested1 linked violation
February 2, 2004State Formal Notice of Violation issued2 linked violations
February 2, 2004State Formal Notice of Violation issued8 linked violations
February 2, 2004State Public Notification requested1 linked violation
February 2, 2004State Formal Notice of Violation issued3 linked violations
February 2, 2004State Formal Notice of Violation issued9 linked violations
February 2, 2004State Formal Notice of Violation issued4 linked violations
February 2, 2004State Public Notification requested4 linked violations
February 2, 2004State Public Notification requested5 linked violations
February 2, 2004State Public Notification requested4 linked violations
February 2, 2004State Formal Notice of Violation issued1 linked violation
February 2, 2004State Formal Notice of Violation issued3 linked violations
February 2, 2004State Formal Notice of Violation issued1 linked violation
February 2, 2004State Public Notification requested3 linked violations
February 2, 2004State Public Notification requested4 linked violations
February 2, 2004State Formal Notice of Violation issued4 linked violations
February 2, 2004State Formal Notice of Violation issued3 linked violations
February 2, 2004State Formal Notice of Violation issued3 linked violations
February 2, 2004State Public Notification requested2 linked violations
February 2, 2004State Public Notification requested3 linked violations
February 2, 2004State Public Notification requested4 linked violations
February 2, 2004State Public Notification requested1 linked violation
February 2, 2004State Public Notification requested2 linked violations
January 30, 2004State Public Notification requested3 linked violations
December 16, 2003State Compliance achieved1 linked violation
December 16, 2003State Compliance achieved1 linked violation
September 26, 2003State Compliance achievedgeneral compliance action — not tied to a specific violation on record
September 18, 2003State Formal Notice of Violation issued6 linked violations
September 18, 2003State Public Notification requested3 linked violations
April 17, 2002State Public Notification received5 linked violations
March 25, 2002State Bilateral Compliance Agreement signed9 linked violations
February 7, 2000State Compliance achieved2 linked violations
February 7, 2000State Compliance achieved6 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved6 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved5 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved5 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved4 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved3 linked violations
February 7, 2000State Compliance achieved2 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received5 linked violations
February 3, 2000State Public Notification received6 linked violations
February 3, 2000State Public Notification received6 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received5 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received6 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received3 linked violations
February 3, 2000State Public Notification received8 linked violations
February 3, 2000State Public Notification received4 linked violations
February 3, 2000State Public Notification received8 linked violations
February 3, 2000State Public Notification received5 linked violations
February 3, 2000State Public Notification received2 linked violations
February 3, 2000State Public Notification received5 linked violations
February 3, 2000State Public Notification received5 linked violations
February 3, 2000State Public Notification received4 linked violations
January 14, 2000State Formal Notice of Violation issued5 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Public Notification requested4 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Public Notification requested2 linked violations
January 14, 2000State Public Notification requested2 linked violations
January 14, 2000State Public Notification requested2 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested4 linked violations
January 14, 2000State Public Notification requested5 linked violations
January 14, 2000State Public Notification requested31 linked violations
January 14, 2000State Public Notification requested4 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested2 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested9 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued7 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Formal Notice of Violation issued5 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued2 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued34 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued3 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Formal Notice of Violation issued4 linked violations
January 14, 2000State Formal Notice of Violation issued5 linked violations
January 14, 2000State Formal Notice of Violation issued5 linked violations
January 14, 2000State Formal Notice of Violation issued6 linked violations
January 14, 2000State Public Notification requested4 linked violations
January 14, 2000State Public Notification requested18 linked violations
January 14, 2000State Public Notification requested3 linked violations
January 14, 2000State Public Notification requested6 linked violations
January 14, 2000State Public Notification requested5 linked violations
January 14, 2000State Public Notification requested5 linked violations
January 14, 2000State Public Notification requested4 linked violations
January 14, 2000State Public Notification requested5 linked violations
July 12, 1993State Compliance achieved3 linked violations
March 25, 1992State Compliance achieved1 linked violation
March 6, 1992State Public Notification requested4 linked violations
March 6, 1992State Formal Notice of Violation issued2 linked violations
March 6, 1992State Formal Notice of Violation issued1 linked violation
December 1, 1989State Formal Notice of Violation issued1 linked violation
October 20, 1989State Compliance achieved1 linked violation
November 16, 1986State Formal Notice of Violation issued1 linked violation
September 20, 1985State Bilateral Compliance Agreement signed3 linked violations

Contact

MASON CITY WATER DEPARTMENT

641-421-3683

MASON CITY, IA 50401