Diamond K Supply Ltd
Active WDID 2 07I014181 Lafayette, Contra Costa County Region 2 · San Francisco Bay
At a glance
- Permit Evidence: SMARTS record
- Active Industrial
- Notice of Intent (WDID code I) · Permits and applications
- Location Evidence: facility-reported
- Lafayette, Contra Costa County
- Region 2 · San Francisco Bay · Location · Statewide map
- 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
- 1 waterbody; 1 on the 2026 303(d) list
- Proximity only; not a discharge pathway · Nearby waterbodies
- Monitoring results Evidence: facility-reported
- 124 distinct results, 11 reporting years (2015 to 2025)
- Most recent sample Feb 17, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 0 inspections · 1 violation record · 1 enforcement action
- Counts as published in SMARTS; not a compliance determination · Details
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
Reported location Evidence: facility-reported
- Coordinates
- 37.8905, -122.12871
- Precision
- 4 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
- 3671 Mt Diablo Blvd, Lafayette 94549
- Regional Water Board
- 2 — San Francisco Bay
HUC12 watershed Evidence: spatial
- Las Trampas Creek HUC12 180500010202
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
- Magrath Property
- Primary industry (SIC)
- 1411-Dimension Stone
- Secondary SIC
- 3251-Brick and Structural Clay Tile
- Application ID
- 181913
- NOI processed
- Jun 18, 1998
- Last certified
- May 08, 2015
- Facility size
- 44936 SqFt
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 181913 | Industrial | Active | Jun 18, 1998 | — | May 08, 2015 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Creek
- Discharges directly / indirectly
- N / Y (as answered in the permit application)
Evidence: not confirmed Not matchable to a single waterbody
Receiving-water text as reported by the discharger in SMARTS; no waterbody identification has been confirmed.
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.
| Waterbody (2026 Integrated Report) | Distance | 2026 303(d) list | Appendix A decisions |
|---|---|---|---|
| Las Trampas Creek subwatershed (Contra Costa County, tributary to Walnut Creek) CAR2073201120110723171335 | 236 m | listed | 2 |
Waterbodies within 1.0 km of the reported facility location. Method proximity/1.
SMARTS TMDL records Evidence: SMARTS-reported
No TMDL records for this facility in the SMARTS TMDL export.
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.
124 distinct measurements across 5 parameters, most recent sample Feb 17, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 8 | 4 | 0 | Nov 13, 2025 | Feb 17, 2026 |
| 2024 | 8 | 4 | 0 | Jan 03, 2025 | Feb 04, 2025 |
| 2023 | 12 | 4 | 0 | Dec 20, 2023 | Mar 29, 2024 |
| 2022 | 16 | 4 | 0 | Dec 01, 2022 | Feb 03, 2023 |
| 2021 | 8 | 4 | 0 | Dec 13, 2021 | Dec 29, 2021 |
| 2020 | 4 | 4 | 0 | Mar 18, 2021 | Mar 18, 2021 |
| 2019 | 9 | 5 | 0 | Jan 16, 2020 | Mar 14, 2020 |
| 2018 | 12 | 4 | 0 | Dec 24, 2018 | Feb 13, 2019 |
| 2017 | 12 | 4 | 0 | Jan 08, 2018 | Apr 06, 2018 |
| 2016 | 20 | 5 | 0 | Dec 10, 2016 | Mar 24, 2017 |
| 2015 | 15 | 5 | 0 | Dec 21, 2015 | Mar 11, 2016 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 29 | 25 | Dec 21, 2015 | Feb 17, 2026 | Results |
| pH | SU | 29 | 0 | Dec 21, 2015 | Feb 17, 2026 | Results |
| Total Organic Carbon (TOC) | mg/L | 29 | 0 | Dec 21, 2015 | Feb 17, 2026 | Results |
| Total Suspended Solids (TSS) | mg/L | 29 | 0 | Dec 21, 2015 | Feb 17, 2026 | Results |
| Electrical Conductivity @ 25 Deg. C | umhos/cm | 8 | 0 | Dec 21, 2015 | Jan 16, 2020 | Results |
All results (124 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Feb 17, 2026 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1369631 | |
| Feb 17, 2026 | pH | 7.81 | SU | Effluent | Qualifying Storm Event | pH_Field | 1369631 | |
| Feb 17, 2026 | Total Organic Carbon (TOC) | 2.5 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1369631 | |
| Feb 17, 2026 | Total Suspended Solids (TSS) | 48.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1369631 | |
| Nov 13, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1359499 | |
| Nov 13, 2025 | pH | 7.95 | SU | Effluent | Qualifying Storm Event | pH_Field | 1359499 | |
| Nov 13, 2025 | Total Organic Carbon (TOC) | 4.8 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1359499 | |
| Nov 13, 2025 | Total Suspended Solids (TSS) | 81.6 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1359499 | |
| Feb 04, 2025 | Oil and Grease | 5.3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1322389 | |
| Feb 04, 2025 | pH | 7.93 | SU | Effluent | Qualifying Storm Event | pH_Field | 1322389 | |
| Feb 04, 2025 | Total Organic Carbon (TOC) | 5 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1322389 | |
| Feb 04, 2025 | Total Suspended Solids (TSS) | 22.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1322389 | |
| Jan 03, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1319677 | |
| Jan 03, 2025 | pH | 7.85 | SU | Effluent | Qualifying Storm Event | pH_Field | 1319677 | |
| Jan 03, 2025 | Total Organic Carbon (TOC) | 2.5 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1319677 | |
| Jan 03, 2025 | Total Suspended Solids (TSS) | 29 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1319677 | |
| Mar 29, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1283762 | |
| Mar 29, 2024 | pH | 7.82 | SU | Effluent | Qualifying Storm Event | pH_Field | 1283762 | |
| Mar 29, 2024 | Total Organic Carbon (TOC) | 2 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1283762 | |
| Mar 29, 2024 | Total Suspended Solids (TSS) | 56 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1283762 | |
| Feb 07, 2024 | Oil and Grease | 2.9 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1278720 | |
| Feb 07, 2024 | pH | 7.93 | SU | Effluent | Qualifying Storm Event | pH_Field | 1278720 | |
| Feb 07, 2024 | Total Organic Carbon (TOC) | 3.9 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1278720 | |
| Feb 07, 2024 | Total Suspended Solids (TSS) | 60 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1278720 | |
| Dec 20, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1272222 | |
| Dec 20, 2023 | pH | 7.88 | SU | Effluent | Qualifying Storm Event | pH_Field | 1272222 | |
| Dec 20, 2023 | Total Organic Carbon (TOC) | 4.2 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1272222 | |
| Dec 20, 2023 | Total Suspended Solids (TSS) | 48 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1272222 | |
| Feb 03, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1228083 | |
| Feb 03, 2023 | pH | 7.76 | SU | Effluent | Qualifying Storm Event | pH_Field | 1228083 | |
| Feb 03, 2023 | Total Organic Carbon (TOC) | 2.9 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1228083 | |
| Feb 03, 2023 | Total Suspended Solids (TSS) | 14 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1228083 | |
| Jan 05, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1223893 | |
| Jan 05, 2023 | pH | 7.85 | SU | Effluent | Qualifying Storm Event | pH_Field | 1223893 | |
| Jan 05, 2023 | Total Organic Carbon (TOC) | 3.2 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1223893 | |
| Jan 05, 2023 | Total Suspended Solids (TSS) | 14 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1223893 | |
| Dec 29, 2022 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1223889 | |
| Dec 29, 2022 | pH | 7.87 | SU | Effluent | Qualifying Storm Event | pH_Field | 1223889 | |
| Dec 29, 2022 | Total Organic Carbon (TOC) | 2.1 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1223889 | |
| Dec 29, 2022 | Total Suspended Solids (TSS) | 20 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1223889 | |
| Dec 01, 2022 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1218879 | |
| Dec 01, 2022 | pH | 7.91 | SU | Effluent | Qualifying Storm Event | pH_Field | 1218879 | |
| Dec 01, 2022 | Total Organic Carbon (TOC) | 4.5 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1218879 | |
| Dec 01, 2022 | Total Suspended Solids (TSS) | 30 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1218879 | |
| Dec 29, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1175588 | |
| Dec 29, 2021 | pH | 7.72 | SU | Effluent | Qualifying Storm Event | pH_Field | 1175588 | |
| Dec 29, 2021 | Total Organic Carbon (TOC) | 2.8 | mg/L | Effluent | Qualifying Storm Event | E415.1 | 1175588 | |
| Dec 29, 2021 | Total Suspended Solids (TSS) | 16 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1175588 | |
| Dec 13, 2021 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1172223 | |
| Dec 13, 2021 | pH | 7.86 | SU | Effluent | Qualifying Storm Event | pH_Field | 1172223 |
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.
| Record type | Records | As published | Dates | Retrieved | List |
|---|---|---|---|---|---|
| Violations | 1 | 0 Violation · 0 Potential (preliminary) · 1 Dismissed | Jul 04, 2005 – Jul 04, 2005 | Oct 21, 2026 | All violations |
| Enforcement actions | 1 | 0 issued · 1 draft · 0 withdrawn, rescinded or superseded | Aug 05, 2005 – Aug 05, 2005 | Oct 21, 2026 | All actions |
| Inspections | 0 | inspections, not findings | — | Oct 21, 2026 | |
| Annual reports | 11 | certified reports (contents not shown) | 2015 – 2025 | Oct 21, 2026 | All reports |
| Water-quality-based corrective action reports | 0 | reports, 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 (13 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 09, 2026 | Annual reports | 1337406 | Annual report 2025 | — | |
| Jul 10, 2025 | Annual reports | 1296321 | Annual report 2024 | — | |
| Jul 12, 2024 | Annual reports | 1245524 | Annual report 2023 | — | |
| Jul 11, 2023 | Annual reports | 1191637 | Annual report 2022 | — | |
| Jul 14, 2022 | Annual reports | 1115221 | Annual report 2021 | — | |
| Jul 13, 2021 | Annual reports | 1063315 | Annual report 2020 | — | |
| Jul 13, 2020 | Annual reports | 980199 | Annual report 2019 | — | |
| Jul 14, 2019 | Annual reports | 956456 | Annual report 2018 | — | |
| Jul 10, 2018 | Annual reports | 941883 | Annual report 2017 | — | |
| Jul 13, 2017 | Annual reports | 881289 | Annual report 2016 | — | |
| Jul 13, 2016 | Annual reports | 839308 | Annual report 2015 | — | |
| Aug 05, 2005 | Enforcement actions | 311307 | NNC (Notice of Non-Compliance) | Draft | 97-03DWQ |
| Jul 04, 2005 | Violations | 435443 | Late Report | Dismissed | Report |
Sources and provenance
| Information | Source | Retrieved or published |
|---|---|---|
| Permit, location, receiving-water text | SMARTS Industrial Application Specific Data | Oct 20, 2026 |
| Permit history | SMARTS Storm Water Applications | Oct 20, 2026 |
| Monitoring results | SMARTS Industrial Parameter Data | Oct 20, 2026 |
| Watershed Boundary Dataset HU2 GeoPackages 15, 16, 18 (WBDHU12) | USGS | 2026-10-22 |
| 2026 California Integrated Report, Appendix A: 2026 303(d) List (final) | SWRCB | 2026-10-22 |
| Final_2026_Rivers_and_Streams + Final_2026_Lakes_and_Reservoirs (FeatureServer 0) | SWRCB GIS | 2026-10-22 |
| SMARTS TMDL requirements | SMARTS | 2026-10-21 |
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
- Evidence: SMARTS record Evidence: facility-reported Information as published in SMARTS or reported by the discharger.
- Evidence: identification corroborated The reported receiving-water name identifies one official waterbody and the facility's location is consistent with it. It does not establish a discharge pathway.
- Evidence: candidate, awaiting review Evidence: not confirmed The reported name could match one or more official waterbodies, but no identification has been confirmed; nothing is assigned without review.
- Evidence: spatial Evidence: geographic proximity Derived from the reported location only.
- Evidence: SMARTS-reported Source records whose links to official references are not yet reviewed.
- Evidence: unavailable The information could not be loaded or is not in the sources.
Records are shown as published and are not compliance determinations. How geographic context is derived.