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Industrial stormwater facility

Westak

2 43I006896 · Notice of Intent · Sunnyvale, Santa Clara

Official record — State Water Resources Control Board, Industrial General Permit

Official

Facility record

Facility name
Westak
WDID
2 43I006896
Application type
Notice of Intent
City
Sunnyvale
County
Santa Clara
ZIP
94089
Primary SIC code
3672
SIC description
Printed Circuit Boards
Date active
1992-05-07
Regional Water Board
Regional Board 2 - San Francisco Bay Region

Hydrologic

Geographic context

Official facility coordinate plotted against the official 2026 impaired-water geometry.

Official facility point
37.40931, -121.99204
HUC12 subwatershed
Calabazas Creek-Frontal San Francisco Bay Estuaries
HUC12 code
180500030405
Impaired-water associations (derived)
3
Loading map…

303(d) context

Associated impaired waters

Grouped by derived geographic association class.

Derived

Subwatershed + nearby

3 waterbodies
Calabazas Creek (Santa Clara County)

River & Stream · Integrated Report category 4a · TMDL approved by USEPA

Listed pollutants / stressors (1) Diazinon

Distance 0.47 km

Confidence high

Fact sheet

San Tomas Aquino Creek (Santa Clara County)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (4) Ammonia, Benthic Community Effects, Toxicity, Trash

Distance 0.87 km

Confidence high

Fact sheet

Guadalupe Slough

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (1) Toxicity

Distance 0.97 km

Confidence high

Fact sheet

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.

TMDL requirements

Water Board-stated TMDL waste load allocations applied to this industrial permit in SMARTS.

Official record — SMARTS TMDL dataset, State Water Board

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

SMARTS monitoring

Self-reported industrial stormwater sampling results as submitted by the discharger to SMARTS.

Official record — SMARTS parameter data, State Water Board
Reported results
142
Sample events
24
Distinct parameters
10
Reporting years
2015 – 2025
First sample
2016-01-06
Latest sample
2026-04-21
Source regional dataset
Region 2 - San Francisco Bay
Source retrieved
Aug 21, 2026

Official SMARTS public reports

Parameters reported

Reported results over time

Loading reported results…

Most recent reported results

Latest 25 of 142
Sample dateLocationParameterResultUnitsEvent
2026-04-21SL-1 1272-4 Forgewood AveAmmonia as N, Total.1mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AveCopper.084mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AveNickel.007mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AveNitrate/Nitrite (Nitrite + Nitrate as N).427mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AveOil and GreaseND 1.1(non-detect / est.)mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AvepH6.11SUQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AvePhosphorus.54mg/LQualifying Storm Event
2026-04-21SL-1 1272-4 Forgewood AveTotal Suspended Solids (TSS)9mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveAmmonia as N, Total.108mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveCopper.082mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveNickel.0072mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveNitrate/Nitrite (Nitrite + Nitrate as N).463mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveOil and GreaseND .1(non-detect / est.)mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AvepH6.03SUQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AvePhosphorus.58mg/LQualifying Storm Event
2026-04-21SL-2 1276 Forgewood AveTotal Suspended Solids (TSS)7mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveAmmonia as N, Total.729mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveCopper.26mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveNickel.078mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveNitrate/Nitrite (Nitrite + Nitrate as N)1.6mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveOil and Grease< 1.1(non-detect / est.)mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AvepH6.13SUQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AvePhosphorus.65mg/LQualifying Storm Event
2025-12-31SL-1 1272-4 Forgewood AveTotal Suspended Solids (TSS)6mg/LQualifying Storm Event
2025-12-31SL-2 1276 Forgewood AveAmmonia as N, Total.322mg/LQualifying 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

Numeric Action Level comparison

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).

Derived
Reporting years evaluated
5
Years with an NAL exceedance
5
Most recent evaluated year
RY 2025
Ruleset
igp_nal_ruleset_v1 / igp_nal_v1
ParameterNAL typeCalculated valueNALResultSamples usedMethod

Ammonia, Total (as N)

ammonia_n

Annual0.405 mg/L2.14 mg/LAt or below NALAnnual average of 6 eligible result(s) compared with the annual NAL.0.19× threshold6 eligiblearithmetic 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)

Copper, Total

copper_total

Annual0.136 mg/L0.033 mg/LAbove NALAnnual average of 6 eligible result(s) compared with the annual NAL.4.1× threshold6 eligiblearithmetic 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)

Nickel, Total

nickel_total

Annual0.021 mg/l1.02 mg/lAt or below NALAnnual average of 6 eligible result(s) compared with the annual NAL.0.02× threshold6 eligiblearithmetic 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

Annual0.724 mg/L as N0.68 mg/L as NAbove NALAnnual average of 6 eligible result(s) compared with the annual NAL.1.06× threshold6 eligiblearithmetic 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 maximum0 samples above25 mg/LAt or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL.6 eligible4 non-detect as zerocount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

pH

ph

Instantaneous maximum0 samples above6 – 9 pH unitsWithin NAL rangeNo eligible result in this reporting year was outside the instantaneous maximum NAL.6 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

Phosphorus, Total (as P)

phosphorus_total

Annual0.39 mg/L as P2 mg/L as PAt or below NALAnnual average of 6 eligible result(s) compared with the annual NAL.0.2× threshold6 eligiblearithmetic 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 maximum0 samples above400 mg/LAt or below NALNo eligible result in this reporting year was outside the instantaneous maximum NAL.6 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

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

Source & provenance

Source agency
California State Water Resources Control Board
Source dataset
Industrial General Permit — permitted facilities (statewide GIS layer)
WDID
2 43I006896
Source feature ID
10329
Application type
Notice of Intent
Regional board derivation
WDID region prefix
Geometry status
valid
Last successful facility import
Aug 21, 2026, 1:57 AM UTC

Official IGP permitted facilities feature layer