| Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
| 1157209 |
06/30/2026 |
DMON |
1. North City Water Reclamation Plant (NCWRP) Laboratory failed to produce valid Biochemical Oxygen Demand (BOD) results for sample sources N01-PD on June 3, 2026, and MBC_COMBCN on June 10-11, and June 26-27. Results did not meet method acceptance criteria due to improper dilution selection. Samples exceeded holding time and could not be reanalyzed; results were deemed non-reportable. This resulted in the laboratory not meeting the daily sampling requirement for the system wide percent removal calculation.
2. NCWRP laboratory failed to meet duplicate precision (RPD) quality control criteria for BOD analysis for sample sources N01-PS_INF, N01-PEN, N20-SE, N_DIV_STRUCT, and N34-REC WATER on June 12 and June 19, and MBC_COMBCN on June 12. Results were invalid due to inadequate sample homogenization. Samples exceeded holding time and could not be reanalyzed; results were deemed non-reportable. This resulted in the laboratory not meeting the daily sampling requirement for the system wide percent removal calculation.
3. NCWRP laboratory failed to meet BOD method blank acceptance criteria for sample sources N01-PS_INF, N01-PEN, N01-FB, N20-SE, N_DIV_STRUCT, N34-REC WATER, NCPWF-CW, and MBC_COMBCN on June 29¿30. Elevated blank results indicate contamination in the analytical process. Samples exceeded holding time and could not be reanalyzed; results were deemed non-reportable. This resulted in the laboratory not meeting the daily sampling requirement for the system wide percent removal calculation.
4. NCWRP laboratory failed to obtain a representative Total Suspended Solids (TSS) result for sample source N_DIV_STRUCT on June 18, 2026, due to insufficient sample volume. Analysis was conducted on a reduced volume, resulting in an elevated reporting limit and a non-quantifiable result. Reanalysis was not possible. This resulted in the laboratory not meeting the daily sampling requirement for the system wide percent removal calculation.
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1. The NCWRP lab supervisor has trained staff to consider the visible color of the sample in determining an appropriate dilution for BOD analysis. For samples lacking historical data, additional dilution bottles will be prepared to ensure at least one dilution meets method criteria. These procedures will be incorporated into the SOP.
2. The NCWRP lab supervisor has retrained staff on proper homogenization techniques for BOD duplicate analyses, ensuring thorough mixing prior to each aliquot. Acceptable methods include shaking, inversion, blending, or use of a stir plate. This requirement will be incorporated into the SOP.
3. The NCWRP lab supervisor will conduct a comprehensive investigation of potential contamination sources within the BOD analytical system, including but not limited to SEAL system tubing and lines, aeration tubing to nutrient buffer carboys, glassware cleaning procedures, DO probe performance, and reagent water quality (Mill-Q system). Findings and corrective actions will be documented in maintenance logs, and ongoing monitoring will be implemented.
4. The NCWRP lab supervisor will train staff to promptly notify supervision when insufficient sample volume is received and to document this condition on the chain of custody. For low-volume, low-solids samples, staff will prioritize allocation of sufficient volume for TSS (1000 mL) and BOD (300 mL) analyses prior to other testing to maintain standard reporting limits. This requirement will be incorporated into the sample receiving SOP.
|
Violation |
U |
eSMR |
| 1157208 |
06/30/2026 |
DMON |
1. The relative percent difference (RPD) for the Volatile Suspended Solids sample duplicates in batch #26154TSS97 exceeded the method¿s quality control acceptance criteria. After the holding time for these samples had passed, laboratory supervision discovered that the spreadsheet formulas had not been updated to reflect the new RPD calculations and criteria from the recently adopted solids method revision. Because the holding time had expired, the samples could not be reanalyzed, and the results were flagged as non-reportable. This resulted in the laboratory not meeting the daily sampling requirement for the PLWTP influent (PLR/INF-001) and effluent (PLE/EFF-001) from June 1 through 2, 2026.
2. Due to a scheduling oversight, the EPA Method 625.1 Phenols extraction exceeded the holding time limits defined in Section 9.4.2 of Standard Operating Procedure (SOP) #6144. As a result, June 1 influent (PLR/INF-001) and effluent (PLE/EFF-001) composite samples were flagged as non-reportable, and the laboratory did not meet the required weekly sampling frequency for this parameter.
|
1. The laboratory supervisor conducted a comprehensive evaluation of the entire Volatile Suspended Solids methodology. During this review, the spreadsheet was corrected to properly align with the quality control criteria specified in the new Standard Methods revision for solids and laboratory personnel were retrained on the criteria update and the sample holding times.
2. The laboratory supervisor evaluated the EPA Method 625.1 Phenols preparation and extraction processes to identify opportunities for systematic improvement. As part of the corrective actions, staff were directed to review Section 9.4.2 of SOP #6144, and a shared group calendar was implemented featuring an extraction date calculator that displays sample dates and sources to prevent scheduling errors. SOP #6144 will also be updated to clarify holding time calculations specific to EPA Method 625.1. In addition, all relevant laboratory staff will undergo mandatory retraining, participate in a new monthly rotation assigning a dedicated staff member to schedule extractions and be required to obtain second-level review by another analyst to verify scheduling accuracy.
|
Violation |
U |
eSMR |
| 1157211 |
06/30/2026 |
DMON |
1. The relative percent difference (RPD) for the Volatile Suspended Solids sample duplicates in batch #26154TSS97 exceeded the method¿s quality control acceptance criteria. After the holding time for these samples had passed, laboratory supervision discovered that the spreadsheet formulas had not been updated to reflect the new RPD calculations and criteria from the recently adopted solids method revision. Because the holding time had expired, the samples could not be reanalyzed, and the results were flagged as non-reportable. This resulted in the laboratory not meeting the daily sampling requirement for the PLWTP influent (PLR/INF-001) and effluent (PLE/EFF-001) from June 1 through 2, 2026.
2. Due to a scheduling oversight, the EPA Method 625.1 Phenols extraction exceeded the holding time limits defined in Section 9.4.2 of Standard Operating Procedure (SOP) #6144. As a result, June 1 influent (PLR/INF-001) and effluent (PLE/EFF-001) composite samples were flagged as non-reportable, and the laboratory did not meet the required weekly sampling frequency for this parameter.
|
1. The laboratory supervisor conducted a comprehensive evaluation of the entire Volatile Suspended Solids methodology. During this review, the spreadsheet was corrected to properly align with the quality control criteria specified in the new Standard Methods revision for solids and laboratory personnel were retrained on the criteria update and the sample holding times.
2. The laboratory supervisor evaluated the EPA Method 625.1 Phenols preparation and extraction processes to identify opportunities for systematic improvement. As part of the corrective actions, staff were directed to review Section 9.4.2 of SOP #6144, and a shared group calendar was implemented featuring an extraction date calculator that displays sample dates and sources to prevent scheduling errors. SOP #6144 will also be updated to clarify holding time calculations specific to EPA Method 625.1. In addition, all relevant laboratory staff will undergo mandatory retraining, participate in a new monthly rotation assigning a dedicated staff member to schedule extractions and be required to obtain second-level review by another analyst to verify scheduling accuracy.
|
Violation |
U |
eSMR |
| 1157205 |
06/30/2026 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60 mg/L and reported value was 75.7 mg/L at EFF-001. |
Plant management has initiated several mitigation measures to reduce the impact of the Pump Station 2 Wet Well Emergency Project on the PLWTP. Mitigation measures include:
¿ Sedimentation Basin Recovery: Overtime staffing is being used to return as many basins as possible to service. Since initiating this effort, two basins have been repaired and brought back online enabling rotation of two other basins for repair.
¿ Vactor Services: Procurement for supplemental Vactor services is underway to support basin cleaning and address scum related soluble BOD.
¿ Vivianite Control: Sludge line jetting will begin upon contract approval to address vivianite buildup that is hindering sludge blanket management.
¿ Wet Well Oxidation: The City is evaluating oxidizer addition or direct oxygen injection at Pump Stations 1 and 2 to mitigate septicity during extended shutdowns.
¿ Plant Performance: The City is exploring procurement options, including an emergency directive, to address grit removal and sedimentation basin capacity and performance.
¿ Point Loma Wastewater Treatment Plant Headworks CIP: The City is in the preliminary design phase of a CIP to replace the five bar screens and rehabilitate the five bar screen channels to improve screening at the headworks of the plant.
|
Violation |
U |
eSMR |
| 1157207 |
06/30/2026 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 80 % and reported value was 76.3 % at EFF-001. |
Plant management has initiated several mitigation measures to reduce the impact of the Pump Station 2 Wet Well Emergency Project on the PLWTP. Mitigation measures include:
¿ Sedimentation Basin Recovery: Overtime staffing is being used to return as many basins as possible to service. Since initiating this effort, two basins have been repaired and brought back online enabling rotation of two other basins for repair.
¿ Vactor Services: Procurement for supplemental Vactor services is underway to support basin cleaning and address scum related soluble BOD.
¿ Vivianite Control: Sludge line jetting will begin upon contract approval to address vivianite buildup that is hindering sludge blanket management.
¿ Wet Well Oxidation: The City is evaluating oxidizer addition or direct oxygen injection at Pump Stations 1 and 2 to mitigate septicity during extended shutdowns.
¿ Plant Performance: The City is exploring procurement options, including an emergency directive, to address grit removal and sedimentation basin capacity and performance.
¿ Point Loma Wastewater Treatment Plant Headworks CIP: The City is in the preliminary design phase of a CIP to replace the five bar screens and rehabilitate the five bar screen channels to improve screening at the headworks of the plant.
|
Violation |
U |
eSMR |
| 1157210 |
06/27/2026 |
OEV |
Turbidity Weekly Average limit is 100 NTU and reported value was 103 NTU at EFF-001. |
Plant management has initiated several mitigation measures to reduce the impact of the Pump Station 2 Wet Well Emergency Project on the PLWTP. Mitigation measures include:
¿ Sedimentation Basin Recovery: Overtime staffing is being used to return as many basins as possible to service. Since initiating this effort, two basins have been repaired and brought back online enabling rotation of two other basins for repair.
¿ Vactor Services: Procurement for supplemental Vactor services is underway to support basin cleaning and address scum related soluble BOD.
¿ Vivianite Control: Sludge line jetting will begin upon contract approval to address vivianite buildup that is hindering sludge blanket management.
¿ Wet Well Oxidation: The City is evaluating oxidizer addition or direct oxygen injection at Pump Stations 1 and 2 to mitigate septicity during extended shutdowns.
¿ Plant Performance: The City is exploring procurement options, including an emergency directive, to address grit removal and sedimentation basin capacity and performance.
¿ Point Loma Wastewater Treatment Plant Headworks CIP: The City is in the preliminary design phase of a CIP to replace the five bar screens and rehabilitate the five bar screen channels to improve screening at the headworks of the plant.
|
Violation |
U |
eSMR |
| 1157212 |
06/27/2026 |
CAT1 |
Settleable Solids Weekly Average limit is 1.5 ml/L and reported value was 1.7 ml/L at EFF-001. |
Plant management has initiated several mitigation measures to reduce the impact of the Pump Station 2 Wet Well Emergency Project on the PLWTP. Mitigation measures include:
¿ Sedimentation Basin Recovery: Overtime staffing is being used to return as many basins as possible to service. Since initiating this effort, two basins have been repaired and brought back online enabling rotation of two other basins for repair.
¿ Vactor Services: Procurement for supplemental Vactor services is underway to support basin cleaning and address scum related soluble BOD.
¿ Vivianite Control: Sludge line jetting will begin upon contract approval to address vivianite buildup that is hindering sludge blanket management.
¿ Wet Well Oxidation: The City is evaluating oxidizer addition or direct oxygen injection at Pump Stations 1 and 2 to mitigate septicity during extended shutdowns.
¿ Plant Performance: The City is exploring procurement options, including an emergency directive, to address grit removal and sedimentation basin capacity and performance.
¿ Point Loma Wastewater Treatment Plant Headworks CIP: The City is in the preliminary design phase of a CIP to replace the five bar screens and rehabilitate the five bar screen channels to improve screening at the headworks of the plant.
|
Violation |
U |
eSMR |
| 1157206 |
06/24/2026 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 5.5 ml/L at EFF-001. |
Plant management has initiated several mitigation measures to reduce the impact of the Pump Station 2 Wet Well Emergency Project on the PLWTP. Mitigation measures include:
¿ Sedimentation Basin Recovery: Overtime staffing is being used to return as many basins as possible to service. Since initiating this effort, two basins have been repaired and brought back online enabling rotation of two other basins for repair.
¿ Vactor Services: Procurement for supplemental Vactor services is underway to support basin cleaning and address scum related soluble BOD.
¿ Vivianite Control: Sludge line jetting will begin upon contract approval to address vivianite buildup that is hindering sludge blanket management.
¿ Wet Well Oxidation: The City is evaluating oxidizer addition or direct oxygen injection at Pump Stations 1 and 2 to mitigate septicity during extended shutdowns.
¿ Plant Performance: The City is exploring procurement options, including an emergency directive, to address grit removal and sedimentation basin capacity and performance.
¿ Point Loma Wastewater Treatment Plant Headworks CIP: The City is in the preliminary design phase of a CIP to replace the five bar screens and rehabilitate the five bar screen channels to improve screening at the headworks of the plant.
|
Violation |
U |
eSMR |
| 1155917 |
05/31/2026 |
DMON |
The BOD laboratory control sample recovery for batch #26133BOD29 was outside of the established method quality control acceptance criteria. Therefore, the result values for the 05/11 and 05/12 Effluent and Influent samples were flagged as non-reportable. Due to the 5-day incubation period required for BOD testing, these samples could not be reanalyzed once the criteria failure was identified. This resulted in the laboratory not meeting the minimum sampling frequency of 1/Day.
The relative percent difference (RPD) of the sample duplicates for Total Suspended Solids (TSS) batch #26149TSS71 exceeded the established method quality control acceptance criteria. Because an error in the spreadsheet's RPD calculation formula was identified after the holding time for the 05/27 and 05/28 samples, the samples could not be reanalyzed to resolve the issue. Consequently, the result values for the Effluent and Influent samples were flagged as non-reportable. This resulted in the laboratory not meeting the minimum sampling frequency of 1/Day. |
The laboratory supervisor conducted a comprehensive evaluation of the Biochemical Oxygen Demand (BOD) source water quality, sample preparation, and analytical processes to identify potential contamination, training needs, or systemic factors causing the internal control standard recovery failure. Additionally, the supervisor will continue working on Corrective Action #25022 to establish a traceable monitoring record of the BOD corrective action plan implementation, employee training, and analytical improvement efforts.
The supervisor conducted a comprehensive evaluation of the entire Total Suspended Solids (TSS) methodology. During this review, the spreadsheet was corrected to properly align with the quality control criteria specified in the new Standard Methods revision for solids, and laboratory personnel were reminded of this criteria update and sample holding times. |
Violation |
U |
eSMR |
| 1155916 |
05/31/2026 |
DMON |
The BOD laboratory control sample recovery for batch #26133BOD29 was outside of the established method quality control acceptance criteria. Therefore, the result values for the 05/11 and 05/12 Effluent and Influent samples were flagged as non-reportable. Due to the 5-day incubation period required for BOD testing, these samples could not be reanalyzed once the criteria failure was identified. This resulted in the laboratory not meeting the minimum sampling frequency of 1/Day.
The relative percent difference (RPD) of the sample duplicates for Total Suspended Solids (TSS) batch #26149TSS71 exceeded the established method quality control acceptance criteria. Because an error in the spreadsheet's RPD calculation formula was identified after the holding time for the 05/27 and 05/28 samples, the samples could not be reanalyzed to resolve the issue. Consequently, the result values for the Effluent and Influent samples were flagged as non-reportable. This resulted in the laboratory not meeting the minimum sampling frequency of 1/Day. |
The laboratory supervisor conducted a comprehensive evaluation of the Biochemical Oxygen Demand (BOD) source water quality, sample preparation, and analytical processes to identify potential contamination, training needs, or systemic factors causing the internal control standard recovery failure. Additionally, the supervisor will continue working on Corrective Action #25022 to establish a traceable monitoring record of the BOD corrective action plan implementation, employee training, and analytical improvement efforts.
The supervisor conducted a comprehensive evaluation of the entire Total Suspended Solids (TSS) methodology. During this review, the spreadsheet was corrected to properly align with the quality control criteria specified in the new Standard Methods revision for solids, and laboratory personnel were reminded of this criteria update and sample holding times. |
Violation |
U |
eSMR |
| 1155919 |
05/31/2026 |
DMON |
The Total Suspended Solids (TSS) batch for the dates indicated below did not meet quality control acceptance criteria due to duplicate analyses exceeding the allowable Relative Percent Difference (RPD) limits. As a result, the affected data have been excluded from reporting. Affected sample locations and dates: May 25, 2026: N_DIV_STRUCT, N34-REC, N20-SE, N01-PD, N01-FB, N10-EFF, N01-PS_INF, N01-PEN; and May 26, 2026: N20-RAS COMB, N15-WAS HCP, N15-AE.
The QC failure was attributed to inconsistent sample homogenization prior to duplicate aliquot measurement. While samples were mixed prior to pouring the first aliquot, they were not re-mixed immediately before pouring the second aliquot, allowing suspended solids to settle. This resulted in non-representative duplicate measurements and RPD values outside acceptance limits. The current SOP assumes adequate mixing prior to each aliquot; however, it does not explicitly require immediate re-mixing before every individual aliquot withdrawal. This gap contributed to the variability observed in the duplicate results. In addition, the samples were disposed of before the failure was identified and therefore could not be reanalyzed.
The Biological Oxygen Demand (BOD) analyses for samples MBC_COMBCN dated May 30, 2026 and May 31, 2026 are not available due to a software failure during probe readings for final dissolved oxygen measurements. The sample bottles were disposed of before the issue was identified, and the original samples exceeded holding time for this analysis and could not be rerun.
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For the TSS, the following Corrective Actions will be implemented to prevent a reoccurrence: 1. The SOP is being revised to explicitly require that samples be thoroughly mixed and immediately poured or withdrawn for each aliquot to ensure representativeness. 2. Laboratory staff will be retrained on proper homogenization techniques and required to review and acknowledge the updated SOP. 3. Samples will be retained for potential reanalysis until the analyst confirms that all QC criteria have been met.
For BOD, analysts will be required to verify that all electronic data have been properly recorded and saved prior to disposing of sample bottles following analysis. |
Violation |
U |
eSMR |
| 1155918 |
05/31/2026 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60 mg/L and reported value was 64.3 mg/L at EFF-001. |
PLWTP Operations/Maintenance, with PUD-wide support, will continue to maximize sedimentation tank availability by prioritizing repairs and returning out-of-service tanks to service as quickly as practical. Operations will also increase monitoring of sludge blanket levels and the frequency of vacuuming and removing scum from sedimentation tank scum troughs and effluent weir areas to improve solids removal efficiency and minimize solids carryover.
PLWTP Operations will strengthen coordination with Wastewater Collections and the Environmental Monitoring & Technical Services Divisions to improve communication regarding significant PS2 operational changes and, whenever practical, coordinate planned PS2 shutdowns and restoration of pumping to minimize hydraulic surges and their impact on treatment performance.
|
Violation |
U |
eSMR |
| 1154877 |
04/30/2026 |
DMON |
For Return Stream Monitoring (Monitoring Location RS-001):
During the reporting period, all required BOD analyses were performed by the NCWRP Laboratory (ELAP 2477); however, several results were determined to be invalid due to not meeting method specific quality control criteria. Because these QC failures prevented the generation of valid analytical results, the affected samples are considered non reportable and constitute a failure to monitor. The impacted samples at sources (N01-PS_INF, N01-PEN, N01-PD, N01-FB, N_DIV_STRUCTURE, N34 REC WATER, MBC_COMBCN) could not be resampled, as the required 48 hour holding time had elapsed by the time the analyses were completed five days later.
|
A review of the laboratory¿s performance for April 2026 showed that 7 of 17 BOD batches experienced QC failures. These included five failures associated with method blanks, one failure of method blank and laboratory control samples, and one failure related to duplicate RPD exceedances. Given that most nonconformances were linked to blank failure, the laboratory has initiated an immediate and comprehensive investigation into potential contamination sources within the BOD analytical process. Initial actions included visual inspection of all glassware and plasticware, evaluation of water lines connected to the robotic system, assessment of carboy cleanliness, and inspection of the BOD probe for potential damage or electrical issues. In addition, calibration processes were examined, and guidance was sought from the probe manufacturer. |
Violation |
U |
eSMR |
| 1153690 |
03/31/2026 |
DMON |
During the reporting period, all required BOD analyses were performed by the NCWRP Laboratory (ELAP 2477); however, several results were determined to be invalid due to not meeting method specific quality control criteria. Because these QC failures prevented the generation of valid analytical results, the affected samples are considered non reportable and constitute a failure to monitor. The impacted samples at Monitoring Location RS-001 could not be resampled, as the required 48 hour holding time had elapsed by the time the analyses were completed five days later. |
A review of the laboratory¿s performance for March 2026 showed that 12 of 19 BOD batches experienced QC failures. These included six failures associated with method blanks, three failures of laboratory control samples, two failures related to duplicate RPD exceedances, and one seed control failure. Given that most nonconformances were linked to blank contamination, the laboratory has initiated an immediate and comprehensive investigation into potential contamination sources within the BOD analytical process. Initial actions include visual inspection of all glassware and plasticware, evaluation of water lines connected to the robotic system, assessment of carboy cleanliness, and inspection of the BOD probe for potential damage or electrical issues.
Following the initial assessment, staff will undergo retraining, including review of the applicable standard operating procedure and method requirements. In addition, the Quality Assurance Group has issued a Corrective Action Request through the automated tracking system to ensure that root causes are identified, corrective measures are implemented, and effectiveness is verified through follow up monitoring.
|
Violation |
U |
eSMR |
| 1152873 |
02/08/2026 |
DMON |
The BOD internal control standard recovery was outside of the method acceptance limits values established in the Current MDLs & Acceptance Criteria (Document #13584). Therefore, the result values for the 02/08/26 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known. |
The laboratory supervisor conducted an evaluation of the laboratory¿s BOD source water quality and the sample preparation and analytical processes to identify any potential contamination, need for training and/or systematic factors that could lead to an internal control standard recovery outside of the method acceptance limits. Additionally, as part of the remedial action the laboratory supervisor will continue working in the Corrective Action #25022 to establish a traceable monitoring record of the Biochemical Oxygen Demand analysis corrective action plan implementation, employee training, and analytical improvement efforts. |
Violation |
U |
eSMR |
| 1152874 |
02/08/2026 |
DMON |
The BOD internal control standard recovery was outside of the method acceptance limits values established in the Current MDLs & Acceptance Criteria (Document #13584). Therefore, the result values for the 02/08/26 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known. |
The laboratory supervisor conducted an evaluation of the laboratory¿s BOD source water quality and the sample preparation and analytical processes to identify any potential contamination, need for training and/or systematic factors that could lead to an internal control standard recovery outside of the method acceptance limits. Additionally, as part of the remedial action the laboratory supervisor will continue working in the Corrective Action #25022 to establish a traceable monitoring record of the Biochemical Oxygen Demand analysis corrective action plan implementation, employee training, and analytical improvement efforts. |
Violation |
U |
eSMR |
| 1151688 |
01/31/2026 |
DMON |
Due to issues with PLWTP Lab¿s BOD source water the method QC performance was impacted; deficiencies include method blanks exceeding the depletion criteria established in the SOP (1467) BOD_WW_SED_SLDS Revision 11 Section 16.1.1 and internal control standard recovery being outside of the method acceptance limits values stablished in the Current MDLs & Acceptance Criteria (Document #13584). Additionally, the relative percent difference (RPD) of sample duplicates exceeded the method acceptance criteria established in the SOP (1467) BOD_WW_SED_SLDS Revision 11 Section 16.1.4. Hereby, the result values for the 01/09, 01/10, 01/16, 01/17 and 01/25 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known. |
The laboratory supervisor coordinated a plan to supply the PLWTP lab with ASTM Type I water from another facility, determined the pre-filter system to be installed based on the laboratory¿s needs, and conducted an evaluation of the laboratory¿s BOD source water quality, sample preparation and analytical process to identify any potential contamination, need for training and/or systematic factor(s) that could lead to an internal control standard recovery outside of the method acceptance limits. Additionally, as part of the remedial action the laboratory supervisor will conduct training reinforcement (SOP review, supervisor-analysts walk through) and continued monitoring the staff improvement through the Corrective Action Request (CAR #: 25022). |
Violation |
U |
eSMR |
| 1151689 |
01/31/2026 |
DMON |
Due to issues with PLWTP Lab¿s BOD source water the method QC performance was impacted; deficiencies include method blanks exceeding the depletion criteria established in the SOP (1467) BOD_WW_SED_SLDS Revision 11 Section 16.1.1 and internal control standard recovery being outside of the method acceptance limits values stablished in the Current MDLs & Acceptance Criteria (Document #13584). Additionally, the relative percent difference (RPD) of sample duplicates exceeded the method acceptance criteria established in the SOP (1467) BOD_WW_SED_SLDS Revision 11 Section 16.1.4. Hereby, the result values for the 01/09, 01/10, 01/16, 01/17 and 01/25 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known. |
The laboratory supervisor coordinated a plan to supply the PLWTP lab with ASTM Type I water from another facility, determined the pre-filter system to be installed based on the laboratory¿s needs, and conducted an evaluation of the laboratory¿s BOD source water quality, sample preparation and analytical process to identify any potential contamination, need for training and/or systematic factor(s) that could lead to an internal control standard recovery outside of the method acceptance limits. Additionally, as part of the remedial action the laboratory supervisor will conduct training reinforcement (SOP review, supervisor-analysts walk through) and continued monitoring the staff improvement through the Corrective Action Request (CAR #: 25022). |
Violation |
U |
eSMR |
| 1150740 |
12/22/2025 |
DMON |
Due to a laboratory scheduling deficiency, the sample preparation and testing processes for the Total Cyanide method were carried out outside the holding time defined by the Standard Operating Procedure (Document # 1411) Section 9.4. Therefore, the result value reported in batch 26006CN42 for the 12/22/25 influent composite sample was flagged as non-reportable. |
The laboratory supervisor conducted an evaluation of the Total Cyanide method sample preparation and testing processes to identify improvement opportunities, any need for a SOP update, and/or systematic factor(s) that could prevent future sample holding time deficiencies. Additionally, the group supervisor re-trained laboratory personnel on the SOP #1411 specifically the section 9.4 ¿Storage and holding time¿ as part of the remedial action. |
Violation |
U |
eSMR |
| 1150171 |
11/03/2025 |
DMON |
For both Effluent and Influent composite samples collected in 11/03/25 the phenol, 4-methylphenol, 2,4-dinitrophenol, 4-nitrophenol, and 4,6-dinitro-2-methylphenol analytes¿ Matrix spike duplicate (MSD) Relative Percent Difference recoveries were outside the QC criteria stablished by SOP (6144) 625.1 Rev: 11 Section 16.5. Plus, due to a broken sample vial there was no LCS precision calculated for the mentioned analytes. Therefore, the PLWTP monthly monitoring is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007 for the Non-Chlorinated Phenols Sum. |
The Alvarado GC-MS laboratory group (ELAP Cert. 1609) will continue monitoring and implementing the necessary quality assurance protocols on the Phenols analysis under EPA 625.1, to reduce the Matrix spike duplicate (MSD) Relative Percent Difference recoveries outside the stablished QC criteria instances; including but not limited to source water tracking, labware cleaning procedures, sample preparation improvements, evaluate any training need for personnel and identify any systematic factor impacting the extraction process. |
Violation |
U |
eSMR |
| 1150172 |
11/03/2025 |
DMON |
For both Effluent and Influent composite samples collected in 11/03/25 the phenol, 4-methylphenol, 2,4-dinitrophenol, 4-nitrophenol, and 4,6-dinitro-2-methylphenol analytes¿ Matrix spike duplicate (MSD) Relative Percent Difference recoveries were outside the QC criteria stablished by SOP (6144) 625.1 Rev: 11 Section 16.5. Plus, due to a broken sample vial there was no LCS precision calculated for the mentioned analytes. Therefore, the PLWTP monthly monitoring is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007 for the Non-Chlorinated Phenols Sum. |
The Alvarado GC-MS laboratory group (ELAP Cert. 1609) will continue monitoring and implementing the necessary quality assurance protocols on the Phenols analysis under EPA 625.1, to reduce the Matrix spike duplicate (MSD) Relative Percent Difference recoveries outside the stablished QC criteria instances; including but not limited to source water tracking, labware cleaning procedures, sample preparation improvements, evaluate any training need for personnel and identify any systematic factor impacting the extraction process. |
Violation |
U |
eSMR |
| 1149636 |
10/01/2025 |
DMON |
Due to a laboratory scheduling deficiency, the sample extraction process for the 625.1 Phenols method was carried out outside the holding time defined by the Standard Operating Procedure (Document # 6144) Section 9.4.2. Hereby, the result values reported in batch 25282PHN18 for the 10/01/25 influent and effluent composite samples were flagged as non-reportable. |
The laboratory supervisor conducted an evaluation of the 625.1 method sample preparation and extraction processes to identify improvement opportunities, any need for a SOP update, and/or systematic factor(s) that could prevent future sample holding time deficiencies. Additionally, the group supervisor reminded the laboratory personnel instructed the laboratory personnel to review the SOP # 6144 section 9.4.2 and initiated a shared group calendar to track sample receiving and processing as part of the remedial action. |
Violation |
U |
eSMR |
| 1149637 |
10/01/2025 |
DMON |
Due to a laboratory scheduling deficiency, the sample extraction process for the 625.1 Phenols method was carried out outside the holding time defined by the Standard Operating Procedure (Document # 6144) Section 9.4.2. Hereby, the result values reported in batch 25282PHN18 for the 10/01/25 influent and effluent composite samples were flagged as non-reportable. |
The laboratory supervisor conducted an evaluation of the 625.1 method sample preparation and extraction processes to identify improvement opportunities, any need for a SOP update, and/or systematic factor(s) that could prevent future sample holding time deficiencies. Additionally, the group supervisor reminded the laboratory personnel instructed the laboratory personnel to review the SOP # 6144 section 9.4.2 and initiated a shared group calendar to track sample receiving and processing as part of the remedial action. |
Violation |
U |
eSMR |
| 1148822 |
09/30/2025 |
DMON |
Due to a sample preparation deficiency during the initial weight and extraction process described in the SOP (1418) O_G_HEM Revision: 7 Section 14.4; the Oil and Grease result values processed in batch 25272OG40 for the 9/23, 9/24, 9/25 and 9/26 effluent and influent grab samples were flagged as non-reportable. |
The laboratory supervisor walked through the Oil and Grease sample preparation and initial weight - extraction processes to identify any potential sample preparation deficiencies. Analytical procedure improvements will be included in the upcoming Standard Operating Procedure #1418 revision plus the Alvarado¿s Wet chemistry laboratory staff will be instructed to acknowledge the reflected changes. |
Violation |
U |
eSMR |
| 1148821 |
09/09/2025 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 6 ml/L at EFF-001. |
Regional Board notifications sent by the PUD, EMTS¿ program manager.
- The PLWTP laboratory personnel followed the work instruction #22714 by re-collecting and processing second effluent grab samples on 09/03/25 at 1350 and 09/09/25 at 1123. The obtained values for the mentioned PLE samples were <0.1 mL/L and 0.6 mL/L respectively.
- The WWTD OPS team continued implementing an effluent line flushing protocol following each shutdown. In addition, they continued testing operational adjustments:
-Increasing ferric chloride dosage to enhance primary treatment, and
-Using offline tanks to buffer surge flows.
|
Violation |
B |
eSMR |
| 1148820 |
09/03/2025 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 3.5 ml/L at EFF-001. |
Regional Board notifications sent by the PUD, EMTS¿ program manager.
- The PLWTP laboratory personnel followed the work instruction #22714 by re-collecting and processing second effluent grab samples on 09/03/25 at 1350 and 09/09/25 at 1123. The obtained values for the mentioned PLE samples were <0.1 mL/L and 0.6 mL/L respectively.
- The WWTD OPS team continued implementing an effluent line flushing protocol following each shutdown. In addition, they continued testing operational adjustments:
-Increasing ferric chloride dosage to enhance primary treatment, and
-Using offline tanks to buffer surge flows.
|
Violation |
U |
eSMR |
| 1147845 |
08/31/2025 |
DMON |
1. Due to a programmed power outage at the PLWTP, the composite effluent and influent samples from the 08/26/25 collection may differ from the composite sample definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409 Part 2. ¿ Glossary of Common Terms ¿Daily Discharge¿.
The 08/26/2025 effluent and influent composite samples were obtained from a combination of at least eight sample aliquots of at least 100 mL at periodic intervals during the time frame from 0001 to 0110 and 1300 to 2359; therefore, the samples not necessarily reflect the plant¿s operating hours over a 24-hour period for the following analyses: Floatable solids, BOD, TDS, TSS_VSS.
2. The BOD internal control standard recovery was outside of the method acceptance limits values stablished in the Current MDLs & Acceptance Criteria (Document #13584). Herby, the result values for the 8/22, 8/23 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known.
3. Due to contamination during the batch 25219BN35 continuous liquid-liquid extraction; the Hexachlorocyclopentadiene internal control standard recovery and RPD percentages were outside of the method acceptance limits values stablished in the SOP (6144) 625.1 Revision: 11, Section 16. Herby, the result values for the 08/06 Effluent and Influent composite samples processed in were flagged as non-reportable. Additionally, the Bis(2-ethylhexyl) phthalate compound was detected in the Method Blank above the Method Detection Level; the result values for the 08/06 Influent composite sample processed in batch 25219BN35 were flagged as non-reportable.
|
1. Reported data for the 08/26/25 effluent and influent composite samples was flagged. Through validation, historical tendency outliers were not identified for the following analyses obtained values: Floatable solids, BOD, TDS, TSS_VSS.
Additionally, the EMTS and the WWTD staff conducted a meeting to discuss and brainstorm on possible corrective action plan(s) to approach the PLWTP¿s flowmeter ¿ compositing issues during power outages.
2. The laboratory supervisor conducted an evaluation of the BOD sample preparation and analytical process to identify any potential contamination, need for training and/or systematic factor(s) that could lead to an internal control standard recovery outside of the method acceptance limits. Additionally, as part of the remedial action the laboratory supervisor will conduct training reinforcement (SOP review, supervisor-analysts walk through) and initiate a Corrective Action Request (CAR #: 25022) to stablish a traceable precedent of the Biochemical Oxygen Demand analysis corrective action plan implementation and monitoring.
3. The Alvarado Wastewater Chemistry Lab, GC-MS laboratory group (ELAP Cert. 1609) conducted an evaluation on the CLLE procedures to identify any potential contamination and/or need for equipment repairing. The CLLE equipment¿s tubing/connections detected leaks were successfully fixed to ensure effective method performance and QC parameters within the method acceptance limits for the Base Neutral compounds.
|
Violation |
U |
eSMR |
| 1147846 |
08/26/2025 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 4 ml/L at EFF-001. |
Regional Board notification sent by the Public Utilities Department, Environmental Monitoring & Technical Services Division¿s program manager.
- The PLWTP laboratory personnel followed work instruction #22714 ¿Settleable Solids Analysis on PLE¿ and re-collected a second PLE grab sample which was processed in batch 25238SET02 on 08/26/25 at 1637. The obtained value for the mentioned PLE sample (unique id P1562069) was 0.4 mL/L which is within the effluent limitation permit criteria.
- The WWTD OPS team have already implemented a protocol to flush the PLE lines following each shutdown. In addition, we are testing operational adjustments to minimize impacts, including:
¿ Increasing ferric chloride dosage to enhance primary treatment, and
¿ Using offline tanks to buffer surge flows.
|
Violation |
U |
eSMR |
| 1146463 |
07/31/2025 |
DMON |
Due to a Control Standard preparation deficiency during the dilution series process described in the SOP (1467) BOD_WW_SED_SLDS Revision: 11, Section 14.2.12; The Biochemical Oxygen Demand internal control standard recovery was outside of the method acceptance limits values stablished in the Current MDLs & Acceptance Criteria (Document #13584). Hereby, the result values for the 07/18, 07/19 Effluent and Influent composite samples were flagged as non-reportable. Due to the nature of the BOD testing, the samples could not be reanalyzed after the 5-day incubation period when results become known. |
The laboratory supervisor walked through the Biochemical Oxygen Demand analytical process and positively identified the Control Standard preparation deficiency. To prevent having any internal control standard recovery outside of the method acceptance limits the SOP (1467) BOD_WW_SED_SLDS, section 14.2.12; will be revised to ensure the correct supplies are used and good quality assurance practices are followed during the Control standard dilution series preparation. Additionally, the PLWTP laboratory staff will be instructed to acknowledge the SOP 1467 new revision reflected changes. |
Violation |
U |
eSMR |
| 1145236 |
06/30/2025 |
DMON |
1. The Week One phenols analysis under EPA Method 625.1 did not meet the precision criteria for 2,4-Dimethylphenol. Precision failure was observed in all associated QC samples; therefore, in accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.8, the results for 2,4-Dimethylphenol are considered non-reportable.
2. The monthly Base Neutral analysis under EPA Method 625.1 did not meet precision criteria for Benzidine. Precision failure was due to poor recoveries in all associated QC samples; therefore, in accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.8, the results for Benzidine are considered non-reportable.
3. The monthly Base Neutral analysis under EPA Method 625.1 failed accuracy criteria for Hexachloroethane in all associated QC samples. In accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.3.2, the results for Hexachloroethane are considered non-reportable.
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1. The failure for 2,4-Dimethylphenol is attributed to potential active sites within the GCMS instrumentation, which may have contributed to low recoveries and inconsistent results. Corrective maintenance will be performed on the GCMS system to address this issue.
2. Benzidine is a known challenging compound for recovery, and recent data suggests that it has lost solubility during the concentration step, likely due to a decline in the quality of the solvent used in extraction. The laboratory plans to troubleshoot the compound's stability issues and redevelop the method accordingly.
3. The failure for Hexachloroethane is attributed to possible over-concentration during the concentration step. Laboratory staff were reminded of proper protocols related to the sample concentration process.
|
Violation |
U |
eSMR |
| 1145237 |
06/30/2025 |
DMON |
1. During 06/14/25 and 06/15/25 the PLWTPs low flow caused that the effluent autosampler malfunctioned by pulling air from the stinger; herby both composite effluent samples collections from the 06/14/25 and 06/15/25 may differ from the composite sample definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409 Part 2 Glossary of Common Terms: Daily Discharge. Consequently, the mentioned samples not necessarily reflect the plants operating hours over a 24-hour period for the following analyses: Floatable solids, Biochemical Oxygen Demand, Total Dissolved Solids, Total Suspended Solids and Total Volatile Suspended Solids. 2. The Week One phenols analysis under EPA Method 625.1 did not meet the precision criteria for 2,4-Dimethylphenol. Precision failure was observed in all associated QC samples; therefore, in accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.8, the results for 2,4-Dimethylphenol are considered non-reportable. 3. The monthly Base Neutral analysis under EPA Method 625.1 did not meet precision criteria for Benzidine. Precision failure was due to poor recoveries in all associated QC samples; therefore, in accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.8, the results for Benzidine are considered non-reportable. 4. The monthly Base Neutral analysis under EPA Method 625.1 failed accuracy criteria for Hexachloroethane in all associated QC samples. In accordance with QA criteria outlined in SOP ID 6144, Revision 11, Section 16.3.2, the results for Hexachloroethane are considered non-reportable. |
1. The PLWTPs grab sampling event historical trend for both 06/14/25 and 06/15/25 effluent samples were validated. Based on the result values for Turbidity, pH, O&G and Settleable solids no abnormalities were identified during the plants operating hours. Both the PLWTP Laboratory and WWTD OPS personnel were reminded on the importance of collecting representative samples regardless of a possible autosampler malfunction by completing the Autosampler Deficiency Report (Document ID: 23244 Revision #2), engaging the manual composite ¿ flow proportional sampling procedure by using a pre-prepared sampling package located in the plants control room (labeled bottles plus Chains of Custody) for both sources as soon as an autosampler compositing deficiency emergency is identified. 2. The failure for 2,4-Dimethylphenol is attributed to potential active sites within the GCMS instrumentation, which may have contributed to low recoveries and inconsistent results. Corrective maintenance will be performed on the GCMS system to address this issue. 3. Benzidine is a known challenging compound for recovery, and recent data suggests that it has lost solubility during the concentration step, likely due to a decline in the quality of the solvent used in extraction. The laboratory plans to troubleshoot the compound's stability issues and redevelop the method accordingly. 4. The failure for Hexachloroethane is attributed to possible over-concentration during the concentration step. Laboratory staff were reminded of proper protocols related to the sample concentration process. |
Violation |
U |
eSMR |
| 1144385 |
05/31/2025 |
DMON |
Due to a sample identification deficiency during the extraction process described in the SOP (1418) O_G_HEM Revision: 7 Section 14.4; the Oil and Grease result values for the 05/22, 05/23 Influent grab samples were flagged as non-reportable.
During the Base Neutral analysis under EPA 625.1, Diethyl phthalate was detected above the method detection limit in the method blank. Per stablished Quality Control criteria in SOP ID 6144 revision 11 section 16.4.2,3 results are non-reportable if the concentration in the blank is greater than one tenth the concentration in sample. Hence, the Diethyl phthalate obtained results for both 05/06 PLWTP¿s effluent and influent composite samples were flagged as non-reportable. |
Based on the section¿s Quality manual (document ID: 14496 Revision:11); The Alvarado Wet Chemistry laboratory (ELAP Cert. 1609) personnel received a reminder from their supervisor emphasizing on the proper quality assurance practices to successfully identify the samples during the Oil and Grease extraction process. Additionally, no other abnormalities were identified after validating the Oil and Grease historical trend for both PLWTP effluent and influent grab samples results for the month of May.
Diethyl phthalate is an incredibly prevalent material derivative from plastics; therefore, the Alvarado GC-MS laboratory group (ELAP Cert. 1609) will start researching and implementing the necessary quality assurance protocols on the Base Neutral analysis under EPA 625.1, to reduce the instances of phthalate contamination, including but not limited to source water tracking, labware cleaning procedures and personnel¿s analytical technique improvements. |
Violation |
U |
eSMR |
| 1144386 |
05/31/2025 |
DMON |
Due to a sample identification deficiency during the extraction process described in the SOP (1418) O_G_HEM Revision: 7 Section 14.4; the Oil and Grease result values for the 05/23, 05/24 Effluent grab samples were flagged as non-reportable.
During the Base Neutral analysis under EPA 625.1, Diethyl phthalate was detected above the method detection limit in the method blank. Per stablished Quality Control criteria in SOP ID 6144 revision 11 section 16.4.2,3 results are non-reportable if the concentration in the blank is greater than one tenth the concentration in sample. Hence, the Diethyl phthalate obtained results for both 05/06 PLWTP¿s effluent and influent composite samples were flagged as non-reportable. |
Based on the section¿s Quality manual (document ID: 14496 Revision:11); The Alvarado Wet Chemistry laboratory (ELAP Cert. 1609) personnel received a reminder from their supervisor emphasizing on the proper quality assurance practices to successfully identify the samples during the Oil and Grease extraction process. Additionally, no other abnormalities were identified after validating the Oil and Grease historical trend for both PLWTP effluent and influent grab samples results for the month of May.
Diethyl phthalate is an incredibly prevalent material derivative from plastics; therefore, the Alvarado GC-MS laboratory group (ELAP Cert. 1609) will start researching and implementing the necessary quality assurance protocols on the Base Neutral analysis under EPA 625.1, to reduce the instances of phthalate contamination, including but not limited to source water tracking, labware cleaning procedures and personnel¿s analytical technique improvements.
|
Violation |
U |
eSMR |
| 1143743 |
04/30/2025 |
DMON |
During 04/27/25 the turbidity grab samples for both Effluent and Influent were not processed by the PLWTP laboratory (ELAP Cert. 2474); Therefore, the PLWTP daily monitoring during the mentioned date is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409; Table E-2. Influent and Emergency Connection Monitoring and Table E-4. Effluent Monitoring.
The PLWTP monitoring for Benzidine is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409; Table E-2. Influent and Emergency Connection Monitoring and Table E-4. Effluent Monitoring. Due to the QC accuracy percent recoveries for the EPA 625.1 Base Neutral analysis for both 04/09/25 PLWTP Effluent and Influent were below the acceptance criteria stated in SOP ID 6144 revision 10 section 16.3.2, hence the results for the mentioned analyte are not reportable.
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The PLWTP laboratory (ELAP Cert. 2474) will implement workload distribution improvements and supply additional training to personnel on the NPDES permit NO. CA0107409 ¿Minimum Sampling Frequency¿ definitions through the Corrective Action request #23968 to ensure proper daily monitoring at the PLWTP. Additionally, the WWTD Operations section validated the 04/27/25 turbidity historian trend at the PLWTP effluent. The highest turbidity point value at the PLWTP effluent during 04/27/25 was 65 NTU at 09:07 am. No abnormalities were identified during the plant¿s operating hours.
The Alvarado Wastewater Chemistry Lab (ELAP Cert. 1609) will conduct a study to evaluate the benzidine stability ensuring lower detection limits during the EPA 625.1 Base Neutral analysis extraction and solvent concentration. Any procedure improvement will be reflected in the Standard Operational Procedure ID 6144; plus, training to personnel will be supplied to ensure effective NPDES permit NO. CA0107409 ¿Minimum Sampling Frequency¿ monitoring at the PLWTP.
|
Violation |
U |
eSMR |
| 1143744 |
04/30/2025 |
DMON |
During 04/27/25 the turbidity grab samples for both Effluent and Influent were not processed by the PLWTP laboratory (ELAP Cert. 2474); Therefore, the PLWTP daily monitoring during the mentioned date is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409; Table E-2. Influent and Emergency Connection Monitoring and Table E-4. Effluent Monitoring.
The PLWTP monitoring for Benzidine is not in compliance with the ¿Minimum Sampling Frequency¿ definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409; Table E-2. Influent and Emergency Connection Monitoring and Table E-4. Effluent Monitoring. Due to the QC accuracy percent recoveries for the EPA 625.1 Base Neutral analysis for both 04/09/25 PLWTP Effluent and Influent were below the acceptance criteria stated in SOP ID 6144 revision 10 section 16.3.2, hence the results for the mentioned analyte are not reportable.
|
The PLWTP laboratory (ELAP Cert. 2474) will implement workload distribution improvements and supply additional training to personnel on the NPDES permit NO. CA0107409 ¿Minimum Sampling Frequency¿ definitions through the Corrective Action request #23968 to ensure proper daily monitoring at the PLWTP. Additionally, the WWTD Operations section validated the 04/27/25 turbidity historian trend at the PLWTP effluent. The highest turbidity point value at the PLWTP effluent during 04/27/25 was 65 NTU at 09:07 am. No abnormalities were identified during the plant¿s operating hours.
The Alvarado Wastewater Chemistry Lab (ELAP Cert. 1609) will conduct a study to evaluate the benzidine stability ensuring lower detection limits during the EPA 625.1 Base Neutral analysis extraction and solvent concentration. Any procedure improvement will be reflected in the Standard Operational Procedure ID 6144; plus, training to personnel will be supplied to ensure effective NPDES permit NO. CA0107409 ¿Minimum Sampling Frequency¿ monitoring at the PLWTP.
|
Violation |
U |
eSMR |
| 1142755 |
03/31/2025 |
DMON |
Due to a power outage at the PLWTP and an autosampler sensor malfunction, the composite effluent samples from the 03/30/25 and 03/31/25 collections may have been affected. The collected sample during 03/30/25 may differ from the composite sample definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409 Part 2. ¿ Glossary of Common Terms ¿Daily Discharge¿. The 03/30/2025 effluent composite sample was obtained from a combination of at least eight sample aliquots of at least 100 mL at periodic intervals during the time frame from 12:00 am to 09:30 am; therefore, the sample not necessarily reflects the plant¿s operating hours over a 24-hour period for the following analyses: Floatable solids, BOD, TDS, TSS_VSS.
The 03/31/2025 effluent composite sample was obtained from a combination of at least eight sample aliquots of at least 100 mL at periodic intervals during the time frame from 12:00 am to 23:59 pm. Due to autosampler sensor malfunction it¿s possible that the effluent composite sample collected during 03/31/25 may differ from the ¿flow proportional¿ composite sample definition stated in the ORDER NO. R9-2017-0007; NPDES NO. CA0107409 Part 2. ¿ Glossary of Common Terms ¿Daily Discharge¿; affecting the following analyses: Floatable solids, BOD, TDS, TSS_VSS.
|
A NPDES Permit No. R9-2017-0007 ¿daily discharge¿ and ¿composite sample¿ definitions reminder was distributed among PLWTP¿s WWTD OPS and EMTS Laboratory personnel.
To ensure collecting representative samples regardless of a possible autosampler sensor malfunction and engaging the manual composite ¿ flow proportional sampling procedure as soon as an autosampler compositing deficiency emergency is identified. The PLWTP Laboratory personnel will supply the WWTD OPS team a previously prepared sampling package (labeled bottles plus Chains of Custody) for both sources to be located in the plant¿s control room.
The PLWTP laboratory personnel successfully updated the composite-flow based calculation file to be used for when an autosampler compositing deficiency emergency is identified and the WWTD OPS team are required to engage the manual composite ¿ flow proportional sampling procedure.
WWTD Operations section validated the turbidity 03/30/25 historical trend at PLWTP. The highest turbidity point at the PLWTP during 03/30/25 was 66.77 NTU at 08:00 am, which occurred during the composite sample collection mentioned time frame. No abnormalities were identified during the plant¿s operating hours.
|
Violation |
U |
eSMR |
| 1140744 |
01/17/2025 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 8 ml/L at EFF-001. |
The PLWTP laboratory personnel followed work instruction #22714 ¿Settleable Solids Analysis on PLE¿ and re-collected a second PLE grab sample which was processed in batch 25017SET24 on 1/17/2025 at 14:15. The obtained value for the mentioned PLE sample (unique id P1507237) was 0.5 mL/L which is within the effluent limitation permit criteria. Subsequent settleable solids data to batch 25017SET28 (01/17/25) was monitored to identify any possible analytical and/or systematic problem in the PLWTP. Additionally, the plant discharge tendency was evaluated through TSS, BOD, TDS, and floatable solids PLE 01/17/25 composite samples analyses. No other non-conformances and/or fluctuations were determined. |
Violation |
B |
eSMR |
| 1139565 |
12/31/2024 |
DMON |
1. Due to the matrix sample nature the percent RPD value in batch 24341BOD55 was outside the method acceptance criteria stated on SOP (1467) BOD_WW_SED_SLDS Revision 10; Section 16.1.4; For the Biochemical Oxygen Demand (BOD) analysis of Effluent samples, collected on 12/04/24 and 12/05/24. The analytical batch was deemed non-reportable. Due to the nature of BOD testing, the sample could not be reanalyzed after the 5-day incubation period when results become known. Therefore, the permit BOD frequency requirements of 1/Day were not met.
2. Base Neutral analysis under EPA 625.1 results showed %RPD outside of criteria for Hexachlorocyclopentadiene. The results for effluent, effluent duplicate where all not-detected (ND). The Internal Check 1, Matrix Spike 1 and Matrix Spike duplicate were within acceptance recovery limits. Batch met accuracy but not precision criteria therefore, per QA criteria the results in SOP ID 6144 revision 10 section 16.8 and 16.9, the results for Hexachlorocyclopentadiene are not reportable.
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1. Subsequent data to batch 24341BOD55 (12/06/24) was monitored to identify any possible analytical and/or systematic problem. No other non-conformances and/or RPD > 10% fluctuations were determined.
2. Hexachlorocyclopentadiene stability during extraction is currently being studied by the laboratory. Compound as noted in the EPA 625.1 published method is particularly sensitive to thermal, chemical, and photochemical decomposition introducing variable recoveries that are reflected by the %RPD failures. |
Violation |
U |
eSMR |
| 1139564 |
12/31/2024 |
DMON |
1. Due to the matrix sample nature the percent RPD value in batch 24341BOD55 was outside the method acceptance criteria stated on SOP (1467) BOD_WW_SED_SLDS Revision 10; Section 16.1.4; For the Biochemical Oxygen Demand (BOD) analysis of Influent samples, collected on 12/04/24 and 12/05/24. The analytical batch was deemed non-reportable. Due to the nature of BOD testing, the sample could not be reanalyzed after the 5-day incubation period when results become known. Therefore, the permit BOD frequency requirements of 1/Day were not met.
2. Base Neutral analysis under EPA 625.1 results showed %RPD outside of criteria for Hexachlorocyclopentadiene. The results for influent, influent duplicate where all not-detected (ND). The Internal Check 1, Matrix Spike 1 and Matrix Spike duplicate were within acceptance recovery limits. Batch met accuracy but not precision criteria therefore, per QA criteria the results in SOP ID 6144 revision 10 section 16.8 and 16.9, the results for Hexachlorocyclopentadiene are not reportable.
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1. Subsequent data to batch 24341BOD55 (12/06/24) was monitored to identify any possible analytical and/or systematic problem. No other non-conformances and/or RPD > 10% fluctuations were determined.
2. Hexachlorocyclopentadiene stability during extraction is currently being studied by the laboratory. Compound as noted in the EPA 625.1 published method is particularly sensitive to thermal, chemical, and photochemical decomposition introducing variable recoveries that are reflected by the %RPD failures.
|
Violation |
U |
eSMR |
| 1138564 |
11/30/2024 |
DMON |
For the Biochemical Oxygen Demand (BOD) analysis of Influent and Effluent samples, collected on 11/08/24 and 11/09/24, the Method blank value in batch 24315BOD26 was outside the method acceptance criteria stated on SOP (1467) BOD_WW_SED_SLDS Revision 10; Section 16.1. The analytical batch was deemed non-reportable. Due to the nature of BOD testing, the sample could not be reanalyzed after the 5-day incubation period when results become known.
Therefore, the permit BOD frequency requirements of 1/Day were not met. |
Subsequent data to batch 24315BOD26 (11/10/24) was monitored to identify any possible analytical system contamination. No other non-conformances and/or method blank contaminations were determined. Plus, the PLWTP laboratory staff will be reminded to engage the proper BOD labware cleaning protocols as rinsing the BOD Carboys for the dilution water to discard and/or reduce any possible contamination source. |
Violation |
U |
eSMR |
| 1138563 |
11/30/2024 |
DMON |
For the Biochemical Oxygen Demand (BOD) analysis of Influent and Effluent samples, collected on 11/08/24 and 11/09/24, the Method blank value in batch 24315BOD26 was outside the method acceptance criteria stated on SOP (1467) BOD_WW_SED_SLDS Revision 10; Section 16.1. The analytical batch was deemed non-reportable. Due to the nature of BOD testing, the sample could not be reanalyzed after the 5-day incubation period when results become known. Therefore, the permit BOD frequency requirements of 1/Day were not met. |
Subsequent data to batch 24315BOD26 (11/10/24) was monitored to identify any possible analytical system contamination. No other non-conformances and/or method blank contaminations were determined. Plus, the PLWTP laboratory staff will be reminded to engage the proper BOD labware cleaning protocols as rinsing the BOD Carboys for the dilution water to discard and/or reduce any possible contamination source. |
Violation |
U |
eSMR |
| 1138562 |
11/30/2024 |
DMON |
PLWTP experienced a power outage November 2-3, 2024 which affected effluent autosamplers. As a result of the outage, the autosamplers remained inoperable on November 3 - 4, 2024. Operations staff manually collected and composited 200 mL of both effluent and influent samples every 2 hours for 24 hours on November 3 ¿ 4, 2024; however the resulting composites were not flow proportioned as required by the permit. Analyses affected include BOD, TSS, VSS, TDS, and Floatables. |
The PLWTP power outage procedure has been modified by Operations staff to include a flow proportional manual sampling procedure and PLWTP operations staff received training November 8 ¿ 21, 2024 on this procedure. |
Violation |
U |
eSMR |
| 1138561 |
11/30/2024 |
DMON |
PLWTP experienced a power outage November 2-3, 2024 which affected the influent autosamplers. As a result of the outage, the autosamplers remained inoperable on November 3 - 4, 2024. Operations staff manually collected and composited 200 mL of both effluent and influent samples every 2 hours for 24 hours on November 3 ¿ 4, 2024; however the resulting composites were not flow proportioned as required by the permit. Analyses affected include BOD, TSS, VSS, TDS, and Floatables. |
The PLWTP power outage procedure has been modified by Operations staff to include a flow proportional manual sampling procedure and PLWTP operations staff received training November 8 ¿ 21, 2024 on this procedure. |
Violation |
U |
eSMR |
| 1135094 |
09/04/2024 |
DMON |
Organophosphorus Pesticides: PLR and PLE samples collected on 9/4/2024 were outsourced to Weck Laboratory and the analyte Parathion was analyzed using EPA method 625.1 instead of method 614 as required under 40 CFR part 136. |
Organophosphorus Pesticides: The City has identified and contracted with a new laboratory that is certified to perform EPA method 614 as required for specific organophosphorus compounds under 40 CFR part 136. Samples for the month of October have been sent to the new laboratory. |
Violation |
U |
eSMR |
| 1132922 |
08/31/2024 |
DMON |
1. Organophosphorus Pesticides: PL Influent samples collected on 8/7/2024 were outsourced and the analyte Parathion was analyzed using EPA method 625.1 instead of method 614 as required under 40 CFR part 136.
2. TCDD Equivalents: PLR collected on 8/7/24 was outsourced and analyzed for Dioxins method 1613B. The laboratory report revealed the analytical batch internal check recovery for 2,3,7,8-TCDF was non-detect and the analyte was therefore deemed non-reportable. |
1. Organophosphorus Pesticides: The City is currently searching for alternative laboratories that are certified to perform EPA method 614. One laboratory has been identified in California and staff are in the process of determining if they can meet our requirements for future analyses.
2. TCDD Equivalents: The City will work with the external laboratory in order to be notified of QC failures immediately in order to attempt to re-sample and re-analyze to fulfill the monthly requirement with acceptable QC. The 2,3,7,8-TCDF was not included in the sum for TCDD Equivalents. |
Violation |
U |
eSMR |
| 1132921 |
08/31/2024 |
DMON |
1. Organophosphorus Pesticides: PL effluent samples collected on 8/7/2024 were outsourced and the analyte Parathion was analyzed using EPA method 625.1 instead of method 614 as required under 40 CFR part 136. |
1. Organophosphorus Pesticides: The City is currently searching for alternative laboratories that are certified to perform EPA method 614. One laboratory has been identified in California and staff are in the process of determining if they can meet our requirements for future analyses. |
Violation |
U |
eSMR |
| 1134375 |
04/30/2024 |
DMON |
Parathion was not run with the appropriate method due to difficulties finding a lab certified to run the appropriate method (influent and effluent). |
|
Violation |
B |
Report |
| 1126788 |
03/15/2024 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 4 ml/L at EFF-001. |
Operations was notified and an additional grab sample was taken later and re-analyzed with the result of 0.1 mL/L. |
Violation |
U |
eSMR |
| 1124676 |
01/31/2024 |
DMON |
Pesticides listed at 40 CFR section 125.58 (P) for Demeton, Guthion, Malathion, and Parathion were not analyzed or reported for PL influent of effluent due to incorrect method of 8270 and not 625.1 listed on chain of custody for January 2024 sample. When this error was discovered, the outsourced lab was contacted and informed to update the requested analysis. The outsourced lab was experiencing personnel issues and the request for the method correction was miscommunicated, although the correct method of 625.1 was annotated on the quote for services. Frequent correspondences with the lab were not effective due to staff changes where three lab mangers cycled through. |
To avoid this reoccurrence will include a thorough review of the chain of custody will be performed by the project support group and the supervisor of the ECS pesticides group prior to sample outsourcing. Also, direct communication with outsourced lab will be documented and included as an attachment with the chain of custody. |
Violation |
U |
eSMR |
| 1123527 |
12/29/2023 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 4.25 ml/L at EFF-001. |
Laboratory staff waited an additional hour before collecting another sample to allow the system to return to normal after disruption. This sample result was 0.1 ml/L. |
Violation |
B |
eSMR |
| 1143571 |
12/13/2023 |
LREP |
The report was submitted on December 13, 2023, 12 days after the deadline of December 1, 2023. |
|
Violation |
B |
Report |
| 1134374 |
11/30/2023 |
DMON |
Method blank was contaminated for di-n-butyl phthalate (effluent and influent) and discharger wasn't able to resample within the month. |
|
Violation |
B |
Report |
| 1134373 |
09/30/2023 |
DMON |
Method was contaminated for di-n-butyl phthalate (influent and effluent) and discharger was not able to resample within the month. |
|
Violation |
B |
Report |
| 1120817 |
08/22/2023 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 3.2 ml/L at EFF-001. |
1. CAR 20035 Was initiated.
2. The QA TRAINING Review took place on 083023.
3. Master edited on 08/24/23. New update includes the comment/reminder:
"PLE > Inst. Max; Follow work instruction PL-21349-3" for whenever the PLE value is > than 3.0 mL/L.
4. A remark / flag was included both in the report and in LIMS during the report review on 08/23/23 (attached). Plus a
notification email (attached) was sent to our customer (OPS) and QADM [analyst & assigned OCA].
5. Settleable solids set up was relocated in order to provide the analyst:
5a. A bigger analytical space to be able locate the written instructions - PL-21349-3.
5b. A ergonomic environment improvement (light) to be able to make a better determination of the SS value.
|
Violation |
U |
eSMR |
| 1134372 |
07/31/2023 |
DMON |
Method blank was contaminated for di-n-butyl phthalate and discharger wasn't able to resample within the month (effluent and influent). |
|
Violation |
B |
Report |
| 1134371 |
05/31/2023 |
DMON |
Deficient monitoring for benzidine (effluent) and 1,2-diphenylhydrazine (effluent and influent). |
|
Violation |
B |
Report |
| 1119778 |
03/31/2023 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average (Mean) limit is 80 % and reported value was 79.8 % at EFF-001. |
Progress has been observed and the plant anticipates the following month¿s solids removal to be within the guidelines of the permit. |
Violation |
U |
eSMR |
| 1121327 |
12/31/2022 |
CAT1 |
BOD5 @ 20 Deg. C, Percent Removal Annual Average (Mean) limit is 58 % and reported value was 56.5 % at EFF-001. |
Normal operations resumed in June and systemwide and facility %BOD removals returned to prior levels. |
Violation |
U |
eSMR |
| 1112917 |
12/21/2022 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 5.0 ml/L at EFF-001. |
Subsequent daily analytical results for this parameter were within historically low values. Laboratory staff resampled at approximately 1250 p.m. and the reanalysis yielded sample and duplicate results of 0.6 mL/L and 0.7 mL/L (or an average of 0.65 mL/L). The settleable solids measurement is, therefore, not deemed indicative of the treatment performance of the plant, but rather is associated with a likely flow disturbance to the plant on this particular day at the time of sample collection |
Violation |
B |
eSMR |
| 1111623 |
11/30/2022 |
DMON |
Salinity is calculated by the laboratory based on the conductivity and temperature of a sample. Results for Salinity could not be calculated for the weekly effluent samples collected on 11/17/2022 and 11/21/2022 due to missing temperature values of the samples during the conductivity analysis. |
The Conductivity analytical batch 22326CON80 analyzed on 11/22/2022 with both the 11/17/22 and 11/21/22 effluent samples was reported without the sample temperature values. This was discovered to be due to the loss of connection for unknown reasons between the daily bench PC and the Winwedge software, which automatically uploads the data from the conductivity meter to the bench PC. The issue was not determined quickly enough, and the samples were already discarded, so reanalysis was not possible. Because salinity is a new monitoring parameter for the facility, the requirement was not yet fully entrenched in the lab analysts. The supervisor worked to restore the connection and reminded the analysts to make sure that temperature is recorded and/or available for every conductivity value. Further, the supervisor initiated a Corrective Action Report (CAR # 18196) to document and prevent recurrence of this event. |
Violation |
U |
eSMR |
| 1111624 |
11/30/2022 |
DMON |
There is deficient monitoring due to the unavailability of the November monthly influent and effluent radioactivity results for this month's reporting. |
The November monthly influent and effluent samples for radioactivity analysis were collected per the permit-prescribed sampling frequency and were promptly outsourced to an external laboratory; however, the external laboratory report has not been received by the City in-house laboratory to date. Per the external laboratory, results will be sent as soon as possible; unfortunately, data will not meet the reporting deadline. The monitoring result for radioactivity analysis will be reported in CIWQS as soon as the external lab report is received. The City of San Diego in-house laboratory has started to look into outsourcing permit-required radiation samples to other external laboratories. |
Violation |
U |
eSMR |
| 1110861 |
10/24/2022 |
DMON |
Ammonia was not analyzed on the weekly influent samples collected on 10/24/2022.
The laboratory updated the Point Loma sampling routine with the additional parameter requirements as soon as the permit amendment became effective on 9/25/2022. However, during this Sample Control update to include the add-on influent nutrients monitoring, the influent ammonia parameter was inadvertently changed from weekly to quarterly frequency as aligned with the other nitrogen species. |
Lab supervisors and staff have been reminded to increase communication when samples anticipated for permit monitoring analysis are missing. While lab analysts are expected to be cognizant of the frequency requirements in their assigned analysis and are consistently and promptly informed of regulatory changes, lab supervisors will also provide supplemental group training to reinforce awareness of permit requirements. An additional supervisor position has also been requested by the laboratory for increased oversight to sample control activities. |
Violation |
U |
eSMR |
| 1110863 |
10/19/2022 |
DMON |
Ammonia was not analyzed on the weekly influent samples collected on 10/19/2022. The laboratory updated the Point Loma sampling routine with the additional parameter requirements as soon as the permit amendment became effective on 9/25/2022. However, during this Sample Control update to include the add-on influent nutrients monitoring, the influent ammonia parameter was inadvertently changed from weekly to quarterly frequency as aligned with the other nitrogen species. |
Lab supervisors and staff have been reminded to increase communication when samples anticipated for permit monitoring analysis are missing. While lab analysts are expected to be cognizant of the frequency requirements in their assigned analysis and are consistently and promptly informed of regulatory changes, lab supervisors will also provide supplemental group training to reinforce awareness of permit requirements. An additional supervisor position has also been requested by the laboratory for increased oversight to sample control activities. |
Violation |
U |
eSMR |
| 1110860 |
10/10/2022 |
DMON |
Ammonia was not analyzed on the weekly influent samples collected on 10/10/2022. The laboratory updated the Point Loma sampling routine with the additional parameter requirements as soon as the permit amendment became effective on 9/25/2022. However, during this Sample Control update to include the add-on influent nutrients monitoring, the influent ammonia parameter was inadvertently changed from weekly to quarterly frequency as aligned with the other nitrogen species. |
Lab supervisors and staff have been reminded to increase communication when samples anticipated for permit monitoring analysis are missing. While lab analysts are expected to be cognizant of the frequency requirements in their assigned analysis and are consistently and promptly informed of regulatory changes, lab supervisors will also provide supplemental group training to reinforce awareness of permit requirements. An additional supervisor position has also been requested by the laboratory for increased oversight to sample control activities. |
Violation |
U |
eSMR |
| 1110859 |
10/07/2022 |
DMON |
The daily influent and effluent samples for Total Suspended Solids (TSS) analysis were collected on 10/7/2022 with other daily required parameters from the 24-hour composites to comply with the permit-prescribed sampling frequency. However, due to the inexperience of the new analyst, a ¿unique constraint error¿ was received in the Laboratory Information Management System (LIMS) database when the analyst tried to reassign TSS to the monitoring samples after inadvertently deleting this specific parameter that is initially and automatically added by the sampling routine. |
increase communication when samples anticipated for permit monitoring analysis are missing. While lab analysts are expected to be cognizant of the frequency requirements in their assigned analysis and are consistently and promptly informed of regulatory changes, lab supervisors will also provide supplemental group training to reinforce awareness of permit requirements. |
Violation |
U |
eSMR |
| 1110862 |
10/07/2022 |
DMON |
The daily influent and effluent samples for Total Suspended Solids (TSS) analysis were collected on 10/7/2022 with other daily required parameters from the 24-hour composites to comply with the permit-prescribed sampling frequency. However, due to the inexperience of the new analyst, a ¿unique constraint error¿ was received in the Laboratory Information Management System (LIMS) database when the analyst tried to reassign TSS to the monitoring samples after inadvertently deleting this specific parameter that is initially and automatically added by the sampling routine. |
increase communication when samples anticipated for permit monitoring analysis are missing. While lab analysts are expected to be cognizant of the frequency requirements in their assigned analysis and are consistently and promptly informed of regulatory changes, lab supervisors will also provide supplemental group training to reinforce awareness of permit requirements. |
Violation |
U |
eSMR |
| 1109707 |
09/30/2022 |
Deficient Reporting |
There is deficient monitoring due to the unavailability of the September monthly influent and effluent radioactivity results for this month¿s reporting. |
The September monthly influent and effluent samples for radioactivity analysis were collected per the permit-prescribed sampling frequency and were promptly outsourced to an external laboratory; however, the external laboratory report has not been received by the City in-house laboratory to date. Per the external laboratory, results will be sent as soon as possible; unfortunately, data will not meet the reporting deadline. The monitoring results for radioactivity analysis will be reported in CIWQS as soon as the external lab report is received. |
Violation |
U |
eSMR |
| 1109858 |
09/01/2022 |
SSOS |
SSO |
|
Violation |
B |
Report |
| 1110834 |
08/31/2022 |
Deficient Reporting |
Radioactivity monitoring results were not included in the August 2022 monthly self-monitoring report |
|
Violation |
B |
Report |
| 1108792 |
07/31/2022 |
Deficient Reporting |
Effluent radioactivity results were not included in the July 2022 monthly monitoring report because they were analyzed late by the City's contract lab. A revised July 2022 monthly monitoring report will be submitted by the City. |
|
Violation |
B |
Report |
| 1107679 |
07/08/2022 |
DMON |
Total Suspended Solids (TSS), Volatile Suspended Solids (VSS), and Total Dissolved Solids (TDS) were not analyzed on 7/8/2022. |
The group supervisor will reinforce awareness of permit requirements among staff and will include this important topic in the periodic and/or refresher training of the group¿s laboratory analysts. |
Violation |
U |
eSMR |
| 1107680 |
07/08/2022 |
DMON |
Total Suspended Solids (TSS), Volatile Suspended Solids (VSS), and Total Dissolved Solids (TDS) were not analyzed on 7/8/2022. |
The group supervisor will reinforce awareness of permit requirements among staff and will include this important topic in the periodic and/or refresher training of the group¿s laboratory analysts. |
Violation |
U |
eSMR |
| 1106735 |
06/30/2022 |
OEV |
Turbidity Monthly Average limit is 75 NTU and reported value was 82.1 NTU at EFF-001. |
1. Vivianite Build-Up in the Sludge Piping:
To overcome this, Operations staff are currently feeding two digesters at a time to increase pumping capacity. Plant staff have removed some build-up themselves and are in the process of getting a contract to have a vendor continue vivianite removal from the sludge piping.
2. Extra Solids Coming In:
The chemical dose at PLWTP was increased during these evolutions to improve solids settling.
|
Violation |
B |
eSMR |
| 1106736 |
06/30/2022 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60 mg/L and reported value was 79.8 mg/L at EFF-001. |
1. Vivianite Build-Up in the Sludge Piping:
To overcome this, Operations staff are currently feeding two digesters at a time to increase pumping capacity. Plant staff have removed some build-up themselves and are in the process of getting a contract to have a vendor continue vivianite removal from the sludge piping.
2. Extra Solids Coming In:
The chemical dose at PLWTP was increased during these evolutions to improve solids settling.
|
Violation |
B |
eSMR |
| 1106737 |
06/30/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 80 % and reported value was 79.1 % at EFF-001. |
1. Vivianite Build-Up in the Sludge Piping:
To overcome this, Operations staff are currently feeding two digesters at a time to increase pumping capacity. Plant staff have removed some build-up themselves and are in the process of getting a contract to have a vendor continue vivianite removal from the sludge piping.
2. Extra Solids Coming In:
The chemical dose at PLWTP was increased during these evolutions to improve solids settling. |
Violation |
B |
eSMR |
| 1105874 |
05/31/2022 |
OEV |
Turbidity Monthly Average limit is 75 NTU and reported value was 90.4 NTU at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105873 |
05/31/2022 |
CAT1 |
Oil and Grease Monthly Average limit is 25 mg/L and reported value was 30 mg/L at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105877 |
05/31/2022 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60 mg/L and reported value was 118 mg/L at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105876 |
05/31/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 75 % and reported value was 66.2 % at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105875 |
05/31/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 80 % and reported value was 66.8 % at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105879 |
05/07/2022 |
OEV |
Turbidity Weekly Average limit is 100 NTU and reported value was 107 NTU at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105871 |
05/07/2022 |
CAT1 |
Settleable Solids Weekly Average limit is 1.5 ml/L and reported value was 1.8 ml/L at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105878 |
05/04/2022 |
CAT1 |
Oil and Grease Instantaneous Maximum limit is 75 mg/L and reported value was 85.5 mg/L at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1105872 |
05/04/2022 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 7.0 ml/L at EFF-001. |
1) While Operations staff have removed some build up themselves, they await the City vendor to conduct more line cleaning. For the meantime, Operations staff resorted to a temporary solution, i.e. staff are currently feeding two digesters at a time instead of one.
2) The polymer dose was increased to improve solids settling. To increase the velocity in the tanks and flush out suspended solids through the system, eight tanks were also placed in service. It is projected that once the other facilities return to normal operations, this would help alleviate the PLWTP issue.
|
Violation |
B |
eSMR |
| 1104711 |
04/30/2022 |
OEV |
Turbidity Monthly Average limit is 75 NTU and reported value was 83.4 NTU at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1104713 |
04/30/2022 |
OEV |
Turbidity Weekly Average (Mean) limit is 100 NTU and reported value was 108 NTU at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1104709 |
04/30/2022 |
CAT1 |
Oil and Grease Monthly Average limit is 25 mg/L and reported value was 28.5 mg/L at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1104710 |
04/30/2022 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60 mg/L and reported value was 128 mg/L at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1104712 |
04/30/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 75 % and reported value was 62 % at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1104714 |
04/30/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 80 % and reported value was 62.7 % at EFF-001. |
Operations staff immediately addressed the issues by line cleaning to remove the vivianite buildup in the lines. The repair to the plant¿s dewatering line was completed on April 29, 2022. The work completion at NCWRP¿s influent pump station in May 2022 should help lower the solids. The plant superintendent spoke with the Regional Board¿s Fisayo Osidobu who confirmed that aside from continuing remedial actions, the City needs to also continue noting the problems, exceedances/violations and corrective actions being taken in the monthly regulatory self-monitoring reports. |
Violation |
B |
eSMR |
| 1103678 |
03/31/2022 |
CAT1 |
Total Suspended Solids (TSS) Monthly Average limit is 60.0 mg/L and reported value was 83.7 mg/L at E-001. |
Operations staff immediately addressed the issue by line cleaning to remove the vivianite buildup in the lines. However, parts to repair the dewatering line break have been delayed due to supply chain issues. The work completion at NCWRP's influent pump station anticipated by May 2022 should help lower the solids. |
Violation |
B |
eSMR |
| 1103679 |
03/31/2022 |
CAT1 |
Total Suspended Solids (TSS), Percent Removal Monthly Average limit is 80 % and reported value was 75.5 % at E-001. |
Operations staff immediately addressed the issue by line cleaning to remove the vivianite buildup in the lines. However, parts to repair the dewatering line break have been delayed due to supply chain issues. The work completion at NCWRP's influent pump station anticipated by May 2022 should help lower the solids. |
Violation |
U |
eSMR |
| 1100006 |
12/14/2021 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 3.5 ml/L at EFF-001. |
A repeat sample was collected at 1340 p.m. with analysis duplicate results of 0.1 mg/L. Subsequent daily analytical results for this parameter were within historically low values. |
Violation |
B |
eSMR |
| 1094764 |
08/30/2021 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 4.0 ml/L at EFF-001. |
Laboratory staff will rely on Operations staff to give them the green light on when to collect a grab sample for settleable solid testing during times when maintenance work or other non-routine events, e.g. changes in flow, among others that affect this particular test procedure, are happening at the plant. The plant superintendent resent the Operations SOP on Laboratory Communications Protocol for Sampling Events (PL-SOP-066.0) to reinforce communication between laboratory and Operations staff. The laboratory supervisor discussed with the new analyst the importance of the work instruction to determine the time that the plant returns to compliance. |
Violation |
B |
eSMR |
|
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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