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The tables below list all violations that the state reported to EPA for this water system. Health-based violations are listed first, followed by treatment technique, MRDL, monitoring, reporting, and other violations.

Health-based	Violations of maximum contaminant levels (MCLs) or maximum residual disinfectant levels (MRDLs), which specify the highest concentrations of contaminants or disinfectants, respectively, allowed in drinking water; or of treatment technique (TT) rules, which specify required processes intended to reduce the amounts of contaminants in drinking water. MCLs, MRDLs, and treatment technique rules are all health-based drinking water standards.
Maximum Contaminant Level or MCL	The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
Treatment Technique	A required process intended to reduce the level of a contaminant in drinking water.
Maximum residual disinfectant level or MRDL	The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Monitoring & reporting	Failure to conduct regular monitoring of drinking water quality, as required by SDWA, or to submit monitoring results in a timely fashion to the primacy agency or EPA.
Public notification & other	Failure to provide notification to the public as required by the Violations of Public Notification Rule and the Consumer Confidence Report Rule, and violations of other requirements such as those violations related to variances and exemptions.

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Violations

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Violation Category Code	Violation Type Description	Rule Name	Contaminant Name	Violation ID	Compliance Status Description	Compliance Period Begin Date	Compliance Period End Date	Is Health Based Ind
RPT	Notification, Known or Potential LSL	Lead and Copper Rule Revisions	LEAD AND COPPER RULE REVISIONS	7096523	Open	02-JUL-2025	-	No
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096521	Returned to Compliance	01-JUL-2009	30-SEP-2009	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096520	Returned to Compliance	01-APR-2009	30-JUN-2009	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096516	Returned to Compliance	01-JAN-2009	31-MAR-2009	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096515	Returned to Compliance	01-OCT-2008	31-DEC-2008	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096514	Returned to Compliance	01-JUL-2008	30-SEP-2008	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096513	Returned to Compliance	01-APR-2008	30-JUN-2008	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096512	Returned to Compliance	01-JAN-2008	31-MAR-2008	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096511	Returned to Compliance	01-OCT-2007	31-DEC-2007	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096510	Returned to Compliance	01-JUL-2007	30-SEP-2007	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096509	Returned to Compliance	01-APR-2007	30-JUN-2007	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096508	Returned to Compliance	01-JAN-2007	31-MAR-2007	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096507	Returned to Compliance	01-OCT-2006	31-DEC-2006	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096407	Returned to Compliance	01-JUL-2006	30-SEP-2006	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096306	Returned to Compliance	01-APR-2006	30-JUN-2006	Yes
MCL	Maximum Contaminant Level Violation, Average	Arsenic Rule	Arsenic	7096206	Returned to Compliance	23-JAN-2006	31-MAR-2006	Yes
MR	Monitoring, Regular	Radionuclides and Revised Rad Rule	Gross Alpha, Excl. Radon and U	7095880	Known	30-JUN-1977	29-JUN-1981	No

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Enforcement Actions

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Latest Enforcement ID	Associated To Violation ID	Enforcement Action Type Code	Enforcement Action Description	Enforcement Date	Originator Description	Enforcement Comment
1644	7096523	SIE	State Public Notification requested	03-JUL-2025	State	-
1640	7096306	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096407	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096507	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096508	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096509	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096510	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096511	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096512	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096513	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096514	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096515	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096516	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096520	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096521	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l
1640	7096206	SOX	State Compliance achieved	22-OCT-2009	State	with 2009Q4 result RAA = 0.010 mg/l

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All Facilities

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Facility Name	Facility ID	Is Source	Facility Type Description	Water Type Description	Availability Description	Facility Activity Status
WELL 3 (50277) ABANDONED	21961	Yes	Well	Ground water	Other	Inactive
WELL 8 (02165)	43635	Yes	Well	Ground water	Permanent	Active
WELL 7 (02037)	40805	Yes	Well	Ground water	Permanent	Active
WELL 6 (01744)	34740	Yes	Well	Ground water	Permanent	Active
WELL 5 (50279) ABANDONED	21963	Yes	Well	Ground water	Other	Inactive
WELL 4 (50278) ABANDONED	21962	Yes	Well	Ground water	Other	Inactive
MASON CITY	24621	No	Distribution System/Zone	-	-	Active
SCHOOL LEAD SAMPLING	46472	No	Distribution System/Zone	-	-	Active
CHILD CARE FACILITY LEAD SAMPLING	46473	No	Distribution System/Zone	-	-	Active
GENERIC FINISHED SAMPLING STATION	28280	No	Sampling Station	-	-	Active
GENERIC RAW SAMPLING STATION	30702	No	Sampling Station	-	-	Active
DISTRIBUTION ELEVATED STORAGE	11576	No	Storage	-	-	Active
TP 01-TREATMENT PLANT	16743	No	Treatment Plant	-	-	Active
TP 02-TREATMENT PLANT	16744	No	Treatment Plant	-	-	Inactive

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Treatment Processes

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Facility Name	Facility ID	Treatment Process	Treatment Objective
TP 01-TREATMENT PLANT	16743	Fluoridation	Other
TP 01-TREATMENT PLANT	16743	Innovative	Inorganics removal
TP 01-TREATMENT PLANT	16743	Permanganate	Iron removal
TP 01-TREATMENT PLANT	16743	Permanganate	Manganese removal
TP 01-TREATMENT PLANT	16743	Hypochlorination, Post	Disinfection
TP 01-TREATMENT PLANT	16743	Hypochlorination, Pre	Disinfection
TP 01-TREATMENT PLANT	16743	Inhibitor, Orthophosphate	Corrosion control
TP 02-TREATMENT PLANT	16744	Fluoridation	Other
TP 02-TREATMENT PLANT	16744	Gaseous Chlorination, Pre	Disinfection
TP 02-TREATMENT PLANT	16744	Gaseous Chlorination, Pre	Iron removal
TP 02-TREATMENT PLANT	16744	Sequestration	Iron removal

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