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Industrial stormwater facility

Free Builders Supply Incorporated

9 37I026525 · Notice of Intent · San Marcos, San Diego

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

Official

Facility record

Facility name
Free Builders Supply Incorporated
WDID
9 37I026525
Application type
Notice of Intent
City
San Marcos
County
San Diego
ZIP
92078
Primary SIC code
3449
SIC description
Miscellaneous Structural Metal Work
Date active
2016-04-08
Regional Water Board
Regional Board 9 - San Diego Region

Hydrologic

Geographic context

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

Official facility point
33.14010, -117.19943
HUC12 subwatershed
San Marcos Creek
HUC12 code
180703030503
Impaired-water associations (derived)
5
Loading map…

303(d) context

Associated impaired waters

Grouped by derived geographic association class.

Derived

Subwatershed + nearby

1 waterbodies
San Marcos Creek, Upper (above San Marcos Lake)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (9) Benthic Community Effects, Bifenthrin, DDE (Dichlorodiphenyldichloroethylene), Indicator Bacteria, Nitrogen, Phosphorus +3 more

Distance 0.98 km

Confidence high

Fact sheet

Same impaired-water subwatershed

4 waterbodies
Batiquitos Lagoon

Estuary · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (1) Toxicity

Distance

Confidence low

Fact sheet

Encinitas Creek

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (6) Benthic Community Effects, Indicator Bacteria, Nitrogen, Phosphorus, Selenium, Toxicity

Distance

Confidence low

Fact sheet

Lake San Marcos

Lake & Reservoir · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (4) Ammonia as Nitrogen, Copper, Nutrients, Phosphorus

Distance

Confidence low

Fact sheet

San Marcos Creek, Lower (below San Marcos Lake)

River & Stream · Integrated Report category 5 · TMDL required

Listed pollutants / stressors (4) Nitrogen, Phosphorus, Selenium, Toxicity

Distance

Confidence low

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
105
Sample events
15
Distinct parameters
7
Reporting years
2015 – 2021
First sample
2016-04-07
Latest sample
2022-03-28
Source regional dataset
Region 9 - San Diego
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 105
Sample dateLocationParameterResultUnitsEvent
2022-03-28S-1Aluminum2.4mg/LQualifying Storm Event
2022-03-28S-1Iron2.8mg/LQualifying Storm Event
2022-03-28S-1Nitrate/Nitrite (Nitrite + Nitrate as N)2.2mg/LQualifying Storm Event
2022-03-28S-1Oil and Grease17mg/LQualifying Storm Event
2022-03-28S-1pH9.73SUQualifying Storm Event
2022-03-28S-1Total Suspended Solids (TSS)51mg/LQualifying Storm Event
2022-03-28S-1Zinc.16mg/LQualifying Storm Event
2021-03-11S-1Aluminum1.8mg/LQualifying Storm Event
2021-03-11S-1Iron3mg/LQualifying Storm Event
2021-03-11S-1Nitrate/Nitrite (Nitrite + Nitrate as N).063mg/LQualifying Storm Event
2021-03-11S-1Oil and GreaseND (non-detect / est.)mg/LQualifying Storm Event
2021-03-11S-1pH9.63SUQualifying Storm Event
2021-03-11S-1Total Suspended Solids (TSS)32mg/LQualifying Storm Event
2021-03-11S-1Zinc.091mg/LQualifying Storm Event
2021-02-12S-1Aluminum9.2mg/LQualifying Storm Event
2021-02-12S-1Iron13mg/LQualifying Storm Event
2021-02-12S-1Nitrate/Nitrite (Nitrite + Nitrate as N)1mg/LQualifying Storm Event
2021-02-12S-1Oil and Grease2.8mg/LQualifying Storm Event
2021-02-12S-1pH10.11SUQualifying Storm Event
2021-02-12S-1Total Suspended Solids (TSS)190mg/LQualifying Storm Event
2021-02-12S-1Zinc.37mg/LQualifying Storm Event
2020-10-28S-1Aluminum4.4mg/LQualifying Storm Event
2020-10-28S-1Iron5.4mg/LQualifying Storm Event
2020-10-28S-1Nitrate/Nitrite (Nitrite + Nitrate as N)2.2mg/LQualifying Storm Event
2020-10-28S-1Oil and Grease4.1mg/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
7
Years with an NAL exceedance
7
Most recent evaluated year
RY 2021
Ruleset
igp_nal_ruleset_v1 / igp_nal_v1
ParameterNAL typeCalculated valueNALResultSamples usedMethod

Aluminum, Total

aluminum_total

Annual2.4 mg/L0.75 mg/LAbove NALAnnual average of 1 eligible result(s) compared with the annual NAL.3.2× threshold1 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)

Iron, Total

iron_total

Annual2.8 mg/L1 mg/LAbove NALAnnual average of 1 eligible result(s) compared with the annual NAL.2.8× threshold1 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

Annual2.2 mg/L as N0.68 mg/L as NAbove NALAnnual average of 1 eligible result(s) compared with the annual NAL.3.24× threshold1 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.1 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

pH

ph

Instantaneous maximum1 sample above6 – 9 pH unitsWithin NAL rangeOne 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.1 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

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.1 eligiblecount of eligible effluent results outside the instantaneous maximum NAL within the July 1 - June 30 reporting year

Zinc, Total

zinc_total

Annual0.16 mg/L0.26 mg/LAt or below NALAnnual average of 1 eligible result(s) compared with the annual NAL.0.62× threshold1 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)

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
9 37I026525
Source feature ID
17686
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