| Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
| 1124538 |
01/31/2024 |
CAT1 |
BOD5 @ 20 Deg. C, Percent Removal Monthly Average limit is 85 % and reported value was 79 % at EFF-001 (M-001). |
Laboratory staff took precaution with heavy rains and sampled on non-rainy days and or before or after a heavy storm, however, substantial flows were consistent throughout the whole month of January. A five-day report pertaining to the exceedance was not submitted to the RWQCB rather than a phone communication with the RWQCB on February 2, 2024, describing the substantial rain and increased January flows, also, the Agency received the final BOD analytical report from Caltest Analytical Laboratory on February 12, 2024, to complete the monthly average percent removal calculations. While Effluent BOD results were not altered by substantial rain, the formula to obtain the percent removal for BOD relies on both Effluent and Influent numbers. Lower Influent BOD results affect the removal efficiency calculations. |
Violation |
U |
eSMR |
| 1122191 |
10/31/2023 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 14 mg/L at EFF-001 (M-001). |
The Agency continues to monitor the ammonia concentrations and is working to determine the best options to control the performance of the new cross flow media that was installed in 2022. The current Spulkraft (SK) Index for the trickling filters is too low compared to what is targeted for the best trickling filter performance, which means the distributer arms are moving too fast. The optimal SK value should encourage additional growth at the lower depth of the media to remove ammonia, where lower SK rates often result in viable growth in just the upper portions. The Agency has already installed opposing nozzles to slow the rotation of the distributor arms and increase the SK value but is limited in options to prevent the complete stoppage of the distributor arms. Furthermore, Agency staff continues and has increased the number of days for manual flushing of the trickling filters to prevent biological buildup on the media. |
Violation |
U |
eSMR |
| 1119655 |
07/31/2023 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 17 mg/L at EFF-001 (M-001). |
The Agency continues to monitor the ammonia levels and has observed results of less than 12.3 mg/l through August. The Agency continues to monitor these numbers and is working to determine the best performance of the new cross flow media that was installed in 2022. It has been determined that the current Spulkraft (SK) Index for the trickling filters is too low compared to what is targeted for the best trickling filter performance, which means the distributer arms are moving too fast. The optimal SK should encourage additional growth through the depth of the media, where lower SK rates often result in viable growth in just the upper portions of the media bed. The Agency has already installed opposing nozzles to increase the SK rate but is limited in options in controlling the distributor¿s arms speed to prevent the complete stoppage of the distributor arms. |
Violation |
U |
eSMR |
| 1117204 |
04/30/2023 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 16.5 mg/L at EFF-001 (M-001). |
The first ammonia sample was collected on April 12, 2023, with a result of 24 mg/l. SASM proceeded to monitor the ammonia levels and sent out additional samples to Caltest on April 24th, 26th, 27th, 28th, and 30th. The average of the cumulative samples resulted in 16.5 mg/l, however, the six compliance samples sent to the contract laboratory did not ultimately meet the requirement of 12 mg/l for the monthly calculated average limit. The elevated concentrations are likely due to the recirculation valve failure the plant experienced during the heavy rainstorms earlier this year. The 30¿ valve has been repaired, and performance of the trickling filters is gradually improving. Our ammonia process control results have demonstrated a significant improvement through the end of April and throughout the month of May with results lower than the average limit.
|
Violation |
U |
eSMR |
| 1115607 |
03/31/2023 |
CAT1 |
BOD5 @ 20 Deg. C, Percent Removal Monthly Average limit is 85 % and reported value was 77 % at EFF-001 (M-001). |
April results for influent BOD have shown a significant increase as weather improves. We can associate March BOD and TSS low percent removal results due to the rain events. The plant collects samples for BOD and TSS twice a week, the compliance frequency is once a week. Week of March 14th, we sampled 3 times. Due to the heavy rains, low BOD influent results continued through the month, no matter the frequency of sampling. As we monitor this current month of April, and improved weather, we have seen a significant change in our percent removals.
|
Violation |
U |
eSMR |
| 1115606 |
03/31/2023 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 85 % and reported value was 80 % at EFF-001 (M-001). |
April results for influent BOD have shown a significant increase as weather improves. We can associate March BOD and TSS low percent removal results due to the rain events. The plant collects samples for BOD and TSS twice a week, the compliance frequency is once a week. Week of March 14th, we sampled 3 times. Due to the heavy rains, low BOD influent results continued through the month, no matter the frequency of sampling. As we monitor this current month of April, and improved weather, we have seen a significant change in our percent removals. |
Violation |
U |
eSMR |
| 1114989 |
02/28/2023 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 22 mg/L at EFF-001 (M-001). |
Ultimately, the increased ammonia values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent. We hired a contractor to repair and open the 20-feet deep valve. Valve was repaired and reopened on February 24, 2023, allowing for normal operation and improved effluent quality. |
Violation |
U |
eSMR |
| 1114990 |
02/04/2023 |
CAT1 |
Biochemical Oxygen Demand (BOD) (5-day @ 20 Deg. C) Weekly Average limit is 45 mg/L and reported value was 49 mg/L at EFF-001 (M-001). |
Ultimately, the increased BOD values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent. We hired a contractor to repair and open the 20-feet deep valve. Valve was repaired and reopened on February 24, 2023, allowing for normal operation and improved effluent quality. |
Violation |
U |
eSMR |
| 1113872 |
01/20/2023 |
OEV |
Total Coliform Daily Maximum limit is 10000 MPN/100 mL and reported value was 16000 MPN/100 mL at EFF-001 (M-001). |
The Agency first became aware of the first exceedance on January 17th and took immediate action to correct the issue by increasing the chlorine residual for disinfection. Since were sending our samples to an outside laboratory, we had already sent out a sample on January 17th that resulted in another exceedance. We notified the SFBRWQCB and started accelerated monitoring to determine what residual would best lower the Total Coliform results. With accelerated monitoring, the Agency was able to achieve a 110 MPN/100mL Average Monthly value that is lower than the 240 MPN/100mL limit.
Ultimately, the increased Total Coliform values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. We hired a contractor to repair and open the 20-feet deep valve. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent.
|
Violation |
U |
eSMR |
| 1113873 |
01/19/2023 |
OEV |
Total Coliform Daily Maximum limit is 10000 MPN/100 mL and reported value was 16000 MPN/100 mL at EFF-001 (M-001). |
The Agency first became aware of the first exceedance on January 17th and took immediate action to correct the issue by increasing the chlorine residual for disinfection. Since were sending our samples to an outside laboratory, we had already sent out a sample on January 17th that resulted in another exceedance. We notified the SFBRWQCB and started accelerated monitoring to determine what residual would best lower the Total Coliform results. With accelerated monitoring, the Agency was able to achieve a 110 MPN/100mL Average Monthly value that is lower than the 240 MPN/100mL limit.
Ultimately, the increased Total Coliform values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. We hired a contractor to repair and open the 20-feet deep valve. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent.
|
Violation |
U |
eSMR |
| 1113874 |
01/17/2023 |
OEV |
Total Coliform Daily Maximum limit is 10000 MPN/100 mL and reported value was 16000 MPN/100 mL at EFF-001 (M-001). |
The Agency first became aware of the first exceedance on January 17th and took immediate action to correct the issue by increasing the chlorine residual for disinfection. Since were sending our samples to an outside laboratory, we had already sent out a sample on January 17th that resulted in another exceedance. We notified the SFBRWQCB and started accelerated monitoring to determine what residual would best lower the Total Coliform results. With accelerated monitoring, the Agency was able to achieve a 110 MPN/100mL Average Monthly value that is lower than the 240 MPN/100mL limit.
Ultimately, the increased Total Coliform values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. We hired a contractor to repair and open the 20-feet deep valve. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent.
|
Violation |
U |
eSMR |
| 1113871 |
01/10/2023 |
OEV |
Total Coliform Daily Maximum limit is 10000 MPN/100 mL and reported value was 16000 MPN/100 mL at EFF-001 (M-001). |
The Agency first became aware of the first exceedance on January 17th and took immediate action to correct the issue by increasing the chlorine residual for disinfection. Since were sending our samples to an outside laboratory, we had already sent out a sample on January 17th that resulted in another exceedance. We notified the SFBRWQCB and started accelerated monitoring to determine what residual would best lower the Total Coliform results. With accelerated monitoring, the Agency was able to achieve a 110 MPN/100mL Average Monthly value that is lower than the 240 MPN/100mL limit.
Ultimately, the increased Total Coliform values are related to a 30-inch plug valve that broke in the closed position during a rainstorm on December 30th, 2022, hindering our ability to recirculate trickling filter effluent for process control. We hired a contractor to repair and open the 20-feet deep valve. Without the valve open we recirculate trickling filter effluent through the secondary clarifiers that increases the hydraulic loading that in turn increases the solids in the effluent. |
Violation |
U |
eSMR |
| 1110644 |
10/19/2022 |
OEV |
pH Instantaneous Minimum limit is 6.0 SU and reported value was 5.91 SU at EFF-001 (M-001). |
Once it was determined that this was occurring, the Agency put the trickling filters in Parallel mode and the pH returned to compliance. The pH data provided shows the change in pH after the trickling filters were put into parallel mode. |
Violation |
B |
eSMR |
| 1109561 |
09/30/2022 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 12.3 mg/L and reported value was 20.7 mg/L at EFF-001 (M-001). |
To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the stabilization of the new media of trickling filter no. 1 and the decommission of trickling filter no. 2 for its media replacement. Now that both trickling filters media has been replaced, laboratory results for effluent Ammonia have shown single digit values for Ammonia in October. The replacement of the trickling filters media will help improve nitrification and ammonia removal. |
Violation |
U |
eSMR |
| 1108824 |
08/31/2022 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 12.3 mg/L and reported value was 27.8 mg/L at EFF-001 (M-001). |
On April 14, 2022, WWTP Director notified RWQCB about the plan to minimize potential risk for ammonia violations during construction. The project began on April 17, 2022. The replacement for one of the trickling filters was completed on June 9 when the seeding of the new media began. On July 17, 2022, the second trickling filter was decommissioned for the replacement of its media. On September 22, 2022, the entire project to replace all the media was completed and the Agency began seeding trickling filter no. 2. To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the stabilization of the new media of trickling filter no. 1 and the decommission of trickling filter no. 2 for its media replacement. However, in-house analysis for effluent Ammonia on September 29th and 30th, 2022 was 12.7 mg/L and 6.8 mg/L, respectively. The replacement of the trickling filters media will help improve nitrification and ammonia removal. SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1108823 |
08/12/2022 |
CAT1 |
Ammonia, Total (as N) Daily Maximum limit is 32 mg/L and reported value was 33 mg/L at EFF-001 (M-001). |
On April 14, 2022, WWTP Director notified RWQCB about the plan to minimize potential risk for ammonia violations during construction. The project began on April 17, 2022. The replacement for one of the trickling filters was completed on June 9 when the seeding of the new media began. On July 17, 2022, the second trickling filter was decommissioned for the replacement of its media. On September 22, 2022, the entire project to replace all the media was completed and the Agency began seeding trickling filter no. 2. To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the stabilization of the new media of trickling filter no. 1 and the decommission of trickling filter no. 2 for its media replacement. However, in-house analysis for effluent Ammonia on September 29th and 30th, 2022 was 12.7 mg/L and 6.8 mg/L, respectively. The replacement of the trickling filters media will help improve nitrification and ammonia removal. SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1107685 |
07/31/2022 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 12.3 mg/L and reported value was 21.0 mg/L at EFF-001 (M-001). |
On April 14, 2022, WWTP Director notified RWQCB about the plan to minimize potential risk for ammonia violations during construction. The project began on April 17, 2022. The replacement for one of the trickling filters was completed on June 9 when the seeding of the new media began. On July 17, 2022, the second trickling filter was decommissioned for the replacement of its media. The entire project to replace all the media and seeding is still expected to be completed by October 2022. To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the stabilization of the new media of trickling filter no. 1 and the decommission of trickling filter no. 2 for its media replacement. The replacement of the trickling filters media will help improve nitrification and ammonia removal.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point.
|
Violation |
B |
eSMR |
| 1107051 |
06/30/2022 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 22.7 mg/L at EFF-001 (M-001). |
On April 14, 2022, WWTP Director notified RWQCB about the plan to minimize potential risk for ammonia violations during construction. The project began on April 17, 2022. The replacement for one of the trickling filters was completed on June 9 when the seeding of the new media began. On July 17, 2022, the second trickling filter was decommissioned for the replacement of its media. The entire project to replace all the media and seeding is expected to be completed by October 2022. To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the stabilization of the new media of trickling filter no. 1 and the decommission of trickling filter no. 2 for its media replacement. The replacement of the trickling filters media will help improve nitrification and ammonia removal.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point.
|
Violation |
B |
eSMR |
| 1105623 |
05/31/2022 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 29.0 mg/L at EFF-001 (M-001). |
On April 14, 2022, WWTP Director notified RWQCB about the plan to minimize potential risk for ammonia violations during construction. The project began on April 17, 2022. The replacement for one of the trickling filters was completed on June 9 when the seeding of the new media began. The entire project to replace all the media is expected to be completed by October 2022. To address the high ammonia, the Agency has been using chemically enhanced primary treatment (CEPT). The exceedance was attributed by the inadequate old media of trickling filter no. 2 and the decommission of trickling filter no. 1 for its media replacement. The replacement of the trickling filters media will help improve nitrification and ammonia removal.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point.
|
Violation |
U |
eSMR |
| 1097011 |
10/31/2021 |
OEV |
Enterococci Monthly Geometric mean limit is 35 % and reported value was 67.9 % at EFF-001 (M-001). |
The Agency continued accelerated monitoring into November since the Agency did not demonstrate compliance. The Agency achieved compliance and halted accelerated monitoring on November 2. Four effluent samples were collected and analyzed for enterococcus bacteria during the month. The exceedance occurred due to a blended effluent sample collected on October 24. This blended effluent sample had an enterococcus bacteria result of 57.3 MPN/100 mL. Due to the continuous rain event of October 24, the blending event required additional effluent monitoring. The last two samples collected and analyzed during the month demonstrated compliance. Increasing the chlorine dosage during disinfection addressed the exceedance. |
Violation |
U |
eSMR |
| 1095613 |
09/30/2021 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 13 mg/L at EFF-001 (M-001). |
The Agency continued accelerated monitoring into October since the Agency did not demonstrate compliance. Ammonia results from five effluent samples collected during the month were below the maximum daily ammonia limit of 32 mg/L. SASM staff has been monitoring levels of ammonia in its effluent samples since July 2018 and noticed that ammonia levels have never returned to its low levels prior to construction. In the consultant¿s opinion, trickling filters continue to underperform because of inadequate media specified by design engineer. On October 21, the SASM Board approved the action to replace the trickling filters media. The replacement of the trickling filters media will help improve nitrification. The Staff Report is attached for your review.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1092277 |
06/30/2021 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 14.4 mg/L at EFF-001 (M-001). |
In addition to underperforming media, the Agency suspects that the high calculated average monthly ammonia result is attributed to abnormal BOD and ammonia loads to the trickling filters. During the month of June, staff continued to be challenged by the sludge levels in the primary clarifiers and gravity thickener due to ongoing problems with digesters. In October 2020, the floating cover of the primary digester sank and caused operations to hold sludge in the primaries for about four weeks until the secondary digester reached its set temperature and desired microbial population. The sludge backup was eventually within manageable control by February 2021. As for the recurring issue with foaming in the secondary digester, it was determined on May 28 that the digester roof may have been compromised. This situation caused the gas pressure to be erratic and the cover to slant. It took majority of June to get the digester and the sludge levels under control. Once the sludge levels approached normal range, two of the four basins were taken offline on June 22, which helped reduce the detention time and sludge bulking. On June 25, the sludge levels in the primary clarifiers and gravity thickener began reading within normal range. It took about two weeks after that for the effluent ammonia to return to normal levels.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1084931 |
12/31/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 22.1 mg/L at EFF-001 (M-001). |
In addition to underperforming media, the Agency suspects that the ammonia result of 37 mg/L is attributed to abnormal BOD and ammonia loads to the trickling filters. During that week, the Agency was performing digester cleaning on one of its units which, in coupled with our own dewatering needs, contributed to high ammonia loads from the filtrate. In October, the floating cover of the primary digester sank and caused operations to hold sludge in the primaries for about four weeks until the secondary digester reached its set temperature and desired microbial population. In the meantime, primary clarifiers became overloaded with solids and continued to carry a high sludge blanket through December. As a result, the primary effluent contained high concentrations of solids that reached the recirculation wet wells. During the month of December, sludge was removed directly from the Gravity Thickener. Approximately 13,000 gallons of sludge was trucked out and 115,740 gallons of it was dewatered through our belt filter press.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1084932 |
12/15/2020 |
CAT1 |
Ammonia, Total (as N) Maximum Daily (MDEL) limit is 32 mg/L and reported value was 37 mg/L at EFF-001 (M-001). |
In addition to underperforming media, the Agency suspects that the ammonia result of 37 mg/L is attributed to abnormal BOD and ammonia loads to the trickling filters. During that week, the Agency was performing digester cleaning on one of its units which, in coupled with our own dewatering needs, contributed to high ammonia loads from the filtrate. In October, the floating cover of the primary digester sank and caused operations to hold sludge in the primaries for about four weeks until the secondary digester reached its set temperature and desired microbial population. In the meantime, primary clarifiers became overloaded with solids and continued to carry a high sludge blanket through December. As a result, the primary effluent contained high concentrations of solids that reached the recirculation wet wells. During the month of December, sludge was removed directly from the Gravity Thickener. Approximately 13,000 gallons of sludge was trucked out and 115,740 gallons of it was dewatered through our belt filter press.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. |
Violation |
U |
eSMR |
| 1083150 |
11/30/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 12.3 mg/L and reported value was 12.5 mg/L at EFF-001 (M-001). |
To address this observation, Agency questioned performance of the new trickling filter media and hired consultants to assist the Agency in addressing the noncompliance since May 2020. In the consultant¿s opinion, trickling filters continue to underperform because of inadequate media specified by design engineer. SASM is in discussions with design engineer and media manufacturer to determine the suitable media required to achieve nitrification. In addition to underperforming media, the Agency suspects that the ammonia result of 18 mg/L is due, in part, to an abnormal BOD load to the trickling filters. In October, the floating cover of the primary digester sank and caused operations to hold sludge in the primaries for about four weeks until the secondary digester reached its set temperature and desired microbial population. Emergency funding was approved by SASM Board for cleaning of Digester No. 1 and replacing the cover. In the meantime, primary clarifiers became hydraulically overloaded with solids and caused high concentrations of solids to reach the recirculation wet wells. The Agency is arranging removal and proper disposal of excess sludge.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point.
|
Violation |
U |
eSMR |
| 1080682 |
09/30/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 12.3 mg/L and reported value was 16.8 mg/L at EFF-001 (M-001). |
To address this observation, the Agency questioned the new trickling filter media and hired a consultant in May 2020 to provide support regarding trickling filter process optimization with the specific goal/pursuit of reliable nitrification in the SASM nitrification process. From May 2020 to the present, the consultant has been collecting data and continues to summarize his findings. SASM staff has been and continues to support efforts in data collection and have implemented several of the consultant¿s suggestions to improve nitrification, including the manual flushing of the filters to improve sloughing and retrofitting the distribution arms to improve the Skulkraft ratio. In the consultant¿s opinion, the trickling filters continue to underperform because of the inadequate media specified by the design engineer. SASM is in discussions with the design engineer and the media manufacturer to determine the suitable media required to achieve nitrification.
SASM would like the RWQCB to consider the fact that SASM shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for SASM, the effluent from SASM will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point. As an update, the Agency has demonstrated compliance for the average monthly ammonia during the consecutive month. |
Violation |
U |
eSMR |
| 1079681 |
08/31/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 12.3 mg/L and reported value was 16 mg/L at EFF-001 (M-001). |
To address this observation, the Agency hired a consultant in May 2020 to provide support regarding trickling filter process optimization with the specific goal of reliable nitrification in the secondary treatment process. From May 2020 to the present, the consultant has collected data and summarized his findings. The staff has supported efforts in data collection and have implemented several of the consultant¿s suggestions to improve nitrification. In the consultant¿s opinion, the trickling filters continue to underperform because of the inadequate media specified by the design engineer. The Agency has implemented temporary measures, including the manual flushing of the filters to improve sloughing, and retrofitting the distribution arms to improve the Skulkraft ratio. The Agency is also in discussions with the design engineer and the media manufacturer to determine the appropriate solution required to achieve nitrification.
The Agency would like the RWQCB to consider the fact that it shares an outfall with Sanitary District No. 5 of Marin County (SD#5). Since SD#5 contributes high concentrations of ammonia in its effluent based on its discharge limit that is 12-fold higher compared to ammonia discharge limit for the Agency, the effluent from the Agency will likely have negligible impact once blended with effluent from SD#5 prior to the discharge point.
|
Violation |
U |
eSMR |
|
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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