CORVALLIS, OR · Benton County

KNOLL TERRACE PARK 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 Oregon’s official records. Always confirm current status with Oregon before making decisions based on this information.

System facts

System ID (PWSID): OR4100174
System type: Community Water System
Population served: 452
Service connections: 210
Ownership: privately owned
Water source: groundwater (wells)

Violation history

Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2025 – July 18, 2025
Resolved
LSL Inventory
Health-based
LEAD AND COPPER RULE REVISIONS
October 17, 2024 – February 28, 2025
Resolved
Monitoring, Regular
—
Nitrate
January 1, 2024 – December 31, 2024
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2023 – August 21, 2023
Resolved
Monitoring, Regular
—
Carbofuran
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Picloram
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Dinoseb
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Hexachlorocyclopentadiene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Atrazine
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
LASSO
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Heptachlor
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Heptachlor epoxide
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
2,4-D
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
2,4,5-TP
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
HEXACHLOROBENZENE
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Benzo(a)pyrene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Pentachlorophenol
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Total Polychlorinated Biphenyls (PCB)
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,2-DIBROMO-3-CHLOROPROPANE
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
ETHYLENE DIBROMIDE
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Chlordane
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,2,4-Trichlorobenzene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
cis-1,2-Dichloroethylene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Xylenes, Total
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
DICHLOROMETHANE
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
o-Dichlorobenzene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
p-Dichlorobenzene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Vinyl chloride
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,1-Dichloroethylene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
trans-1,2-Dichloroethylene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,2-Dichloroethane
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,1,1-Trichloroethane
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Carbon tetrachloride
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,2-Dichloropropane
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Trichloroethylene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
1,1,2-Trichloroethane
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Tetrachloroethylene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
CHLOROBENZENE
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Benzene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Toluene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Ethylbenzene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Styrene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Endrin
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
BHC-GAMMA
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Methoxychlor
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Toxaphene
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Dalapon
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Diquat
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Endothall
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Glyphosate
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Di(2-ethylhexyl) adipate
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
OXAMYL
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Simazine
January 1, 2023 – December 31, 2025
Archived
Monitoring, Regular
—
Di(2-ethylhexyl) phthalate
January 1, 2023 – December 31, 2025
Archived
Monitoring, Routine (RTCR)
—
Revised Total Coliform Rule
May 1, 2018 – May 31, 2018
Resolved
Failure to Conduct Assessment Monitoring
—
COLIPHAGE
January 1, 2012 – December 31, 2012
Resolved
Failure to Conduct Assessment Monitoring
—
COLIPHAGE
January 1, 2012 – December 31, 2012
Resolved
Monitoring and Reporting (DBP)
—
Total Haloacetic Acids (HAA5)
January 1, 2005 – December 31, 2007
Resolved
Consumer Confidence Report Inadequate Reporting
—
Consumer Confidence Rule
October 19, 2003 – November 8, 2006
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2003 – November 8, 2006
Resolved
Consumer Confidence Report Inadequate Reporting
—
Consumer Confidence Rule
October 19, 2002 – November 8, 2006
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2002 – November 8, 2006
Resolved
Monitoring, Regular
—
Arsenic
January 1, 2002 – December 31, 2004
Resolved
Monitoring, Regular
—
cis-1,2-Dichloroethylene
January 1, 2002 – December 31, 2004
Resolved
Monitoring, Regular
—
DICHLOROMETHANE
January 1, 2002 – December 31, 2004
Resolved
Monitoring, Regular
—
o-Dichlorobenzene
January 1, 2002 – December 31, 2004
Resolved
Monitoring, Regular
—
p-Dichlorobenzene
January 1, 2002 – December 31, 2004
Resolved
Monitoring, Regular
—
Gross Alpha, Excl. Radon and U
January 1, 1996 – December 31, 1999
Resolved
Monitoring, Regular
—
Gross Alpha, Excl. Radon and U
June 1, 1976 – May 31, 1980
Archived
Monitoring, Regular
—
Combined Radium (-226 and -228)
June 1, 1976 – May 31, 1980
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
July 1, 2025 – July 18, 2025	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
October 17, 2024 – February 28, 2025	LSL Inventory	LEAD AND COPPER RULE REVISIONS	Health-based	Resolved
January 1, 2024 – December 31, 2024	Monitoring, Regular	Nitrate	—	Resolved
July 1, 2023 – August 21, 2023	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
January 1, 2023 – December 31, 2025	Monitoring, Regular	Carbofuran	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Picloram	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Dinoseb	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Hexachlorocyclopentadiene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Atrazine	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	LASSO	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Heptachlor	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Heptachlor epoxide	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	2,4-D	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	2,4,5-TP	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	HEXACHLOROBENZENE	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Benzo(a)pyrene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Pentachlorophenol	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Total Polychlorinated Biphenyls (PCB)	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,2-DIBROMO-3-CHLOROPROPANE	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	ETHYLENE DIBROMIDE	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Chlordane	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,2,4-Trichlorobenzene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	cis-1,2-Dichloroethylene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Xylenes, Total	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	DICHLOROMETHANE	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	o-Dichlorobenzene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	p-Dichlorobenzene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Vinyl chloride	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,1-Dichloroethylene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	trans-1,2-Dichloroethylene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,2-Dichloroethane	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,1,1-Trichloroethane	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Carbon tetrachloride	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,2-Dichloropropane	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Trichloroethylene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	1,1,2-Trichloroethane	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Tetrachloroethylene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	CHLOROBENZENE	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Benzene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Toluene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Ethylbenzene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Styrene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Endrin	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	BHC-GAMMA	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Methoxychlor	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Toxaphene	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Dalapon	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Diquat	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Endothall	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Glyphosate	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Di(2-ethylhexyl) adipate	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	OXAMYL	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Simazine	—	Archived
January 1, 2023 – December 31, 2025	Monitoring, Regular	Di(2-ethylhexyl) phthalate	—	Archived
May 1, 2018 – May 31, 2018	Monitoring, Routine (RTCR)	Revised Total Coliform Rule	—	Resolved
January 1, 2012 – December 31, 2012	Failure to Conduct Assessment Monitoring	COLIPHAGE	—	Resolved
January 1, 2012 – December 31, 2012	Failure to Conduct Assessment Monitoring	COLIPHAGE	—	Resolved
January 1, 2005 – December 31, 2007	Monitoring and Reporting (DBP)	Total Haloacetic Acids (HAA5)	—	Resolved
October 19, 2003 – November 8, 2006	Consumer Confidence Report Inadequate Reporting	Consumer Confidence Rule	—	Resolved
July 1, 2003 – November 8, 2006	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
October 19, 2002 – November 8, 2006	Consumer Confidence Report Inadequate Reporting	Consumer Confidence Rule	—	Resolved
July 1, 2002 – November 8, 2006	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
January 1, 2002 – December 31, 2004	Monitoring, Regular	Arsenic	—	Resolved
January 1, 2002 – December 31, 2004	Monitoring, Regular	cis-1,2-Dichloroethylene	—	Resolved
January 1, 2002 – December 31, 2004	Monitoring, Regular	DICHLOROMETHANE	—	Resolved
January 1, 2002 – December 31, 2004	Monitoring, Regular	o-Dichlorobenzene	—	Resolved
January 1, 2002 – December 31, 2004	Monitoring, Regular	p-Dichlorobenzene	—	Resolved
January 1, 1996 – December 31, 1999	Monitoring, Regular	Gross Alpha, Excl. Radon and U	—	Resolved
June 1, 1976 – May 31, 1980	Monitoring, Regular	Gross Alpha, Excl. Radon and U	—	Archived
June 1, 1976 – May 31, 1980	Monitoring, Regular	Combined Radium (-226 and -228)	—	Archived

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

Enforcement actions

No enforcement actions on record for this system.

Contact

KNOLL TERRACE PARK

541-752-2225

CORVALLIS, OR 97330