| Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
| 1135035 |
09/30/2024 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.4 ug/L at EFF-003. |
The City is actively seeking resolution to effluent limitation violations for cyanide, including replacement of the chemical disinfection system with an ultraviolet light disinfection system, hold time studies, and additional sampling to understand the fate of cyanide in the wastewater treatment system. Elimination of the chemical disinfection system has reduced the frequency of violations. |
Violation |
U |
eSMR |
| 1135036 |
09/18/2024 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.4 ug/L at EFF-003. |
The City is actively seeking resolution to effluent limitation violations for cyanide, including replacement of the chemical disinfection system with an ultraviolet light disinfection system, hold time studies, and additional sampling to understand the fate of cyanide in the wastewater treatment system. Elimination of the chemical disinfection system has reduced the frequency of violations. |
Violation |
U |
eSMR |
| 1135038 |
07/10/2024 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 1.3 ug/L at EFF-003. |
The City is actively seeking resolution to effluent limitation violations for cyanide, including replacement of the chemical disinfection system with an ultraviolet light disinfection system, hold time studies, and additional sampling to understand the fate of cyanide in the wastewater treatment system. Elimination of the chemical disinfection system has reduced the frequency of violations. |
Violation |
U |
eSMR |
| 1135037 |
07/02/2024 |
DMON |
1 sample collected during the monitoring period |
The BOD sample collected on 7/2/2024 was analyzed past hold time due to excessive oxygen depletion during the initial analysis. |
Violation |
U |
eSMR |
| 1135034 |
06/30/2024 |
Deficient Reporting |
Quarter 2,2024 fecal monthly median and 90th percentile not reported for INT-001. |
Quarter 2, 2024 fecal monthly median and 90th percentile for INT-001 reported in Quarter 3, 2024 SMR. |
Violation |
U |
eSMR |
| 1130329 |
06/30/2024 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.2 ug/L at EFF-003. |
The City is actively seeking resolution to effluent limitation violations for cyanide, including replacement of the chemical disinfection system with an ultraviolet light disinfection system, hold time studies, and additional sampling to understand the fate of cyanide in the wastewater treatment system. Actions taken thus far have reduced the frequency of violations. |
Violation |
U |
eSMR |
| 1130330 |
06/25/2024 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 1.2 ug/L at EFF-003. |
The City is actively seeking resolution to effluent limitation violations for cyanide, including replacement of the chemical disinfection system with an ultraviolet light disinfection system, hold time studies, and additional sampling to understand the fate of cyanide in the wastewater treatment system. Actions taken thus far have reduced the frequency of violations. |
Violation |
U |
eSMR |
| 1130327 |
04/30/2024 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.014 pg/L and reported value was 0.685 pg/L at EFF-001. |
Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations, although investigative sampling of construction groundwater did not show elevated TCDD-equivalents in the accumulated construction groundwater. Accelerated monitoring was not performed because Outfall-001 was taken offline (i.e., discharge ceased) before the sample results were received. It is noted that the second quarter results are an order of magnitude lower than the TCDD-Equivalent value determined for the first quarter 2024. |
Violation |
U |
eSMR |
| 1130328 |
04/24/2024 |
CAT2 |
TCDD Equivalents Maximum Daily (MDEL) limit is 0.033 pg/L and reported value was 0.685 pg/L at EFF-001. |
Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations, although investigative sampling of construction groundwater did not show elevated TCDD-equivalents in the accumulated construction groundwater. Accelerated monitoring was not performed because Outfall-001 was taken offline (i.e., discharge ceased) before the sample results were received. It is noted that the second quarter results are an order of magnitude lower than the TCDD-Equivalent value determined for the first quarter 2024. |
Violation |
U |
eSMR |
| 1135033 |
03/31/2024 |
Deficient Reporting |
Quarter 1, 2024 fecal monthly median and 90th percentile not reported for INT-001. |
Quarter 1, 2024 fecal monthly median and 90th percentile for INT-001 reported in Quarter 3, 2024 SMR. |
Violation |
U |
eSMR |
| 1126637 |
03/31/2024 |
CAT1 |
BOD5 @ 20 Deg. C, Percent Removal Monthly Average limit is 85 % and reported value was 83 % at EFF-001. |
Low influent BOD concentrations during March, due to dilution from rainfall and inflow and infiltration, resulted in a low BOD percent removal. |
Violation |
U |
eSMR |
| 1126638 |
03/13/2024 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.014 pg/L and reported value was 0.281 pg/L at EFF-001. |
Accelerated monitoring performed at Effluent-001 indicates elevated levels of TCDD-Equivalents throughout the monitoring and reporting period. Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations. The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126639 |
03/13/2024 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.014 pg/L and reported value was 0.370 pg/L at EFF-001. |
Accelerated monitoring performed at Effluent-001 indicates elevated levels of TCDD-Equivalents throughout the monitoring and reporting period. Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations. The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126635 |
03/07/2024 |
CAT1 |
Settleable Solids Daily Maximum limit is 0.2 ml/L and reported value was 0.4 ml/L at EFF-001. |
The pipe that conveys wastewater from the treatment wetlands to the UV basin burst on 3/6/2024. Due to high influent flow and anticipated storm events, the treatment plant did not have hydraulic storage capacity to attenuate flows during the repair. The emergency pond pump station was used to discharge directly from oxidation pond 2 to the UV basin. Increased settleable solids were due to the discharge of wastewater that had not undergone treatment in the treatment wetlands. |
Violation |
U |
eSMR |
| 1126643 |
03/07/2024 |
CAT1 |
Settleable Solids Maximum Daily (MDEL) limit is 0.2 ml/L and reported value was 0.4 ml/L at EFF-002. |
The pipe that conveys wastewater from the treatment wetlands to the UV basin burst on 3/6/2024. Due to high influent flow and anticipated storm events, the treatment plant did not have hydraulic storage capacity to attenuate flows during the repair. The emergency pond pump station was used to discharge directly from oxidation pond 2 to the UV basin. Increased settleable solids were due to the discharge of wastewater that had not undergone treatment in the treatment wetlands. |
Violation |
U |
eSMR |
| 1126641 |
03/06/2024 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.014 pg/L and reported value was 0.46 pg/L at EFF-001. |
Accelerated monitoring performed at Effluent-001 indicates elevated levels of TCDD-Equivalents throughout the monitoring and reporting period. Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations. The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126636 |
01/31/2024 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.00000001 ug/L and reported value was 0.00000027 ug/L at EFF-003. |
The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126632 |
01/31/2024 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.00000001 ug/L and reported value was 0.00000159 ug/L at EFF-001. |
Accelerated monitoring performed at Effluent-001 indicates elevated levels of TCDD-Equivalents throughout the monitoring and reporting period. Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations. The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126642 |
01/24/2024 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.00000003 ug/L and reported value was 0.00000027 ug/L at EFF-003. |
The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126633 |
01/24/2024 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.00000003 ug/L and reported value was 0.00000159 ug/L at EFF-001. |
Accelerated monitoring performed at Effluent-001 indicates elevated levels of TCDD-Equivalents throughout the monitoring and reporting period. Construction activities associated with the Arcata Wastewater Treatment Plant Upgrade Project Phase I may be the cause of the elevated concentrations. The city plans to perform investigative sampling to determine if construction activities may be the cause of the elevated concentrations. |
Violation |
U |
eSMR |
| 1126640 |
01/11/2024 |
DMON |
A single sample was collected during the monitoring period. |
The BOD sample collected for the monitoring period was over-depleted for BOD. BOD results cannot be reported when over depletion occurs. The laboratory had insufficient sample volume remaining to rerun the sample past hold time.
|
Violation |
U |
eSMR |
| 1126634 |
01/11/2024 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.7 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the first quarter of 2024, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123719 |
12/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.3 ug/L at EFF-003. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123715 |
12/31/2023 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.00000001 ug/L and reported value was 0.00000041 ug/L at EFF-003. |
Historical performance indicates that TCDD Equivalent violations do not occur consistently, indicating that it is unlikely that TCDD Equivalent levels remained above the effluent limit through the compliance period. |
Violation |
U |
eSMR |
| 1123721 |
12/17/2023 |
DMON |
Violation is applicable to Effluent-001, Effluent-002 and Effluent-003 |
A deficient monitoring violation is reported for pH on 12/17/2023 at Effluent-003. pH data was not collected at this location on the reported date. Additionally, a pH duplicate sample was not collected at any site on this date. All other quality control criteria were met; therefore, the results for Effluent-001 and Effluent-002 are accepted.
|
Violation |
U |
eSMR |
| 1123720 |
12/13/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.3 ug/L at EFF-003. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123710 |
12/13/2023 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.00000003 ug/L and reported value was 0.00000041 ug/L at EFF-003. |
Historical performance indicates that TCDD Equivalent violations do not occur consistently, indicating that it is unlikely that TCDD Equivalent levels remained above the effluent limit through the compliance period. |
Violation |
U |
eSMR |
| 1123714 |
11/30/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123717 |
11/29/2023 |
DMON |
Deficient monitoring violation applicable to monitoring locations EFF-001 and EFF-002. |
The duplicate sample was analyzed past the 15 minute hold time. The original sample was analyzed within the hold time and all other quality control criteria were met, therefore the result is accepted by the laboratory. |
Violation |
U |
eSMR |
| 1123713 |
11/28/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123711 |
11/08/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.3 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123718 |
11/01/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123709 |
10/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.9 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1124615 |
10/30/2023 |
Deficient Reporting |
Applies to effluent violation at EFF-001 and EFF-002 |
Permittee failed to self report a Total Chlorine Residual effluent violation and dishcarge specification violation in the Quater 4 2023 self-monitoring report. The violation was verbally reported to the Regional Board within 24-hours of the occurance. The violation is self reported in the Annual SMR. |
Violation |
U |
eSMR |
| 1124613 |
10/30/2023 |
CAT2 |
Chlorine, Total Residual Daily Maximum limit is 0.02 mg/L and reported value was 3.56 mg/L at EFF-001. |
On October 30, 2023, at 2:00 p.m., chlorinated effluent was discharged to Outfall-001 and Outfall-002. A closer inspection of our records indicates that the discharge lasted approximately 15 minutes, rather than the 30 minutes that was initially reported. During that time, 9,740 gallons were discharged to Outfall-001 and 10,520 gallons were discharged to Outfall-002.
Maintenance staff observed the sulfur dioxide rotometer showing that sulfur dioxide was feeding into the chlorine contact basin during the event. While we cannot definitively identify the cause of the excursion, there are two possible scenarios. (1) The event happened while a contractor was working on the chlorine and sulfur dioxide regulators and controllers. It is possible that air was entrained in the sulfur dioxide regulator during maintenance, causing the system to feed air instead of sulfur dioxide gas. This could explain why the rotometer showed that gas was fed into the system when the violation was occurring. Or (2) the Marsh 5/6 pump station failed earlier in the day due to an electrical issue. The chlorine controller was set to feed manually (i.e., not flow-paced). With the decrease in chlorine demand, because Marsh 5 and 6 were no longer feeding into the contact basin, chlorine residual increased and eventually overwhelmed the sulfur dioxide feed rate.
The contractor completed scheduled annual maintenance on the chlorine and sulfur dioxide regulators and controllers, and they are in good working order. An electrician is scheduled to investigate the electrical issue causing the Marsh 5/6 pump station to lose power.
|
Violation |
U |
eSMR |
| 1123708 |
10/10/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.5 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1123716 |
10/06/2023 |
DMON |
Deficient monitoring violation applicable to locations EFF-001 and EFF-002 |
A deficient monitoring violation is reported for Total Residual Chlorine samples analyzed on 10/6/2023 and 10/7/2023 at monitoring locations Effluent-001 and Effluent-002. Expired Iodine reagent was used for titrant calibration. The titration reagent calibrated within acceptance limits and therefore the results are considered acceptable by the laboratory |
Violation |
U |
eSMR |
| 1123712 |
10/03/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.3 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121378 |
09/30/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.5 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121381 |
09/20/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.5 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121377 |
08/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.3 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121382 |
08/28/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121376 |
08/23/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121379 |
08/15/2023 |
Order Conditions |
EFF-001 discharge offline due to construction activities. Unable to collect on the specified date. Sample collected 08/23/2023. |
On 8/8/2023, the City was in receipt of a laboratory report indicating that the cyanide sample collected on 8/2/2023 exceeded the maximum daily effluent limit. Accelerated monitoring requirements contained in Order No. R1-2019-0006 requires additional sampling within 7- and 14-days following receipt of the initial sample result. However, during this timeframe, discharge location EFF-001 was closed for construction activities. Accelerated monitoring samples were collected on 8/23/2023 and 8/28/2023 after discharge resumed at discharge location EFF-001. |
Violation |
U |
eSMR |
| 1121375 |
08/09/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.1 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121380 |
08/02/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.3 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1121374 |
07/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.8 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1124614 |
07/27/2023 |
Deficient Reporting |
Applies to Effluent-001 and Effluent-002 |
The permittee failed to report four monitoring results for Effluent-001 and Effluent-002 in the Quarter 3 2023 self monitoring report for pH, settleable solids and total residual chlorine. The data is reported in the annual report. |
Violation |
U |
eSMR |
| 1121373 |
07/19/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.8 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 are presented in the cover letter to this SMR and support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118675 |
06/30/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.1 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118670 |
06/22/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118671 |
06/15/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.1 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118678 |
06/01/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.7 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118672 |
05/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.8 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118677 |
05/25/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.9 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118676 |
05/16/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.7 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1118674 |
04/30/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 0.93 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the second quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
U |
eSMR |
| 1124616 |
04/13/2023 |
Deficient Reporting |
Applies to Effluent-001 |
During a routine data review, it was observed that incorrect flow data for Effluent-001 was reported in the Quater 2 2023 report. Corrected flow data is incorporated into the Annual report summary and is provided below:
Date Flow Data Type
4/13/23 2.675 MGD Single
4/14/23 2.423 MGD Single
4/15/23 2.505 MGD Single
4/16/23 2.686 MGD Single
4/17/23 2.390 MGD Single
4/18/23 2.607 MGD Single
4/19/23 2.459 MGD Single
4/30/23 2.640 MGD AMEL |
Violation |
U |
eSMR |
| 1118673 |
03/31/2023 |
Deficient Reporting |
A single deficient reporting violation is reported for fifteen inaccurately reported daily flow (single) and three Average Monthly (AMEL) values at Effluent-002. |
A review of data reported in Quarter 1 2023 SMR identified fifteen instances between January 5, 2023, and March 31, 2023, where the daily flow (single) for Effluent-002 was reported inaccurately. The corrected data also resulted in recalculated daily average monthly flow values for EFF-002 for January, February, and March 2023.
This violation serves to report and correct the deficient reporting violation. Corrected flow values are reported in the violation description included in the cover letter for this report. |
Violation |
U |
eSMR |
| 1115835 |
03/31/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the first quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1115832 |
03/16/2023 |
DMON |
Deficient monitoring violation applicable to monitoring locations EFF-001 and EFF-002 |
The duplicate sample was outside of the acceptance limits and the analyst did not re-analyze or collect a new sample. All other quality control criteria were met. Analysts responsible for these samples were retrained on quality control criteria for pH testing. |
Violation |
B |
eSMR |
| 1115829 |
03/14/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.5 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the first quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
B |
eSMR |
| 1115837 |
03/09/2023 |
DMON |
Deficient monitoring violation applicable to monitoring locations EFF-001 and EFF-002 |
A deficient monitoring violation is reported for Total Residual Chlorine samples analyzed on 3/9/2023 through 3/13/2023 at Effluent-001 and Effluent-002. Expired Iodine reagent was used for titrant calibration. The titration reagent calibrated within acceptance limits and therefore the results are considered acceptable by the laboratory. |
Violation |
B |
eSMR |
| 1115831 |
03/07/2023 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the first quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
B |
eSMR |
| 1115830 |
02/28/2023 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.0 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the first quarter of 2023, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1115836 |
02/03/2023 |
DMON |
Deficient monitoring violation applicable to monitoring locations EFF-001 and EFF-002 |
The duplicate sample was outside of the acceptance limits and the analyst did not re-analyze or collect a new sample. All other quality control criteria were met. Analysts responsible for these samples were retrained on quality control criteria for pH testing. |
Violation |
B |
eSMR |
| 1115834 |
01/31/2023 |
CAT2 |
TCDD Equivalents Monthly Average limit is 0.00000001 ug/L and reported value was 0.00000039 ug/L at EFF-001. |
Historical performance indicates that TCDD Equivalent violations do not occur consistently, indicating that it is unlikely that TCDD Equivalent levels remained above the effluent limit through the compliance period. |
Violation |
A |
eSMR |
| 1115833 |
01/25/2023 |
CAT2 |
TCDD Equivalents Daily Maximum limit is 0.00000003 ug/L and reported value was 0.00000039 ug/L at EFF-001. |
Historical performance indicates that TCDD Equivalent violations do not occur consistently, indicating that it is unlikely that TCDD Equivalent levels remained above the effluent limit through the compliance period. |
Violation |
A |
eSMR |
| 1113032 |
12/24/2022 |
DMON |
Deficient monitoring violation applicable to monitoring locations EFF-001 and EFF-002.` |
A deficient monitoring violation is reported for pH and settleable solids samples analyzed on 12/24/2022-12/26/2022 and Total Residual Chlorine samples analyzed on 12/25/2022 and 12/26/2022. The laboratory analyst performing the test was not up to date on all laboratory training. The analyst is experienced in all test methods and the missing training is not expected to affect performance, therefore the results are considered valid by the laboratory. |
Violation |
B |
eSMR |
| 1110922 |
11/30/2022 |
CAT2 |
Chlorine, Total Residual Maximum Daily (MDEL) limit is 0.02 mg/L and reported value was 1.8 mg/L at EFF-001. |
|
Violation |
A |
Report |
| 1110921 |
11/30/2022 |
CAT2 |
Chlorine, Total Residual Monthly Average limit is 0.01 mg/L and reported value was 1.8 mg/L at EFF-001. |
|
Violation |
A |
Report |
| 1113034 |
11/16/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
B |
eSMR |
| 1113035 |
10/31/2022 |
CAT2 |
Cyanide, Free Available Monthly Average limit is 0.43 ug/L and reported value was 2.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109944 |
10/28/2022 |
CAT2 |
Chlorine, Free Available Maximum Daily (MDEL) limit is 0.02 mg/L and reported value was 1.8 mg/L at EFF-001. |
|
Violation |
B |
Report |
| 1109943 |
10/28/2022 |
CAT2 |
Chlorine, Total Residual Monthly Average limit is 0.01 mg/L and reported value was 1.8 mg/L at EFF-001. |
|
Violation |
B |
Report |
| 1113033 |
10/11/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1113036 |
10/05/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.2 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the fourth quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109942 |
10/03/2022 |
CAT2 |
Chlorine, Total Residual Maximum Daily (MDEL) limit is 0.02 mg/L and reported value was 2.99 mg/L at EFF-001. |
|
Violation |
B |
Report |
| 1109941 |
10/03/2022 |
CAT2 |
Chlorine, Total Residual Monthly Average limit is 0.01 mg/L and reported value was 2.99 mg/L at EFF-001. |
|
Violation |
B |
Report |
| 1109682 |
09/30/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.55 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109684 |
09/19/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.9 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109683 |
09/14/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109681 |
08/31/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.7 ug/L. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109689 |
08/24/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.9 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109685 |
08/15/2022 |
DMON |
Deficient monitoring violation applicable to EFF-001 and EFF-002. |
A deficient monitoring violation occurred during the monitoring period due to quality control issues associated with laboratory analysis of Total Residual Chlorine samples collected at monitoring locations EFF-001 and EFF-002.
Between 8/15/2022-8/18/2022, the laboratory used expired Phenylarsine Oxide (PAO) for Total Residual Chlorine testing. The PAO calibrated within the acceptable calibration range and therefore the laboratory accepted the results of the tests run during this period.
On 9/24/2022 at 12:53 pm, a Total Residual Chlorine sample result was 0.02 mg/L with an error "out of range" and may be biased high. A sample collected at 13:16 was "not detected" at or above the Method Detection Limit for Total Residual Chlorine. |
Violation |
B |
eSMR |
| 1109687 |
08/03/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.5 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109680 |
07/31/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/day and reported value was 2.55 ug/day at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109688 |
07/27/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples. |
Violation |
A |
eSMR |
| 1109686 |
07/06/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.7 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated the formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling during the third quarter of 2022, collecting unpreserved samples concurrent with required monitoring. The results of unpreserved and preserved cyanide sampling at Effluent-001 support the finding that there is a positive bias in cyanide concentration in preserved samples. Additionally, the samples collected on 9/19/2022 were analyzed within 25 hours of sample collection. The results of this analysis support the theory that positive bias is occurring due to sample preservation and not because of a loss of cyanide in unpreserved samples during the holding time. The City is working to design a study plan to support a request to remove preservation requirements for cyanide samples.
|
Violation |
A |
eSMR |
| 1106512 |
06/30/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 3.0 ug/L and reported value was 0.43 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling in June 2022, collecting unpreserved and pretreated samples in addition to required monitoring. Additional sampling is planned for third quarter 2022.
The AWTF plans to initiate an additional study to understand the presence of cyanide in the effluent and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board by September 2022.
|
Violation |
A |
eSMR |
| 1111692 |
06/29/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 3.5 ug/L at EFF-001. |
|
Violation |
A |
Report |
| 1106510 |
06/15/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 3.0 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling in June 2022, collecting unpreserved and pretreated samples in addition to required monitoring. Additional sampling is planned for third quarter 2022.
The AWTF plans to initiate an additional study to understand the presence of cyanide in the effluent and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board by September 2022. |
Violation |
A |
eSMR |
| 1106509 |
06/08/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 3.2 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling in June 2022, collecting unpreserved and pretreated samples in addition to required monitoring. Additional sampling is planned for third quarter 2022.
The AWTF plans to initiate an additional study to understand the presence of cyanide in the effluent and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board by September 2022.
|
Violation |
A |
eSMR |
| 1106511 |
05/31/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling in June 2022, collecting unpreserved and pretreated samples in addition to required monitoring. Additional sampling is planned for third quarter 2022.
The AWTF plans to initiate an additional study to understand the presence of cyanide in the effluent and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board by September 2022.
|
Violation |
A |
eSMR |
| 1106513 |
05/18/2022 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.6 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF conducted additional cyanide sampling in June 2022, collecting unpreserved and pretreated samples in addition to required monitoring. Additional sampling is planned for third quarter 2022.
The AWTF plans to initiate an additional study to understand the presence of cyanide in the effluent and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board by September 2022.
|
Violation |
A |
eSMR |
| 1103367 |
03/31/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.9 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
A |
eSMR |
| 1103362 |
03/30/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
A |
eSMR |
| 1103366 |
03/23/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 1.7 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
B |
eSMR |
| 1103365 |
03/08/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 2.1 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
A |
eSMR |
| 1103363 |
03/01/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 1.8 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
B |
eSMR |
| 1103368 |
02/28/2022 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
A |
eSMR |
| 1103364 |
02/16/2022 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 1.0 ug/L and reported value was 1.4 ug/L at EFF-001. |
A study conducted on the AWTF effluent to determine the source of cyanide in the effluent showed a positive bias in cyanide samples from the AWTF. The study demonstrated formation of cyanide in the presence of sodium hydroxide added as a chemical preservation agent. The AWTF plans to initiate an additional study to confirm results and make observations on sample quality without chemical preservation. The City anticipates submitting an additional study final report to the Regional Water Quality Control Board in September 2022. |
Violation |
B |
eSMR |
| 1099684 |
12/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.4 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1099686 |
12/15/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.1 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
B |
eSMR |
| 1099680 |
12/08/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.7 ug/L. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
B |
eSMR |
| 1099682 |
11/30/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.8 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1099679 |
11/17/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.8 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
B |
eSMR |
| 1099687 |
10/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.4 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1099681 |
10/27/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1099683 |
10/20/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.9 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1099685 |
10/06/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.3 ug/L at EFF-001. |
The City is conducting a study to determine the source of cyanide in the AWTF effluent to determine whether the preservation method for the cyanide test causes false-positive results in effluent samples. The study is complete and the City anticipates submitting a final study report to the Regional Board by January 31, 2022. |
Violation |
A |
eSMR |
| 1096035 |
09/30/2021 |
DMON |
Discharger failed to collect three required monitoring samples during the reporting period. |
The AWTF failed to collect a BOD sample at INF-001 during the compliance monitoring period ending on July 24, 2021. The AWTF also failed to collect a TSS sample at INF-001 during the compliance monitoring period ending on 7/24/2021. The AWTF was not discharging to effluent locations Outfall-001 or Outfall-002 during the monitoring period and therefore did not collect effluent BOD or TSS samples for the compliance monitoring period. Due to operator error, an influent BOD and TSS sample were also not collected. Corrective action consisted of providing written notice to the Chief Plant Operator that influent BOD and TSS sampling is required regardless of the status of effluent flow. The AWTF failed to collect a settlable solids sample at Outfall-001 and Outfall-002 on 7/20/2022 due to staffing shortage and operator miscommunication. Corrective action included a staff meeting to review monitoring requirements and actions to take if any employee observes that an operator has not been active in the lab during the normal business day. Additionally, a plan is in place to train additional laboratory staff on compliance testing techniques. |
Violation |
B |
eSMR |
| 1096043 |
09/30/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.6 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096038 |
09/29/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.5 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096046 |
09/14/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.7 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096044 |
08/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 3.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096040 |
08/24/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096045 |
08/18/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 4.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096042 |
08/04/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096041 |
07/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096036 |
07/28/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096037 |
07/13/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1096039 |
07/07/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Figure 1 shows the results of Influent-001, Point 9 and Effluent-001 cyanide testing in second quarter 2021.
Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide. In third quarter 2021, the City initiated a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
A |
eSMR |
| 1092290 |
06/30/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092293 |
06/23/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092292 |
05/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.5 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092284 |
05/26/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.7 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092286 |
05/19/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092285 |
05/04/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.6 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092291 |
04/30/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.7 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092289 |
04/27/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1092288 |
04/14/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1092287 |
04/07/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.6 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001) and periodic samples from the enhancement marsh effluent (Point 15). Cyanide levels in treatment wetlands effluent (Point 9) and enhancement marsh effluent are on average greater than cyanide levels measured in the plant influent. AWTF effluent cyanide levels, post-chlorination/dechlorination, are also higher than the cyanide measured coming into the AWTF. The data suggest that there is either cyanide formation occurring in the wetlands and the chlorine contact basin, or that the complex sample matrix contains interferences that are causing false positive tests for cyanide.
In third quarter 2021, the City is initiating a study to determine if there are sample matrix interferences contributing to cyanide formation within the sample or creating a false positive test. Matthew Hurst, PhD., Department of Chemistry, Humboldt State University will conduct the study. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant project that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1089228 |
03/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001).
Influent concentration has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. With few exceptions, data shows a increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin.
The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1089229 |
03/17/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.1 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001).
Influent concentration has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. With few exceptions, data shows a increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin.
The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1089230 |
02/28/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001).
Influent concentration has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. With few exceptions, data shows a increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin.
The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1089225 |
02/17/2021 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.2 ug/L. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001).
Influent concentration has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. With few exceptions, data shows a increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin.
The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action.
|
Violation |
B |
eSMR |
| 1089226 |
01/31/2021 |
CAT1 |
BOD5 @ 20 Deg. C, Percent Removal Monthly Minimum limit is 85 % and reported value was 84 % at EFF-001. |
In January 2021, a single influent BOD sample collected on 1/14/2021 had a lower than normal concentration. This was likely due, in part, to influent dilution due to inflow/infiltration associated with wet weather during the sampling event. Another factor that may have played a role is poor mixing of the sample; a process control sample analyzed by the City laboratory on a duplicate sample had a BOD value 20% higher than the compliance data. Other influent BOD values for January ranged from 120-240 mg/L. Effluent BOD for January 2021 ranged from 11-27 mg/L, indicating that the treatment system achieved secondary treatment standards for BOD during the reporting period. However, due to a low influent BOD sample collected on 1/14/2021, the monthly percent removal calculation was lower than the 85% percent removal effluent limitation. The City completed a $7M inflow and infiltration reduction project in 2019. Early data indicate a large reduction in groundwater infiltration into the sewer system, which has reduced the frequency of percent reduction violations due to influent dilution. |
Violation |
B |
eSMR |
| 1089227 |
01/31/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001).
Influent concentration has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. With few exceptions, data shows a increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin.
The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085143 |
12/31/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.7 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085140 |
12/28/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.3 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085136 |
12/01/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1085138 |
11/30/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.1 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1085142 |
11/24/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.6 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1085141 |
11/16/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085139 |
11/09/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.4 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085137 |
10/31/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.3 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085145 |
10/21/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.0 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085144 |
10/08/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.2 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1085135 |
10/01/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.6 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring at Effluent-001, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent). The AWTF also collected a monthly cyanide sample at the facility influent (INF-001). Influent data has not increased from the previously established baseline contribution from domestic and commercial sources. The data suggests that there is limited cyanide treatment in the secondary treatment process and further evaluation is needed to determine the fate of cyanide within the oxidation ponds and treatment marshes. The data shows a clear increase in cyanide pre- and post-chlorination, suggesting that cyanide is forming in the chlorine contact basin. The AWTF will continue to monitor the influent to determine if there are any increases in influent cyanide concentration. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080741 |
09/30/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.5 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080740 |
09/17/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.5 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080742 |
08/31/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 2.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080737 |
08/11/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.9 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080739 |
08/04/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1080738 |
07/08/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 2.8 ug/L at EFF-001. |
Concurrent to routine and accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (treatment marsh effluent) and Point 15 (enhancement wetlands effluent) to determine if chlorination may play a role in cyanide formation. With the exception of one outlier, results of concurrent sampling indicate that chlorination might play a role in cyanide formation in the chlorine contact basin. The AWTF collected a cyanide sample at the facility influent (INF-001) in September 2020. The result indicates that cyanide concentration in the influent has not increased from previously established baseline contribution from domestic sources. the AWTF will continue to monitor the influent to determine if there are any fluctuation in influent cyanide concentration or potential controllable sources. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light as the primary disinfectant. Time Order R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1077679 |
06/30/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.3 ug/L at EFF-001. |
Historical performance data that indicates cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period.
Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent) and Point 15 (Enhancement Wetlands Effluent) to determine if chlorination may play a role in cyanide formation. Although not conclusive, the results of concurrent sampling indicate that chlorination may play a role in cyanide formation. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1077683 |
06/17/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.3 ug/L at EFF-001. |
Historical performance data that indicates cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period.
Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent) and Point 15 (Enhancement Wetlands Effluent) to determine if chlorination may play a role in cyanide formation. Although not conclusive, the results of concurrent sampling indicate that chlorination may play a role in cyanide formation. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1077684 |
04/30/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.5 ug/L at EFF-001. |
Accelerated monitoring for cyanide, conducted in May 2020 indicated that the concentration of cyanide in the effluent did not remain above the maximum daily effluent limit through the May compliance period. This supports historical performance data that indicates cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period.
Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent) and Point 15 (Enhancement Wetlands Effluent) to determine if chlorination may play a role in cyanide formation. Although not conclusive, the results of concurrent sampling indicate that chlorination may play a role in cyanide formation. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1077682 |
04/21/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.5 ug/L at EFF-001. |
Accelerated monitoring for cyanide, conducted in May 2020 indicated that the concentration of cyanide in the effluent did not remain above the maximum daily effluent limit through the May compliance period. This supports historical performance data that indicates cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period.
Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection at Point 9 (Treatment Marsh Effluent) and Point 15 (Enhancement Wetlands Effluent) to determine if chlorination may play a role in cyanide formation. Although not conclusive, the results of concurrent sampling indicate that chlorination may play a role in cyanide formation. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time |
Violation |
B |
eSMR |
| 1077680 |
04/01/2020 |
CTOX |
Chronic Toxicity-Red Abalone-Larval development Single Sample Maximum limit is 0 % effluent and reported value was 1 % effluent at EFF-001. |
As previously reported, on 2/11/2020, the AWTF initiated chronic WET testing using a plant, invertebrate, and fish species to determine the most sensitive species. The results of chronic WET testing on red abalone, Haliotis rufescens, were "fail" using the TST statistical method, and 100 percent effect. The AWTF collected a sample for the first accelerated monitoring test on 3/18/2020 and for the second accelerated monitoring test on 4/1/2020.
Based on accelerated monitoring results, a TRE was triggered on 4/22/2020, when results of the second accelerated monitoring test were received. |
Violation |
B |
eSMR |
| 1077681 |
04/01/2020 |
CTOX |
Chronic Toxicity-Red Abalone-Larval development Single Sample Maximum limit is 50 % effluent and reported value was 52.3 % effluent. |
As previously reported, on 2/11/2020, the AWTF initiated chronic WET testing using a plant, invertebrate, and fish species to determine the most sensitive species. The results of chronic WET testing on red abalone, Haliotis rufescens, were "fail" using the TST statistical method, and 100 percent effect. The AWTF collected a sample for the first accelerated monitoring test on 3/18/2020 and for the second accelerated monitoring test on 4/1/2020.
Based on accelerated monitoring results, a TRE was triggered on 4/22/2020, when results of the second accelerated monitoring test were received. |
Violation |
B |
eSMR |
| 1073185 |
02/29/2020 |
CAT2 |
Cyanide, Total (as CN) Monthly Average limit is 0.43 ug/L and reported value was 1.1 ug/L at EFF-001. |
Historical performance indicates that cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period. Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection to determine if chlorination may play a role in cyanide formation. Cyanide concentration in the sample collected immediately upstream of chlorination on 2/20/2020 was detected not quantifiable while cyanide concentration in the sample collected immediately upstream of chlorination on 2/27/2020 was 1.0 µg/L, compared to detected not quantifiable concurrently at Effluent-001. Although not conclusive, the results of concurrent sampling indicate that cyanide may form in the chlorine contact basin. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
A |
eSMR |
| 1073187 |
02/20/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.3 ug/L at EFF-001. |
Historical performance indicates that cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period. Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection to determine if chlorination may play a role in cyanide formation. Cyanide concentration in the sample collected immediately upstream of chlorination on 2/20/2020 was detected not quantifiable while cyanide concentration in the sample collected immediately upstream of chlorination on 2/27/2020 was 1.0 µg/L, compared to detected not quantifiable concurrently at Effluent-001. Although not conclusive, the results of concurrent sampling indicate that cyanide may form in the chlorine contact basin. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1073186 |
02/12/2020 |
CAT2 |
Cyanide, Total (as CN) Daily Maximum limit is 1.0 ug/L and reported value was 1.1 ug/L at EFF-001. |
Historical performance indicates that cyanide violations occur occasionally but not consistently, indicating that it is unlikely that cyanide levels remained above the effluent limit through the compliance period. Concurrent to accelerated monitoring, samples were collected immediately upstream of disinfection to determine if chlorination may play a role in cyanide formation. Cyanide concentration in the sample collected immediately upstream of chlorination on 2/20/2020 was detected not quantifiable while cyanide concentration in the sample collected immediately upstream of chlorination on 2/27/2020 was 1.0 µg/L, compared to detected not quantifiable concurrently at Effluent-001. Although not conclusive, the results of concurrent sampling indicate that cyanide may form in the chlorine contact basin. The City is in the final design stage of an upgraded treatment plant that will replace chlorine disinfection with ultraviolet light disinfection as the primary disinfectant. Time Schedule Order No. R1-2019-0011 Table 1 addresses the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1073188 |
02/10/2020 |
CTOX |
Chronic Toxicity-Red Abalone-Larval development Other limit is 0 Pass/Fail (Pass = 0, Fail = 1) and reported value was 1 Pass/Fail (Pass = 0, Fail = 1) at EFF-001. |
Haliotis rufescens (red abalone), Pimephales promelas (fathead minnow), and Selenastrum capricornutum (green algae) were selected as the invertebrate, fish and algae species for chronic toxicity sensitive species screening. The screening test was performed to provide a comparative assessment of the sensitivity of alternative test species to toxicity that might be present in the treatment plant effluent. Based on the test results, Haliotis rufescens is the most sensitive species and will be used for subsequent chronic WET of Effluent-001. The Percent Effect for this sample was 100% effect. Accelerated monitoring was triggered. |
Violation |
B |
eSMR |
| 1070126 |
12/31/2019 |
CAT1 |
Biochemical Oxygen Demand (BOD) (5-day @ 20 Deg. C) Monthly Average limit is 30 mg/L and reported value was 31 mg/L at EFF-001. |
A seasonal increase in BOD typically occurs in the fall due to a variety of factors, including decrease in water temperature, slowing microbial activity and increase flow through the natural treatment system. The City is in the final design phase of a treatment plant project that addresses treatment capacity. Time Schedule Order No. R1-2019-0011 Table 1 and Table 2 address the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1070124 |
12/31/2019 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 30 mg/L and reported value was 35 mg/L at EFF-001. |
A seasonal increase in TSS typically occurs in the fall due to a variety of factors, including decrease in water temperature, slowing microbial activity and increase flow through the natural treatment system. The City is in the final design phase of a treatment plant project that addresses treatment capacity. Time Schedule Order No. R1-2019-0011 Table 1 and Table 2 address the time schedule for corrective action. |
Violation |
B |
eSMR |
| 1070125 |
12/07/2019 |
CAT1 |
Total Suspended Solids (TSS) Weekly Average limit is 45 mg/L and reported value was 46 mg/L at EFF-001. |
A seasonal increase in TSS typically occurs in the fall due to a variety of factors, including decrease in water temperature, slowing microbial activity and increase flow through the natural treatment system. The City is in the final design phase of a treatment plant project that addresses treatment capacity. Time Schedule Order No. R1-2019-0011 Table 1 and Table 2 address the time schedule for corrective action. |
Violation |
B |
eSMR |
|
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
|
