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
SMARTS TMDL records Evidence: SMARTS-reported
0 records
TMDL records

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

Open this facility on the statewide map

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

Storm water applications for this WDID, newest first
ApplicationTypeStatusProcessedTerminatedCertified
475245 IndustrialActiveJul 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).

2026 Appendix A decisions for the identified receiving water
PollutantCategoryListing decisionTMDL requirementDecision ID
Diazinon4aList on 303(d) list (being addressed by USEPA approved TMDL) 5B · San Francisco Bay Urban Creeks Diazinon70498
Trash4aDo Not Delist from 303(d) list (being addressed with action other than TMDL) 5C71350

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.

Nearest 2026 Integrated Report waterbodies
Waterbody (2026 Integrated Report)Distance2026 303(d) listAppendix A decisions
Atherton Creek (San Mateo) CAR2044004020210406047019592 m not listed0

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

Distinct results by reporting year
Reporting year (July–June)Distinct resultsParametersWith several versionsFirst sampleLast sample
202523010 0 Nov 05, 2025Feb 25, 2026
202433910 0 Nov 22, 2024Mar 26, 2025
2023879 0 Nov 29, 2023Jan 31, 2024
20221419 0 Dec 01, 2022May 02, 2023
2021819 0 Nov 09, 2021Apr 11, 2022
2020909 0 Dec 17, 2020Feb 02, 2021
20191249 0 Dec 07, 2019Jan 16, 2020
20181989 0 Nov 29, 2018Feb 08, 2019
20171989 0 Nov 16, 2017Apr 16, 2018
201614810 0 Oct 14, 2016Mar 24, 2017

By parameter

Distinct results by parameter
ParameterUnitsMeasurementsBelow detectionFirst sampleLast sampleResults
Oil and Greasemg/L173 166Oct 14, 2016Feb 25, 2026 Results
Total Suspended Solids (TSS)mg/L173 7Oct 14, 2016Feb 25, 2026 Results
pHSU172 0Oct 14, 2016Feb 25, 2026 Results
Chemical Oxygen Demand (COD)mg/L171 55Oct 14, 2016Feb 25, 2026 Results
Aluminum, Totalmg/L108 4Oct 14, 2016May 02, 2023 Results
Copper, Totalmg/L108 0Oct 14, 2016May 02, 2023 Results
Iron, Totalmg/L108 2Oct 14, 2016May 02, 2023 Results
Lead, Totalmg/L108 34Oct 14, 2016May 02, 2023 Results
Zinc, Totalmg/L108 0Oct 14, 2016May 02, 2023 Results
Aluminum, Total Recoverableug/L67 6Nov 29, 2023Feb 25, 2026 Results
Copper, Total Recoverableug/L67 2Nov 29, 2023Feb 25, 2026 Results
Iron, Total Recoverableug/L67 9Nov 29, 2023Feb 25, 2026 Results
Show 5 more parameters
More parameters
ParameterUnitsMeasurementsBelow detectionFirst sampleLast sampleResults
Lead, Total Recoverableug/L67 22Nov 29, 2023Feb 25, 2026 Results
Zinc, Total Recoverableug/L67 6Nov 29, 2023Feb 25, 2026 Results
Nitrite Plus Nitrate (as N)ug/L34 1Nov 22, 2024Mar 17, 2025 Results
Nitrite Plus Nitrate (as N)mg/L23 0Nov 05, 2025Feb 25, 2026 Results
Diazinonug/L15 15Oct 14, 2016Mar 24, 2017 Results

All results (1,636 distinct rows)

Reported monitoring results, newest first
Sample dateParameterResultUnitsLocation typeEventMethodReportVersions
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.

Compliance and enforcement records by type
Record typeRecordsAs publishedDatesRetrievedList
Violations0 0 Violation · 0 Potential (preliminary) · 0 Dismissed — Oct 21, 2026
Enforcement actions0 0 issued · 0 draft · 0 withdrawn, rescinded or superseded — Oct 21, 2026
Inspections0inspections, not findings — Oct 21, 2026
Annual reports10certified reports (contents not shown) 2016 – 2025 Oct 21, 2026 All reports
Water-quality-based corrective action reports0reports, 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)
Compliance and enforcement records, newest first
DateRecordIDType or purposeStatus as publishedDetail
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

Sources behind this page
InformationSourceRetrieved or published
Permit, location, receiving-water textSMARTS Industrial Application Specific DataOct 20, 2026
Permit historySMARTS Storm Water ApplicationsOct 20, 2026
Monitoring resultsSMARTS Industrial Parameter DataOct 20, 2026
Watershed Boundary Dataset HU2 GeoPackages 15, 16, 18 (WBDHU12)USGS2026-10-22
2026 California Integrated Report, Appendix A: 2026 303(d) List (final)SWRCB2026-10-22
Final_2026_Rivers_and_Streams + Final_2026_Lakes_and_Reservoirs (FeatureServer 0)SWRCB GIS2026-10-22
SMARTS TMDL requirementsSMARTS2026-10-21

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

Records are shown as published and are not compliance determinations. How geographic context is derived.