← Facilities

Industrial stormwater facility

Mt Diablo Unified Sch Dist Mai

2 07I018308 · Notice of Intent · Concord, Contra Costa

Official record — State Water Resources Control Board, Industrial General Permit

Official

Facility record

Facility name
Mt Diablo Unified Sch Dist Mai
WDID
2 07I018308
Application type
Notice of Intent
City
Concord
County
Contra Costa
ZIP
94520
Primary SIC code
4151
SIC description
School Buses
Date active
2003-08-21
Regional Water Board
Regional Board 2 - San Francisco Bay Region

Hydrologic

Geographic context

Official facility coordinate plotted against the official 2026 impaired-water geometry.

Official facility point
37.98176, -122.04429
HUC12 subwatershed
Walnut Creek-Frontal Suisin Bay Estuaries
HUC12 code
180500010204
Impaired-water associations (derived)
3
Loading map…

303(d) context

Associated impaired waters

Grouped by derived geographic association class.

Derived

Subwatershed + nearby

2 waterbodies
Walnut Creek

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (5) Benthic Community Effects, Bifenthrin, Diazinon, Pyrethroids, Toxicity

Distance 0.60 km

Confidence high

Fact sheet

Pine Creek subwatershed (Contra Costa Co, tributary to Walnut Creek)

River & Stream · Integrated Report category 4a · TMDL approved by USEPA

Listed pollutants / stressors (1) Diazinon

Distance 0.88 km

Confidence high

Fact sheet

Same impaired-water subwatershed

1 waterbodies
Grayson Creek

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (5) Benthic Community Effects, Bifenthrin, Deltamethrin, Pyrethroids, Trash

Distance

Confidence low

Fact sheet

Associations are calculated from official facility coordinates, USGS HUC12 boundaries, and official 2026 impaired-water geometry. They do not establish a discharge connection or causation.

TMDL requirements

Water Board-stated TMDL waste load allocations applied to this industrial permit in SMARTS.

Official record — SMARTS TMDL dataset, State Water Board

No SMARTS TMDL requirement is recorded for this WDID. In the statewide TMDL export only permits in Regions 4, 8 and 9 currently carry industrial TMDL requirements, so an absence here is not a statement that the facility discharges to an unimpaired water.

Official monitoring

SMARTS monitoring

Self-reported industrial stormwater sampling results as submitted by the discharger to SMARTS.

Official record — SMARTS parameter data, State Water Board
Reported results
446
Sample events
90
Distinct parameters
7
Reporting years
2015 – 2025
First sample
2015-12-03
Latest sample
2026-01-05
Source regional dataset
Region 2 - San Francisco Bay
Source retrieved
Aug 21, 2026

Official SMARTS public reports

Parameters reported

Reported results over time

Loading reported results…

Most recent reported results

Latest 25 of 446
Sample dateLocationParameterResultUnitsEvent
2026-01-05SD 17 DA 1OilND (non-detect / est.)mg/LQualifying Storm Event
2026-01-05SD 17 DA 1GasolineND (non-detect / est.)mg/LQualifying Storm Event
2026-01-05SD 17 DA 1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2026-01-05SD 17 DA 1pH7.4SUQualifying Storm Event
2026-01-05SD 17 DA 1Total Suspended Solids (TSS)ND (non-detect / est.)mg/LQualifying Storm Event
2025-12-22SD 17 DA 1OilND (non-detect / est.)mg/LQualifying Storm Event
2025-12-22SD 17 DA 1GasolineND (non-detect / est.)mg/LQualifying Storm Event
2025-12-22SD 17 DA 1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2025-12-22SD 17 DA 1pH7.6SUQualifying Storm Event
2025-12-22SD 17 DA 1Total Suspended Solids (TSS)3.6mg/LQualifying Storm Event
2025-02-13SD 10 DA 3OilDNQ .074(non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 10 DA 3GasolineND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 10 DA 3Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 10 DA 3pH8.68SUQualifying Storm Event
2025-02-13SD 10 DA 3Total Suspended Solids (TSS)95.6mg/LQualifying Storm Event
2025-02-13SD 24 DA 2OilND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 24 DA 2GasolineND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 24 DA 2Oil and GreaseDNQ 2.1(non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 24 DA 2pH8.43SUQualifying Storm Event
2025-02-13SD 24 DA 2Total Suspended Solids (TSS)66.4mg/LQualifying Storm Event
2025-02-13SD 4 DA 4OilDNQ .058(non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 4 DA 4GasolineND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 4 DA 4Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2025-02-13SD 4 DA 4pH9.02SUQualifying Storm Event
2025-02-13SD 4 DA 4Total Suspended Solids (TSS)5.2mg/LQualifying Storm Event

Monitoring rows are official self-reported SMARTS submissions, joined to this facility by WDID. California Stormwater Intelligence does not restate, correct, average or evaluate reported values, and no benchmark comparison or violation determination is made.

YDOS-derived

Numeric Action Level comparison

Reported SMARTS analytical results compared against the Numeric Action Levels of the Industrial General Permit version in effect for each reporting year (July 1 – June 30).

Derived
Reporting years evaluated
11
Years with an NAL exceedance
2
Most recent evaluated year
RY 2025
Ruleset
igp_nal_ruleset_v1 / igp_nal_v1
ParameterNAL typeCalculated valueNALResultSamples usedMethod

Oil and Grease

oil_grease

Instantaneous maximum0 samples above25 mg/LAt or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL.2 eligible2 non-detect as zerocount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

pH

ph

Instantaneous maximum0 samples above6 – 9 pH unitsWithin NAL rangeNo eligible result in this reporting year was outside the instantaneous maximum NAL.2 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

Total Suspended Solids (TSS)

tss

Instantaneous maximum0 samples above400 mg/LAt or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL.2 eligible1 non-detect as zerocount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

An NAL exceedance is a permit-defined condition that triggers Exceedance Response Actions under the Industrial General Permit. It is not a violation, an enforcement action, or a Water Board compliance determination. Annual values use the arithmetic average of eligible results with non-detects treated as zero; instantaneous maximum NALs (total suspended solids, oil and grease, pH) are exceeded when two or more eligible results in a reporting year fall outside the level. Rules transcribed from 2014-0057-DWQ as amended by 2015-0122-DWQ (effective 2015-07-01, superseded 2020-06-30); 2014-0057-DWQ as amended by 2018-0028-DWQ (effective 2020-07-01).

Provenance

Source & provenance

Source agency
California State Water Resources Control Board
Source dataset
Industrial General Permit — permitted facilities (statewide GIS layer)
WDID
2 07I018308
Source feature ID
9893
Application type
Notice of Intent
Regional board derivation
WDID region prefix
Geometry status
valid
Last successful facility import
Aug 21, 2026, 1:57 AM UTC

Official IGP permitted facilities feature layer