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Industrial stormwater facility

Matheson Tri Gas Vernon

4 19I020625 · Notice of Intent · Vernon, Los Angeles

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

Official

Facility record

Facility name
Matheson Tri Gas Vernon
WDID
4 19I020625
Application type
Notice of Intent
City
Vernon
County
Los Angeles
ZIP
90058
Primary SIC code
2813
SIC description
Industrial Gases
Date active
2007-01-04
Regional Water Board
Regional Board 4 - Los Angeles Region

Hydrologic

Geographic context

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

Official facility point
33.99019, -118.17604
HUC12 subwatershed
Chavez Ravine-Los Angeles River
HUC12 code
180701050401
Impaired-water associations (derived)
3
Loading map…

303(d) context

Associated impaired waters

Grouped by derived geographic association class.

Derived

Subwatershed + nearby

1 waterbodies
Los Angeles River Reach 2 (Carson to Figueroa Street)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (9) Ammonia, Copper, Indicator Bacteria, Lead, Nutrients (Algae), Oil +3 more

Distance 0.06 km

Confidence high

Fact sheet

Same impaired-water subwatershed

2 waterbodies
Lincoln Park Lake

Lake & Reservoir · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (6) Ammonia, Eutrophic, Odor, Organic Enrichment/Low Dissolved Oxygen, PCBs (Polychlorinated biphenyls), Trash

Distance

Confidence low

Fact sheet

Los Angeles River Reach 3 (Figueroa St. to Riverside Dr.)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (5) Copper, Indicator Bacteria, Nutrients (Algae), Toxicity, 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 (3)

Numeric effluent limits and action levels stated by the Water Board for this permit, with the receiving water named in the TMDL.

Official record — SMARTS TMDL dataset, State Water Board
Stated requirements
3
TMDLs
1
Regulated parameters
3
Limit due dates
2020-07-01 – 2020-07-01
Includes interim limits
No
Source regional dataset
Region 4 - Los Angeles
Source retrieved
Aug 21, 2026

Official SMARTS public reports

Los Angeles River Nitrogen TMDL

Receiving water named in TMDL Los Angeles River Watershed

3 limits
ParameterLimit typePeriodBasisLimitDue dateReported results for parameter
Nitrate, Total (as N)Vocabulary match: Nitrate (alias)NELFINALINSTANTANEOUS8 mg/L2020-07-0148 results · latest 2026-02-16
Nitrite Plus Nitrate (as N)Vocabulary match: Nitrate/Nitrite (Nitrite + Nitrate as N) (exact)NELFINALINSTANTANEOUS8 mg/L2020-07-0190 results · latest 2026-02-16
Nitrite, Total (as N)Vocabulary match: Nitrogen, Nitrite (alias)NELFINALINSTANTANEOUS1 mg/L2020-07-0148 results · latest 2026-02-16
Derivedapplies only to the 303(d) waterbody link and the parameter vocabulary match.

Limit values, limit periods, parameters, TMDL names and receiving-water names are reproduced exactly as stated by the Water Board in SMARTS. California Stormwater Intelligence does not compare reported monitoring results to these limits and makes no exceedance, violation or compliance determination. Where a stated receiving-water name is linked to a 2026 303(d) waterbody, that link is a derived exact-name match, not a Water Board determination.

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
632
Sample events
45
Distinct parameters
8
Reporting years
2015 – 2025
First sample
2015-09-15
Latest sample
2026-02-16
Source regional dataset
Region 4 - Los Angeles
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 632
Sample dateLocationParameterResultUnitsEvent
2026-02-16NE Out FallAluminum1.65mg/LQualifying Storm Event
2026-02-16NE Out FallAluminum1.65mg/LQualifying Storm Event
2026-02-16NE Out FallIron2mg/LQualifying Storm Event
2026-02-16NE Out FallIron2mg/LQualifying Storm Event
2026-02-16NE Out FallNitrate.93mg/LQualifying Storm Event
2026-02-16NE Out FallNitrate.93mg/LQualifying Storm Event
2026-02-16NE Out FallNitrate/Nitrite (Nitrite + Nitrate as N).973mg/LQualifying Storm Event
2026-02-16NE Out FallNitrate/Nitrite (Nitrite + Nitrate as N).973mg/LQualifying Storm Event
2026-02-16NE Out FallNitrogen, Nitrite.0432mg/LQualifying Storm Event
2026-02-16NE Out FallNitrogen, Nitrite.0432mg/LQualifying Storm Event
2026-02-16NE Out FallOil and Grease2.72mg/LQualifying Storm Event
2026-02-16NE Out FallOil and Grease2.72mg/LQualifying Storm Event
2026-02-16NE Out FallpH5.5SUQualifying Storm Event
2026-02-16NE Out FallpH5.5SUQualifying Storm Event
2026-02-16NE Out FallTotal Suspended Solids (TSS)58mg/LQualifying Storm Event
2026-02-16NE Out FallTotal Suspended Solids (TSS)58mg/LQualifying Storm Event
2025-11-20NE Out FallAluminum1.49mg/LQualifying Storm Event
2025-11-20NE Out FallAluminum1.49mg/LQualifying Storm Event
2025-11-20NE Out FallIron1.41mg/LQualifying Storm Event
2025-11-20NE Out FallIron1.41mg/LQualifying Storm Event
2025-11-20NE Out FallNitrate1.19mg/LQualifying Storm Event
2025-11-20NE Out FallNitrate1.19mg/LQualifying Storm Event
2025-11-20NE Out FallNitrate/Nitrite (Nitrite + Nitrate as N)1.28mg/LQualifying Storm Event
2025-11-20NE Out FallNitrate/Nitrite (Nitrite + Nitrate as N)1.28mg/LQualifying Storm Event
2025-11-20NE Out FallNitrogen, Nitrite.0946mg/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
11
Most recent evaluated year
RY 2025
Ruleset
igp_nal_ruleset_v1 / igp_nal_v1
ParameterNAL typeCalculated valueNALResultSamples usedMethod

Aluminum, Total

aluminum_total

Annual1.025 mg/L0.75 mg/LAbove NALAnnual average of 8 eligible result(s) compared with the annual NAL.1.37× threshold8 eligiblearithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported)

Iron, Total

iron_total

Annual1.106 mg/L1 mg/LAbove NALAnnual average of 8 eligible result(s) compared with the annual NAL.1.11× threshold8 eligiblearithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported)

Nitrite Plus Nitrate (as N)

nitrate_nitrite_n

Annual1.463 mg/L as N0.68 mg/L as NAbove NALAnnual average of 8 eligible result(s) compared with the annual NAL.2.15× threshold8 eligiblearithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported)

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.8 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

pH

ph

Instantaneous maximum2 samples above6 – 9 pH unitsOutside NAL range2 eligible results in this reporting year were outside the instantaneous maximum NAL. Two or more such results in one reporting year is the condition stated in the Order.8 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.8 eligiblecount 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
4 19I020625
Source feature ID
12072
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