| Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
| 1112476 |
12/31/2022 |
OEV |
Enterococci Monthly 90th% limit is 110.0 CFU/100 mL and reported value was 784.23 CFU/100 mL at EFF-002. |
On 12/15/22 raw effluent that was being stored in equalization basin #1 was returned through the plant main influent channel. Staff believes the water that was being stored in equalization basin #1 was the source of the elevated Enterococci value. In response, equalization basin #1 has been drained and cleaned. |
Violation |
B |
eSMR |
| 1109565 |
09/12/2022 |
DMON |
Samples for BOD & TSS were sent to contract lab for analysis for 09/12, 09/13, & 9/14. Alpha Labs only logged in the BOD's and not the TSS's. All three samples for TSS were run past hold time. |
Alpha Labs contacted us upon discovery of their mistake on Wednesday, September 28th. There was no way to resample at this point. Alpha Labs was asked to run the samples anyway, even though they were out of hold time. Alpha Labs advised their login team and audit team to "be more careful" when it comes to logging in samples. |
Violation |
U |
eSMR |
| 1109566 |
09/12/2022 |
DMON |
Samples for BOD & TSS were sent to contract lab for analysis for 09/12, 09/13, & 9/14. Alpha Labs only logged in the BOD's and not the TSS's. All three samples for TSS were run past hold time. |
Alpha Labs contacted us upon discovery of their mistake on Wednesday, September 28th. There was no way to resample at this point. Alpha Labs was asked to run the samples anyway, even though they were out of hold time. Alpha Labs advised their login team and audit team to "be more careful" when it comes to logging in samples. |
Violation |
U |
eSMR |
| 1095954 |
09/30/2021 |
CAT2 |
Zinc, Total Monthly Average limit is 58 ug/L and reported value was 59.3 ug/L at EFF-001. |
On 9/30/21 the Average Monthly Limit for Zinc was reported as 59.3ug/L. The district is currently conducting a Zinc study to identify potential sources of Zinc in the collection system. We are reviewing our source monitoring program and septic hauler manifests. In addition, we are purchasing and awaiting installation of new chemical feed injection pumps and piping for our Metal Solve and Zeta Floc chemical injection system. |
Violation |
U |
eSMR |
| 1095955 |
09/13/2021 |
DMON |
For Chronic Toxicity:
C. dubia - Three-Sample Median Trigger Maximum limit is 1 TUc and reported value was 4.6 TUc at EFF-001 |
The District continues to perform monthly accelerated monitoring while Operators continue to observe the plant closely before and during the testing time frame. The preliminary results for our October 4th testing are: C. Dubia Survival TUc < 1 TUc, Reproduction < 1 TUc. This result will bring the Three-Sample Median back to <1 TUc. |
Violation |
U |
eSMR |
| 1094436 |
08/03/2021 |
DMON |
For Chronic Toxicity:
C.dubia - (Reproduction) Single Sample Trigger Maximum limit is 2 TUc and reported value was 4.6 TUc at EFF-001.
C.dubia - Three-Sample Trigger Maximum limit is 1 TUc and reported value was 4.6 TUc at EFF-001 |
The district performed its first monthly accelerated monitoring in August. The August 3rd testing produced the following results: C. Dubia Survival TUc < 1 TUc, Reproduction 4.6 TUc. The district will continue performing accelerated monthly monitoring while Operators will continue observing the plant closely before and during the testing time frame. The preliminary results for our September 13th testing are: C. Dubia Survival TUc < 1 TUc, Reproduction < 1 TUc. The district's TRE plan has been included in this month's attachments to the SMR. |
Violation |
U |
eSMR |
| 1093623 |
07/12/2021 |
DMON |
Chronic Toxicity - C.dubia - Reproduction Single Sample Trigger Maximum limit is 2 TUc and reported value was 10.3 TUc at EFF-001. Chronic Toxicity - C.dubia -Survival for the same sample was < 1 TUc. |
The district will be performing accelerated monitoring in August and September. Operators will be monitoring the plant closely before and during that time frame. Operators will be specifically documenting influent visuals, chemical dosing and plant operation. The August 3rd repeat testing produced the following preliminary results: C. Dubia Survival TUc < 1 TUc, Reproduction 4.6 TUc. The district will continue performing accelerated monitoring and begin TRE procedures. |
Violation |
U |
eSMR |
| 1092328 |
06/09/2021 |
DMON |
On June 9, 2021 at 01:07, the Post CL2 residual at the Sonoma Valley Treatment Plant dropped suddenly causing the plant to divert tertiary final effluent into EQ #3. During this time the Monthly Flow-Through Bioassay was in progress. The plant diverted into EQ #3 until 05:02 for a total of approximately 4 hours. During this time there was no flow to the bioassay unit. When the Operator arrived at the plant it was discovered the probe on the CL2 analyzer was fouled with debris. After cleaning the probe and re-calibrating the analyzers, discharge of tertiary final effluent was resumed to the R4 reservoir and flow to the bioassay unit was resumed. |
This is the first time we have experienced a fouled probe on the chlorine analyzer. The probe is checked daily. We do not anticipate this to be a reoccurring event. |
Violation |
U |
eSMR |
| 1080746 |
09/16/2020 |
DMON |
No Total Coliform sampled September 16 through 17. |
Starting Sep 15th, the Sonoma Valley Treatment Plant started a planned shut down to replace the main plant generator switch gear. Unfortunately, the main plant generator failed and parts were unavailable from CATAPILLAR until September 18th. This caused various deficient monitoring events. Please see the September 2020 cover letter detailing the events surrounding this planned shutdown. |
Violation |
U |
eSMR |
| 1080745 |
09/16/2020 |
DMON |
No Total Residual Chlorine Instantaneous Maximum was recorded September 16 through 17. |
Starting Sep 15th, the Sonoma Valley Treatment Plant started a planned shut down to replace the main plant generator switch gear. Unfortunately, the main plant generator failed and parts were unavailable from CATAPILLAR until September 18th. This caused various deficient monitoring events. Please see the September 2020 cover letter detailing the events surrounding this planned shutdown. |
Violation |
U |
eSMR |
| 1080748 |
09/16/2020 |
DMON |
No pH readings for minimum and maximum were recorded September 16 through 17. |
Starting Sep 15th, the Sonoma Valley Treatment Plant started a planned shut down to replace the main plant generator switch gear. Unfortunately, the main plant generator failed and parts were unavailable from CATAPILLAR until September 18th. This caused various deficient monitoring events. Please see the September 2020 cover letter detailing the events surrounding this planned shutdown. |
Violation |
U |
eSMR |
| 1080747 |
09/15/2020 |
DMON |
Daily flow readings for Effluent Flow and Peak Flow were not recorded September 15 through 17. The reported flow readings are shown as 0. All effluent flow was diverted to EQ #3. |
Starting Sep 15th, the Sonoma Valley Treatment Plant started a planned shut down to replace the main plant generator switch gear. Unfortunately, the main plant generator failed and parts were unavailable from CATAPILLAR until September 18th. This caused various deficient monitoring events. Please see the September 2020 cover letter detailing the events surrounding this planned shutdown. |
Violation |
U |
eSMR |
| 1080744 |
09/15/2020 |
DMON |
Daily flow readings for Influent Flow and Peak Flow into the plant were not recorded September 15 through 17 while generator and PG&E power were unavailable. For these days, the reported influent flow readings were estimated using the average of five days prior and five days after the event. |
Starting Sep 15th, the Sonoma Valley Treatment Plant started a planned shut down to replace the main plant generator switch gear. Unfortunately, the main plant generator failed and parts were unavailable from CATAPILLAR until September 18th. This caused various deficient monitoring events. Please see the September 2020 cover letter detailing the events surrounding this planned shutdown.
|
Violation |
U |
eSMR |
| 1075047 |
04/12/2020 |
CTOX |
Chronic Toxicity-C.dubia-Reproduction Single Sample Maximum limit is 2 TUc and reported value was 4.6 TUc at EFF-001. |
The district will be performing repeat sampling in May and June. Operators will be monitoring the plant closely before and during that time frame. Operators will be specifically documenting influent visuals, chemical dosing and plant operation. The May 12th repeat testing produced the following preliminary results: C. Dubia Survival TUc <1, Reproduction TUc <1. |
Violation |
U |
eSMR |
| 1068226 |
11/30/2019 |
CAT2 |
Zinc, Total Monthly Average limit is 58 ug/L and reported value was 61 ug/L at EFF-001. |
In response the district is working to identify sources of Zinc in the collection system. We are reviewing our source monitoring program, septic hauler manifests and all hauled waste requirements. In addition we are working to identify potential improvements for our chemical feed injection system of Metal Solve and Zeta Floc. The district has contacted its chemical supplier to verify the optimum dosage of Metal Solve and Zeta Floc for Zinc remediation is being utilized. |
Violation |
U |
eSMR |
|
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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