Langley Hill Quarry
Active WDID 2 41I011313 Woodside, 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
- Woodside, 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
- None
- Monitoring results Evidence: facility-reported
- 157 distinct results, 11 reporting years (2015 to 2025)
- Most recent sample Apr 22, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 2 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
- 37.34478, -122.22818
- Precision
- 5 decimal places
- Shared point
- 2 permits report this exact point
- Matches application record
- same
Facility location as reported by the discharger in SMARTS; not a discharge point or outfall.
- Facility address
- 19500 Skyline Blvd, Woodside 94062
- Regional Water Board
- 2 — San Francisco Bay
HUC12 watershed Evidence: spatial
- San Francisquito Creek HUC12 180500030404
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
- Dempsey Michael W Patrick K
- Primary industry (SIC)
- 1429-Crushed and Broken Stone, NEC
- Application ID
- 182903
- NOI processed
- Dec 19, 1994
- Last certified
- Apr 10, 2015
- Facility size
- 7 Acres
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 182903 | Industrial | Active | Dec 19, 1994 | — | Apr 10, 2015 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Woodruff 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.
No 2026 Integrated Report waterbody lies within the proximity threshold of the reported location.
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.
157 distinct measurements across 3 parameters, most recent sample Apr 22, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 18 | 3 | 0 | Nov 19, 2025 | Apr 22, 2026 |
| 2024 | 14 | 3 | 0 | Nov 25, 2024 | Mar 31, 2025 |
| 2023 | 15 | 3 | 0 | Nov 20, 2023 | Apr 24, 2024 |
| 2022 | 11 | 3 | 0 | Dec 28, 2022 | May 03, 2023 |
| 2021 | 12 | 3 | 0 | Nov 09, 2021 | Mar 28, 2022 |
| 2020 | 12 | 3 | 0 | Nov 18, 2020 | Mar 15, 2021 |
| 2019 | 15 | 3 | 0 | Dec 08, 2019 | May 18, 2020 |
| 2018 | 12 | 3 | 0 | Nov 28, 2018 | Apr 16, 2019 |
| 2017 | 12 | 3 | 0 | Jan 04, 2018 | Apr 06, 2018 |
| 2016 | 18 | 3 | 0 | Nov 28, 2016 | Apr 07, 2017 |
| 2015 | 18 | 3 | 0 | Dec 10, 2015 | Apr 22, 2016 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| pH | SU | 53 | 0 | Dec 10, 2015 | Apr 13, 2026 | Results |
| Oil and Grease | mg/L | 52 | 29 | Dec 10, 2015 | Apr 22, 2026 | Results |
| Total Suspended Solids (TSS) | mg/L | 52 | 5 | Dec 10, 2015 | Apr 13, 2026 | Results |
All results (157 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Apr 22, 2026 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1376813 | |
| Apr 13, 2026 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1376813 | |
| Apr 13, 2026 | pH | 7.88 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1376813 | |
| Apr 13, 2026 | pH | 7.67 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1376813 | |
| Apr 13, 2026 | Total Suspended Solids (TSS) | 47 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1376813 | |
| Apr 13, 2026 | Total Suspended Solids (TSS) | 42 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1376813 | |
| Feb 25, 2026 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1376813 | |
| Feb 25, 2026 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1376813 | |
| Feb 25, 2026 | pH | 7.49 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1376813 | |
| Feb 25, 2026 | pH | 7.49 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1376813 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 6 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1376813 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 13 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1376813 | |
| Dec 19, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1361542 | |
| Dec 19, 2025 | pH | 7.91 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1361542 | |
| Dec 19, 2025 | Total Suspended Solids (TSS) | 1.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1361542 | |
| Nov 19, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1361542 | |
| Nov 19, 2025 | pH | 7.79 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1361542 | |
| Nov 19, 2025 | Total Suspended Solids (TSS) | 14 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1361542 | |
| Mar 31, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1343391 | |
| Mar 31, 2025 | pH | 7.8 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1343391 | |
| Mar 31, 2025 | Total Suspended Solids (TSS) | 1.2 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1343391 | |
| Feb 06, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1321928 | |
| Feb 06, 2025 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1321928 | |
| Feb 06, 2025 | pH | 7.79 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1321928 | |
| Feb 06, 2025 | pH | 7.77 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1321928 | |
| Feb 06, 2025 | Total Suspended Solids (TSS) | 19 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1321928 | |
| Dec 16, 2024 | Oil and Grease | .86 | mg/L | Effluent | Qualifying Storm Event | E1664B | 1321920 | |
| Dec 16, 2024 | pH | 7.46 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1321920 | |
| Dec 16, 2024 | Total Suspended Solids (TSS) | 4.8 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1321920 | |
| Nov 25, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1321912 | |
| Nov 25, 2024 | pH | 7.46 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1321912 | |
| Nov 25, 2024 | Total Suspended Solids (TSS) | 15 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1321912 | |
| Apr 24, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1290449 | |
| Apr 24, 2024 | pH | 7.89 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1290449 | |
| Apr 24, 2024 | Total Suspended Solids (TSS) | 52 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1290449 | |
| Mar 02, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1290456 | |
| Mar 02, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1290458 | |
| Mar 02, 2024 | pH | 7.85 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1290456 | |
| Mar 02, 2024 | pH | 7.87 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1290458 | |
| Mar 02, 2024 | Total Suspended Solids (TSS) | 34 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1290456 | |
| Mar 02, 2024 | Total Suspended Solids (TSS) | 25 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1290458 | |
| Dec 19, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1290459 | |
| Dec 19, 2023 | pH | 7.92 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1290459 | |
| Dec 19, 2023 | Total Suspended Solids (TSS) | 4.2 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1290459 | |
| Nov 20, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1269494 | |
| Nov 20, 2023 | pH | 7.69 | SU | Effluent | Qualifying Storm Event | pH_Field | 1269494 | |
| Nov 20, 2023 | Total Suspended Solids (TSS) | 9.5 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1269494 | |
| May 03, 2023 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664B | 1239924 | |
| May 03, 2023 | pH | 7.9 | SU | Effluent | Qualifying Storm Event | pH_Paper | 1239924 | |
| May 03, 2023 | Total Suspended Solids (TSS) | 24 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1239924 |
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 14, 2018 – Feb 14, 2018 | Oct 21, 2026 | All violations |
| Enforcement actions | 1 | 1 issued · 0 draft · 0 withdrawn, rescinded or superseded | Jun 28, 2019 – Jun 28, 2019 | Oct 21, 2026 | All actions |
| Inspections | 2 | inspections, not findings | Feb 14, 2018 – Jan 30, 2020 | 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 (15 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 10, 2026 | Annual reports | 1335166 | Annual report 2025 | — | |
| Jul 15, 2025 | Annual reports | 1293969 | Annual report 2024 | — | |
| Jul 16, 2024 | Annual reports | 1243046 | Annual report 2023 | — | |
| Jul 14, 2023 | Annual reports | 1189040 | Annual report 2022 | — | |
| Jun 15, 2022 | Annual reports | 1112397 | Annual report 2021 | — | |
| Jul 14, 2021 | Annual reports | 1068401 | Annual report 2020 | — | |
| Jul 15, 2020 | Annual reports | 985637 | Annual report 2019 | — | |
| Jan 30, 2020 | Inspections | 2046146 | B Type compliance | — | Additional Info Required |
| Jul 09, 2019 | Annual reports | 953178 | Annual report 2018 | — | |
| Jun 28, 2019 | Enforcement actions | 433501 | NOV (Notice of Violation) | Active | |
| Jul 03, 2018 | Annual reports | 938594 | Annual report 2017 | — | |
| Feb 14, 2018 | Inspections | 2036563 | B Type compliance | — | Additional Info Required |
| Feb 14, 2018 | Violations | 866210 | Deficient BMP Implementation | Violation | Inspection |
| Jul 14, 2017 | Annual reports | 877818 | Annual report 2016 | — | |
| Jun 16, 2016 | Annual reports | 847779 | Annual report 2015 | — |
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.