Empire Mine State Historic Park

Active WDID 5S29I019611 Grass Valley, Nevada County Region 5S · Central Valley (Sacramento)

At a glance

Permit Evidence: SMARTS record
Active Industrial
Notice of Intent (WDID code I) · Permits and applications
Location Evidence: facility-reported
Grass Valley, Nevada County
Region 5S · Central Valley (Sacramento) · Location · Statewide map
Receiving water
Little Wolf Creek (as reported by the facility)
Evidence: not confirmed Details
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
3,013 distinct results, 11 reporting years (2015 to 2025)
Most recent sample Feb 16, 2026 · Monitoring
Compliance and enforcement records Evidence: SMARTS record
2 inspections · 3 violation records · 3 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
39.207761, -121.043585
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
10556 E Empire St, Grass Valley 95945
Regional Water Board
5S — Central Valley (Sacramento)

HUC12 watershed Evidence: spatial

  • Rattlesnake Creek-Wolf Creek HUC12 180201260202

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
California State Parks
Primary industry (SIC)
9999-Nonclassifiable Establishments
Application ID
293096
NOI processed
Jun 28, 2005
Last certified
Feb 21, 2020
Facility size
854

Retrieved from SMARTS Oct 20, 2026. Verify against SMARTS before relying on it.

Permit history

Storm water applications for this WDID, newest first
ApplicationTypeStatusProcessedTerminatedCertified
293096 IndustrialActiveJun 28, 2005 —Feb 21, 2020

Every storm water application SMARTS records for this WDID, newest first (1).

Receiving water

Reported by the facility Evidence: facility-reported
Little Wolf Creek
Discharges directly / indirectly
Y / 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.

3,013 distinct measurements across 19 parameters, most recent sample Feb 16, 2026.

By reporting year

Distinct results by reporting year
Reporting year (July–June)Distinct resultsParametersWith several versionsFirst sampleLast sample
2025153 0 Nov 05, 2025Feb 16, 2026
2024183 0 Nov 21, 2024Feb 04, 2025
202333015 0 Dec 19, 2023Feb 19, 2024
202239015 0 Nov 08, 2022Apr 07, 2023
202140515 0 Nov 09, 2021Apr 14, 2022
202026615 0 Dec 17, 2020Jan 28, 2021
201927015 0 Dec 02, 2019Apr 05, 2020
201837615 0 Nov 29, 2018Apr 02, 2019
201727315 0 Nov 16, 2017Mar 01, 2018
201635013 0 Nov 23, 2016Feb 16, 2017
201532017 0 Nov 24, 2015Apr 22, 2016

By parameter

Distinct results by parameter
ParameterUnitsMeasurementsBelow detectionFirst sampleLast sampleResults
Total Suspended Solids (TSS)mg/L220 51Nov 24, 2015Feb 16, 2026 Results
pHSU219 0Nov 24, 2015Feb 16, 2026 Results
Oil and Greasemg/L218 218Nov 24, 2015Feb 16, 2026 Results
Aluminum, Totalmg/L209 31Nov 24, 2015Feb 19, 2024 Results
Arsenic, Totalmg/L209 32Nov 24, 2015Feb 19, 2024 Results
Cadmium, Totalmg/L209 133Nov 24, 2015Feb 19, 2024 Results
Copper, Totalmg/L209 41Nov 24, 2015Feb 19, 2024 Results
Hardness, Total (as CaCO3)mg/L209 2Nov 24, 2015Feb 19, 2024 Results
Lead, Totalmg/L209 94Nov 24, 2015Feb 19, 2024 Results
Mercury, Totalug/L209 192Nov 24, 2015Feb 19, 2024 Results
Zinc, Totalmg/L209 122Nov 24, 2015Feb 19, 2024 Results
Manganese, Totalmg/L200 99Nov 24, 2015Feb 19, 2024 Results
Show 7 more parameters
More parameters
ParameterUnitsMeasurementsBelow detectionFirst sampleLast sampleResults
Iron, Totalmg/L190 50Nov 24, 2015Feb 19, 2024 Results
Iron, Total Recoverableug/L140 47Jan 08, 2018Feb 19, 2024 Results
Manganese, Total Recoverablemg/L133 64Jan 08, 2018Feb 19, 2024 Results
Alkalinity, Carbonate (as CaCO3)mg/L6 6Apr 22, 2016Apr 22, 2016 Results
Alkalinity, Hydroxide (as CaCO3)ug/L6 6Apr 22, 2016Apr 22, 2016 Results
Alkalinity, Total (as CaCO3)mg/L6 0Apr 22, 2016Apr 22, 2016 Results
Alkalinity, Bicarbonate (as CaCO3)mg/L3 0Apr 22, 2016Apr 22, 2016 Results

All results (3,013 distinct rows)

Reported monitoring results, newest first
Sample dateParameterResultUnitsLocation typeEventMethodReportVersions
Feb 16, 2026 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1367035
Feb 16, 2026 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1367035
Feb 16, 2026 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1367035
Feb 16, 2026 pH 7.02 SU Effluent Qualifying Storm Event pH_Field 1367035
Feb 16, 2026 pH 7.02 SU Effluent Qualifying Storm Event pH_Field 1367035
Feb 16, 2026 pH 7.23 SU Effluent Qualifying Storm Event pH_Field 1367035
Feb 16, 2026 Total Suspended Solids (TSS) ND mg/L Effluent Qualifying Storm Event A2540D 1367035
Feb 16, 2026 Total Suspended Solids (TSS) ND mg/L Effluent Qualifying Storm Event A2540D 1367035
Feb 16, 2026 Total Suspended Solids (TSS) ND mg/L Effluent Qualifying Storm Event A2540D 1367035
Nov 05, 2025 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1358131
Nov 05, 2025 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1358131
Nov 05, 2025 pH 7.02 SU Effluent Qualifying Storm Event pH_Field 1358131
Nov 05, 2025 pH 7.04 SU Effluent Qualifying Storm Event pH_Field 1358131
Nov 05, 2025 Total Suspended Solids (TSS) DNQ 1.8 mg/L Effluent Qualifying Storm Event A2540D 1358131
Nov 05, 2025 Total Suspended Solids (TSS) DNQ 1.6 mg/L Effluent Qualifying Storm Event A2540D 1358131
Feb 04, 2025 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1321255
Feb 04, 2025 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1321255
Feb 04, 2025 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1321255
Feb 04, 2025 pH 7.32 SU Effluent Qualifying Storm Event pH_Field 1321255
Feb 04, 2025 pH 7.37 SU Effluent Qualifying Storm Event pH_Field 1321255
Feb 04, 2025 pH 7.5 SU Effluent Qualifying Storm Event pH_Field 1321255
Feb 04, 2025 Total Suspended Solids (TSS) 2.2 mg/L Effluent Qualifying Storm Event A2540D 1321255
Feb 04, 2025 Total Suspended Solids (TSS) ND mg/L Effluent Qualifying Storm Event A2540D 1321255
Feb 04, 2025 Total Suspended Solids (TSS) ND mg/L Effluent Qualifying Storm Event A2540D 1321255
Nov 21, 2024 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1315746
Nov 21, 2024 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1315746
Nov 21, 2024 Oil and Grease ND mg/L Effluent Qualifying Storm Event E1664A 1315746
Nov 21, 2024 pH 7.32 SU Effluent Qualifying Storm Event pH_Field 1315746
Nov 21, 2024 pH 6.68 SU Effluent Qualifying Storm Event pH_Field 1315746
Nov 21, 2024 pH 6.62 SU Effluent Qualifying Storm Event pH_Field 1315746
Nov 21, 2024 Total Suspended Solids (TSS) 1.6 mg/L Effluent Qualifying Storm Event A2540D 1315746
Nov 21, 2024 Total Suspended Solids (TSS) 1 mg/L Effluent Qualifying Storm Event A2540D 1315746
Nov 21, 2024 Total Suspended Solids (TSS) 1.6 mg/L Effluent Qualifying Storm Event A2540D 1315746
Feb 19, 2024 Aluminum, Total .95 mg/L Influent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .23 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .32 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .33 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .21 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .071 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .15 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Aluminum, Total .055 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .004 mg/L Influent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .00062 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .0024 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .0024 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total DNQ .00049 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total DNQ .00035 mg/L Effluent Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .0015 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Arsenic, Total .0015 mg/L Internal Qualifying Storm Event E200.8 1280817
Feb 19, 2024 Cadmium, Total ND mg/L Influent Qualifying Storm Event E200.8 1280817

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
Violations3 3 Violation · 0 Potential (preliminary) · 0 Dismissed Mar 30, 2006 – Oct 14, 2010 Oct 21, 2026 All violations
Enforcement actions3 3 issued · 0 draft · 0 withdrawn, rescinded or superseded Mar 30, 2007 – Oct 14, 2010 Oct 21, 2026 All actions
Inspections2inspections, not findings Nov 04, 2009 – Nov 15, 2017 Oct 21, 2026 All inspections
Annual reports11certified reports (contents not shown) 2015 – 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 (19 records, newest first)
Compliance and enforcement records, newest first
DateRecordIDType or purposeStatus as publishedDetail
Jul 01, 2026 Annual reports 1335328 Annual report 2025 —
Jun 26, 2025 Annual reports 1294140 Annual report 2024 —
Jul 12, 2024 Annual reports 1243223 Annual report 2023 —
Jul 14, 2023 Annual reports 1189225 Annual report 2022 —
Jul 07, 2022 Annual reports 1112596 Annual report 2021 —
Jun 14, 2021 Annual reports 1068603 Annual report 2020 —
Jun 22, 2020 Annual reports 985856 Annual report 2019 —
May 29, 2019 Annual reports 953408 Annual report 2018 —
May 29, 2018 Annual reports 938824 Annual report 2017 —
Nov 15, 2017 Inspections 2035659 B Type compliance —No Further Action
Aug 02, 2017 Annual reports 878056 Annual report 2016 —
Jul 06, 2016 Annual reports 846520 Annual report 2015 —
Oct 14, 2010 Enforcement actions 403186 SEL (Staff Enforcement Letter) Historical
Oct 14, 2010 Violations 842924 Deficient BMP Implementation ViolationReport
Nov 04, 2009 Inspections 2001154 B Type compliance —No Further Action
May 01, 2008 Enforcement actions 347503 SEL (Staff Enforcement Letter) Active
Jul 01, 2007 Violations 765686 Deficient BMP Implementation ViolationStorm Water Discharge
Mar 30, 2007 Enforcement actions 325280 NOV (Notice of Violation) Active
Mar 30, 2006 Violations 496700 Deficient Report ViolationReport

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.