Mt. Diablo Creek

2026 303(d) list Waterbody ID CAR2073104019990217163214 River & Stream Region 2 · San Francisco Bay

At a glance

2026 listing Evidence: State-published: On the 2026 303(d) list · 3 Appendix A decisions; Category 5: a TMDL is required; What a listing means
Pollutants and stressors: 3 pollutants in 3 Appendix A categories; Other Cause (1) · Pesticides (1) · Total Toxics (1); Listing decisions
TMDL information Evidence: State-published: 3 decisions with a TMDL requirement status; 1 name a TMDL project; Status codes as published: 5A, 5B; TMDL details
Regional Water Board: Region 2 · San Francisco Bay; River & Stream · Map
Industrial stormwater facilities: 3 report it as their receiving water Evidence: identification corroborated; 32 within 1 km Evidence: geographic proximity; Neither count establishes a discharge · Facilities

What a 303(d) listing means

The Clean Water Act section 303(d) list names waters that do not meet water quality standards for one or more pollutants or stressors. California publishes it in the Integrated Report; this page shows the 2026 decisions from Appendix A as published.

A listing describes the condition of the waterbody. It does not identify which sources cause the impairment, and it does not by itself place a requirement on any particular facility.
Listed waters do not all have the same status. The Integrated Report category says how an impairment is being addressed: 5, a TMDL is required; 4a, addressed by a USEPA-approved TMDL; 4b, addressed by other pollution control requirements; 4c, impairment not caused by a pollutant. This waterbody's decisions are in category 5.
TMDL requirement status values (such as 5A or 5B) are shown exactly as published in Appendix A.

2026 listing status Evidence: State-published

On the 2026 303(d) list: Yes
Appendix A decisions: 3
Integrated Report category: 5 (a TMDL is required)
Listing cycle: 2026
State Board adoption: 2026-02-03 (Resolution 2026-0005)
USEPA approval: not confirmed — submittal letter to USEPA published; no approval found on the report page (checked 2026-10-22)
Regional Water Board: 2 — San Francisco Bay

Published by the State Water Resources Control Board (2026 California Integrated Report, Appendix A). Listing status is taken from Appendix A only. A listing describes the condition of this waterbody, not of any facility.

Location

Loading the waterbody shape…

Open this area on the statewide map · Browse impaired waters

Listing decisions and pollutants Evidence: State-published

Grouped by the Pollutant Category published in Appendix A. Pollutant names, categories and decisions are exactly as published.

Other Cause (1 decision)

Other Cause: Appendix A decisions
Pollutant	Pollutant category	Category	Final listing decision	Decision status	Sources	Decision ID
Benthic Community Effects	Other Cause	5	List on 303(d) list (TMDL required list)	Revised	A Source Unknown	154164

Pesticides (1 decision)

Pesticides: Appendix A decisions
Pollutant	Pollutant category	Category	Final listing decision	Decision status	Sources	Decision ID
Diazinon	Pesticides	5	List on 303(d) list (being addressed by USEPA approved TMDL)	Original	A Source Unknown	69765

Total Toxics (1 decision)

Total Toxics: Appendix A decisions
Pollutant	Pollutant category	Category	Final listing decision	Decision status	Sources	Decision ID
Toxicity	Total Toxics	5	Do Not Delist from 303(d) list (TMDL required list)	Revised	A Source Unknown	151290

TMDL information Evidence: State-published

TMDL information published for this waterbody
Pollutant	TMDL requirement status	TMDL project	Priority	USEPA approval of TMDL	Expected attainment
Benthic Community Effects	5A	—	Low	—	—
Diazinon	5B	San Francisco Bay Urban Creeks Diazinon	—	2007-05-16	—
Toxicity	5A	—	Low	—	—

This is TMDL information for the waterbody. It does not establish that a TMDL applies to any particular facility. Facility-specific TMDL requirements recorded in SMARTS appear on facility pages and are not linked to this waterbody until reviewed.

HUC12 watersheds

Published with the listing Evidence: publisher-reported

Mount Diablo Creek-Frontal Suisun Bay Estuaries 180500010302
Suisun Bay Estuaries-Frontal Suisun Bay 180500010401

Overlapping the waterbody's shape Evidence: spatial

Mount Diablo Creek-Frontal Suisun Bay Estuaries 180500010302 also published
Suisun Bay Estuaries-Frontal Suisun Bay 180500010401 also published

Industrial stormwater facilities

Evidence: identification corroborated

Shows: the facility named this waterbody as its receiving water in SMARTS, and the name and the facility's location are consistent with it. Does not establish: a discharge pathway, a discharge of any pollutant, or a cause of the listing.

Evidence: geographic proximity

Shows: the facility's reported location is within 1 km of the waterbody's mapped shape. Does not establish: that the facility discharges to this waterbody, or any other relationship.

Report this waterbody as their receiving water Evidence: identification corroborated

Facilities whose reported receiving water is identified as this waterbody
Facility	WDID	Status	Distance from reported location	Map
Bay Area News Group	2 07NEC003084	Terminated	75 m	map
Suns Pad & Foam Recycling	2 07I030664	Active	248 m	map
American Tow	2 07I011628	Terminated	619 m	map

Receiving water reported by facility — waterbody identification corroborated by geographic evidence. 3 facilities.

Within 1 km of a facility's reported location Evidence: geographic proximity

Spatial proximity only; discharge pathway not established. Being near this waterbody does not mean a facility discharges to it.

Facilities whose reported location is within 1 km of this waterbody
Facility	WDID	Status	Distance	Map
Conco Cement Co	2 07I000475	Terminated	54 m	map
Tuthill Pump Co CA	2 07I013135	Terminated	60 m	map
Bay Area News Group	2 07NEC003084	Terminated	75 m	map
Bay Area News Group	2 07NEC013664	Active	106 m	map
Shred It Concord	2 07NEC005288	Terminated	150 m	map
Eagle Iron Fabrication Inc	2 07I030342	Terminated	204 m	map
A G Schwartz Trucking Co Inc	2 07I024112	Terminated	213 m	map
Suns Pad & Foam Recycling	2 07I030664	Active	248 m	map
Military Ocean Terminal Concord	2 07I016964	Active	259 m	map
Stericycle Inc Concord	2 07NEC009466	Active	289 m	map
Concord DC	2 07I019006	Active	448 m	map
SEG Trucking	2 07I018991	Active	476 m	map
Laidlaw Transit Amr Concord	2 07I013516	Terminated	615 m	map
AMR Concord	2 07I019461	Terminated	615 m	map
American Tow	2 07I011628	Terminated	619 m	map
BAY AREA CUSTOM LABORATORIES	2 07NEC006819	Active	648 m	map
County Connection	2 07I000229	Active	707 m	map
Ro Sal Auto Wreckers	2 07I010257	Terminated	732 m	map
Ro Sal Auto Wreckers & Tow	2 07I015587	Terminated	732 m	map
Buds Bugs	2 07I010181	Terminated	743 m	map
Etch Tech	2 07I010768	Terminated	758 m	map
Arnold Electronics Inc	2 07I012636	Terminated	758 m	map
Etch Tech	2 07I016704	Terminated	758 m	map
SFIC	2 07NEC005422	Active	797 m	map
RESAWN INDUSTRIES LLC	2 07I030213	Terminated	814 m	map
Pacific Instruments Inc	2 07NEC009901	Active	889 m	map
Benchmark	2 07I027230	Active	915 m	map
Benchmark Electronics	2 07I027770	Terminated	952 m	map
Mountaire Garden Ctr	2 07I013656	Terminated	960 m	map
American Stage Tours	2 07I015787	Terminated	981 m	map
American Stage Tours	2 07I003015	Terminated	981 m	map
First Student Inc 12605	2 07I023179	Active	984 m	map

32 facilities, nearest first.

Sources and provenance

Sources behind this page
Information	Source	Retrieved
Watershed Boundary Dataset HU2 GeoPackages 15, 16, 18 (WBDHU12)	USGS	2026-10-22
2026 California Integrated Report, Appendix A: 2026 303(d) List (final)	SWRCB	2026-10-22
Final_2026_Rivers_and_Streams + Final_2026_Lakes_and_Reservoirs (FeatureServer 0)	SWRCB GIS	2026-10-22
SMARTS TMDL requirements	SMARTS	2026-10-21

Relationships computed 2026-10-22 (facility_huc12/1, proximity/1, receiving_water/2, tmdl_reference/1, waterbody_huc12_ovl/1, waterbody_huc12_pub/1).

Integrated Report categories: 5, a TMDL is required; 4a, addressed by a USEPA-approved TMDL; 4b, addressed by other pollution control requirements; 4c, impairment not caused by a pollutant.