Twisselman Mine
Active WDID 3 40I023482 California Valley, San Luis Obispo County Region 3 · Central Coast
At a glance
- Permit Evidence: SMARTS record
- Active Industrial
- Notice of Intent (WDID code I) · Permits and applications
- Location Evidence: facility-reported
- California Valley, San Luis Obispo County
- Region 3 · Central Coast · 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
- None in the current exports
- Compliance and enforcement records Evidence: SMARTS record
- 0 inspections · 9 violation records · 13 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
- 35.3884, -119.9365
- Precision
- 4 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
- 12710 Carissa Highway, California Valley 93453
- Regional Water Board
- 3 — Central Coast
HUC12 watershed Evidence: spatial
- Thompson Spring-Carrizo Plain HUC12 180600030202
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
- Rowland and Catherine Twisselman
- Primary industry (SIC)
- 1442-Construction Sand and Gravel
- Application ID
- 423652
- NOI processed
- Jan 25, 2012
- Last certified
- Oct 06, 2016
- Facility size
- 23 Acres
- Impervious area
- 0 %
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 423652 | Industrial | Active | Jan 25, 2012 | — | Oct 06, 2016 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- None
- 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.
No industrial monitoring results for this permit are in the current exports.
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 | 9 | 5 Violation · 0 Potential (preliminary) · 4 Dismissed | Jul 01, 2013 – Jul 16, 2026 | Oct 21, 2026 | All violations |
| Enforcement actions | 13 | 13 issued · 0 draft · 0 withdrawn, rescinded or superseded | Aug 09, 2013 – Jul 22, 2026 | Oct 21, 2026 | All actions |
| Inspections | 0 | inspections, not findings | — | Oct 21, 2026 | |
| Annual reports | 10 | certified reports (contents not shown) | 2015 – 2024 | 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 (32 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| Jul 22, 2026 | Enforcement actions | 470307 | NOV (Notice of Violation) | Active | |
| Jul 16, 2026 | Violations | 904382 | Late Report | Violation | Report |
| Aug 13, 2025 | Annual reports | 1296762 | Annual report 2024 | — | |
| Aug 08, 2025 | Enforcement actions | 457347 | NOV (Notice of Violation) | Active | |
| Jul 15, 2025 | Violations | 892818 | Late Report | Violation | Report |
| Jul 15, 2024 | Annual reports | 1245987 | Annual report 2023 | — | |
| Jun 24, 2023 | Annual reports | 1063868 | Annual report 2020 | — | |
| Jun 24, 2023 | Annual reports | 1115750 | Annual report 2021 | — | |
| Jun 24, 2023 | Annual reports | 1192120 | Annual report 2022 | — | |
| Sep 25, 2020 | Annual reports | 980801 | Annual report 2019 | — | |
| Sep 25, 2020 | Enforcement actions | 437968 | 2nd NNC - AR (Second Notice of Non-Compliance (annual report)) | Historical | |
| Aug 17, 2020 | Enforcement actions | 437267 | 1st NNC - AR (First Notice of Non-Compliance (annual report)) | Historical | |
| Jul 16, 2020 | Violations | 873710 | Late Report | Violation | Report |
| Nov 18, 2019 | Annual reports | 957085 | Annual report 2018 | — | |
| Nov 01, 2019 | Enforcement actions | 435032 | 2nd NNC - AR (Second Notice of Non-Compliance (annual report)) | Historical | |
| Sep 27, 2019 | Enforcement actions | 434193 | 1st NNC - AR (First Notice of Non-Compliance (annual report)) | Historical | |
| Jul 16, 2019 | Violations | 871082 | Late Report | Violation | Report |
| Sep 19, 2018 | Annual reports | 942517 | Annual report 2017 | — | |
| Sep 14, 2018 | Enforcement actions | 430552 | 2nd NNC - AR (Second Notice of Non-Compliance (annual report)) | Historical | |
| Aug 17, 2018 | Enforcement actions | 430235 | 1st NNC - AR (First Notice of Non-Compliance (annual report)) | Historical | |
| Jul 16, 2018 | Violations | 867318 | Late Report | Violation | Report |
| Oct 20, 2017 | Annual reports | 881986 | Annual report 2016 | — | |
| Sep 21, 2017 | Enforcement actions | 427188 | 2nd NNC - AR (Second Notice of Non-Compliance (annual report)) | Historical | |
| Aug 23, 2017 | Enforcement actions | 426852 | 1st NNC - AR (First Notice of Non-Compliance (annual report)) | Historical | |
| Jul 16, 2017 | Violations | 864049 | Late Report | Dismissed | Report |
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.