Arrow Engineering
Active WDID 4 19I027326 Irwindale, 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
- Irwindale, 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
- 2 waterbodies; 1 on the 2026 303(d) list
- Proximity only; not a discharge pathway · Nearby waterbodies
- Monitoring results Evidence: facility-reported
- 71 distinct results, 8 reporting years (2018 to 2025)
- Most recent sample Feb 23, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 2 violation records · 2 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
- 34.10302, -117.94225
- 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
- 4946 Azusa Canyon Road, Irwindale 91706
- Regional Water Board
- 4 — Los Angeles
HUC12 watershed Evidence: spatial
- Santa Fe Flood Control Basin-San Gabriel River HUC12 180701060601
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
- Arrow Engineering
- Primary industry (SIC)
- 3599-Industrial and Commercial Machinery and Equipment, NEC
- Application ID
- 484883
- NOI processed
- Sep 05, 2017
- Last certified
- Feb 16, 2023
- Facility size
- 273192 SqFt
- Impervious area
- 98 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 484883 | Industrial | Active | Sep 05, 2017 | — | Feb 16, 2023 |
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.
| Waterbody (2026 Integrated Report) | Distance | 2026 303(d) list | Appendix A decisions |
|---|---|---|---|
| Big Dalton Wash CAR4052000020210323064004 | 892 m | not listed | 0 |
| Santa Fe Dam Park Lake CAL4053100020000303202907 | 922 m | listed | 3 |
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.
71 distinct measurements across 5 parameters, most recent sample Feb 23, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 5 | 5 | 0 | Feb 23, 2026 | Feb 23, 2026 |
| 2024 | 10 | 5 | 0 | Feb 13, 2025 | Mar 13, 2025 |
| 2023 | 5 | 5 | 0 | Feb 05, 2024 | Feb 05, 2024 |
| 2022 | 10 | 5 | 0 | Dec 12, 2022 | Feb 24, 2023 |
| 2021 | 15 | 5 | 0 | Oct 25, 2021 | Mar 28, 2022 |
| 2020 | 5 | 5 | 0 | Mar 15, 2021 | Mar 15, 2021 |
| 2019 | 12 | 3 | 0 | Nov 20, 2019 | Apr 07, 2020 |
| 2018 | 9 | 3 | 0 | Nov 29, 2018 | May 16, 2019 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 17 | 15 | Nov 29, 2018 | Feb 23, 2026 | Results |
| pH | SU | 17 | 1 | Nov 29, 2018 | Feb 23, 2026 | Results |
| Total Suspended Solids (TSS) | mg/L | 17 | 4 | Nov 29, 2018 | Feb 23, 2026 | Results |
| Lead, Total | mg/L | 10 | 2 | Mar 15, 2021 | Feb 23, 2026 | Results |
| Selenium, Total | mg/L | 10 | 9 | Mar 15, 2021 | Feb 23, 2026 | Results |
All results (71 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Feb 23, 2026 | Lead, Total | .00064 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1369719 | |
| Feb 23, 2026 | Oil and Grease | < 10 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1369719 | |
| Feb 23, 2026 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1369719 | |
| Feb 23, 2026 | Selenium, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1369719 | |
| Feb 23, 2026 | Total Suspended Solids (TSS) | < 5 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1369719 | |
| Mar 13, 2025 | Lead, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1330157 | |
| Mar 13, 2025 | Oil and Grease | < 10 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1330157 | |
| Mar 13, 2025 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1330157 | |
| Mar 13, 2025 | Selenium, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1330157 | |
| Mar 13, 2025 | Total Suspended Solids (TSS) | < 5 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1330157 | |
| Feb 13, 2025 | Lead, Total | .017 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1324187 | |
| Feb 13, 2025 | Oil and Grease | < 10 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1324187 | |
| Feb 13, 2025 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1324187 | |
| Feb 13, 2025 | Selenium, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1324187 | |
| Feb 13, 2025 | Total Suspended Solids (TSS) | 45 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1324187 | |
| Feb 05, 2024 | Lead, Total | .0096 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1281810 | |
| Feb 05, 2024 | Oil and Grease | < 3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1281810 | |
| Feb 05, 2024 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1281810 | |
| Feb 05, 2024 | Selenium, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1281810 | |
| Feb 05, 2024 | Total Suspended Solids (TSS) | 67.5 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1281810 | |
| Feb 24, 2023 | Lead, Total | .0057 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1238180 | |
| Feb 24, 2023 | Oil and Grease | < 3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1238180 | |
| Feb 24, 2023 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1238180 | |
| Feb 24, 2023 | Selenium, Total | < .0005 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1238180 | |
| Feb 24, 2023 | Total Suspended Solids (TSS) | 21 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1238180 | |
| Dec 12, 2022 | Lead, Total | .0034 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1238190 | |
| Dec 12, 2022 | Oil and Grease | < 3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1238190 | |
| Dec 12, 2022 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1238190 | |
| Dec 12, 2022 | Selenium, Total | < .002 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1238190 | |
| Dec 12, 2022 | Total Suspended Solids (TSS) | 15 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1238190 | |
| Mar 28, 2022 | Lead, Total | ND | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1181804 | |
| Mar 28, 2022 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1181804 | |
| Mar 28, 2022 | pH | 6.2 | SU | Effluent | Qualifying Storm Event | A4500HB | 1181804 | |
| Mar 28, 2022 | Selenium, Total | ND | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1181804 | |
| Mar 28, 2022 | Total Suspended Solids (TSS) | 14 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1181804 | |
| Dec 14, 2021 | Lead, Total | .0013 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1176859 | |
| Dec 14, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1176859 | |
| Dec 14, 2021 | pH | 6.25 | SU | Effluent | Qualifying Storm Event | A4500HB | 1176859 | |
| Dec 14, 2021 | Selenium, Total | ND | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1176859 | |
| Dec 14, 2021 | Total Suspended Solids (TSS) | 29 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1176859 | |
| Oct 25, 2021 | Lead, Total | .00655 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1169945 | |
| Oct 25, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1169945 | |
| Oct 25, 2021 | pH | 6.41 | SU | Effluent | Qualifying Storm Event | A4500HB | 1169945 | |
| Oct 25, 2021 | Selenium, Total | .00378 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1169945 | |
| Oct 25, 2021 | Total Suspended Solids (TSS) | 29 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1169945 | |
| Mar 15, 2021 | Lead, Total | .00131 | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1149023 | |
| Mar 15, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1149023 | |
| Mar 15, 2021 | pH | 6.1 | SU | Effluent | Qualifying Storm Event | A4500HB | 1149023 | |
| Mar 15, 2021 | Selenium, Total | ND | mg/L | Effluent | Qualifying Storm Event | E200.8 | 1149023 | |
| Mar 15, 2021 | Total Suspended Solids (TSS) | 63 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1149023 |
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 | 2 | 2 Violation · 0 Potential (preliminary) · 0 Dismissed | Feb 14, 2024 – Jun 12, 2024 | Oct 21, 2026 | All violations |
| Enforcement actions | 2 | 1 issued · 0 draft · 1 withdrawn, rescinded or superseded | Feb 14, 2024 – Jun 12, 2024 | Oct 21, 2026 | All actions |
| Inspections | 1 | inspections, not findings | Feb 20, 2025 – Feb 20, 2025 | Oct 21, 2026 | All inspections |
| Annual reports | 9 | certified reports (contents not shown) | 2017 – 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 (14 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jun 26, 2026 | Annual reports | 1339726 | Annual report 2025 | — | |
| Jun 17, 2025 | Annual reports | 1298801 | Annual report 2024 | — | |
| Feb 20, 2025 | Inspections | 2067264 | B Type compliance | Finalized | Additional Info Required |
| Jun 20, 2024 | Annual reports | 1248100 | Annual report 2023 | — | |
| Jun 12, 2024 | Enforcement actions | 453451 | ACL (Administrative Civil Liability) | Historical | R4-2024-0231 |
| Jun 12, 2024 | Violations | 889140 | Late Report | Violation | Report |
| Feb 14, 2024 | Enforcement actions | 452939 | NOV (Notice of Violation) | Withdrawn | |
| Feb 14, 2024 | Violations | 888518 | Late Report | Violation | Report |
| Jun 22, 2023 | Annual reports | 1194337 | Annual report 2022 | — | |
| Jul 06, 2022 | Annual reports | 1118274 | Annual report 2021 | — | |
| Jul 12, 2021 | Annual reports | 1066552 | Annual report 2020 | — | |
| Jul 14, 2020 | Annual reports | 983682 | Annual report 2019 | — | |
| Jul 01, 2019 | Annual reports | 979615 | Annual report 2018 | — | |
| Jul 09, 2018 | Annual reports | 966648 | Annual report 2017 | — |
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.