Mayhew Canyon Plan
Active WDID 8 33I000838 Corona, Riverside County Region 8 · Santa Ana
At a glance
- Permit Evidence: SMARTS record
- Active Industrial
- Notice of Intent (WDID code I) · Permits and applications
- Location Evidence: facility-reported
- Corona, Riverside County
- Region 8 · Santa Ana · 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
- 4 distinct results, 1 reporting year (2015 to 2015)
- Most recent sample Jan 05, 2016 · Monitoring
- Compliance and enforcement records Evidence: SMARTS record
- 1 inspection · 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
- 33.74589, -117.47792
- Precision
- 5 decimal places
- Shared point
- 4 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
- 25050 Maitri Rd, Corona 92883
- Regional Water Board
- 8 — Santa Ana
HUC12 watershed Evidence: spatial
- Dawson Canyon-Temescal Wash HUC12 180702030602
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
- Werner Corporation
- Primary industry (SIC)
- 1442-Construction Sand and Gravel
- Application ID
- 210673
- NOI processed
- Mar 23, 1992
- Last certified
- May 20, 2015
- Facility size
- 420 Acres
Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.
Permit history
| Application | Type | Status | Processed | Terminated | Certified |
|---|---|---|---|---|---|
| 210673 | Industrial | Active | Mar 23, 1992 | — | May 20, 2015 |
Every storm water application SMARTS records for this WDID, newest first (1).
Receiving water
- Reported by the facility Evidence: facility-reported
- Mayhew Wash
- 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.
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.
4 distinct measurements across 4 parameters, most recent sample Jan 05, 2016.
By reporting year
| Reporting year (July–June) | Distinct results | Parameters | With several versions | First sample | Last sample |
|---|---|---|---|---|---|
| 2015 | 4 | 4 | 0 | Jan 05, 2016 | Jan 05, 2016 |
By parameter
| Parameter | Units | Measurements | Below detection | First sample | Last sample | Results |
|---|---|---|---|---|---|---|
| Nitrite Plus Nitrate (as N) | mg/L | 1 | 0 | Jan 05, 2016 | Jan 05, 2016 | Results |
| Oil and Grease | mg/L | 1 | 1 | Jan 05, 2016 | Jan 05, 2016 | Results |
| pH | SU | 1 | 0 | Jan 05, 2016 | Jan 05, 2016 | Results |
| Total Suspended Solids (TSS) | mg/L | 1 | 0 | Jan 05, 2016 | Jan 05, 2016 | Results |
All results (4 distinct rows)
| Sample date | Parameter | Result | Units | Location type | Event | Method | Report | Versions |
|---|---|---|---|---|---|---|---|---|
| Jan 05, 2016 | Nitrite Plus Nitrate (as N) | .273 | mg/L | Effluent | Qualifying Storm Event | A4500NA | 864268 | |
| Jan 05, 2016 | Oil and Grease | ND | mg/L | Effluent | Qualifying Storm Event | E1664A | 864268 | |
| Jan 05, 2016 | pH | 7 | SU | Effluent | Qualifying Storm Event | A4500HB | 864268 | |
| Jan 05, 2016 | Total Suspended Solids (TSS) | 14 | mg/L | Effluent | Qualifying Storm Event | A2540D | 864268 |
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 | 1 | inspections, not findings | Apr 25, 2017 – Apr 25, 2017 | 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 (12 records, newest first)
| Date | Record | ID | Type or purpose | Status as published | Detail |
|---|---|---|---|---|---|
| May 28, 2026 | Annual reports | 1334210 | Annual report 2025 | — | |
| Jun 05, 2025 | Annual reports | 1292981 | Annual report 2024 | — | |
| Jun 11, 2024 | Annual reports | 1241987 | Annual report 2023 | — | |
| May 22, 2023 | Annual reports | 1187918 | Annual report 2022 | — | |
| Jun 20, 2022 | Annual reports | 1111187 | Annual report 2021 | — | |
| Jul 20, 2021 | Annual reports | 1067125 | Annual report 2020 | — | |
| Jul 01, 2020 | Annual reports | 984281 | Annual report 2019 | — | |
| Jun 27, 2019 | Annual reports | 951784 | Annual report 2018 | — | |
| Jul 02, 2018 | Annual reports | 937195 | Annual report 2017 | — | |
| Jun 05, 2017 | Annual reports | 876344 | Annual report 2016 | — | |
| Apr 25, 2017 | Inspections | 2033523 | B Type compliance | — | No Further Action |
| Jun 17, 2016 | Annual reports | 843481 | 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.