Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
1147679 |
08/31/2025 |
CAT1 |
Oil and Grease Monthly Average limit is 25 mg/L and reported value was 28 mg/L at M-001C. |
To prevent recurrence of this issue, the following corrective measures have been
implemented:
; Secondary effluent composite sampler tubing was replaced and sampler inspected for any potential contamination.
; Site walk conducted to identify any potential contamination sites.
; The Chief Plant Operator and Assistant Director of Resue discussed with the contracted laboratory service provider to emphasize the importance of timely sample
processing, results, and reporting, as outlined and agreed upon in the laboratory
services agreement.
; Requested that the contracted lab provide immediate notification of any delay in
reporting analysis results. |
Violation |
U |
eSMR |
1147678 |
08/09/2025 |
DMON |
On August 4, 2025, Plant MNWD-3A (M-001C) operations staff mistakenly did not submit a secondary effluent composite sample. This was due to using the wrong bottle for sample collection. Operations staff discarded the composite sample for the day and forgot to conduct a makeup sample later in the week. This resulted in a missed monitoring event for the R9-2025-0001 permit. Operations staff collected the secondary effluent daily composite sample in the incorrect sample bottles. The contracted laboratory provides premade sample kits for each
compliance sample day. The collected sample was deemed unusable as it was put into the
incorrect bottle which contained preservative for a different analysis at another sample location; therefore, the sample was discarded because it was now contaminated. Operations staff forgot to schedule a makeup sample collection for this later in the week. |
To prevent recurrence of this issue, the following corrective measures will be implemented:
 Update the Standard Operating Procedures (SOP) for sample collection and delivery. This will be a collective effort with our Operations staff to help identify and correct any potential collection, storing, and delivery issues.
 Ensure Operations staff continue to train quarterly on laboratory procedures and
sampling protocols.
 Ensure that the contracted lab provides redundant sampling kits on site at Plant 3A. |
Violation |
U |
eSMR |
1146547 |
07/11/2025 |
UAUTHDISC |
On Friday, July 11, 2025 at approximately 9:50am, a contractor onsite at MNWD's Plant 3A (26801 Camino Capistrano, Mission Viejo CA) opened an incorrect pipe connected to a digester. Liquid from the digester flowed until the pipe was able to be re-capped around 10:30 am. Total spill volume was calculated at 18,548 gallons of liquid that left the digester. Dirt berms were used to contain flow as best as possible, but approximately 300 gallons did enter a storm drain and subsequently Oso Creek. It was calculated that 18,280 gallons were recovered. MNWD staff set up a portable dam in the Oso Creek channel downstream, equipped with a portable pump, and began pumping this flow into a nearby sewer manhole to return to a treatment plant. Staff observations did not note any downstream impacts during bypass pumping, which continued for approximately 30 hours, removing approximately 630,000 gallons of water over that time period. Surface water sampling was conducted same-day and additionally 2 days of follow up sampling. |
Opened pipe was able to be re-capped around 10:30 am. MNWD staff set up a portable dam in the Oso Creek channel downstream, equipped with a portable pump, and began pumping this flow into a nearby sewer manhole to return to a treatment plant. Surface water sampling was conducted same-day and additionally 2 days of follow up sampling. . |
Violation |
B |
eSMR |
1138553 |
11/09/2024 |
DMON |
I am writing to inform you that the 3A (M-001C) monthly samples from November 4th and November 5th are missing total suspended solids (TSS) analysis. The laboratory reports from the subcontracted lab note that:
Please note, while TSS was requested on the sample, the laboratory stated there was not enough sample volume remaining in order to perform the TSS analysis. Sierra was not made aware of this issue until December 11, 2024 which did not allow them enough time to resample.
|
Collect extra sample volume for monthly samples during the use of the subcontracted laboratory. |
Violation |
U |
eSMR |
1122939 |
11/25/2023 |
CAT1 |
Total Suspended Solids (TSS) Weekly Average limit is 45 mg/L and reported value was 48 mg/L at M-001C. |
In response to this event at 3A M-001C, staff immediately increased wasting, air, and bleach dosing to help remove excessive filaments. Additonally, polymer was added to help improve settling thereby preventing any further settling issues and/or exceedances. Going forward, staff has implemented the following action plan:
- Ensure microscopic analysis are performed frequently to identify filaments
- Add polymer ahead of time once settling issues are observed
- Adjust air and wasting appropriately should conditions not improve |
Violation |
U |
eSMR |
1127510 |
10/02/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.09 mg/L. |
|
Violation |
B |
Report |
1127465 |
10/02/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1103 mg/L. |
|
Violation |
B |
Report |
1127397 |
09/19/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127509 |
09/05/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.12 mg/L. |
|
Violation |
B |
Report |
1127464 |
09/05/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1099 mg/L. |
|
Violation |
B |
Report |
1127508 |
08/07/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.12 mg/L. |
|
Violation |
B |
Report |
1127463 |
08/07/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1115 mg/L. |
|
Violation |
B |
Report |
1128149 |
08/02/2023 |
LREP |
The June 2023 eSMRs was submitted on August 2, 2023, 1 day after the due date of August 1, 2023. |
|
Violation |
B |
Report |
1127507 |
07/20/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.09 mg/L. |
|
Violation |
B |
Report |
1127462 |
07/20/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1135 mg/L. |
|
Violation |
B |
Report |
1127506 |
06/05/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127461 |
06/05/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1140 mg/L. |
|
Violation |
B |
Report |
1127488 |
06/05/2023 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1180 mg/L. |
|
Violation |
B |
Report |
1127505 |
05/03/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.09 mg/L. |
|
Violation |
B |
Report |
1127460 |
05/03/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1138 mg/L. |
|
Violation |
B |
Report |
1127504 |
04/21/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127459 |
04/21/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1159 mg/L. |
|
Violation |
B |
Report |
1127487 |
04/21/2023 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1120 mg/L. |
|
Violation |
B |
Report |
1127503 |
01/09/2023 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127458 |
01/09/2023 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1169 mg/L. |
|
Violation |
B |
Report |
1127486 |
01/09/2023 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1230 mg/L. |
|
Violation |
B |
Report |
1127400 |
12/05/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127330 |
12/05/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1161 mg/L. |
|
Violation |
B |
Report |
1127359 |
12/05/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1170 mg/L. |
|
Violation |
B |
Report |
1127399 |
11/07/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127329 |
11/07/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1161 mg/L. |
|
Violation |
B |
Report |
1127358 |
11/07/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1180 mg/L. |
|
Violation |
B |
Report |
1128476 |
10/26/2022 |
UAUTHDISC |
Recycled water spill of 4,161,413 gallons at Laguna Niguel Regional Park |
|
Violation |
B |
Report |
1127398 |
10/04/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1127328 |
10/04/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1159 mg/L. |
|
Violation |
B |
Report |
1127357 |
10/04/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1150 mg/L. |
|
Violation |
B |
Report |
1127327 |
09/19/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1146 mg/L. |
|
Violation |
B |
Report |
1127396 |
08/15/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1127326 |
08/15/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1154 mg/L. |
|
Violation |
B |
Report |
1127356 |
08/15/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1290 mg/L. |
|
Violation |
B |
Report |
1127395 |
07/05/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1127325 |
07/05/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1141 mg/L. |
|
Violation |
B |
Report |
1127394 |
05/09/2022 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1127324 |
05/09/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1147 mg/L. |
|
Violation |
B |
Report |
1127355 |
05/09/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1190 mg/L. |
|
Violation |
B |
Report |
1104331 |
04/08/2022 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3 ml/L and reported value was 5 ml/L at M-001C. |
A microbiology of wastewater training will be provided to 3A and an additional manual on the subject is being purchased |
Violation |
U |
eSMR |
1103745 |
03/30/2022 |
CAT1 |
Settleable Solids Instantaneous Maximum limit is 3.0 ml/L and reported value was 3.6 ml/L at M-001C. |
A microbiology of wastewater training will be provided to 3A and an additional manual on the subject is being purchased. |
Violation |
U |
eSMR |
1127323 |
03/16/2022 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1136 mg/L. |
|
Violation |
B |
Report |
1127354 |
03/16/2022 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1220 mg/L. |
|
Violation |
B |
Report |
1126747 |
10/04/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126953 |
10/04/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1143 mg/L. |
|
Violation |
B |
Report |
1126746 |
09/06/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126952 |
09/06/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1160 mg/L. |
|
Violation |
B |
Report |
1126745 |
08/04/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126951 |
08/04/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1153 mg/L. |
|
Violation |
B |
Report |
1126744 |
07/06/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.08 mg/L. |
|
Violation |
B |
Report |
1126950 |
07/06/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1144 mg/L. |
|
Violation |
B |
Report |
1126965 |
07/06/2021 |
CAT1 |
Total Dissolved Solids (TDS) Daily Maximum limit is 1100.0 mg/L and reported value was 1130 mg/L. |
|
Violation |
B |
Report |
1126743 |
05/24/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126949 |
05/24/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1130 mg/L. |
|
Violation |
B |
Report |
1126742 |
04/24/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126948 |
04/24/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1260 mg/L. |
|
Violation |
B |
Report |
1126741 |
01/11/2021 |
CAT1 |
Manganese, Total 12-Month Average limit is 0.05 mg/L and reported value was 0.07 mg/L. |
|
Violation |
B |
Report |
1126947 |
01/11/2021 |
CAT1 |
Total Dissolved Solids (TDS) 12-Month Average limit is 1000.0 mg/L and reported value was 1112 mg/L. |
|
Violation |
B |
Report |
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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