CEDAR RAPIDS, IA · Linn County
TWIN KNOLLS 6TH ADDITION Water System
Inactive system
This water system is marked inactive in EPA’s federal records as of September 29, 2009. It is no longer an operating public water system under this PWSID, and no compliance deadlines — including the 2027 Consumer Confidence Report rule — apply to it.
If you are a resident looking for your current water provider, see water systems in Linn County, IA.
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)
- IA5784310
- System type
- Community Water System
- Population served
- 45
- Service connections
- 15
- Ownership
- privately owned
- Water source
- groundwater (wells)
TWIN KNOLLS 6TH ADDITION is one of 1,221 community water systems in Iowa in the 500 or fewer people size category, formerly serving 45 people from groundwater.
EPA's federal records list this system as inactive in 2009; the record below is historical.
As of August 1, 2026, its federal record holds 13 entries between 1980 and 2007, all of which EPA lists as closed. Nothing has been added since 2007.
Of the 13, 12 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, the Total Coliform Rules, and the Lead and Copper Rule.
Violation history
Maximum Contaminant Level Violation, Monthly (TCR)
Health-basedColiform (TCR)
September 1, 2007 – September 30, 2007
ResolvedMonitoring, Routine Major (TCR)
—Coliform (TCR)
March 1, 1993 – March 31, 1993
ResolvedFollow-up Or Routine LCR Tap M/R
—Lead and Copper Rule
October 1, 1989 – February 13, 1991
ResolvedMonitoring, Regular
—Barium
April 1, 1987 – March 31, 1990
ResolvedMonitoring, Regular
—Arsenic
April 1, 1987 – March 31, 1990
ResolvedMonitoring, Regular
—Cadmium
April 1, 1987 – March 31, 1990
ResolvedMonitoring, Regular
—Chromium
April 1, 1987 – March 31, 1990
ResolvedMonitoring, Regular
—Selenium
April 1, 1987 – March 31, 1990
ResolvedMonitoring, Regular
—Chromium
September 30, 1980 – September 29, 1983
ArchivedMonitoring, Regular
—Selenium
September 30, 1980 – September 29, 1983
ArchivedMonitoring, Regular
—Fluoride
September 30, 1980 – September 29, 1983
ArchivedMonitoring, Regular
—Arsenic
September 30, 1980 – September 29, 1983
ArchivedMonitoring, Regular
—Cadmium
September 30, 1980 – September 29, 1983
Archived
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 |
|---|---|---|---|---|
| September 1, 2007 – September 30, 2007 | Maximum Contaminant Level Violation, Monthly (TCR) | Coliform (TCR) | Health-based | Resolved |
| March 1, 1993 – March 31, 1993 | Monitoring, Routine Major (TCR) | Coliform (TCR) | — | Resolved |
| October 1, 1989 – February 13, 1991 | Follow-up Or Routine LCR Tap M/R | Lead and Copper Rule | — | Resolved |
| April 1, 1987 – March 31, 1990 | Monitoring, Regular | Barium | — | Resolved |
| April 1, 1987 – March 31, 1990 | Monitoring, Regular | Arsenic | — | Resolved |
| April 1, 1987 – March 31, 1990 | Monitoring, Regular | Cadmium | — | Resolved |
| April 1, 1987 – March 31, 1990 | Monitoring, Regular | Chromium | — | Resolved |
| April 1, 1987 – March 31, 1990 | Monitoring, Regular | Selenium | — | Resolved |
| September 30, 1980 – September 29, 1983 | Monitoring, Regular | Chromium | — | Archived |
| September 30, 1980 – September 29, 1983 | Monitoring, Regular | Selenium | — | Archived |
| September 30, 1980 – September 29, 1983 | Monitoring, Regular | Fluoride | — | Archived |
| September 30, 1980 – September 29, 1983 | Monitoring, Regular | Arsenic | — | Archived |
| September 30, 1980 – September 29, 1983 | Monitoring, Regular | Cadmium | — | Archived |
Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)
Enforcement actions
- October 22, 2007State Public Notification received8 linked violations
- September 21, 2007State Formal Notice of Violation issued6 linked violations
- September 20, 2007State Public Notification received11 linked violations
- July 16, 2004State Public Notification received6 linked violations
- December 29, 1999State Public Notification requested6 linked violations
- November 15, 1999State Compliance achieved6 linked violations
- November 5, 1999State Compliance achieved8 linked violations
- May 14, 1993State Formal Notice of Violation issued4 linked violations
- June 2, 1992State Public Notification received1 linked violation
- May 19, 1992State Formal Notice of Violation issued2 linked violations
- May 19, 1992State Public Notification requested1 linked violation
- April 30, 1992State Compliance achieved2 linked violations
- February 14, 1991State Public Notification receivedgeneral compliance action — not tied to a specific violation on record
- February 14, 1991State Public Notification received1 linked violation
- February 14, 1991State Public Notification received1 linked violation
- February 13, 1991State Compliance achieved1 linked violation
- February 13, 1991State Compliance achieved1 linked violation
- February 13, 1991State Compliance achieved1 linked violation
- February 13, 1991State Compliance achieved2 linked violations
- January 30, 1991State Administrative/Compliance Order without penalty issued2 linked violations
- January 30, 1991State Administrative Penalty assessed3 linked violations
- January 30, 1991State Administrative/Compliance Order without penalty issued1 linked violation
Last known contact on file (system is inactive)
TWIN KNOLLS 6TH ADDITION
319-851-7514
CEDAR RAPIDS, IA 52411