| Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
| 1125015 |
02/06/2024 |
CAT2 |
Cyanide, Total (as CN) Maximum Daily (MDEL) limit is 14 mg/L and reported value was 15 mg/L at EFF-001. |
The district immediately initiated accelerated monitoring and sent samples to the contract laboratory for additional cyanide testing. The results from the additional sampling reported on March 4, 2024, are as follows: February 28, J1.7 ug/l, and February 29, J2.6 ug/l, which both results were below the maximum daily limit (14 ug/l) and monthly average limit of (6.4 ug/l) for total cyanide. Upon reviewing the influent and effluent cyanide results, for the effluent and influent samples collected on February 6th, the district observed that the cyanide concentration in the influent sample was reported as non-detect (ND). However, the cyanide level in the effluent sample was reported as 15 ug/l.
The district contacted the subcontracted lab (Caltest) to discuss the above Cyanide results. Caltest believes that the presence of Nitrate/Nitrite could have caused interferences and it is a very common interference for Cyanide. The subcontract lab also notified that there was a presence of Nitrate in the effluent sample from 2/6/2024. Although the LGVSD lab treated the sample for Nitrate interference with sulfamic acid, there may still be traces of Nitrate in the sample. Therefore, per Caltest's recommendation, we should continue treating the sample with sulfamic acid immediately after sample collection and check for Nitrate until there is no presence of nitrate in the sample. |
Violation |
B |
eSMR |
| 1115928 |
03/10/2023 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 12 ug/L at EFF-001B (Blending). |
We believe the incident caused by an overabundance of filamentous growth in the activated sludge process which impacted the settleability in the secondary clarifiers. When the settleability issue became apparent around the end of February, staff attempted to resolve the problem through increased wasting from the AS system. This did not resolve the problem and may have made it more difficult to recover over the following weeks until the pipe connections and pump controls were completed for a functional RAS chlorination system.
Staff continue to work with our process engineer experts to monitor this issue closely. We are also in the process of adding a daily chorine dose calculated value to our AS process data spreadsheet to help staff determine an appropriate dose rate for RAS chlorination. The next step will be to slowly reduce this rate until it becomes unnecessary, as it seems to have been effective at fulfilling the intent.
|
Violation |
U |
eSMR |
| 1113963 |
01/16/2023 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0 mg/L and reported value was 0.06 mg/L at EFF-001. |
After reviewing the SCADA trend data, the District found the following evidence that the exceedance was due to a faulty chlorine analyzer. The attached SCADA trend shows, the upstream analyzers reported a calculated sodium bisulfite residual of maximum 4.07 mg/l and minimum of 1.52 mg/l (Green trend) during the time of residual chlorine excursion of 0.06 mg/l (Blue trend). Therefore, we strongly believe this is a false positive reading from the chlorine analyzer. (Please see attached screenshot of LGVSD SCADA Trends for details) |
Violation |
U |
eSMR |
| 1112689 |
12/13/2022 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0 mg/L and reported value was 0.14 mg/L at EFF-001. |
After reviewing the SCADA trend data, the District found the following evidence that the exceedance was due to a faulty chlorine analyzer. The attached SCADA trend shows, the upstream analyzers reported a calculated sodium bisulfite residual of 6.26 ppm (Red trend) at the time of residual chlorine excursion of 0.14 ppm (Blue trend). Therefore, we strongly believe this is a false positive reading from the chlorine analyzer. (Please see attached screenshot of LGVSD SCADA Trends for details)
|
Violation |
U |
eSMR |
| 1104578 |
04/17/2022 |
DMON |
On April 17th, at 6:59 am the duty operator was forced to divert the effluent flow to the reclamation area storage ponds to minimize the duration of a chlorine residual excursion. As a result, the daily effluent monitoring requirement was not met for pH and temperature during discharging to Miller Creek. |
To prevent similar incident in future, the staff were informed to collect the daily sample (EFF-001D) on the same day, even if operating in reclamation mode, to ensure that monitoring and compliance requirements specified in the NPDES permit are met. |
Violation |
U |
eSMR |
| 1103038 |
03/21/2022 |
DMON |
On March 21st an Enterococcus sample (EFF-001D) was collected at the usual location without lab staff aware that the sampling site had been relocated as a result of plant flow reconfiguration associated for the new secondary treatment process. The sample collected was not a represented sample for the EFF-001D Enterococcus sample, therefore result of >2419.6 MPN/100 ml are invalid and disqualified to be reported. |
The lab staff are collecting sample from new location starting week of 3/29/2022. |
Violation |
U |
eSMR |
| 1100895 |
01/26/2022 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0 mg/L and reported value was 0.64 mg/L at EFF-001. |
After receiving an alarm for high chlorine residual from the final effluent chlorine residual analyzer, the plant operator responded immediately by overriding the district's SCADA system to manually increase sodium bisulfite delivery. The operator then tested an effluent sample for chlorine residual using a benchtop amperometric titration unit and the result did not detect the presence of chlorine residual in plant effluent.
|
Violation |
U |
eSMR |
| 1100894 |
01/22/2022 |
OEV |
Enterococci 6-Week Rolling Geometric Mean limit is 30 MPN/100 mL and reported value was 35.5 MPN/100 mL at EFF-001B (Blending). |
On January 24 and 25, the District performed extra monitoring immediately. The results for both Enterococcus samples are less than 1.0 MPN/100 ml, indicate the plant performance had been improved.
|
Violation |
U |
eSMR |
| 1099745 |
12/31/2021 |
OEV |
Enterococci Monthly 90th% limit is 110 MPN/100 mL and reported value was 2419.6 MPN/100 mL at EFF-001B (Blending). |
On December 13, the District initiated accelerated monitoring immediately after becoming aware of the December 12 result. |
Violation |
U |
eSMR |
| 1099743 |
12/31/2021 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 30 mg/L and reported value was 38.6 mg/L at EFF-001B (Blending). |
On December 13, the District initiated accelerated monitoring immediately. The accelerated monitoring results from December 18 through December 21 are listed below, indicate the plant performance had been improved.
|
Violation |
U |
eSMR |
| 1099744 |
12/31/2021 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Percent Reduction limit is 85 % and reported value was 76.8 % at EFF-001B (Blending). |
On December 13, the District initiated accelerated monitoring immediately. The accelerated monitoring results from December 18 through December 21 are listed below, indicate the plant performance had been improved.
|
Violation |
U |
eSMR |
| 1099742 |
12/31/2021 |
CAT2 |
Copper, Total Recoverable Monthly Average limit is 8.6 ug/L and reported value was 10 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent samples to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance. The last three consecative Copper results for the accelerated monitoring samples were below the monthly limit (8.6 ug/l).
|
Violation |
U |
eSMR |
| 1099741 |
12/24/2021 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 15 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent samples to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance. The Copper results for the accelerated monitoring samples were below the maximum daily limit (11 ug/l).
|
Violation |
U |
eSMR |
| 1099746 |
12/23/2021 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 15 ug/L. |
The Distract sent the additional Effluent samples to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance. The Copper results for the accelerated monitoring samples were below the maximum daily limit (11 ug/l).
|
Violation |
U |
eSMR |
| 1099740 |
12/18/2021 |
CAT1 |
Total Suspended Solids (TSS) Weekly Average limit is 45 mg/L and reported value was 58.7 mg/L at EFF-001B (Blending). |
On December 13, the District initiated accelerated monitoring immediately. The accelerated monitoring results from December 18 through December 21 are listed below, indicate the plant performance had been improved. |
Violation |
U |
eSMR |
| 1099748 |
12/15/2021 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 12 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent samples to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance. The Copper results for the accelerated monitoring samples were below the maximum daily limit (11 ug/l).
|
Violation |
U |
eSMR |
| 1099747 |
12/13/2021 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 15 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent samples to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance. The Copper results for the accelerated monitoring samples were below the maximum daily limit (11 ug/l).
|
Violation |
U |
eSMR |
| 1098159 |
11/30/2021 |
OEV |
Enterococci Monthly 90th% limit is 110 MPN/100 mL and reported value was 2419.6 MPN/100 mL at EFF-001. |
On November 12, the District initiated accelerated monitoring immediately after becoming aware of the November 10 result. The accelerated monitoring results from November 12 through 30 indicated adequate disinfection had been restored. |
Violation |
U |
eSMR |
| 1098160 |
11/30/2021 |
CAT2 |
Cyanide, Total (as CN) Monthly Average (Mean) limit is 6.4 ug/L and reported value was 7.5 ug/L at EFF-001. |
The contract laboratory (Caltest) believes that the presence of Nitrate/Nitrite in the sample may have caused interference in the analysis, therefore, the District requested that Caltest staff verify the accuracy of the original result and re-analyze the sample though respecting that the regulatory hold time has expired. The duplicate results of 8.1 ug/l and 6.3 ug/l for the re-analyzed Cynide sample had an RPD>20%, indicating non-homogeneity of sample. Each result, however, was close to the original result of 7.5 ug/l. As a measure of prevention, staff have asked Caltest to provide immediate notification of pre-confirmed results if they approach or exceed permit limits. This should provide staff with increased opportunities for collecting additional samples before months end. |
Violation |
U |
eSMR |
| 1097276 |
10/25/2021 |
CAT1 |
Total Suspended Solids (TSS) Maximum Daily (MDEL) limit is 20 mg/L and reported value was 72 mg/L at EFF-001B (Blending). |
The additional Effluent sample collected on 10/26-29/21 even though the plant switched back to Reclamation mode, terminating discharge to the creek on Monday, October 25, 2021. |
Violation |
U |
eSMR |
| 1097275 |
10/25/2021 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 15 mg/L and reported value was 18.3 mg/L at EFF-001B (Blending). |
The additional Effluent sample collected on 10/26-29/21 even though the plant switched back to Reclamation mode, terminating discharge to the creek on Monday, October 25, 2021. |
Violation |
U |
eSMR |
| 1097274 |
10/25/2021 |
CAT1 |
Total Suspended Solids (TSS) Weekly Average (Mean) limit is 18 mg/L and reported value was 23.6 mg/L at EFF-001B (Blending). |
The additional Effluent sample collected on 10/26-29/21 even though the plant switched back to Reclamation mode, terminating discharge to the creek on Monday, October 25, 2021. |
Violation |
U |
eSMR |
| 1097277 |
10/25/2021 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0 mg/L and reported value was 3.24 mg/L at EFF-001. |
Operators immediately took corrective action upon notification. Operators increased the SBS dose and put the system into manual control. Lab staff collected another effluent sample and confirmed a zero residual. |
Violation |
U |
eSMR |
| 1097272 |
10/25/2021 |
CAT2 |
Copper, Total Recoverable Maximum Daily (MDEL) limit is 11 ug/L and reported value was 21 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent sample collected on 10/26/21 to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance even though the plant switched back to Reclamation mode, terminating discharge to the creek on Monday, October 25, 2021. The Copper result for the second sample collected on 10/26/21 was 7.7 ug/l is below the maximum daily limit (11 ug/l) and the monthly average limit (8.6 ug/l). |
Violation |
U |
eSMR |
| 1097273 |
10/25/2021 |
CAT2 |
Copper, Total Recoverable Monthly Average limit is 8.6 ug/L and reported value was 14.4 ug/L at EFF-001B (Blending). |
The Distract sent the additional Effluent sample collected on 10/26/21 to the contract lab (Caltest) for copper analysis immediately after became aware of the circumstance even though the plant switched back to Reclamation mode, terminating discharge to the creek on Monday, October 25, 2021. The Copper result for the second sample collected on 10/26/21 was 7.7 ug/l is below the maximum daily limit (11 ug/l) and the monthly average limit (8.6 ug/l). |
Violation |
U |
eSMR |
| 1097278 |
10/24/2021 |
OEV |
Enterococci Monthly 90th% limit is 110 MPN/100 mL and reported value was 2419.6 MPN/100 mL at EFF-001B (Blending). |
Results from enterococcus analysis always lag sample collection by 24 hrs. In this case, the conditions that led to the violation had largely passed by the time the result was available. Although the plant was still blending on 10/25 when that day¿s sample was collected, that result (3.1 MPN/100 mL) indicated adequate disinfection had been restored. |
Violation |
U |
eSMR |
| 1086571 |
01/27/2021 |
OEV |
Enterococci Monthly 90th% limit is 110 MPN/100 mL and reported value was 2419.6 MPN/100 mL at EFF-001B (Blending). |
The WWTP is operating under the new permit R2-2020-0022 which includes more stringent enterococcus limits than under the previous permit. This is the first blending event the District has encountered while operating under the new permit. In addition to the more stringent permit limits, the flow path of blended flow has changed due to the major ongoing 3-year capital improvement project to increase the capacity of the secondary treatment process and recycled water production. Since the disinfection process underperformed during the first blending event of the wet weather season, we are taking the following actions:
1) Increase the chlorine residual of the plant effluent, and in particular during blending events.
2) Modify a valve position in the Plant Effluent Splitter Box to extend the chlorine contact time for disinfection.
3) Increase the ferric chloride dosage that is used to enhance settling in the primary clarifiers during blending events.
|
Violation |
U |
eSMR |
| 1069899 |
12/03/2019 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0 mg/L and reported value was 4.92 mg/L at EFF-001. |
1.A new heating element has been ordered for the 2000 gallon chemical storage tank that has been experiencing crystallization. It is expected to arrive and be installed when it arrives at the end of February or in March 2020. Staff have emptied and cleaned the storage tank. The tank will not be returned to service until the new heat element is installed.
2.New heat trace for exposed piping of the 2000 gallon storage tank was installed on December 6th.
3.Operations staff will be checking the new heating element and heat trace as part of their daily plant rounds.
4.ArcSine Engineering, the District 's contract controls integration firm, has been tasked with replacing the SCADA terminal with the primary WIN-911 alarm software installed on it. ArcSine will also investigate and address any reliability issues pertaining to transmitting SCADA alarms to operations staff.
|
Violation |
U |
eSMR |
| 1068526 |
11/30/2019 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0.0 mg/L and reported value was 4.92 mg/L at EFF-001. |
1. A new heating element has been ordered for the chemical storage tank that has been experiencing crystallization. It is expected to arrive and be installed by December 18th.
2. New heat trace for exposed piping has been ordered and will be installed by December 5th.
3. Operations staff will be checking the new heating element and heat trace as part of their daily plant rounds.
4. ArcSine Engineering, the District 's contract controls integration firm, has been tasked with replacing the SCADA terminal with the primary WIN-911 alarm software installed on it. ArcSine will also investigate and address any reliability issues pertaining to transmitting SCADA alarms to operations staff.
5. The entire dechlorination system is being replaced as part of the large Secondary Treatment Upgrade project that is currently under construction. It is anticipated that the new system will be online within the next 12 months
|
Violation |
B |
eSMR |
| 1068525 |
11/29/2019 |
CAT2 |
Chlorine, Total Residual Instantaneous Maximum limit is 0.0 mg/L and reported value was 4.92 mg/L at EFF-001. |
1. A new heating element has been ordered for the chemical storage tank that has been experiencing crystallization. It is expected to arrive and be installed by December 18th.
2. New heat trace for exposed piping has been ordered and will be installed by December 5th.
3. Operations staff will be checking the new heating element and heat trace as part of their daily plant rounds.
4. ArcSine Engineering, the District 's contract controls integration firm, has been tasked with replacing the SCADA terminal with the primary WIN-911 alarm software installed on it. ArcSine will also investigate and address any reliability issues pertaining to transmitting SCADA alarms to operations staff.
5. The entire dechlorination system is being replaced as part of the large Secondary Treatment Upgrade project that is currently under construction. It is anticipated that the new system will be online within the next 12 months
|
Violation |
B |
eSMR |
|
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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