Supreme Steel Treating
Active WDID 4 19I013695 South El Monte, Los Angeles County Region 4 · Los Angeles
At a glance
- Permit Evidence: SMARTS record
- Active Industrial
- Notice of Intent (WDID code I) · Permits and applications
- Location Evidence: facility-reported
- South El Monte, Los Angeles County
- Region 4 · Los Angeles · Location · Statewide map
- Receiving water
- pacific ocean (as reported by the facility)
- Evidence: candidate, awaiting review Details
- Identified receiving water on the 2026 303(d) list
- Not established
- Shown only when the reported receiving water is identified and corroborated.
- 2026 Integrated Report waters within 1.0 km Evidence: geographic proximity
- None
- Monitoring results Evidence: facility-reported
- 57 distinct results, 7 reporting years (2017 to 2025)
- Most recent sample Oct 14, 2025 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 6 violation records · 6 enforcement actions
- Counts as published in SMARTS; not a compliance determination · Details
Each label shows where a statement comes from. How to read the labels.
Overview and location
Reported facility location HUC12 watershed Corroborated receiving water 2026 Integrated Report waterbodies nearby
Reported location Evidence: facility-reported
- Coordinates
- 34.05701, -118.0528
- Precision
- 4 decimal places
- Shared point
- No
- Matches application record
- same
Facility location as reported by the discharger in SMARTS; not a discharge point or outfall.
- Facility address
- 2466 Seaman Ave, South El Monte 91733
- Regional Water Board
- 4 — Los Angeles
HUC12 watershed Evidence: spatial
- Alhambra Wash-Rio Hondo HUC12 180701050303
The facility's reported location lies within this HUC12 watershed (spatial derivation); it is not a discharge location.
Permits and applications Evidence: SMARTS record
Current permit record
- Permit type
- Industrial
- Application type
- Notice of Intent (WDID code I)
- Status
- Active
- Operator
- Supreme Steel Treating
- Primary industry (SIC)
- 3398-Metal Heat Treating
- Application ID
- 190585
- NOI processed
- Jan 13, 1998
- Last certified
- Jun 23, 2015
- Facility size
- 8000 SqFt
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 190585 | Industrial | Active | Jan 13, 1998 | — | Jun 23, 2015 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- pacific ocean
- Discharges directly / indirectly
- N / Y (as answered in the permit application)
Evidence: not confirmed Evidence: candidate, awaiting review Awaiting review
Receiving-water text as reported by the discharger in SMARTS; no waterbody identification has been confirmed.
Why it is not confirmed (1)
- C1 name is only a prefix of official names
290 official waterbodies share this name; none is assigned without review.
Impaired waters and TMDLs
Two kinds of information, kept apart: 2026 Integrated Report waterbodies near the reported location (geographic proximity only), and TMDL records that SMARTS lists for this facility. Neither establishes where the facility discharges; see Receiving water for the facility's own statement.
Nearby waterbodies Evidence: geographic proximity
Spatial proximity only; discharge pathway not established. Being near a waterbody does not mean the facility discharges to it.
No 2026 Integrated Report waterbody lies within the proximity threshold of the reported location.
SMARTS TMDL records Evidence: SMARTS-reported
No TMDL records for this facility in the SMARTS TMDL export.
Reported monitoring results Evidence: facility-reported
Numeric Action Level (NAL) screening is being independently validated and is not shown. Nothing on this page states whether a result exceeded a NAL.
57 distinct measurements across 3 parameters, most recent sample Oct 14, 2025.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 3 | 3 | 0 | Oct 14, 2025 | Oct 14, 2025 |
| 2022 | 6 | 3 | 0 | Nov 08, 2022 | Nov 08, 2022 |
| 2021 | 12 | 3 | 0 | Oct 26, 2021 | Dec 14, 2021 |
| 2020 | 6 | 3 | 0 | Jan 29, 2021 | Jan 29, 2021 |
| 2019 | 6 | 3 | 0 | Nov 20, 2019 | Nov 20, 2019 |
| 2018 | 12 | 3 | 0 | Nov 29, 2018 | Jan 31, 2019 |
| 2017 | 12 | 3 | 0 | Jan 09, 2018 | Mar 02, 2018 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 19 | 8 | Jan 09, 2018 | Oct 14, 2025 | Results |
| pH | SU | 19 | 0 | Jan 09, 2018 | Oct 14, 2025 | Results |
| Total Suspended Solids (TSS) | mg/L | 19 | 3 | Jan 09, 2018 | Oct 14, 2025 | Results |
All results (57 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Oct 14, 2025 | Oil and Grease | 10.2 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1377380 | |
| Oct 14, 2025 | pH | 6.1 | SU | Effluent | Qualifying Storm Event | A4500HB | 1377380 | |
| Oct 14, 2025 | Total Suspended Solids (TSS) | 16 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1377380 | |
| Nov 08, 2022 | Oil and Grease | 1.8 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1240684 | |
| Nov 08, 2022 | Oil and Grease | 1.1 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1240684 | |
| Nov 08, 2022 | pH | 6.31 | SU | Effluent | Qualifying Storm Event | A4500HB | 1240684 | |
| Nov 08, 2022 | pH | 6.34 | SU | Effluent | Qualifying Storm Event | A4500HB | 1240684 | |
| Nov 08, 2022 | Total Suspended Solids (TSS) | 5 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1240684 | |
| Nov 08, 2022 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1240684 | |
| Dec 14, 2021 | Oil and Grease | 1.7 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1175727 | |
| Dec 14, 2021 | Oil and Grease | 1.3 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1175727 | |
| Dec 14, 2021 | pH | 6.28 | SU | Effluent | Qualifying Storm Event | A4500HB | 1175727 | |
| Dec 14, 2021 | pH | 6.35 | SU | Effluent | Qualifying Storm Event | A4500HB | 1175727 | |
| Dec 14, 2021 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1175727 | |
| Dec 14, 2021 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1175727 | |
| Oct 26, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1177286 | |
| Oct 26, 2021 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1177286 | |
| Oct 26, 2021 | pH | 6.64 | SU | Effluent | Qualifying Storm Event | A4500HB | 1177286 | |
| Oct 26, 2021 | pH | 6.6 | SU | Effluent | Qualifying Storm Event | A4500HB | 1177286 | |
| Oct 26, 2021 | Total Suspended Solids (TSS) | 42 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1177286 | |
| Oct 26, 2021 | Total Suspended Solids (TSS) | 64 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1177286 | |
| Jan 29, 2021 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1151814 | |
| Jan 29, 2021 | Oil and Grease | 1.6 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1151814 | |
| Jan 29, 2021 | pH | 7.63 | SU | Effluent | Qualifying Storm Event | A4500HB | 1151814 | |
| Jan 29, 2021 | pH | 7.33 | SU | Effluent | Qualifying Storm Event | A4500HB | 1151814 | |
| Jan 29, 2021 | Total Suspended Solids (TSS) | 10 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1151814 | |
| Jan 29, 2021 | Total Suspended Solids (TSS) | 8 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1151814 | |
| Nov 20, 2019 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1109972 | |
| Nov 20, 2019 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1109972 | |
| Nov 20, 2019 | pH | 6.62 | SU | Effluent | Qualifying Storm Event | A4500HB | 1109972 | |
| Nov 20, 2019 | pH | 6.48 | SU | Effluent | Qualifying Storm Event | A4500HB | 1109972 | |
| Nov 20, 2019 | Total Suspended Solids (TSS) | 10 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1109972 | |
| Nov 20, 2019 | Total Suspended Solids (TSS) | 8 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1109972 | |
| Jan 31, 2019 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | A5220B | 1059983 | |
| Jan 31, 2019 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | A5220B | 1059983 | |
| Jan 31, 2019 | pH | 6.35 | SU | Effluent | Qualifying Storm Event | A4500HB | 1059983 | |
| Jan 31, 2019 | pH | 6.26 | SU | Effluent | Qualifying Storm Event | A4500HB | 1059983 | |
| Jan 31, 2019 | Total Suspended Solids (TSS) | 53 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1059983 | |
| Jan 31, 2019 | Total Suspended Solids (TSS) | 41 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1059983 | |
| Nov 29, 2018 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | A5220B | 1059975 | |
| Nov 29, 2018 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | A5220B | 1059975 | |
| Nov 29, 2018 | pH | 6.46 | SU | Effluent | Qualifying Storm Event | A4500HB | 1059975 | |
| Nov 29, 2018 | pH | 7.74 | SU | Effluent | Qualifying Storm Event | A4500HB | 1059975 | |
| Nov 29, 2018 | Total Suspended Solids (TSS) | 9 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1059975 | |
| Nov 29, 2018 | Total Suspended Solids (TSS) | 3 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1059975 | |
| Mar 02, 2018 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | A5220B | 1007823 | |
| Mar 02, 2018 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | A5220B | 1007823 | |
| Mar 02, 2018 | pH | 7.07 | SU | Effluent | Qualifying Storm Event | A4500HB | 1007823 | |
| Mar 02, 2018 | pH | 6.85 | SU | Effluent | Qualifying Storm Event | A4500HB | 1007823 | |
| Mar 02, 2018 | Total Suspended Solids (TSS) | 40 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1007823 |
Results are shown exactly as reported by the discharger. Identical rows repeated in the State's export are shown once. Where the export contains different versions of the same sample and parameter, each version is listed and flagged. Details.
Compliance and enforcement records Evidence: SMARTS record
These are records as the State Water Board publishes them in SMARTS, with the source's own types and statuses. They are not a compliance determination or rating. A record listed here is not proof of a violation beyond what the source states, and the absence of records does not establish compliance.
| Record type | Records | As published | Dates | Retrieved | List |
|---|---|---|---|---|---|
| Violations | 6 | 5 Violation · 0 Potential (preliminary) · 1 Dismissed | Jun 20, 2008 – Apr 30, 2025 | Oct 21, 2026 | All violations |
| Enforcement actions | 6 | 6 issued · 0 draft · 0 withdrawn, rescinded or superseded | Aug 21, 2008 – Apr 30, 2025 | Oct 21, 2026 | All actions |
| Inspections | 1 | inspections, not findings | Jun 20, 2008 – Jun 20, 2008 | Oct 21, 2026 | All inspections |
| Annual reports | 11 | certified reports (contents not shown) | 2015 – 2025 | Oct 21, 2026 | All reports |
| Water-quality-based corrective action reports | 0 | reports, by parameter | — | Oct 21, 2026 |
Each record type is counted by its own SMARTS identifier. A violation and the enforcement action that cites it are two records in two lists; they are never added together.
Chronological record history (24 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 15, 2026 | Annual reports | 1334177 | Annual report 2025 | — | |
| Jul 12, 2025 | Annual reports | 1292947 | Annual report 2024 | — | |
| Apr 30, 2025 | Enforcement actions | 455809 | NOV (Notice of Violation) | Active | |
| Apr 30, 2025 | Violations | 891135 | Failure to Notify | Violation | Report |
| Feb 20, 2025 | Enforcement actions | 455528 | NOV (Notice of Violation) | Active | |
| Feb 20, 2025 | Violations | 890832 | Incomplete/Insufficient SWPPP | Violation | Report |
| Jul 22, 2024 | Annual reports | 1241949 | Annual report 2023 | — | |
| Jul 07, 2023 | Annual reports | 1187878 | Annual report 2022 | — | |
| Jul 06, 2022 | Annual reports | 1111142 | Annual report 2021 | — | |
| Jul 01, 2021 | Annual reports | 1067077 | Annual report 2020 | — | |
| Jun 29, 2020 | Annual reports | 984231 | Annual report 2019 | — | |
| Jun 18, 2019 | Annual reports | 951734 | Annual report 2018 | — | |
| Jul 12, 2018 | Annual reports | 937144 | Annual report 2017 | — | |
| Dec 05, 2017 | Enforcement actions | 428001 | NOV (Notice of Violation) | Historical | |
| Jul 13, 2017 | Annual reports | 876293 | Annual report 2016 | — | |
| Jun 27, 2016 | Annual reports | 839438 | Annual report 2015 | — | |
| Oct 01, 2013 | Violations | 865068 | Deficient Report | Violation | Report |
| May 11, 2011 | Enforcement actions | 414629 | ACL (Administrative Civil Liability) | Historical | R4-2011-0016-SW |
| Jan 26, 2011 | Enforcement actions | 404494 | EPL (Expedited Payment Letter) | Historical | R4-2011-0016-SW |
| Aug 21, 2008 | Enforcement actions | 353607 | NOV (Notice of Violation) | Historical | NOV |
| Jul 01, 2008 | Violations | 853256 | Late Report | Dismissed | Report |
| Jun 20, 2008 | Inspections | 1495822 | B Type compliance | — | Additional Info Required |
| Jun 20, 2008 | Violations | 790048 | Incomplete/Insufficient SWPPP | Violation | Inspection |
| Jun 20, 2008 | Violations | 790049 | Incomplete/Insufficient SWPPP | Violation | Inspection |
Sources and provenance
| Information | Source | Retrieved or published |
|---|---|---|
| Permit, location, receiving-water text | SMARTS Industrial Application Specific Data | Oct 20, 2026 |
| Permit history | SMARTS Storm Water Applications | Oct 20, 2026 |
| Monitoring results | SMARTS Industrial Parameter Data | Oct 20, 2026 |
| 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 with methods facility_huc12/1, proximity/1, receiving_water/2, tmdl_reference/1, waterbody_huc12_ovl/1, waterbody_huc12_pub/1; proximity threshold 1.0 km.
How to read the evidence labels
- Evidence: SMARTS record Evidence: facility-reported Information as published in SMARTS or reported by the discharger.
- Evidence: identification corroborated The reported receiving-water name identifies one official waterbody and the facility's location is consistent with it. It does not establish a discharge pathway.
- Evidence: candidate, awaiting review Evidence: not confirmed The reported name could match one or more official waterbodies, but no identification has been confirmed; nothing is assigned without review.
- Evidence: spatial Evidence: geographic proximity Derived from the reported location only.
- Evidence: SMARTS-reported Source records whose links to official references are not yet reviewed.
- Evidence: unavailable The information could not be loaded or is not in the sources.
Records are shown as published and are not compliance determinations. How geographic context is derived.