Industrial stormwater facility
4 19I015143 · Notice of Intent · West Covina, Los Angeles
Official
Hydrologic
Official facility coordinate plotted against the official 2026 impaired-water geometry.
303(d) context
Grouped by derived geographic association class.
River & Stream · Integrated Report category 5 · TMDL required
Listed pollutants / stressors (2) Indicator Bacteria, Selenium
River & Stream · Integrated Report category 5 · TMDL required
Listed pollutants / stressors (5) Chlorine, Indicator Bacteria, pH, Total Dissolved Solids, Toxicity
Associations are calculated from official facility coordinates, USGS HUC12 boundaries, and official 2026 impaired-water geometry. They do not establish a discharge connection or causation.
Water Board-stated TMDL waste load allocations applied to this industrial permit in SMARTS.
No SMARTS TMDL requirement is recorded for this WDID. In the statewide TMDL export only permits in Regions 4, 8 and 9 currently carry industrial TMDL requirements, so an absence here is not a statement that the facility discharges to an unimpaired water.
Official monitoring
Self-reported industrial stormwater sampling results as submitted by the discharger to SMARTS.
Loading reported results…
| Sample date | Location | Parameter | Result | Units | Event |
|---|---|---|---|---|---|
| 2026-03-18 | SD02 UDB Outlet | 1,4-Dichlorobenzene | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Ammonia as N, Total | .15 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Arsenic | .0047 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Benzene | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Chemical oxygen demand (COD) | 46 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Chlorobenzene | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Cyanide | .0023 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Dioxane | 5.8 | ug/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Iron | .45 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Lead | .00031 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Magnesium, Total | 89 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Mercury | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Oil and Grease | ND —(non-detect / est.) | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | pH | 7.45 | SU | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Selenium, Total | .00099 | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Silver | ND —(non-detect / est.) | mg/L | Non-Storm Water Discharge Event |
| 2026-03-18 | SD02 UDB Outlet | Total Suspended Solids (TSS) | 19 | mg/L | Non-Storm Water Discharge Event |
| 2026-02-25 | SD02 UDB Outlet | 1,4-Dichlorobenzene | ND —(non-detect / est.) | ug/L | Qualifying Storm Event |
| 2026-02-25 | SD02 UDB Outlet | 1,4-Dichlorobenzene | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
| 2026-02-25 | SD02 UDB Outlet | Ammonia as N, Total | ND —(non-detect / est.) | mg/L | Non-Storm Water Discharge Event |
| 2026-02-25 | SD02 UDB Outlet | Ammonia as N, Total | ND —(non-detect / est.) | mg/L | Qualifying Storm Event |
| 2026-02-25 | SD02 UDB Outlet | Arsenic | .0018 | mg/L | Qualifying Storm Event |
| 2026-02-25 | SD02 UDB Outlet | Arsenic | .0053 | mg/L | Non-Storm Water Discharge Event |
| 2026-02-25 | SD02 UDB Outlet | Benzene | ND —(non-detect / est.) | ug/L | Qualifying Storm Event |
| 2026-02-25 | SD02 UDB Outlet | Benzene | ND —(non-detect / est.) | ug/L | Non-Storm Water Discharge Event |
Monitoring rows are official self-reported SMARTS submissions, joined to this facility by WDID. California Stormwater Intelligence does not restate, correct, average or evaluate reported values, and no benchmark comparison or violation determination is made.
YDOS-derived
Reported SMARTS analytical results compared against the Numeric Action Levels of the Industrial General Permit version in effect for each reporting year (July 1 – June 30).
| Parameter | NAL type | Calculated value | NAL | Result | Samples used | Method |
|---|---|---|---|---|---|---|
Ammonia, Total (as N) ammonia_n | Annual | 0.317 mg/L | 2.14 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0.15× threshold | 15 eligible6 excluded1 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Arsenic, Total arsenic_total | Annual | 0.001 mg/L | 0.15 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0.01× threshold | 15 eligible6 excluded5 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Chemical Oxygen Demand (COD) cod | Annual | 65.2 mg/L | 120 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0.54× threshold | 15 eligible6 excluded | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Cyanide, Total (as CN) cyanide_total | Annual | 0.003 mg/L | 0.022 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0.15× threshold | 15 eligible6 excluded5 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Iron, Total iron_total | Annual | 1.341 mg/L | 1 mg/L | Above NALAnnual average of 15 eligible result(s) compared with the annual NAL.1.34× threshold | 15 eligible6 excluded | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Lead, Total lead_total | Annual | 0.001 mg/L | 0.262 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0× threshold | 15 eligible6 excluded5 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Magnesium, Total magnesium_total | Annual | 9.193 mg/L | 0.064 mg/L | Above NALAnnual average of 15 eligible result(s) compared with the annual NAL.143.65× threshold | 15 eligible6 excluded | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Mercury, Total mercury_total | Annual | 0 mg/L | 0.001 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0× threshold | 15 eligible6 excluded15 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Oil and Grease oil_grease | Instantaneous maximum | —0 samples above | 25 mg/L | At or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL. | 15 eligible6 excluded14 non-detect as zero | count of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year |
pH ph | Instantaneous maximum | —0 samples above | 6 – 9 pH units | Within NAL rangeNo eligible result in this reporting year was outside the instantaneous maximum NAL. | 15 eligible6 excluded | count of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year |
Selenium, Total selenium_total | Annual | 8.73e-4 mg/L | 0.005 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0.17× threshold | 15 eligible6 excluded10 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Silver, Total silver_total | Annual | 4.87e-5 mg/L | 0.018 mg/L | At or below NALAnnual average of 15 eligible result(s) compared with the annual NAL.0× threshold | 15 eligible6 excluded14 non-detect as zero | arithmetic mean of all eligible effluent results in the July 1 - June 30 reporting year (censored results assigned zero only where MDL and ML were both reported) |
Total Suspended Solids (TSS) tss | Instantaneous maximum | —1 sample above | 400 mg/L | At or below NALOne eligible result in this reporting year was outside the instantaneous maximum NAL. The Order states the condition as two or more results in one reporting year. | 15 eligible6 excluded1 non-detect as zero | count of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year |
YDOS-derived overlap
Parameters where this facility has an NAL exceedance in at least one reporting year and the geographically associated waterbody carries a 303(d) listing for the same pollutant.
pHMonitoringAbove NAL303(d) impairmentSan Jose Creek Reach 1 (SG Confluence to Temple St.)
1 reporting year above the instantaneous maximum NAL, most recently RY 2016 · 1 303(d) listing · association: derived watershed association (low confidence)
Overlap is informational co-occurrence between a derived NAL comparison and an official 303(d) listing. It is not evidence that this facility caused or contributed to the impairment.
An NAL exceedance is a permit-defined condition that triggers Exceedance Response Actions under the Industrial General Permit. It is not a violation, an enforcement action, or a Water Board compliance determination. Annual values use the arithmetic average of eligible results with non-detects treated as zero; instantaneous maximum NALs (total suspended solids, oil and grease, pH) are exceeded when two or more eligible results in a reporting year fall outside the level. Rules transcribed from 2014-0057-DWQ as amended by 2015-0122-DWQ ↗ (effective 2015-07-01, superseded 2020-06-30); 2014-0057-DWQ as amended by 2018-0028-DWQ ↗ (effective 2020-07-01).
Provenance