← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Waterbody ID (WBID)
CAR4036400019990202145922
County / counties
Ventura
Regional Water Board
Regional Board 4 - Los Angeles Region
Waterbody type
River & Stream
Condition category
Category 4a — TMDL completed
Integrated Report cycle
2026

303(d) listings (9)

Each row is one official listing decision from Appendix A of the Final 2026 California Integrated Report. Source terminology is preserved as published.

Pollutant / stressorDecision IDFinal listing decisionDecision statusTMDL requirement statusTMDL projectTMDL priority
ChlordanePesticides137347Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—
Chlordane (tissue)Pesticides70499Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—
DDT (Dichlorodiphenyltrichloroethane)Pesticides149456Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—
DDT (tissue)Pesticides70680Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—
DieldrinPesticides137357Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—
PCBs (Polychlorinated biphenyls)Toxic Organics70227List on 303(d) list (being addressed by USEPA approved TMDL)Original5B — Addressed by USEPA-approved TMDLCalleguas Creek PCBs (7)—
SulfatesToxic Inorganics89773Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B — Addressed by USEPA-approved TMDLCalleguas Creek Boron/Sulfate/TDS (4)—
Total Dissolved SolidsSALINITY/TOTAL DISSOLVED SOLIDS/CHLORIDES/SULFATES137383Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B — Addressed by USEPA-approved TMDLCalleguas Creek Boron/Sulfate/TDS (4)—
ToxaphenePesticides68995Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B — Addressed by USEPA-approved TMDLCalleguas Creek Historic Pesticides (5)—

Source & provenance

Agency
California State Water Resources Control Board
Report
Final 2026 California Integrated Report
Dataset
Appendix A — 2026 303(d) List of Impaired Waters
Imported
Sep 16, 2026, 10:57 PM UTC
Waterbody ID
CAR4036400019990202145922
CALWNUM
4408.24
WBD code
180701030104
Geometry
Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)

Location

Official 2026 Water Board geometry. Demonstration facility markers are shown for context only.

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Watershed
—
Assessed size
5.49 Miles

Derived facility associations

Industrial stormwater facilities geographically associated with this waterbody. These are derived spatial associations, not Water Board findings.

Derived
2193 Anchor Court

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Alpha Printing

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

ARC Document Solutions

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Atara Biotherapeutics

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Automated Production Specialties Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Capsida Biotherapeutics

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

CHE Precision Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

City of Thousand Oaks Hill Canyon Wastewater Treatment Plant

Camarillo · Notice of Non-Applicability · 0.68 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Colorful Products Corp

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Concept Matrix Solutions

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Condor Pacific Industries of California Incorporated

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Conejo Valley USD Maintenance

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

CREATIVEDISPLAYPANELSINC

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

CTL SystemWare Inc

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

DALO ENGINEERING INC

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Duss Screw Products

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Eastwind Screenprint

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

ECA Medical Instruments Tourmaline

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

ElectraCraft Power Boats Inc

Westlake Village · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Electronic Sensor Technology HQ

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Envision Avionics Panels Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

FC Management Services Inc DBA PC Recycle

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Flitterman Collection LLC

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Follmer Development Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Follmer Development Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Follmer Development Inc

Newbury Park · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

General Pavement Management Inc

Thousand Oaks · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Golden Valley Tool Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

HK Lighting Group

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

HKL LLC

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Home

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Ibex Engineering

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Implant Direct Sybron LLC

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

JBW PRECISION INC

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

JN Engineering

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

JW Molding Inc

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Kibbetech INC

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

MKM Manufacturing Design

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Multilayer Prototypes Incorporated

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Natren Inc

Westlake Village · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Neet Feet

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Oglesby Machining Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

PERILLO INDUSTRIES

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

R&M Precision

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

RAAS Nutritionals LLC

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

RF Circuits and Assembly Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Richardson Joyce

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Rigger Engineering

Thousand Oaks · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Scientific Surface Industries Inc

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Sinister Arms LLC

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

SKYWORKS SOLUTION INC

Newbury Park · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Smart Tech Imaging

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Smith Precision Products Company

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Smiths Interconnect Inc.

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Specialty Concepts Incorporated

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Steelblox Production

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

TO Hillcrest yard

Thousand Oaks · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

tom anderson guitarworks

Thousand Oaks · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Trend Graphics

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Tyamjo Enterprises DBA Cellar Masters

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

UPS Newbury Park CANEW

Newbury Park · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

van nuys awning co

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Weldlogic Inc

Newbury Park · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

XPRESSGRAFIX INC dba Captured Digital

Newbury Park · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Facility records are official Industrial General Permit registrations, but the association between a facility and this waterbody is derived geographically (proximity or shared HUC12 subwatershed) and is not a Water Board receiving-water determination. Where a permit carries a Water Board-stated TMDL requirement naming this water, it is listed separately above.