Little Dalton Wash

Waterbody ID (WBID): CAR4052000020210323060989
County / counties: Los Angeles
Regional Water Board: Regional Board 4 - Los Angeles Region
Waterbody type: River & Stream
Condition category: Category 5 — 303(d) listed, TMDL required
Integrated Report cycle: 2026

303(d) listings (5)

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

Pollutant / stressor	Decision ID	Final listing decision	Decision status	TMDL requirement status	TMDL project	TMDL priority
alpha-Endosulfan (Endosulfan 1)Pesticides	140194	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low
CopperMetals	140193	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low
Indicator BacteriaPathogens	150296	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low
LeadMetals	140198	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low
ZincMetals	140206	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low

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: Aug 21, 2026, 12:44 AM UTC
Waterbody ID: CAR4052000020210323060989
CALWNUM: 4405.2
WBD code: 180701060402
Geometry: Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)

View official Water Board fact sheet ↗Download Appendix A source file ↗

Location

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

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Watershed: —
Assessed size: 6.96 Miles

Facilities with an NAL exceedance for a listed pollutant (12)

Geographically associated industrial stormwater facilities whose reported results exceeded an Industrial General Permit Numeric Action Level for a pollutant this waterbody is listed for.

Derived

Award Metals Inc4 19I009949

Copper, Zinc · most recent exceedance RY 2024 · association: derived watershed association

Azusa Refinishing Company4 19I027947

Zinc · most recent exceedance RY 2018 · association: derived watershed association

Azusa Sch Dist4 19I000805

Zinc · most recent exceedance RY 2024 · association: derived watershed association

CA Amforge4 19I001029

Copper, Zinc · most recent exceedance RY 2025 · association: derived watershed association

Complete Metal Design Inc4 19I027490

Zinc · most recent exceedance RY 2020 · association: derived nearby in watershed

Davis Wire Corp4 19I010894

Zinc · most recent exceedance RY 2015 · association: derived watershed association

Hydro Fitting Mfg Corp4 19I029788

Zinc · most recent exceedance RY 2025 · association: derived watershed association

INWESCO INCORPORATED4 19I028795

Zinc · most recent exceedance RY 2022 · association: derived watershed association

Lindsey Manufacturing Co4 19I019437

Zinc · most recent exceedance RY 2025 · association: derived watershed association

Stabile Plating4 19I009518

Zinc · most recent exceedance RY 2017 · association: derived watershed association

Tecomet Inc4 19I019285

Copper, Zinc · most recent exceedance RY 2021 · association: derived nearby in watershed

Western Pacific Storage Systems4 19I026682

Zinc · most recent exceedance RY 2017 · association: derived watershed association

This is derived co-occurrence between a calculated NAL comparison and the official 303(d) listing for this waterbody. An NAL exceedance triggers Exceedance Response Actions under the permit; it is not a violation and does not establish that any facility caused or contributed to this impairment.

Derived facility associations

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

Derived

5 Boys Precision Machining

Covina · No Exposure Certification

derived_watershed_association