Martin Marietta Clayton Aggregates
Active WDID 2 07I030489 Concord, 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
- Concord, 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
- 9 distinct results, 2 reporting years (2023 to 2024)
- Most recent sample Dec 27, 2024 · 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
- 37.929653, -121.95867
- 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
- 501 Kaiser Quarry Road, Concord 94521
- Regional Water Board
- 2 — San Francisco Bay
HUC12 watershed Evidence: spatial
- Pine Creek HUC12 180500010203
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
- Martin Marietta Northern California Aggregates LLC
- Primary industry (SIC)
- 1429-Crushed and Broken Stone, NEC
- Application ID
- 567881
- NOI processed
- Nov 28, 2023
- Last certified
- Nov 26, 2023
- Facility size
- 123 Acres
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 567881 | Industrial | Active | Nov 28, 2023 | — | Nov 26, 2023 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Galindo Creek
- Discharges directly / indirectly
- N / N (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 |
|---|---|---|---|
| Pine Creek subwatershed (Contra Costa Co, tributary to Walnut Creek) CAR2073101119990218101152 | 127 m | listed | 1 |
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.
9 distinct measurements across 3 parameters, most recent sample Dec 27, 2024.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2024 | 3 | 3 | 0 | Dec 27, 2024 | Dec 27, 2024 |
| 2023 | 6 | 3 | 0 | Jan 22, 2024 | Feb 05, 2024 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Oil and Grease | mg/L | 3 | 3 | Jan 22, 2024 | Dec 27, 2024 | Results |
| pH | SU | 3 | 0 | Jan 22, 2024 | Dec 27, 2024 | Results |
| Total Suspended Solids (TSS) | mg/L | 3 | 0 | Jan 22, 2024 | Dec 27, 2024 | Results |
All results (9 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Dec 27, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1318820 | |
| Dec 27, 2024 | pH | 7.95 | SU | Effluent | Qualifying Storm Event | pH_Field | 1318820 | |
| Dec 27, 2024 | Total Suspended Solids (TSS) | 20.2 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1318820 | |
| Feb 05, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1281648 | |
| Feb 05, 2024 | pH | 7.6 | SU | Effluent | Qualifying Storm Event | A4500HB | 1281648 | |
| Feb 05, 2024 | Total Suspended Solids (TSS) | 5.4 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1281648 | |
| Jan 22, 2024 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 1281628 | |
| Jan 22, 2024 | pH | 7.95 | SU | Effluent | Qualifying Storm Event | A4500HB | 1281628 | |
| Jan 22, 2024 | Total Suspended Solids (TSS) | 75.6 | mg/L | Effluent | Qualifying Storm Event | A2540D | 1281628 |
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 | 3 | certified reports (contents not shown) | 2023 – 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 (3 records, newest first)
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.