Sonic Plating

Active WDID 4 19I006724 Gardena, 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
Gardena, Los Angeles County
Region 4 · Los Angeles · Location · Statewide map
Receiving water
Los Angeles River (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
138 distinct results, 10 reporting years (2016 to 2025)
Most recent sample Feb 16, 2026 · Monitoring
Compliance and enforcement records Evidence: SMARTS record
2 inspections · 3 violation records · 2 enforcement actions
Counts as published in SMARTS; not a compliance determination · Details
SMARTS TMDL records Evidence: SMARTS-reported
4 records
TMDL records

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

Open this facility on the statewide map

Reported location Evidence: facility-reported

Coordinates
33.90192, -118.31204
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
1930 W Rosecrans Ave, Gardena 90249
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
Sonic Plating Inc
Primary industry (SIC)
3471-Electroplating, Plating, Polishing, Anodizing, and Coloring
Application ID
189641
NOI processed
May 06, 1992
Last certified
Mar 25, 2015
Facility size
4500 SqFt
Impervious area
20 %

Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.

Permit history

Storm water applications for this WDID, newest first
ApplicationTypeStatusProcessedTerminatedCertified
189641 IndustrialActiveMay 06, 1992 —Mar 25, 2015

Every storm water application SMARTS records for this WDID, newest first (1).

Receiving water

Reported by the facility Evidence: facility-reported
Los Angeles River
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

7 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

SMARTS TMDL record as reported for this facility; it is not a determination that the TMDL applies to the facility.

TMDL records SMARTS lists for this facility
TMDLWaterbody (as reported)ParameterLimitTypePeriodDueDischarges to TMDL water
R4 - Los Angeles and Long Beach Harbor Waters TMDLDominguez Channel and Torrance Lateral ChannelCopper, Total .0097 mg/LNEL instantaneous FINAL2032-05-05Y
R4 - Los Angeles and Long Beach Harbor Waters TMDLDominguez Channel and Torrance Lateral ChannelCopper, Total .20751 mg/LTMDL NAL instantaneous INTERIM2020-07-01Y
R4 - Los Angeles and Long Beach Harbor Waters TMDLDominguez Channel and Torrance Lateral ChannelZinc, Total .0697 mg/LNEL instantaneous FINAL2032-05-05Y
R4 - Los Angeles and Long Beach Harbor Waters TMDLDominguez Channel and Torrance Lateral ChannelZinc, Total .89887 mg/LTMDL NAL instantaneous INTERIM2020-07-01Y

4 records. 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.

138 distinct measurements across 9 parameters, most recent sample Feb 16, 2026.

By reporting year

Distinct results by reporting year
Reporting year (July–June)Distinct resultsParametersWith several versionsFirst sampleLast sample
2025189 0 Nov 15, 2025Feb 16, 2026
202499 0 Feb 13, 2025Feb 13, 2025
202399 0 Feb 20, 2024Feb 20, 2024
2022189 0 Nov 11, 2022Jan 30, 2023
2021189 0 Dec 23, 2021Mar 28, 2022
2020189 0 Jan 29, 2021Mar 15, 2021
2019168 0 Dec 04, 2019Apr 09, 2020
2018168 0 Dec 06, 2018Jan 17, 2019
201788 0 Mar 28, 2018Mar 28, 2018
201688 0 Dec 16, 2016Dec 16, 2016

By parameter

Distinct results by parameter
ParameterUnitsMeasurementsBelow detectionFirst sampleLast sampleResults
Aluminum, Totalmg/L16 1Dec 16, 2016Feb 16, 2026 Results
Chromium (Total)mg/L16 9Dec 16, 2016Feb 16, 2026 Results
Iron, Totalmg/L16 1Dec 16, 2016Feb 16, 2026 Results
Nitrite Plus Nitrate (as N)mg/L16 3Dec 16, 2016Feb 16, 2026 Results
Oil and Greasemg/L16 12Dec 16, 2016Feb 16, 2026 Results
pHSU16 0Dec 16, 2016Feb 16, 2026 Results
Total Suspended Solids (TSS)mg/L16 5Dec 16, 2016Feb 16, 2026 Results
Zinc, Totalmg/L16 0Dec 16, 2016Feb 16, 2026 Results
Copper, Totalmg/L10 0Jan 29, 2021Feb 16, 2026 Results

pH results (16 distinct rows, show all)

Reported monitoring results, newest first
Sample dateParameterResultUnitsLocation typeEventMethodReportVersions
Feb 16, 2026 pH 7.5 SU Effluent Qualifying Storm Event pH_Field 1368076
Nov 15, 2025 pH 7.7 SU Effluent Qualifying Storm Event pH_Field 1360807
Feb 13, 2025 pH 6.8 SU Effluent Qualifying Storm Event pH_Field 1327288
Feb 20, 2024 pH 7.8 SU Effluent Qualifying Storm Event pH_Field 1280740
Jan 30, 2023 pH 7.4 SU Effluent Qualifying Storm Event pH_Field 1241258
Nov 11, 2022 pH 6.8 SU Effluent Qualifying Storm Event pH_Field 1241257
Mar 28, 2022 pH 7.2 SU Effluent Qualifying Storm Event pH_Field 1198777
Dec 23, 2021 pH 7 SU Effluent Qualifying Storm Event pH_Field 1198775
Mar 15, 2021 pH 7.23 SU Effluent Qualifying Storm Event A4500HB 1154025
Jan 29, 2021 pH 7.58 SU Effluent Qualifying Storm Event A4500HB 1154028
Apr 09, 2020 pH 6.81 SU Effluent Qualifying Storm Event A4500HB 1108927
Dec 04, 2019 pH 6.78 SU Effluent Qualifying Storm Event A4500HB 1101831
Jan 17, 2019 pH 8.2 SU Effluent Qualifying Storm Event A4500HB 1055423
Dec 06, 2018 pH 6.2 SU Effluent Qualifying Storm Event A4500HB 1037957
Mar 28, 2018 pH 7.55 SU Effluent Qualifying Storm Event A4500HB 1001589
Dec 16, 2016 pH 8.98 SU Effluent Qualifying Storm Event A4500HB 920382

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.

Compliance and enforcement records by type
Record typeRecordsAs publishedDatesRetrievedList
Violations3 3 Violation · 0 Potential (preliminary) · 0 Dismissed Nov 13, 2001 – Mar 19, 2021 Oct 21, 2026 All violations
Enforcement actions2 2 issued · 0 draft · 0 withdrawn, rescinded or superseded Mar 13, 2002 – Sep 06, 2023 Oct 21, 2026 All actions
Inspections2inspections, not findings Nov 13, 2001 – Nov 04, 2008 Oct 21, 2026 All inspections
Annual reports11certified reports (contents not shown) 2015 – 2025 Oct 21, 2026 All reports
Water-quality-based corrective action reports0reports, 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)
Compliance and enforcement records, newest first
DateRecordIDType or purposeStatus as publishedDetail
Jun 23, 2026 Annual reports 1335455 Annual report 2025 —
Jul 02, 2025 Annual reports 1294274 Annual report 2024 —
Jul 10, 2024 Annual reports 1243361 Annual report 2023 —
Sep 06, 2023 Enforcement actions 450862 ACL (Administrative Civil Liability) HistoricalR4-2023-0147
Jul 12, 2023 Annual reports 1189365 Annual report 2022 —
Jul 12, 2022 Annual reports 1112747 Annual report 2021 —
Jul 14, 2021 Annual reports 1068759 Annual report 2020 —
Mar 19, 2021 Violations 886046 Late Report ViolationReport
Jul 14, 2020 Annual reports 986027 Annual report 2019 —
Jul 12, 2019 Annual reports 953586 Annual report 2018 —
Jul 12, 2018 Annual reports 939002 Annual report 2017 —
Jul 07, 2017 Annual reports 878246 Annual report 2016 —
Jul 15, 2016 Annual reports 846687 Annual report 2015 —
Nov 04, 2008 Inspections 1733286 B Type compliance —
Mar 13, 2002 Enforcement actions 241553 NTC (Notice to Comply) HistoricalUNKNOWN
Nov 13, 2001 Inspections 1733503 B Type compliance —Additional Info Required
Nov 13, 2001 Violations 204813 Incomplete/Insufficient SWPPP ViolationInspection
Nov 13, 2001 Violations 844650 Deficient Report ViolationInspection

Sources and provenance

Sources behind this page
InformationSourceRetrieved or published
Permit, location, receiving-water textSMARTS Industrial Application Specific DataOct 20, 2026
Permit historySMARTS Storm Water ApplicationsOct 20, 2026
Monitoring resultsSMARTS Industrial Parameter DataOct 20, 2026
Watershed Boundary Dataset HU2 GeoPackages 15, 16, 18 (WBDHU12)USGS2026-10-22
2026 California Integrated Report, Appendix A: 2026 303(d) List (final)SWRCB2026-10-22
Final_2026_Rivers_and_Streams + Final_2026_Lakes_and_Reservoirs (FeatureServer 0)SWRCB GIS2026-10-22
SMARTS TMDL requirementsSMARTS2026-10-21

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

Records are shown as published and are not compliance determinations. How geographic context is derived.