SLAC National Accelerator Laboratory
Active WDID 2 41I026697 Menlo Park, 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
- Menlo Park, San Mateo County
- Region 2 · San Francisco Bay · Location · Statewide map
- Receiving water
- San Francisquito Creek (as reported by the facility)
- Evidence: identification corroborated San Francisquito Creek Details
- Identified receiving water on the 2026 303(d) list
- Yes · 2 Appendix A decisions, category 4a Evidence: State-published
- Describes the waterbody, not this facility · Waterbody profile
- 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
- 1,636 distinct results, 10 reporting years (2016 to 2025)
- Most recent sample Feb 25, 2026 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 0 inspections · 0 violation records · 0 enforcement actions
- 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
- 37.420191, -122.204551
- Precision
- 6 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
- 2575 Sand Hill Rd M/S 84, Menlo Park 94025
- 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
- SLAC National Accelerator Laboratory
- Primary industry (SIC)
- 9999-Nonclassifiable Establishments
- Application ID
- 475245
- NOI processed
- Jul 15, 2016
- Last certified
- Oct 24, 2023
- Facility size
- 426 Acres
- Impervious area
- 27 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 475245 | Industrial | Active | Jul 15, 2016 | — | Oct 24, 2023 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- San Francisquito Creek
- Discharges directly / indirectly
- N / Y (as answered in the permit application)
Evidence: identification corroborated San Francisquito Creek CAR2055004019980929144005
Receiving water reported by facility — waterbody identification corroborated by geographic evidence.
Nearest distance from the reported facility location: 1.0 km. Method receiving_water/2.
2026 Integrated Report status Evidence: State-published
San Francisquito Creek is on the 2026 Clean Water Act section 303(d) list (2 Appendix A decisions; category 4a).
| Pollutant | Category | Listing decision | TMDL requirement | Decision ID |
|---|---|---|---|---|
| Diazinon | 4a | List on 303(d) list (being addressed by USEPA approved TMDL) | 5B · San Francisco Bay Urban Creeks Diazinon | 70498 |
| Trash | 4a | Do Not Delist from 303(d) list (being addressed with action other than TMDL) | 5C | 71350 |
Published by the State Water Resources Control Board (2026 California Integrated Report, Appendix A). Listing status is taken from Appendix A only. State Board adoption 2026-02-03; USEPA approval not confirmed. A listing describes the waterbody, not this facility. Waterbody profile.
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 |
|---|---|---|---|
| Atherton Creek (San Mateo) CAR2044004020210406047019 | 592 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.
1,636 distinct measurements across 16 parameters, most recent sample Feb 25, 2026.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2025 | 230 | 10 | 0 | Nov 05, 2025 | Feb 25, 2026 |
| 2024 | 339 | 10 | 0 | Nov 22, 2024 | Mar 26, 2025 |
| 2023 | 87 | 9 | 0 | Nov 29, 2023 | Jan 31, 2024 |
| 2022 | 141 | 9 | 0 | Dec 01, 2022 | May 02, 2023 |
| 2021 | 81 | 9 | 0 | Nov 09, 2021 | Apr 11, 2022 |
| 2020 | 90 | 9 | 0 | Dec 17, 2020 | Feb 02, 2021 |
| 2019 | 124 | 9 | 0 | Dec 07, 2019 | Jan 16, 2020 |
| 2018 | 198 | 9 | 0 | Nov 29, 2018 | Feb 08, 2019 |
| 2017 | 198 | 9 | 0 | Nov 16, 2017 | Apr 16, 2018 |
| 2016 | 148 | 10 | 0 | Oct 14, 2016 | Mar 24, 2017 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 173 | 166 | Oct 14, 2016 | Feb 25, 2026 | Results |
| Total Suspended Solids (TSS) | mg/L | 173 | 7 | Oct 14, 2016 | Feb 25, 2026 | Results |
| pH | SU | 172 | 0 | Oct 14, 2016 | Feb 25, 2026 | Results |
| Chemical Oxygen Demand (COD) | mg/L | 171 | 55 | Oct 14, 2016 | Feb 25, 2026 | Results |
| Aluminum, Total | mg/L | 108 | 4 | Oct 14, 2016 | May 02, 2023 | Results |
| Copper, Total | mg/L | 108 | 0 | Oct 14, 2016 | May 02, 2023 | Results |
| Iron, Total | mg/L | 108 | 2 | Oct 14, 2016 | May 02, 2023 | Results |
| Lead, Total | mg/L | 108 | 34 | Oct 14, 2016 | May 02, 2023 | Results |
| Zinc, Total | mg/L | 108 | 0 | Oct 14, 2016 | May 02, 2023 | Results |
| Aluminum, Total Recoverable | ug/L | 67 | 6 | Nov 29, 2023 | Feb 25, 2026 | Results |
| Copper, Total Recoverable | ug/L | 67 | 2 | Nov 29, 2023 | Feb 25, 2026 | Results |
| Iron, Total Recoverable | ug/L | 67 | 9 | Nov 29, 2023 | Feb 25, 2026 | Results |
Show 5 more parameters
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Lead, Total Recoverable | ug/L | 67 | 22 | Nov 29, 2023 | Feb 25, 2026 | Results |
| Zinc, Total Recoverable | ug/L | 67 | 6 | Nov 29, 2023 | Feb 25, 2026 | Results |
| Nitrite Plus Nitrate (as N) | ug/L | 34 | 1 | Nov 22, 2024 | Mar 17, 2025 | Results |
| Nitrite Plus Nitrate (as N) | mg/L | 23 | 0 | Nov 05, 2025 | Feb 25, 2026 | Results |
| Diazinon | ug/L | 15 | 15 | Oct 14, 2016 | Mar 24, 2017 | Results |
All results (1,636 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Feb 25, 2026 | Aluminum, Total Recoverable | 577 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Aluminum, Total Recoverable | ND 9.7 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Aluminum, Total Recoverable | DNQ 15.8 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Aluminum, Total Recoverable | 91.9 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Aluminum, Total Recoverable | 92.9 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Chemical Oxygen Demand (COD) | 33.9 | mg/L | Effluent | Qualifying Storm Event | A5220D | 1368138 | |
| Feb 25, 2026 | Chemical Oxygen Demand (COD) | 23.7 | mg/L | Effluent | Qualifying Storm Event | A5220D | 1368138 | |
| Feb 25, 2026 | Chemical Oxygen Demand (COD) | 11.5 | mg/L | Effluent | Qualifying Storm Event | A5220D | 1368138 | |
| Feb 25, 2026 | Chemical Oxygen Demand (COD) | 35.9 | mg/L | Effluent | Qualifying Storm Event | A5220D | 1368138 | |
| Feb 25, 2026 | Chemical Oxygen Demand (COD) | 25.7 | mg/L | Effluent | Qualifying Storm Event | A5220D | 1368138 | |
| Feb 25, 2026 | Copper, Total Recoverable | 4.76 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Copper, Total Recoverable | 3.98 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Copper, Total Recoverable | 4.64 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Copper, Total Recoverable | 7.41 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Copper, Total Recoverable | DNQ 1.06 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Iron, Total Recoverable | DNQ 25.1 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Iron, Total Recoverable | DNQ 29.2 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Iron, Total Recoverable | 50.7 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Iron, Total Recoverable | 129 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Iron, Total Recoverable | DNQ 22.3 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Lead, Total Recoverable | ND .17 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Lead, Total Recoverable | ND .17 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Lead, Total Recoverable | ND .17 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Lead, Total Recoverable | 1.48 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Lead, Total Recoverable | ND .17 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Nitrite Plus Nitrate (as N) | 1.3 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1368138 | |
| Feb 25, 2026 | Nitrite Plus Nitrate (as N) | .55 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1368138 | |
| Feb 25, 2026 | Nitrite Plus Nitrate (as N) | .96 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1368138 | |
| Feb 25, 2026 | Nitrite Plus Nitrate (as N) | .43 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1368138 | |
| Feb 25, 2026 | Nitrite Plus Nitrate (as N) | 1.2 | mg/L | Effluent | Qualifying Storm Event | A4500NE | 1368138 | |
| Feb 25, 2026 | Oil and Grease | ND 2 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368138 | |
| Feb 25, 2026 | Oil and Grease | ND 1.9 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368138 | |
| Feb 25, 2026 | Oil and Grease | ND 1.9 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368138 | |
| Feb 25, 2026 | Oil and Grease | ND 1.9 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368138 | |
| Feb 25, 2026 | Oil and Grease | ND 1.9 | mg/L | Effluent | Qualifying Storm Event | E1664A | 1368138 | |
| Feb 25, 2026 | pH | 7.75 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368138 | |
| Feb 25, 2026 | pH | 7.33 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368138 | |
| Feb 25, 2026 | pH | 8.13 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368138 | |
| Feb 25, 2026 | pH | 7.61 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368138 | |
| Feb 25, 2026 | pH | 7.42 | SU | Effluent | Qualifying Storm Event | pH_Field | 1368138 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 4.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368138 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 2.2 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368138 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 1.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368138 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 12.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368138 | |
| Feb 25, 2026 | Total Suspended Solids (TSS) | 1.6 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1368138 | |
| Feb 25, 2026 | Zinc, Total Recoverable | 129 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Zinc, Total Recoverable | ND 8.2 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Zinc, Total Recoverable | 181 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Zinc, Total Recoverable | 61.1 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 | |
| Feb 25, 2026 | Zinc, Total Recoverable | DNQ 10.3 | ug/L | Effluent | Qualifying Storm Event | E200.8 | 1368138 |
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 | 0 | 0 Violation · 0 Potential (preliminary) · 0 Dismissed | — | Oct 21, 2026 | |
| Enforcement actions | 0 | 0 issued · 0 draft · 0 withdrawn, rescinded or superseded | — | Oct 21, 2026 | |
| Inspections | 0 | inspections, not findings | — | Oct 21, 2026 | |
| Annual reports | 10 | certified reports (contents not shown) | 2016 – 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 (10 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 07, 2026 | Annual reports | 1339171 | Annual report 2025 | — | |
| Jul 11, 2025 | Annual reports | 1298206 | Annual report 2024 | — | |
| Jul 11, 2024 | Annual reports | 1247480 | Annual report 2023 | — | |
| Jul 11, 2023 | Annual reports | 1193681 | Annual report 2022 | — | |
| Jul 13, 2022 | Annual reports | 1117531 | Annual report 2021 | — | |
| Jul 09, 2021 | Annual reports | 1065754 | Annual report 2020 | — | |
| Jul 08, 2020 | Annual reports | 982870 | Annual report 2019 | — | |
| Jul 10, 2019 | Annual reports | 959225 | Annual report 2018 | — | |
| Jul 12, 2018 | Annual reports | 944660 | Annual report 2017 | — | |
| Jul 14, 2017 | Annual reports | 889724 | Annual report 2016 | — |
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.