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Industrial stormwater facility

Hexpol Compounding

4 19I027166 · Notice of Intent · Industry, Los Angeles

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

Official

Facility record

Facility name
Hexpol Compounding
WDID
4 19I027166
Application type
Notice of Intent
City
Industry
County
Los Angeles
ZIP
91744
Primary SIC code
3069
SIC description
Fabricated Rubber Products, NEC
Date active
2017-05-16
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
34.01556, -117.95791
HUC12 subwatershed
Lower San Jose Creek
HUC12 code
180701060502
Impaired-water associations (derived)
2
Loading map…

303(d) context

Associated impaired waters

Grouped by derived geographic association class.

Derived

Subwatershed + nearby

1 waterbodies
San Jose Creek Reach 1 (SG Confluence to Temple St.)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (5) Chlorine, Indicator Bacteria, pH, Total Dissolved Solids, Toxicity

Distance 0.16 km

Confidence high

Fact sheet

Same impaired-water subwatershed

1 waterbodies
Puente Creek

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (2) Indicator Bacteria, Selenium

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 (1)

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
1
TMDLs
1
Regulated parameters
1
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

R4 - San Gabriel River Metals and Selenium TMDL

Receiving water named in TMDL San Gabriel River Reach 2 and its tributary/ies

1 limits
ParameterLimit typePeriodBasisLimitDue dateReported results for parameter
Lead, TotalVocabulary match: Lead (narrower)NELFINALINSTANTANEOUS.166 mg/L2020-07-016 results · latest 2024-02-19
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
66
Sample events
15
Distinct parameters
5
Reporting years
2017 – 2023
First sample
2018-01-08
Latest sample
2024-02-19
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 66
Sample dateLocationParameterResultUnitsEvent
2024-02-19D1LeadND (non-detect / est.)mg/LQualifying Storm Event
2024-02-19D1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2024-02-19D1pH8.7SUQualifying Storm Event
2024-02-19D1Total Suspended Solids (TSS)6.5mg/LQualifying Storm Event
2024-02-19D1Zinc.49mg/LQualifying Storm Event
2024-01-20D1Lead.00048mg/LQualifying Storm Event
2024-01-20D1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2024-01-20D1pH7SUQualifying Storm Event
2024-01-20D1Total Suspended Solids (TSS)ND (non-detect / est.)mg/LQualifying Storm Event
2024-01-20D1Zinc.21mg/LQualifying Storm Event
2023-03-14D1Lead.0037mg/LQualifying Storm Event
2023-03-14D1Oil and Grease1.7mg/LQualifying Storm Event
2023-03-14D1pH7SUQualifying Storm Event
2023-03-14D1Total Suspended Solids (TSS)22mg/LQualifying Storm Event
2023-03-14D1Zinc.42mg/LQualifying Storm Event
2023-01-10D1LeadND (non-detect / est.)mg/LQualifying Storm Event
2023-01-10D1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2023-01-10D1pH6SUQualifying Storm Event
2023-01-10D1Total Suspended Solids (TSS)30mg/LQualifying Storm Event
2023-01-10D1Zinc.21mg/LQualifying Storm Event
2022-12-12D1Lead.000057mg/LQualifying Storm Event
2022-12-12D1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2022-12-12D1pH6SUQualifying Storm Event
2022-12-12D1Total Suspended Solids (TSS)ND (non-detect / est.)mg/LQualifying Storm Event
2022-12-12D1Zinc.46mg/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
6
Years with an NAL exceedance
6
Most recent evaluated year
RY 2023
Ruleset
igp_nal_ruleset_v1 / igp_nal_v1
ParameterNAL typeCalculated valueNALResultSamples usedMethod

Lead, Total

lead_total

Annual2.40e-4 mg/L0.262 mg/LAt or below NALAnnual average of 2 eligible result(s) compared with the annual NAL.9.16e-4× threshold2 eligible1 non-detect as zeroarithmetic 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.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

Zinc, Total

zinc_total

Annual0.35 mg/L0.26 mg/LAbove NALAnnual average of 2 eligible result(s) compared with the annual NAL.1.35× threshold2 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)

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 19I027166
Source feature ID
12695
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