Industrial stormwater facility
5S34I021915 · Notice of Intent · Walnut Grove, Sacramento
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 (10) Arsenic, Chlordane, DDT (Dichlorodiphenyltrichloroethane), Dieldrin, Fipronil, Mercury +4 more
River & Stream · Integrated Report category 5 · TMDL required
Listed pollutants / stressors (1) Toxicity
River & Stream · Integrated Report category 5 · TMDL required
Listed pollutants / stressors (2) Mercury, Toxicity
River & Stream · Integrated Report category 5 · TMDL required
Listed pollutants / stressors (1) Nitrate/Nitrite (Nitrite + Nitrate as N)
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 |
|---|---|---|---|---|---|
| 2023-02-24 | Outfall | Iron | 3 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | Lead | .0028 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | Nitrate/Nitrite (Nitrite + Nitrate as N) | 11 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | Oil and Grease | 2.3 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | pH | 6 | SU | Qualifying Storm Event |
| 2023-02-24 | Outfall | Phosphorus | 3.6 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | Total Suspended Solids (TSS) | 37 | mg/L | Qualifying Storm Event |
| 2023-02-24 | Outfall | Zinc | .12 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Iron | 7.1 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Lead | .008 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Nitrate/Nitrite (Nitrite + Nitrate as N) | 1.8 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Oil and Grease | ND —(non-detect / est.) | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | pH | 6 | SU | Qualifying Storm Event |
| 2023-01-09 | Outfall | Phosphorus | 1.1 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Total Suspended Solids (TSS) | 85 | mg/L | Qualifying Storm Event |
| 2023-01-09 | Outfall | Zinc | .078 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Iron | 3.5 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Lead | .0039 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Nitrate/Nitrite (Nitrite + Nitrate as N) | 3.5 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Oil and Grease | ND —(non-detect / est.) | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | pH | 7 | SU | Qualifying Storm Event |
| 2022-12-27 | Outfall | Phosphorus | 1.2 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Total Suspended Solids (TSS) | 91 | mg/L | Qualifying Storm Event |
| 2022-12-27 | Outfall | Zinc | .16 | mg/L | Qualifying Storm Event |
| 2022-11-08 | Outfall | Iron | 6.2 | mg/L | Qualifying Storm 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 |
|---|---|---|---|---|---|---|
Iron, Total iron_total | Annual | 4.95 mg/L | 1 mg/L | Above NALAnnual average of 4 eligible result(s) compared with the annual NAL.4.95× threshold | 4 eligible | 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 | 0.005 mg/L | 0.262 mg/L | At or below NALAnnual average of 4 eligible result(s) compared with the annual NAL.0.02× threshold | 4 eligible | 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) |
Nitrite Plus Nitrate (as N) nitrate_nitrite_n | Annual | 8.075 mg/L as N | 0.68 mg/L as N | Above NALAnnual average of 4 eligible result(s) compared with the annual NAL.11.88× threshold | 4 eligible | 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. | 4 eligible3 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. | 4 eligible | count of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year |
Phosphorus, Total (as P) phosphorus_total | Annual | 1.55 mg/L as P | 2 mg/L as P | At or below NALAnnual average of 4 eligible result(s) compared with the annual NAL.0.78× threshold | 4 eligible | 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 | —0 samples above | 400 mg/L | At or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL. | 4 eligible | count of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year |
Zinc, Total zinc_total | Annual | 0.127 mg/L | 0.26 mg/L | At or below NALAnnual average of 4 eligible result(s) compared with the annual NAL.0.49× threshold | 4 eligible | 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) |
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.
Nitrate/Nitrite (Nitrite + Nitrate as N)MonitoringAbove NAL303(d) impairmentStaten Island Drain (in Delta Waterways, central portion)
6 reporting years above the annual NAL, most recently RY 2022 · 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