MHX LLC Carson
Active WDID 4 19I028625 Carson, 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
- Carson, Los Angeles County
- Region 4 · Los Angeles · Location · Statewide map
- Receiving water
- Machado Lake (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
- 58 distinct results, 6 reporting years (2020 to 2025)
- Most recent sample Dec 26, 2025 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 0 violation records · 0 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
- 33.81933, -118.24734
- Precision
- 5 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
- 22707 S Wilmington Ave 22707 S Wilmington Ave, Carson 90745
- Regional Water Board
- 4 — Los Angeles
HUC12 watershed Evidence: spatial
- Lower Dominguez Channel HUC12 180701060102
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
- MHX LLC
- Primary industry (SIC)
- 4212-Local Trucking Without Storage
- Application ID
- 519966
- NOI processed
- Apr 22, 2020
- Last certified
- Aug 06, 2026
- Facility size
- 15 Acres
- Impervious area
- 100 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 519966 | Industrial | Active | Apr 22, 2020 | — | Aug 06, 2026 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Machado Lake
- 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
1 official waterbody shares 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
SMARTS TMDL record as reported for this facility; it is not a determination that the TMDL applies to the facility.
| TMDL | Waterbody (as reported) | Parameter | Limit | Type | Period | Due | Discharges to TMDL water |
|---|---|---|---|---|---|---|---|
| R4 - Los Angeles and Long Beach Harbor Waters TMDL | Dominguez Channel Estuary | Zinc, Total | .095 mg/L | TMDL NAL instantaneous | FINAL | 2032-05-05 | Y |
1 record. Links between these records and specific TMDL projects or listed waterbodies have not been reviewed and are not shown.
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.
58 distinct measurements across 4 parameters, most recent sample Dec 26, 2025.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 8 | 4 | 0 | Dec 26, 2025 | Dec 26, 2025 |
| 2024 | 8 | 4 | 0 | Feb 12, 2025 | Feb 12, 2025 |
| 2023 | 8 | 4 | 0 | Feb 01, 2024 | Feb 01, 2024 |
| 2022 | 22 | 4 | 0 | Nov 08, 2022 | Mar 10, 2023 |
| 2021 | 6 | 3 | 0 | Oct 25, 2021 | Mar 28, 2022 |
| 2020 | 6 | 3 | 0 | Dec 28, 2020 | Mar 03, 2021 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 16 | 5 | Dec 28, 2020 | Dec 26, 2025 | Results |
| pH | SU | 16 | 0 | Dec 28, 2020 | Dec 26, 2025 | Results |
| Total Suspended Solids (TSS) | mg/L | 16 | 4 | Dec 28, 2020 | Dec 26, 2025 | Results |
| Zinc, Total | mg/L | 10 | 0 | Nov 08, 2022 | Dec 26, 2025 | Results |
All results (58 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Dec 26, 2025 | Oil and Grease | 1.7 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1363012 | |
| Dec 26, 2025 | Oil and Grease | 3.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1363012 | |
| Dec 26, 2025 | pH | 6.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1363012 | |
| Dec 26, 2025 | pH | 6.4 | SU | Effluent | Qualifying Storm Event | pH_Field | 1363012 | |
| Dec 26, 2025 | Total Suspended Solids (TSS) | 9.2 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1363012 | |
| Dec 26, 2025 | Total Suspended Solids (TSS) | 15 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1363012 | |
| Dec 26, 2025 | Zinc, Total | .14 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1363012 | |
| Dec 26, 2025 | Zinc, Total | .2 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1363012 | |
| Feb 12, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1322347 | |
| Feb 12, 2025 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1322347 | |
| Feb 12, 2025 | pH | 6.7 | SU | Effluent | Qualifying Storm Event | pH_Field | 1322347 | |
| Feb 12, 2025 | pH | 6.3 | SU | Effluent | Qualifying Storm Event | pH_Field | 1322347 | |
| Feb 12, 2025 | Total Suspended Solids (TSS) | 10 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1322347 | |
| Feb 12, 2025 | Total Suspended Solids (TSS) | 10 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1322347 | |
| Feb 12, 2025 | Zinc, Total | .11 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1322347 | |
| Feb 12, 2025 | Zinc, Total | .17 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1322347 | |
| Feb 01, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1277068 | |
| Feb 01, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1277068 | |
| Feb 01, 2024 | pH | 6.4 | SU | Effluent | Qualifying Storm Event | pH_Field | 1277068 | |
| Feb 01, 2024 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | pH_Field | 1277068 | |
| Feb 01, 2024 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1277068 | |
| Feb 01, 2024 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1277068 | |
| Feb 01, 2024 | Zinc, Total | .027 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1277068 | |
| Feb 01, 2024 | Zinc, Total | .076 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1277068 | |
| Mar 10, 2023 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1232598 | |
| Mar 10, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1232598 | |
| Mar 10, 2023 | pH | 6.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1232598 | |
| Mar 10, 2023 | pH | 6.3 | SU | Effluent | Qualifying Storm Event | pH_Field | 1232598 | |
| Mar 10, 2023 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1232598 | |
| Mar 10, 2023 | Total Suspended Solids (TSS) | 18 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1232598 | |
| Mar 10, 2023 | Zinc, Total | .041 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1232598 | |
| Mar 10, 2023 | Zinc, Total | .085 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1232598 | |
| Jan 10, 2023 | Oil and Grease | 2.2 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1223695 | |
| Jan 10, 2023 | Oil and Grease | 2.4 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1223695 | |
| Jan 10, 2023 | pH | 6.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1223695 | |
| Jan 10, 2023 | pH | 6.6 | SU | Effluent | Qualifying Storm Event | pH_Field | 1223695 | |
| Jan 10, 2023 | Total Suspended Solids (TSS) | ND | mg/L | Effluent | Qualifying Storm Event | A2540D | 1223695 | |
| Jan 10, 2023 | Total Suspended Solids (TSS) | 9.6 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1223695 | |
| Nov 08, 2022 | Oil and Grease | 3.8 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1217535 | |
| Nov 08, 2022 | Oil and Grease | 1.7 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1217535 | |
| Nov 08, 2022 | pH | 7.8 | SU | Effluent | Qualifying Storm Event | pH_Field | 1217535 | |
| Nov 08, 2022 | pH | 6.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1217535 | |
| Nov 08, 2022 | Total Suspended Solids (TSS) | 25 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1217535 | |
| Nov 08, 2022 | Total Suspended Solids (TSS) | 29 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1217535 | |
| Nov 08, 2022 | Zinc, Total | .22 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1217535 | |
| Nov 08, 2022 | Zinc, Total | .44 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1217535 | |
| Mar 28, 2022 | Oil and Grease | 1.5 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1179998 | |
| Mar 28, 2022 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Field | 1179998 | |
| Mar 28, 2022 | Total Suspended Solids (TSS) | 47 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1179998 | |
| Oct 25, 2021 | Oil and Grease | 7.2 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1169030 |
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 | 0 | 0 Violation · 0 Potential (preliminary) · 0 Dismissed | — | Oct 21, 2026 | |
| Enforcement actions | 0 | 0 issued · 0 draft · 0 withdrawn, rescinded or superseded | — | Oct 21, 2026 | |
| Inspections | 1 | inspections, not findings | Apr 22, 2022 – Apr 22, 2022 | Oct 21, 2026 | All inspections |
| Annual reports | 7 | certified reports (contents not shown) | 2019 – 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 (8 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 09, 2026 | Annual reports | 1339842 | Annual report 2025 | — | |
| Jul 16, 2025 | Annual reports | 1298923 | Annual report 2024 | — | |
| Jul 15, 2024 | Annual reports | 1248223 | Annual report 2023 | — | |
| Jun 14, 2023 | Annual reports | 1194469 | Annual report 2022 | — | |
| Jun 15, 2022 | Annual reports | 1118418 | Annual report 2021 | — | |
| Apr 22, 2022 | Inspections | 2057249 | Complaint | Finalized | Follow-up Inspection Needed |
| Jun 23, 2021 | Annual reports | 1110318 | Annual report 2020 | — | |
| Jun 17, 2020 | Annual reports | 1105600 | Annual report 2019 | — |
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.