SIXTEEN TO ONE MINE
NPDES ID: CA0081809
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
Violations
March 31, 2026
Iron, total recoverable
719% over limit
Discharged 4.83000023 mg/L against a permitted limit of 0.59000003 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Antimony, total recoverable
152% over limit
Discharged 0.0277 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Antimony, total recoverable
395% over limit
Discharged 0.0277 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nickel, total recoverable
88% over limit
Discharged 0.0847 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Iron, total recoverable
527% over limit
Discharged 4.83000023 mg/L against a permitted limit of 0.77000004 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.08745 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Antimony, total recoverable
370% over limit
Discharged 0.0263 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Overdue
Antimony, total recoverable
370% over limit
Discharged 0.0263 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Arsenic, total recoverable
8190% over limit
Discharged 0.82900004 mg/L against a permitted limit of 0.01 mg/L (MO AVG)
DMR, Limited - Overdue
Arsenic, total recoverable
8190% over limit
Discharged 0.82900004 mg/L against a permitted limit of 0.01 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Hardness, total [as CaCO3]
0% over limit
Discharged 479 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Copper, total recoverable
0% over limit
Discharged 0.00867 mg/L against a permitted limit of 0.30000001 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0.001 mg/L against a permitted limit of 0.001 mg/L (MO AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 4.3 mg/L against a permitted limit of 0 mg/L (INST MIN)
DMR, Monitor Only - Overdue
Iron, total recoverable
356% over limit
Discharged 3.51000017 mg/L against a permitted limit of 0.77000004 mg/L (DAILY MX)
DMR, Limited - Overdue
Iron, total recoverable
356% over limit
Discharged 3.51000017 mg/L against a permitted limit of 0.77000004 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Lead, total recoverable
0% over limit
Discharged 0.000882 mg/L against a permitted limit of 0.30000001 mg/L (MO AVG)
DMR, Limited - Overdue
Specific conductance
0% over limit
Discharged 1540 umho/cm against a permitted limit of 2200 umho/cm (ANNL AVG)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0.0245 mg/L against a permitted limit of 1.50000007 mg/L (DAILY MX)
DMR, Limited - Overdue
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.1 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0.001 mg/L against a permitted limit of 0.002 mg/L (DAILY MX)
DMR, Limited - Overdue
Iron, total recoverable
495% over limit
Discharged 3.51000017 mg/L against a permitted limit of 0.59000003 mg/L (MO AVG)
DMR, Limited - Overdue
Iron, total recoverable
495% over limit
Discharged 3.51000017 mg/L against a permitted limit of 0.59000003 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
0% over limit
Discharged 14 mg/L against a permitted limit of 20 mg/L (MO AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 7.66 SU against a permitted limit of 6.5 SU (MINIMUM)
DMR, Limited - Overdue
Arsenic, total recoverable
3668% over limit
Discharged 0.82900004 mg/L against a permitted limit of 0.022 mg/L (DAILY MX)
DMR, Limited - Overdue
Arsenic, total recoverable
3668% over limit
Discharged 0.82900004 mg/L against a permitted limit of 0.022 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total recoverable
0% over limit
Discharged 0.00867 mg/L against a permitted limit of 0.15000001 mg/L (MO AVG)
DMR, Limited - Overdue
Lead, total recoverable
0% over limit
Discharged 0.000882 mg/L against a permitted limit of 0.60000003 mg/L (DAILY MX)
DMR, Limited - Overdue
Nickel, total recoverable
88% over limit
Discharged 0.0844 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Overdue
Nickel, total recoverable
88% over limit
Discharged 0.0844 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (MO AVG)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0.0245 mg/L against a permitted limit of 0.75000004 mg/L (MO AVG)
DMR, Limited - Overdue
Antimony, total recoverable
139% over limit
Discharged 0.0263 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Overdue
Antimony, total recoverable
139% over limit
Discharged 0.0263 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 7.66 SU against a permitted limit of 8.5 SU (MAXIMUM)
DMR, Limited - Overdue
Nickel, total recoverable
0% over limit
Discharged 0.0844 mg/L against a permitted limit of 0.089 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 14 mg/L against a permitted limit of 30 mg/L (DAILY MX)
DMR, Limited - Overdue
March 31, 2025
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Iron, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.77000004 mg/L (DAILY MX)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 1.50000007 mg/L (DAILY MX)
DMR, Limited - Overdue
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.1 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.15000001 mg/L (MO AVG)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.75000004 mg/L (MO AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (INST MIN)
DMR, Monitor Only - Overdue
Antimony, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 20 mg/L (MO AVG)
DMR, Limited - Overdue
Arsenic, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.01 mg/L (MO AVG)
DMR, Limited - Overdue
Lead, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.30000001 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 30 mg/L (DAILY MX)
DMR, Limited - Overdue
Antimony, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Overdue
Nickel, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.001 mg/L (MO AVG)
DMR, Limited - Overdue
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (MO AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 6.5 SU (MINIMUM)
DMR, Limited - Overdue
Lead, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.60000003 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.002 mg/L (DAILY MX)
DMR, Limited - Overdue
Hardness, total [as CaCO3]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Copper, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.30000001 mg/L (DAILY MX)
DMR, Limited - Overdue
Specific conductance
0% over limit
Discharged 0 umho/cm against a permitted limit of 2200 umho/cm (ANNL AVG)
DMR, Limited - Overdue
Nickel, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.089 mg/L (DAILY MX)
DMR, Limited - Overdue
Arsenic, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.022 mg/L (DAILY MX)
DMR, Limited - Overdue
Iron, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.59000003 mg/L (MO AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 8.5 SU (MAXIMUM)
DMR, Limited - Overdue
December 31, 2024
Antimony, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Overdue
Iron, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.77000004 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.15000001 mg/L (MO AVG)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.002 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Lead, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.60000003 mg/L (DAILY MX)
DMR, Limited - Overdue
Nickel, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.75000004 mg/L (MO AVG)
DMR, Limited - Overdue
Iron, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.59000003 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.30000001 mg/L (DAILY MX)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (INST MIN)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 20 mg/L (MO AVG)
DMR, Limited - Overdue
Specific conductance
0% over limit
Discharged 0 umho/cm against a permitted limit of 2200 umho/cm (ANNL AVG)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.001 mg/L (MO AVG)
DMR, Limited - Overdue
Arsenic, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.01 mg/L (MO AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 8.5 SU (MAXIMUM)
DMR, Limited - Overdue
Arsenic, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.022 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 30 mg/L (DAILY MX)
DMR, Limited - Overdue
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (MO AVG)
DMR, Limited - Overdue
Cadmium, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.1 mg/L (DAILY MX)
DMR, Limited - Overdue
Nickel, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.089 mg/L (DAILY MX)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 6.5 SU (MINIMUM)
DMR, Limited - Overdue
Lead, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.30000001 mg/L (MO AVG)
DMR, Limited - Overdue
Hardness, total [as CaCO3]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Antimony, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Overdue
Zinc, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 1.50000007 mg/L (DAILY MX)
DMR, Limited - Overdue
September 30, 2024
Antimony, total recoverable
382% over limit
Discharged 0.027 mg/L against a permitted limit of 0.0056 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Arsenic, total recoverable
8370% over limit
Discharged 0.84700004 mg/L against a permitted limit of 0.01 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Arsenic, total recoverable
3750% over limit
Discharged 0.84700004 mg/L against a permitted limit of 0.022 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nickel, total recoverable
74% over limit
Discharged 0.0784 mg/L against a permitted limit of 0.045 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Antimony, total recoverable
145% over limit
Discharged 0.027 mg/L against a permitted limit of 0.011 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)