Granite Rock Company Redwood City
Active WDID 2 41I009419 Redwood City, San Mateo 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
- Redwood City, San Mateo 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; 0 on the 2026 303(d) list
- Proximity only; not a discharge pathway · Nearby waterbodies
- Monitoring results Evidence: facility-reported
- 299 distinct results, 11 reporting years (2015 to 2025)
- Most recent sample Feb 16, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 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
- 37.49297, -122.21475
- Precision
- 5 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
- 355 Blomquist St, Redwood City 94063
- Regional Water Board
- 2 — San Francisco Bay
HUC12 watershed Evidence: spatial
- San Francisco Bay Estuaries-Frontal San Francisco Bay HUC12 180500041001
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
- Granite Rock Co Road Materials
- Primary industry (SIC)
- 3273-Ready-Mixed Concrete
- Secondary SIC
- 2951-Asphalt Paving Mixtures and Blocks
- Tertiary SIC
- 5093-Scrap and Waste Materials
- Application ID
- 182889
- NOI processed
- Nov 23, 1992
- Last certified
- Dec 22, 2023
- Facility size
- 30 Acres
- Impervious area
- 70 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 182889 | Industrial | Active | Nov 23, 1992 | — | Dec 22, 2023 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Steinberger 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 |
|---|---|---|---|
| Redwood Creek, tidal portion (San Mateo County) CAE2044004020011017115206 | 244 m | not listed | 0 |
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.
299 distinct measurements across 7 parameters, most recent sample Feb 16, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 20 | 4 | 0 | Oct 14, 2025 | Feb 16, 2026 |
| 2024 | 16 | 4 | 0 | Nov 22, 2024 | Feb 13, 2025 |
| 2023 | 24 | 4 | 0 | Nov 29, 2023 | Jan 22, 2024 |
| 2022 | 20 | 4 | 0 | Nov 08, 2022 | Feb 24, 2023 |
| 2021 | 20 | 4 | 0 | Oct 22, 2021 | Apr 21, 2022 |
| 2020 | 24 | 4 | 0 | Dec 12, 2020 | Mar 10, 2021 |
| 2019 | 24 | 4 | 0 | Nov 27, 2019 | Mar 24, 2020 |
| 2018 | 20 | 4 | 0 | Jan 09, 2019 | Mar 05, 2019 |
| 2017 | 61 | 7 | 0 | Nov 16, 2017 | Apr 13, 2018 |
| 2016 | 40 | 5 | 0 | Dec 15, 2016 | Feb 24, 2017 |
| 2015 | 30 | 5 | 0 | Dec 03, 2015 | Jan 06, 2016 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 70 | 34 | Dec 03, 2015 | Feb 16, 2026 | Results |
| pH | SU | 70 | 0 | Dec 03, 2015 | Feb 16, 2026 | Results |
| Total Suspended Solids (TSS) | mg/L | 70 | 1 | Dec 03, 2015 | Feb 16, 2026 | Results |
| Iron, Total | mg/L | 68 | 3 | Dec 03, 2015 | Feb 16, 2026 | Results |
| Electrical Conductivity @ 25 Deg. C | umhos/cm | 18 | 0 | Dec 03, 2015 | Nov 16, 2017 | Results |
| Mercury, Total | ug/L | 2 | 2 | Mar 22, 2018 | Apr 13, 2018 | Results |
| Mercury, Total Recoverable | ug/L | 1 | 1 | Mar 16, 2018 | Mar 16, 2018 | Results |
All results (299 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Feb 16, 2026 | Iron, Total | 4.3 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1368672 | |
| Feb 16, 2026 | Oil and Grease | 5.3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368672 | |
| Feb 16, 2026 | pH | 8.1 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368672 | |
| Feb 16, 2026 | Total Suspended Solids (TSS) | 97 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368672 | |
| Feb 10, 2026 | Iron, Total | 1.5 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1368671 | |
| Feb 10, 2026 | Oil and Grease | 3.3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368671 | |
| Feb 10, 2026 | pH | 7.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368671 | |
| Feb 10, 2026 | Total Suspended Solids (TSS) | 27 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368671 | |
| Dec 26, 2025 | Iron, Total | 1.2 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1363684 | |
| Dec 26, 2025 | Oil and Grease | .93 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1363684 | |
| Dec 26, 2025 | pH | 7.3 | SU | Effluent | Qualifying Storm Event | pH_Field | 1363684 | |
| Dec 26, 2025 | Total Suspended Solids (TSS) | 41 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1363684 | |
| Nov 13, 2025 | Iron, Total | 6.8 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1358720 | |
| Nov 13, 2025 | Oil and Grease | 4 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1358720 | |
| Nov 13, 2025 | pH | 7.9 | SU | Effluent | Qualifying Storm Event | pH_Field | 1358720 | |
| Nov 13, 2025 | Total Suspended Solids (TSS) | 160 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1358720 | |
| Oct 14, 2025 | Iron, Total | 4.9 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1355489 | |
| Oct 14, 2025 | Oil and Grease | 3.1 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1355489 | |
| Oct 14, 2025 | pH | 7.6 | SU | Effluent | Qualifying Storm Event | pH_Field | 1355489 | |
| Oct 14, 2025 | Total Suspended Solids (TSS) | 100 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1355489 | |
| Feb 13, 2025 | Iron, Total | 2.4 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1343593 | |
| Feb 13, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1343593 | |
| Feb 13, 2025 | pH | 6.7 | SU | Effluent | Qualifying Storm Event | pH_Field | 1343593 | |
| Feb 13, 2025 | Total Suspended Solids (TSS) | 35 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1343593 | |
| Feb 04, 2025 | Iron, Total | 2.3 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1321849 | |
| Feb 04, 2025 | Oil and Grease | 4.3 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1321849 | |
| Feb 04, 2025 | pH | 6.7 | SU | Effluent | Qualifying Storm Event | pH_Field | 1321849 | |
| Feb 04, 2025 | Total Suspended Solids (TSS) | 48 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1321849 | |
| Dec 12, 2024 | Iron, Total | 2.5 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1317627 | |
| Dec 12, 2024 | Oil and Grease | 4 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1317627 | |
| Dec 12, 2024 | pH | 6.8 | SU | Effluent | Qualifying Storm Event | pH_Field | 1317627 | |
| Dec 12, 2024 | Total Suspended Solids (TSS) | 76 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1317627 | |
| Nov 22, 2024 | Iron, Total | 8.2 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1316423 | |
| Nov 22, 2024 | Oil and Grease | 7.2 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1316423 | |
| Nov 22, 2024 | pH | 8.17 | SU | Effluent | Qualifying Storm Event | pH_Field | 1316423 | |
| Nov 22, 2024 | Total Suspended Solids (TSS) | 180 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1316423 | |
| Jan 22, 2024 | Iron, Total | 1.6 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1274562 | |
| Jan 22, 2024 | Iron, Total | 7.4 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1274562 | |
| Jan 22, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1274562 | |
| Jan 22, 2024 | Oil and Grease | 4.1 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1274562 | |
| Jan 22, 2024 | pH | 8 | SU | Effluent | Qualifying Storm Event | pH_Field | 1274562 | |
| Jan 22, 2024 | pH | 9.83 | SU | Effluent | Qualifying Storm Event | pH_Field | 1274562 | |
| Jan 22, 2024 | Total Suspended Solids (TSS) | 31 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1274562 | |
| Jan 22, 2024 | Total Suspended Solids (TSS) | 172 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1274562 | |
| Jan 17, 2024 | Iron, Total | 3.9 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1274561 | |
| Jan 17, 2024 | Oil and Grease | 4.4 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1274561 | |
| Jan 17, 2024 | pH | 7.5 | SU | Effluent | Qualifying Storm Event | pH_Field | 1274561 | |
| Jan 17, 2024 | Total Suspended Solids (TSS) | 20 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1274561 | |
| Jan 03, 2024 | Iron, Total | 5 | mg/L | Effluent | Qualifying Storm Event | E200.7 | 1272633 | |
| Jan 03, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1272633 |
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 | 1 Violation · 0 Potential (preliminary) · 0 Dismissed | Feb 06, 2003 – Feb 06, 2003 | Oct 21, 2026 | All violations |
| Enforcement actions | 1 | 1 issued · 0 draft · 0 withdrawn, rescinded or superseded | Jun 26, 2003 – Jun 26, 2003 | Oct 21, 2026 | All actions |
| Inspections | 1 | inspections, not findings | Feb 06, 2003 – Feb 06, 2003 | Oct 21, 2026 | All inspections |
| 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 (14 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 13, 2026 | Annual reports | 1336420 | Annual report 2025 | — | |
| Jul 10, 2025 | Annual reports | 1295282 | Annual report 2024 | — | |
| Jul 09, 2024 | Annual reports | 1244416 | Annual report 2023 | — | |
| Jul 14, 2023 | Annual reports | 1190472 | Annual report 2022 | — | |
| Jul 13, 2022 | Annual reports | 1113956 | Annual report 2021 | — | |
| Jul 01, 2021 | Annual reports | 1070026 | Annual report 2020 | — | |
| Jul 14, 2020 | Annual reports | 987383 | Annual report 2019 | — | |
| Jun 29, 2019 | Annual reports | 954993 | Annual report 2018 | — | |
| Jul 12, 2018 | Annual reports | 940411 | Annual report 2017 | — | |
| Jul 06, 2017 | Annual reports | 879738 | Annual report 2016 | — | |
| Sep 01, 2016 | Annual reports | 839583 | Annual report 2015 | — | |
| Jun 26, 2003 | Enforcement actions | 242607 | NOV (Notice of Violation) | Active | UNKNOWN |
| Feb 06, 2003 | Inspections | 330975 | Inspection from Vehicle | — | |
| Feb 06, 2003 | Violations | 236495 | Deficient BMP Implementation | Violation | Inspection |
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.