Vanderhorst Brothers Inc
Active WDID 4 56I017880 Simi Valley, Ventura 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
- Simi Valley, Ventura County
- Region 4 · Los Angeles · Location · Statewide map
- 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
- 1 waterbody; 1 on the 2026 303(d) list
- Proximity only; not a discharge pathway · Nearby waterbodies
- Monitoring results Evidence: facility-reported
- 259 distinct results, 10 reporting years (2015 to 2025)
- Most recent sample Feb 16, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 3 violation records · 3 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
- 34.26877, -118.71887
- 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
- 1715 Surveyor Ave, Simi Valley 93063
- Regional Water Board
- 4 — Los Angeles
HUC12 watershed Evidence: spatial
- Upper Arroyo Simi HUC12 180701030101
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
- Vanderhorst Brothers Inc
- Primary industry (SIC)
- 3599-Industrial and Commercial Machinery and Equipment, NEC
- Secondary SIC
- 3728-Aircraft Parts and Auxiliary Equipment, NEC
- Application ID
- 192830
- NOI processed
- Mar 11, 2003
- Last certified
- Jun 27, 2025
- Facility size
- 22000 SqFt
- Impervious area
- 0 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 192830 | Industrial | Active | Mar 11, 2003 | — | Jun 27, 2025 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Simi Valley Wash
- Discharges directly / indirectly
- N / Y (as answered in the permit application)
Evidence: not confirmed Not matchable to a single waterbody
Receiving-water text as reported by the discharger in SMARTS; no waterbody identification has been confirmed.
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.
| Waterbody (2026 Integrated Report) | Distance | 2026 303(d) list | Appendix A decisions |
|---|---|---|---|
| Calleguas Creek Reach 7 (Arroyo Simi) CAR4036200020000228103510 | 196 m | listed | 22 |
Waterbodies within 1.0 km of the reported facility location. Method proximity/1.
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.
259 distinct measurements across 10 parameters, most recent sample Feb 16, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 12 | 6 | 0 | Feb 16, 2026 | Feb 16, 2026 |
| 2024 | 14 | 7 | 0 | Feb 13, 2025 | Feb 13, 2025 |
| 2023 | 14 | 7 | 0 | Jan 22, 2024 | Jan 22, 2024 |
| 2022 | 28 | 7 | 0 | Jan 05, 2023 | Mar 10, 2023 |
| 2021 | 52 | 7 | 0 | Oct 25, 2021 | Mar 28, 2022 |
| 2019 | 34 | 7 | 0 | Nov 27, 2019 | Mar 12, 2020 |
| 2018 | 14 | 7 | 0 | Jan 31, 2019 | Jan 31, 2019 |
| 2017 | 28 | 7 | 0 | Mar 02, 2018 | Mar 21, 2018 |
| 2016 | 35 | 7 | 0 | Jan 09, 2017 | Feb 17, 2017 |
| 2015 | 28 | 7 | 0 | Jan 05, 2016 | May 06, 2016 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 38 | 35 | Jan 05, 2016 | Feb 16, 2026 | Results |
| pH | SU | 37 | 0 | Jan 05, 2016 | Feb 13, 2025 | Results |
| Total Suspended Solids (TSS) | mg/L | 37 | 2 | Jan 05, 2016 | Feb 16, 2026 | Results |
| Nitrite Plus Nitrate (as N) | mg/L | 36 | 6 | Jan 05, 2016 | Feb 16, 2026 | Results |
| Aluminum, Total Recoverable | mg/L | 35 | 0 | Jan 05, 2016 | Feb 13, 2025 | Results |
| Iron, Total Recoverable | mg/L | 35 | 0 | Jan 05, 2016 | Feb 13, 2025 | Results |
| Zinc, Total Recoverable | mg/L | 35 | 0 | Jan 05, 2016 | Feb 13, 2025 | Results |
| Aluminum, Total | mg/L | 2 | 0 | Feb 16, 2026 | Feb 16, 2026 | Results |
| Iron, Total | mg/L | 2 | 0 | Feb 16, 2026 | Feb 16, 2026 | Results |
| Zinc, Total | mg/L | 2 | 2 | Feb 16, 2026 | Feb 16, 2026 | Results |
All results (259 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Feb 16, 2026 | Aluminum, Total | .22 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1367755 | |
| Feb 16, 2026 | Aluminum, Total | .21 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1367755 | |
| Feb 16, 2026 | Iron, Total | .21 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1367755 | |
| Feb 16, 2026 | Iron, Total | .19 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1367755 | |
| Feb 16, 2026 | Nitrite Plus Nitrate (as N) | DNQ .1 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1367755 | |
| Feb 16, 2026 | Nitrite Plus Nitrate (as N) | DNQ .074 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1367755 | |
| Feb 16, 2026 | Oil and Grease | ND 0 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1367755 | |
| Feb 16, 2026 | Oil and Grease | ND 0 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1367755 | |
| Feb 16, 2026 | Total Suspended Solids (TSS) | ND 0 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1367755 | |
| Feb 16, 2026 | Total Suspended Solids (TSS) | ND 0 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1367755 | |
| Feb 16, 2026 | Zinc, Total | DNQ .03 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1367755 | |
| Feb 16, 2026 | Zinc, Total | DNQ .026 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1367755 | |
| Feb 13, 2025 | Aluminum, Total Recoverable | .22 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1328038 | |
| Feb 13, 2025 | Aluminum, Total Recoverable | .45 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1328038 | |
| Feb 13, 2025 | Iron, Total Recoverable | .22 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1328038 | |
| Feb 13, 2025 | Iron, Total Recoverable | .4 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1328038 | |
| Feb 13, 2025 | Nitrite Plus Nitrate (as N) | .23 | mg/L | Effluent | Qualifying Storm Event | A4500NOF | 1328038 | |
| Feb 13, 2025 | Nitrite Plus Nitrate (as N) | .23 | mg/L | Effluent | Qualifying Storm Event | A4500NOF | 1328038 | |
| Feb 13, 2025 | Oil and Grease | ND 1.7 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1328038 | |
| Feb 13, 2025 | Oil and Grease | ND 1.7 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1328038 | |
| Feb 13, 2025 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1328038 | |
| Feb 13, 2025 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1328038 | |
| Feb 13, 2025 | Total Suspended Solids (TSS) | 7 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1328038 | |
| Feb 13, 2025 | Total Suspended Solids (TSS) | 16 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1328038 | |
| Feb 13, 2025 | Zinc, Total Recoverable | .014 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1328038 | |
| Feb 13, 2025 | Zinc, Total Recoverable | .022 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1328038 | |
| Jan 22, 2024 | Aluminum, Total Recoverable | .77 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1278191 | |
| Jan 22, 2024 | Aluminum, Total Recoverable | .59 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1278191 | |
| Jan 22, 2024 | Iron, Total Recoverable | .99 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1278191 | |
| Jan 22, 2024 | Iron, Total Recoverable | .77 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1278191 | |
| Jan 22, 2024 | Nitrite Plus Nitrate (as N) | .24 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1278191 | |
| Jan 22, 2024 | Nitrite Plus Nitrate (as N) | .24 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1278191 | |
| Jan 22, 2024 | Oil and Grease | ND 1.4 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1278191 | |
| Jan 22, 2024 | Oil and Grease | ND 1.4 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1278191 | |
| Jan 22, 2024 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1278191 | |
| Jan 22, 2024 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1278191 | |
| Jan 22, 2024 | Total Suspended Solids (TSS) | 8 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1278191 | |
| Jan 22, 2024 | Total Suspended Solids (TSS) | 8.9 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1278191 | |
| Jan 22, 2024 | Zinc, Total Recoverable | .046 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1278191 | |
| Jan 22, 2024 | Zinc, Total Recoverable | .039 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1278191 | |
| Mar 10, 2023 | Aluminum, Total Recoverable | .52 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1234382 | |
| Mar 10, 2023 | Aluminum, Total Recoverable | .65 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1234382 | |
| Mar 10, 2023 | Iron, Total Recoverable | .59 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1234382 | |
| Mar 10, 2023 | Iron, Total Recoverable | .78 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1234382 | |
| Mar 10, 2023 | Nitrite Plus Nitrate (as N) | .19 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1234382 | |
| Mar 10, 2023 | Nitrite Plus Nitrate (as N) | .27 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1234382 | |
| Mar 10, 2023 | Oil and Grease | ND 6.8 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1234382 | |
| Mar 10, 2023 | Oil and Grease | 8.4 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1234382 | |
| Mar 10, 2023 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1234382 | |
| Mar 10, 2023 | pH | 7 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1234382 |
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 | 3 | 3 Violation · 0 Potential (preliminary) · 0 Dismissed | Feb 05, 2009 – Aug 31, 2022 | Oct 21, 2026 | All violations |
| Enforcement actions | 3 | 3 issued · 0 draft · 0 withdrawn, rescinded or superseded | Jul 20, 2010 – Aug 31, 2022 | Oct 21, 2026 | All actions |
| Inspections | 1 | inspections, not findings | May 22, 2019 – May 22, 2019 | 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 (18 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 09, 2026 | Annual reports | 1337335 | Annual report 2025 | — | |
| Jun 18, 2025 | Annual reports | 1296244 | Annual report 2024 | — | |
| Jul 15, 2024 | Annual reports | 1245443 | Annual report 2023 | — | |
| Aug 30, 2023 | Annual reports | 1191551 | Annual report 2022 | — | |
| Aug 31, 2022 | Enforcement actions | 447139 | NOV (Notice of Violation) | Historical | |
| Aug 31, 2022 | Violations | 882494 | Deficient Report | Violation | Report |
| Jun 04, 2022 | Annual reports | 1115126 | Annual report 2021 | — | |
| Jul 14, 2021 | Annual reports | 1063220 | Annual report 2020 | — | |
| Jan 26, 2021 | Enforcement actions | 439791 | NOV (Notice of Violation) | Historical | |
| Jan 26, 2021 | Violations | 876092 | Late Report | Violation | Report |
| Jul 15, 2020 | Annual reports | 980095 | Annual report 2019 | — | |
| Jul 01, 2019 | Annual reports | 956350 | Annual report 2018 | — | |
| May 22, 2019 | Inspections | 2043022 | B Type compliance | — | No Further Action |
| Jul 18, 2018 | Annual reports | 941777 | Annual report 2017 | — | |
| Jul 13, 2017 | Annual reports | 881178 | Annual report 2016 | — | |
| Jul 14, 2016 | Annual reports | 840164 | Annual report 2015 | — | |
| Jul 20, 2010 | Enforcement actions | 404910 | SEL (Staff Enforcement Letter) | Historical | |
| Feb 05, 2009 | Violations | 844162 | Deficient BMP Implementation | Violation | Report |
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.