Staff Report — Simi Valley City Council, December 2, 2024

CITY OF SIMI VALLEY

MEMORANDUM

December 2, 2024

TO: City Council

FROM: Department of Public Works

SUBJECT: GRANT AUTHORITY TO THE CITY MANAGER TO ACCEPT SETTLEMENT OFFER NO. R4 -2024-0176 AND AUTHORIZE A
SUPPLEMENTAL BUDGET REQUEST OF $195,000 FOR PAYMENT OF

MANDATORY MINIMUM PENALTIES FOR NATIONAL POLLUTION

DISCHARGE ELIMINATION SYSTEM PERMIT VIOLATIONS FOR THE

SIMI VALLEY WATER QUALITY CONTROL PLANT

STAFF RECOMMENDATION

It is recommended that the City Council:

1. Grant authority to City Manager, or her designee, to sign and accept the terms of Settlement Offer No. R4-2024-0176 from the Los Angeles Regional Water Quality Control Board (RWQCB); and,

2. Authorize a supplemental budget request in the amount of $19 5,000 in the Sanitation Fund (700) for payment of the mandatory minimum penalties associated with National Pollution Discharge Elimination System (N PDES) permit violations for the Simi Valley Water Quality Control Plant (WQCP).

BACKGROUND AND OVERVIEW

On May 30, 2024, the City of Simi Valley (City) received Settlement Offer No. R4-2024- 0176 from RWQCB (Attachment A, page 4) permitting the City to participate in the expedited payment program, relating to violations of the NPDES permit for the Simi Valley Water Quality Control Plant Order No. R4 -2019-0135, NPDES Permit No. CA0055221.

On June 27, 2024, the City sent a Response Letter (Attachment B, page 16), regarding Settlement Offer No. R4 -2024-0176, explaining that a Single Operational Upset (SOU) related to construction activities and malfunction of new equipment caused and contributed to the permit violations from September 12, 2022, to December 31, 2022. On November 7, 2024, the City received a response (Attachment C, page 50) from RWQCB regarding the City’s claim of SOU and the mandatory minimum penalties (MMPs) for NPDES violations. The RWQCB disagreed with the City’s claim that the permit violations between September 12, 2022 and December 31, 2022 were the direct result of an SOU and instead said that they were part of a series of failures and treatment limitations at the treatment facility that resulted in the multiple violations.

AGENDA ITEM NO.

Consent (5)

ADMIN2404.SR.MG

FINDINGS AND ALTERNATIVES

The City received a response and settlement offer with an Acceptance of Conditional Resolution and Waiver of Right to Hearing that establishes mandatory minimum penalties for the NPDES permit violations that occurred between September 12, 2022, and December 31, 2022. Should the City agree to the terms of the settlement offer, the C ity will then participate in the Expedited Payment Program by signing and returning the Acceptance of Conditional Resolution and Waiver of Right to Hearing form to the RWQCB by December 9, 2024. By signing the revised Acceptance and Waiver, the City agrees to pay the penalty of $195,000 as indicated in Settlement Offer No. R4-2024-0176.

The WQCP experienced a series of failures and treatment limitations at the f acility that resulted in turbidity and ammonia violations between September 2022 and December 2022. From September 2022 through December 2022 the C ity was in correspondence with RWQCB for NPDES permit violations related to equipment failures while under construction and other contributing factors related to weather conditions and power failures. Non-Compliance Notifications were sent to the RWQCB in September 2022, October 2022, November 2022, and December 2022, documenting the equipment failure as the ultimate root cause of the Biological Nutrient Removal (BNR) treatment upset. The critical failure and non-mixing of the BNR influent channels and the anoxic zones for over 17 hours resulted in the majority of the biomass, specifically all of the sensitive and slow- growing autotrophic bacteria that are responsible for removing ammonia and ensuring a clear (not-turbid) effluent to be killed. The delayed mitigation efforts affected the ac tive biomass in the BNR and promoted solids accumulation which could have affected the regrowth of the biomass and impacted the BNR diffusers. The prolonged lack of mixing also caused an accumulation of solids in the BNR aeration tanks that reduced the efficiency of the air diffusion and possibly damaged the air diffusers, prohibiting efficient air diffusion to support nitrification and regrowth of the biomass. Staff took immediate and timely actions and measures necessary to minimize permit violations by diverting over 28 million gallons of discharge to the lined lagoon storage and made appropriate operational adjustments to create an environment best suited for the biomass and slow- growing nitrifying bacteria to regrow.

By allowing the City Manager to execute the Settlement Offer ( Attachment C ) and authorizing a Supplemental Budget Request , the City will be relieved of any further obligation to the violations that occurred from September 12, 2022, through December 31, 2022. The settlement will also facilitate the City's compliance with the permit.

Approval of the supplemental budget request in the amount of $195,000 from the FY 2024-25 Sanitation fund will settle the mandatory minimum penalties for the NPDES permit violations for the WQCP.

The following alternatives are available to the City Council:

1. Grant authority to the City Manager, or her designee, to accept the terms of the attached settlement agreement (page 4 ) and authorize a supplemental budget request in the amount of $195,000 in the Sanitation Fund (700) for payment of the mandatory minimum penalties associated with NPDES permit violations for the WQCP;
2 ADMIN2404.SR.MG

2. Do not grant authority to the City Manager, or her designee, to accept terms of the settlement agreement and do not authorize a supplemental budget to the Sanitation Fund (700) for payment of the mandatory minimum penalties associated with NPDES permit violations for the WQCP and provide staff with other direction.

Staff recommends Alternative No. 1.

SUGGESTED CITY COUNCIL MOTION

I move to authorize the City Manager, or her designee, to accept the terms of the Settlement Offer and sign the Acceptance of Conditional Resolution and Waiver of Right to Hearing, from the Los Angeles Regional Water Quality Control Board and, authorize a supplemental budget request in the amount of $195,000 in the Sanitation Fund (700) for payment of NPDES permit violations for the Simi Valley Water Quality Control Plant (WQCP).

SUMMARY

The City has been in correspondence with RWQCB for NPDES permit violations related to equipment failures during construction activities and other contributing factors related to weather conditions and power failures. The City received a settlement offer that establishes mandatory minimum penalties for the NPDES permit violations that occurred between September 12, 2022 and December 31, 2022. The City intends to participate in the Expedited Payment Program, sign and return the Acceptance of Conditional Resolution and Waiver of Right to Hearing form by December 9, 2024, to the RWQCB.

By signing the revised Acceptance and Waiver, the City agrees to pay the penalty of $195,000 as indicated in Settlement offer No. R4-2024-0176.

_______________for___________________
Ronald K. Fuchiwaki
Public Works Director

Prepared by: Al Sexton, Acting Assistant Public Works Director (Operations)

INDEX Page

Attachment A – Settlement Offer No. R4-2024-0176 ....................... 4 Attachment B – City Response Letter - June 2024 ........................ 16 Attachment C – Response from RWQCB - November 2024 .......... 50

3 Los Angeles Regional Water Quality Control Board
May 30, 2024
Al Sexton
Deputy Public Works Director - Sanitation
City of Simi Valley
600 West Los Angeles Avenue
Simi Valley, CA 93065
Via Certified Mail
Return Receipt Requested
Claim No. 7020 2450 0001 1825 7363
SETTLEMENT OFFER NO. R4-2024-0176; OFFER TO PARTICIPATE IN THE

EXPEDITED PAYMENT PROGRAM RELATING TO VIOLATIONS OF THE NPDES

PERMIT FOR CITY OF SIMI VALLEY, SIMI VALLEY WATER QUALITY CONTROL PLANT, 600 WEST LOS ANGELES AVENUE , SIMI VALLEY, CALIFORNIA (ORDER NO. R4-2019-0135, NPDES PERMIT NO. CA0055221, CI NO. 3021) Dear Al Sexton:

This letter is to notify the City of Simi Valley (hereinafter “Permittee” or “you”) of alleged violations of the California Water Code identified in the State Water Resources Control Board’s water quality data system and to allow the Permittee to participate in the Los Angeles Regional Water Quality Control Board’s (Regional Water Board) Expedited Payment Program for Effluent and/or Reporting Violations (Expedited Payment Program) to address mandatory minimum penalties that must be assessed pursuant to California Water Code sections 13385 and 13385.1.

NOTICE OF VIOLATION:

Based on information in the California Integrated Water Quality System (CIWQS), the Regional Water Board alleges that the Permittee has violated the effluent limitations, reporting violations, or California Water Code provisions identified in the Notice of Violation (NOV) attached as Exhibit “1”. The Permittee will have the opportunity to address the alleged violations as discussed below.

STATUTORY LIABILITY:

Subdivisions (h) and (i) of California Water Code section 13385 require the assessment of a mandatory minimum penalty of three thousand dollars ($3,000) for specified serious and chronic effluent limit and reporting violations. For the purposes of subdivision (h) of section 13385, failure to file a discharge monitoring report required pursuant to sections 13383 for each complete period of 30 days following the deadline for submitting the report constitutes a serious violation. The Permittee is also subject to discretionary administrative civil liabilities of up to ten thousand dollars ($10,000) for each day in which

ATTACHMENT A
4 Al Sexton May 30, 2024
City of Simi Valley
the violation occurs, plus ten dollars ($10) for each gallon discharged but not cleaned up in excess of 1,000 gallons. These mandatory minimum penalties and discretionary administrative civil liabilities may be assessed by the Regional Water Board beginning with the date that the violations first occurred.
1 The formal enforcement action that the
Regional Water Board uses to assess such li ability is an administra tive civil liability complaint, although the Regional Water Board may instead refer such matters to the Attorney General’s Office for prosecution. If referred to the Attorney General for prosecution, the Superior Court may assess up to twenty-five thousand dollars ($25,000) per violation. In addition, the Superior Court may assess up to twenty-five dollars ($25) per gallon discharged but not cleaned up in excess of 1,000 gallons.

OFFER TO PARTICIPATE IN EXPEDITED PAYMENT PROGRAM:

The Permittee can avoid the issuance of a formal enforcement action and settle the alleged violations identified in the attached NOV by participating in the Regional Water Board’s Expedited Payment Program. Details of the proposed settlement are described below and addressed in the enclosed documents.

To promote the resolution of these violations, the Regional Water Board makes this Conditional Offer. The Permittee may accept this offer, waive the Permittee’s right to a hearing, and pay the mandatory minimum penalty of $195,000 for the violations described in the NOV. If the Permittee elects to do so, subject to the conditions below, the Regional Water Board will accept that payment in settlement of any enforcement action that would otherwise arise out of the violations identified in the NOV. Accordingly, the Regional Water Board will forego issuance of a formal administrative complaint, will not refer the violations to the Attorney General, and will waive its right to seek additional discretionary civil liabilities for the violations identified in the NOV.

The Expedited Payment Program does not address or resolve liability for any violation that is not specifically identified in the NOV regardless of the date that the violation occurred.

PERMITTEE’S OPTIONS FOR RESPONSE TO OFFER:

If you accept this offer, please complete and return the enclosed “Acceptance of Conditional Resolution and Waiver of Right to Hearing; (proposed) Order” (Acceptance and Waiver) on or before July 1, 2024.
1 Please note that there are no statutes of limitation that apply to administrative proceedings to assess mandatory minimum penalties. See City of Oakland v. Public Employees’ Retirement System, (2002) 95 Cal.App.4th 29, 48; 3 Witkin, Cal. Procedure (4th ed. 1996) Actions, §405(2), p. 510.)
5 Al Sexton May 30, 2024
City of Simi Valley
If the Permittee chooses to contest any of the violations alleged in the NOV, please identify the specific violation and the basis for the challenge (factual error, affirmative defense, etc.) on or before the due date specified above.

Responses contesting any of the violations alleged in the NOV shall be submitted as a pdf via email or CD to John Salguero, [email protected], (213) 620- 2273, and submitted by you under penalty of perjury.

The Regional Water Board staff will evaluate the contested violation and take one of two actions:
1) The Regional Water Board st aff will determine that the violation is not supported, expunge the alleged violation from the CIWQS database, take no further action against the Permittee for the alleged violation, and notify the Permittee of that determination. The Permittee will be given thirty (30) days from the date of receipt of the Regional Water Board staff determination to complete and return the Acceptance and Waiver for the remainder of the violations; or 2) The Regional Water Board staff will determine that the alleged violation is meritorious and will notify the Permittee of that determination. The Permittee will be given thirty (30) days from the date of the receipt of the Regional Water Board staff determination to complete and return the Acceptance and Waiver.

If the Permittee chooses not to make a payment in response to the Regional Water Board staff’s determination, the Permittee should expect to be contacted regarding formal enforcement action that will be initiated with regard to the contested violations. In a formal enforcement action, the liability amount sought and/or imposed may exceed the liability amount set forth in this Conditional Offer. Moreover, the cost of enforcement is a factor that can be considered in assessing the liability amount.

CONDITIONS FOR REGIONAL WATER BOARD ACCEPTANCE OF RESOLUTION:

Federal regulations require the Regional Water Board to publish and allow the public thirty (30) days to comment on any settlement of an enforcement action addressing NPDES permit violations (40 C.F.R. section 123.27(d)(2)(iii)). Upon receipt of the Permittee’s Acceptance and Waiver, the Regional Water Board staff will publish a notice of the proposed resolution of the violations.

If no comments are received within the 30-day comment period, and unless there are new material facts that become available to the Regional Water Board, the Acceptance and Waiver will be presented to the Executive Officer for consideration and adoption of a stipulated order assessing the uncontested mandatory minimum penalty amount pursuant to Water Code sections 13385 and 13385.1.

If, however, significant comments are received in opposition to the settlement, this offer may be withdrawn. In that case, the Permittee’s waiver pursuant to the Acceptance and Waiver will also be treated as withdrawn. In that case, the violations will be addressed in 6 Al Sexton May 30, 2024
City of Simi Valley
a liability assessment proceeding. At the liability assessment hearing the Permittee will be free to make arguments as to any of the alleged violations, and the Permittee’s agreement to accept this conditional offer will not in any way be binding or used as evidence against the Permittee. The Permittee will be provided with further information on the liability assessment proceeding.

In the event the Acceptance and Waiver is executed by the Regional Water Board Executive Officer, full payment of the assessed amount shall be due within thirty (30) calendar days after the date the Acceptance and Waiver is executed. In accordance with California Water Code section 13385(n)(1) and California Water Code section 13385.1(c)(1), funds collected for violations of effluent limitations and reporting requirements pursuant to sections 13385 and 13385.1 shall be deposited in the State Water Pollution Cleanup and Abatement Account. Accordingly, the $195,000 liability shall be paid by cashiers or certified check made out to the “State Water Pollution Cleanup and Abatement Account”. Failure to pay the full penalty within the required time period may subject the Permittee to further liability.

Should you have questions about this Condi tional Offer of Notice of Violation, please contact Enforcement Unit staff John Salguero at (213) 620-2273 / [email protected] or Ching Yin To at (213) 620-6373 / [email protected] regarding this matter.

Sincerely,
Russ Colby
Acting Assistant Executive Officer
Enclosures:

Exhibit “1” – Notice of Violation
Acceptance of Conditional Resolution and Waiver to Right of Hearing; (proposed) Order
Russ Colby
Digitally signed by Russ
Colby
Date: 2024.05.30
08:19:30 -07'00'
7 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 1 of 6 ends

EXHIBIT “1” – NOTICE OF VIOLATION
Effluent Limit Violations
Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
04/30/20 2nd Quarter
2020
Monthly
Average Nitrate N 9.3 9.0 mg/L 1 3% Chronic (i)1 $0
04/30/20 2nd Quarter
2020
Monthly
Average
Nitrite Plus
Nitrate 9.6 9. 0 mg/L 1 7% Chr onic (i)1 $0
02/09/21 1st Quarter
2021
Daily
Maximum
Ammonia
Nitrogen 189 172 lbs/day 1 10% Chronic (i)1 $0
09/11/22 3rd Quarter
2022 Daily Average Turbidity 2.3 2.0 NTU OEV 15% Chronic (i)1 $0 09/12/22 3rd Quarter
2022 Daily Average Turbidity 2.6 2.0 NTU OEV 30% Chronic (i)1 $0 09/14/22 3rd Quarter
2022
Time
Concentration Turbidity
> 5 NTU
f or 390
mi
ns
> 5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $0
09/16/22 3rd Quarter
2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/17/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/18/22 3rd Quarter
2022 Daily Average Turbidity 3.4 2.0 NTU OEV 70% Chronic (i)1 $3,000 09/19/22 3rd Quarter
2022 Daily Average Turbidity 3.3 2.0 NTU OEV 65% Chronic (i)1 $3,000 09/20/22 3rd Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 09/21/22 3rd Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 8 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 2 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
09/22/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/23/22 3rd Quarter
2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/26/22 3rd Quarter
2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/27/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/28/22 3rd Quarter
2022 Daily Average Turbidity 2.3 2.0 NTU OEV 15% Chronic (i)1 $3,000 09/29/22 3rd Quarter
2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/30/22 3rd Quarter
2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/01/22 4th Quarter
2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/02/22 4th Quarter
2022 Daily Average Turbidity 4.2 2.0 NTU OEV 110% Chronic (i)1 $3,000 10/03/22 4th Quarter
2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 10/04/22 4th Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 10/07/22 4th Quarter
2022
Time
Concentration Turbidity
>5 NTU
f or 120
mi
ns
>5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $3,000
10/08/22 4th Quarter
2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 9 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 3 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
10/08/22 4th Quarter
2022
Time
Concentration Turbidity
>5 NTU
f or 350
mi
ns
>5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $3,000
10/11/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 19 3. 3 mg/L 1 476% Seri ous (h)1 $3,000
10/11/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,030 157 lbs/day 1 556% Serious (h)1 $3,000
10/31/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 25 3. 3 mg/L 1 658% Seri ous (h)1 $3,000
10/31/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,376 160 lbs/day 1 760% Serious (h)1 $3,000
10/31/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 22 2. 4 mg/L 1 817% Seri ous (h)1 $3,000
11/06/22 4th Quarter
2022 Daily Average Turbidity 3.1 2 NTU OEV 55% Chronic (i)1 $3,000 11/07/22 4th Quarter
2022 Daily Average Turbidity 3.7 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter
2022 Daily Average Turbidity 3.6 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 30.6 3.3 mg/L 1 827% Serious (h)1 $3,000
11/08/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,761 167 lbs/day 1 954% Serious (h)1 $3,000
11/10/22 4th Quarter
2022
Daily
Maximum
Total
Coliform 920 240 MPN/100
mL OEV 283% Chronic (i)1 $3,000
11/11/22 4th Quarter
2022 Daily Average Turbidity 2.3 2 NTU OEV 15% Chronic (i)1 $3,000 10 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 4 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
11/16/22 4th Quarter
2022 Daily Average Turbidity 2.9 2 NTU OEV 45% Chronic (i)1 $3,000 11/17/22 4th Quarter
2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/17/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 42.6 3.3 mg/L 1 1,191% Serious (h)1 $3,000
11/17/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 2,345 160 lbs/day 1 1,366% Serious (h)1 $3,000 11/21/22 4th Quarter
2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/22/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/22/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 40.8 3.3 mg/L 1 1,136% Serious (h)1 $3,000
11/22/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 2,348 167 lbs/day 1 1,306% Serious (h)1 $3,000 11/22/22 4th Quarter
2022
30-Day
Per iod
Tot al
Coliform 130 23 M PN/100
mL OEV 465% Chronic (i)1 $3,000
11/23/22 4th Quarter
2018 Daily Average Turbidity 2.9 2 NTU OEV 368% Chronic (i)1 $3,000 11/24/22 4th Quarter
2018 Daily Average Turbidity 2.7 2 NTU OEV 131% Chronic (i)1 $3,000 11/24/22 4th Quarter
2018 30-day Period Tot al
Coliform 130 23 M PN/100
mL OEV 15,614% Chronic (i)1 $3,000
11/25/22 4th Quarter
2018 Daily Average Turbidity 2.6 2 NTU OEV 7,500% Chronic (i)1 $3,000 11/26/22 4th Quarter
2022 Daily Average Turbidity 2.5 2 NTU OEV 25% Chronic (i)1 $3,000 11 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 5 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
11/27/22 4th Quarter
2022 Daily Average Turbidity 2.2 2 NTU OEV 10% Chronic (i)1 $3,000 11/28/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/29/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 42 3.3 mg/L 1 1,173% Serious (h)1 $3,000
11/30/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,856 128 lbs/day 1 1,350% Serious (h)1 $3,000 11/30/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 39 2.4 mg/L 1 1,525% Serious (h)1 $3,000
12/6/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 23.4 3.3 mg/L 1 609% Serious (h)1 $3,000
12/6/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,366 169 lbs/day 1 708% Serious (h)1 $3,000
12/15/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 170 164 lbs/day 1 4% Chronic (i)1 $3,000
12/31/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 3.2 2.4 mg/L 1 33% Chronic (i)1 $3,000
01/30/23 1st Quarter
2023 Daily Average Turbidity 2.8 2 NTU OEV 40% Chronic (i)1 $3,000 02/01/23 1st Quarter
2023 Daily Average Turbidity 3.2 2 NTU OEV 60% Chronic (i)1 $3,000 02/02/23 1st Quarter
2023 Daily Average Turbidity 3.4 2 NTU OEV 70% Chronic (i)1 $3,000 12 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 6 of 6 ends

13 Settlement Offer No. R4-2024-0176
CI No. 3021, NPDES Permit No. CA0055221

ACCEPTANCE OF CONDITIONAL RESOLUTION
AND WAIVER OF RIGHT TO HEARING; (proposed) ORDER
City of Simi Valley
Settlement Offer No. R4-2024-0176
NPDES Permit No. CA0055221
By signing below and returning this Acceptance of Conditional Resolution and Waiver of Right to Hearing (Acceptance and Waiver) to the Los Angeles Regional Water Quality Control Board (Regional Water Board), the City of Simi Valley (Permittee) hereby accepts the “Offer to Participate in Expedited Payment Program” and waives the right to a hearing before the Regional Water Board to dispute the allegations of violations described in the Notice of Violation (NOV), which is attached hereto as Exhibit “1” and incorporated herein by reference.

The Permittee agrees that the NOV shall serve as a complaint pursuant to Article 2.5 of the California Water Code and that no separate complaint is required for the Regional Water Board to assert jurisdiction over the alleged violations through its Chief Prosecutor. The Permittee agrees to pay the penalties required by California Water Code section 13385 in the sum of $195,000 (Expedited Payment Amount) which shall be deemed payment in full of any civil liability pursuant to California Water Code sections 13385 and 13385.1 that otherwise might be assessed for the violations described in the NOV. The Permittee understands that this Acceptance and Waiver waives its right to contest the allegations in the NOV and the amount of civil liability for such violations.

The Permittee understands that this Acceptance and Waiver does not address or resolve liability for any violation that is not specifically identified in the NOV.

Upon execution by the Permittee, the completed Acceptance and Waiver shall be returned to:

John Salguero, Enforcement I Unit
Expedited Payment Program
Los Angeles Regional Water Quality Control Board
320 West 4
th Street, Suite 200
Los Angeles, CA 90013
The Permittee understands that federal regulations set forth by title 40, Code of Federal Regulations, section 123.27(d)(2)(iii) require the Regional Water Board to publish notice of and provide at least thirty (30) days for public comment on any proposed resolution of an enforcement action addressing NPDES permit violations. Accordingly, the Acceptance and Waiver, prior to execution by the Regional Water Board Executive Officer, will be published as required by law for public comment.

If no comments are received within the notice period that causes the Regional Water Board Assistant Executive Officer to question the Expedited Payment Amount, the Acceptance and Waiver will be presented to the Executive Officer for consideration and adoption of a stipulated order.
14 Settlement Offer No. R4-2024-0176
CI No. 3021, NPDES Permit No. CA0055221
The Permittee understands that if significant comments are received in opposition to the Expedited Payment Amount, the offer on behalf of the Regional Water Board to resolve the violations set forth in the NOV may be withdrawn. In that circumstance, the Permittee will be advised of the withdrawal and an administrative civil liability complaint may be issued and the matter may be set for a hearing before the Regional Water Board. For such a liability hearing, the Permittee understands that this Acceptance and Waiver executed by the Permittee will not in any way be binding or used as evidence in that hearing.

The Permittee further understands that once the Acceptance and Waiver is executed by the Regional Water Board Executive Officer, the full payment required by the deadline set forth below is a condition of this Acceptance and Waiver. In accordance with California Water Code sections 13385(n)(1) and 13385.1(c)(1), funds collected for violations of effluent limitations and reporting requirements pursuant to sections 13385 and 13385.1 shall be deposited in the State Water Pollution Cleanup and Abatement Account. Accordingly, the $195,000 liability shall be paid by a cashiers or certified check made out to the “State Water Pollution Cleanup and Abatement Account”. The payment must be submitted to the State Water Resources Control Board no later than thirty (30) calendar days after the date the Acceptance and Waiver is executed by the Regional Water Board Executive Officer.

Please mail the check to:

State Water Resources Control Board
ATTN: ACL PAYMENT
Division of Administrative Services, Accounting Branch
P.O. Box 1888
Sacramento, California 95812-1888
I hereby affirm that I am duly authorized to act on behalf of and to bind the Permittee in the making and giving of this Acceptance and Waiver.

City of Simi Valley
B y :
(Signed Name)
(Printed or Typed Name)
(Date)
(Title)
IT IS SO ORDERED PURSUANT TO CALIFORNIA WATER CODE SECTION 13323 AND GOVERNMENT CODE SECTION 11415.60
B y :

Susana Arredondo
Executive Officer
(Date)
15 CITY OF SIMI VALLEY
June 27, 2024 Home of The Ronald Reagan Presidential Library John Salguero, Enforcement I Unit
Los Angeles Regional Water Quality Control Board
320 West 4th Street, Suite 200
Los Angeles, CA 90013
SUBJECT: RESPONSE TO SETTLEMENT OFFER NO. R4-2024-0176, NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

VALLEY WATER QUALITY CONTROL PLANT REQUESTING SINGLE

OPERATIONAL UPSET JUSTIFICATION BE USED TO LIMIT LIABILITY

FOR VIOLATIONS
Dear Mr. Salguero:

The City of Simi Valley owns and operates the Simi Valley Water Quality Control Plant (Permittee) and is in receipt of the May 30, 2024 letter notifying the Permittee of alleged violations of the California Water Code identified in the State Water Resources Control Board's water quality data system. This system allows the Permittee to participate in the Los Angeles Regional Water Quality Control Board's (RWQCB) Expedited Payment Program for Effluent and/or Reporting Violations to address mandatory minimum penalties that must be assessed pursuant to California Water Code sections 13385 and 13385.1. As. discussed, the Permittee previously submitted information regarding a September 12, 2022 Single Operational Upset (SOU) incident and is requesting, per Section VII. COMPLIANCE DETERMINATION Part U. Single Operational Upset (SOU) on page 38 of the ORDER R4-2019-0135, NPDES NO. CA0055221, that this SOU be used to limit liability for the effluent violations which the Permittee submitted notice.

The multiple effluent turbidity and ammonia limit violations from September 12, 2022 through December 31, 2022 listed on attached Table 1 -Violations Subject to SOU were the direct result of the SOU that occurred after work hours on Monday, September 12, 2022 into the morning of Tuesday, September 13, 2022. A newly installed mixing system (Enviromix) failed and shut down unexpectedly without warning or alarming. The attached Non-Compliance Notifications, previously sent to the RWQCB in September 2022, October 2022, November 2022 and December 2022, document the Enviromix SOU failure as the root cause of the Biological Nutrient Removal (BNR) treatment upset. The non-operation of the BNR mixing system for over 17 hours, that did not alarm and/or call out operations staff for response to the problem, caused the BNR treatment process to completely fail, not provide treatment and caused the multiple effluent turbidity and ammonia discharge violations listed in attached Table 1 -Violations Subject to SOU. The attached SCADA screens, with descriptions, outline the beginning and duration of the SOU and that electrical power dips shutdown the Enviromix mixing systems, controls and other critical mixing and pumping systems. The critical failure and non-mixing of the BNR influent channels and the anoxic zones for 17 plus hours, resulted in the majority of the biomass, specifically all of the sensitive and slow growing autotrophic bacteria that are responsible for removing ammonia and ensuring a clear (not-turbid) effluent were killed.

The prolonged lack of mixing also caused an accumulation of solids in the BNR aeration tanks that reduced the efficiency of the air diffusion and possibly damaged the air diffusers, prohibiting efficient air diffusion to support nitrification and regrowth of the biomass.

Fred D. Thomas, Mayor Rocky Rhodes, Mayor Pro Tern Mike Judge, Council Member Dee Dee Cavanaugh, Council Member Elaine P. Litster, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805.583.6700 www.simivafley.org

ATTACHMENT B
16 RESPONSE TO SETTLEMENT OFFER NO. R4-2024-0176, NPDES NO. CA0055221, ORDER R4-2019-0135, Cl-3021

Page 2 of 2 ends

The SOU was not caused by wastewater treatment operator error and was not due to negligence. Had the biological treatment process not failed and alarmed properly, no violations would have occurred because the Permittee has the flexibility to divert discharges from 001 to lined lagoon storage for future treatment and on-call, standby personnel would have responded in 30 minutes or less to reactivate the system. Additionally, the Permittee could have immediately carried out all reasonable and immediately feasible actions to reduce noncompliance that led to multiple effluent turbidity and ammonia limit violations.

The Permittee did take immediate and timely actions on Tuesday, September 13, 2022 by diverting over 28 million gallons, approximately four plus days; from 001 discharge to lined lagoon storage, and made all appropriate operational adjustments to create the best biological conditions for the biomass and extremely slow growing nitrifying bacteria to regrow. The Permittee had bacteriological analysis performed (attached) that verified how the reestablishment of nitrification treatment was slowly progressing. The purchasing of liquid nitrifying bacteria from Envirozyme was used to seed and assisted the regrowth of nitrifying bacteria and helped speed up the recovery of the BNR treatment system to consistently meet turbidity and ammonia effluent limits.

The mandatory minimum penalties for the multiple turbidity and ammonia permit violations caused by the SOU on attached Table 1 - Violations Subject to SOU currently total $162,000. The SOU that led to the simultaneous and cumulative violations of more than one pollutant parameter on attached Table 1 -Violations Subject to SOU should be expunged or treated as a single violation to limit the liability of the settlement offer to no greater than $33,000. The Permittee has never had an SOU event that temporarily disrupted the usually above standard operation and regulatory compliant Simi Valley Water Quality Control Plant in such a way that resulted in violation of multiple pollutant parameters. Thank you for your consideration of an SOU that limits liability.

If you need any additional information, please contact me at (805) 583-6462 or [email protected].

Sincerely,
O{�
Al Sexton, Deputy Public Works Director (Sanitation Services) Attachments:

Table 1 -Violations Subject to SOU
SVWQCP Cl-3021 September 2022 Non-Compliance Notification -Turbidity SVWQCP Cl-3021 October 2022 Non-Compliance Notification -Turbidity and Ammonia SVWQCP Cl-3021 November 2022 Non-Compliance Notification - Turbidity and Ammonia SVWQCP Cl-3021 December 2022 Non-Compliance Notification -Ammonia Enviromix Failure -SCADA Screens
City of Simi Valley 102722 Mixed liquor 10-27-22
City of Simi Valley 120822 Mixed liquor 12-8-22
17 Table 1
Violations Applicable to SOU
Violation Monitoring Violation Type Parameter Reported Permit Units Pollutant % Serious/ Water Penalty Date Period Value Limit Category Exceeded Chronic Code
Section
13385
09/12/22 3rd Quarter 2022 Daily Average Turbidity 2.6 2.0 NTU OEV 30% Chronic (i)1 $0 09/14/22 3rd Quarter 2022 Time Turbidity >5NTU >5 NTU NTU OEV N/A Chronic (i)1 $0 Concentration for 390 mins for 72 mins
09/16/22 3rd Quarter 2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/17/22 3rd Quarter 2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/18/22 3rd Quarter 2022 Daily Average Turbidity 3.4 2.0 NTU OEV 70% Chronic (i)1 $3,000 09/19/22 3rd Quarter 2022 Daily Average Turbidity 3.3 2.0 NTU OEV 65% Chronic (i)1 $3,000 09/20/22 3rd Quarter 2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 09/21/22 3rd Quarter 2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 09/22/22 3rd Quarter 2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/23/22 3rd Quarter 2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/26/22 3rd Quarter 2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/27/22 3rd Quarter 2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/28/22 3rd Quarter 2022 Daily Average Turbidity 2.3 2.0 NTU OEV 15% Chronic (i)1 $3,000 09/29/22 3rd Quarter 2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/30/22 3rd Quarter 2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/01/22 4th Quarter 2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/02/22 4th Quarter 2022 Daily Average Turbidity 4.2 2.0 NTU OEV 110% Chronic (i)1 $3,000 10/03/22 4th Quarter 2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 18 10/04/22 4th Quarter 2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 10/07/22 4th Quarter 2022 Time Turbidity >5NTU >5NTU NTU OEV N/A Chronic (i)1 $3,000 Concentration for 120 mins for 72 mins
10/08/22 4th Quarter 2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 10/08/22 4th Quarter 2022 Time Turbidity >5NTU >5NTU NTU OEV N/A Chronic (i)1 $3,000 Concentration for 350 mins for 72 mins
10/11/22 4th Quarter 2022 Daily Maximum Ammonia 19 3.3 mg/L 1 476% Serious (h)1 $3,000 Nitrogen
10/11/22 4th Quarter 2022 Daily Maximum Ammonia 1,030 157 lbs/day 1 556% Serious (h)1 $3,000 Nitrogen
10/31/22 4th Quarter 2022 Daily Maximum Ammonia 25 3.3 mg/L 1 658% Serious (h)1 $3,000 Nitrogen
10/31/22 4th Quarter 2022 Daily Maximum Ammonia 1,376 160 lbs/day 1 760% Serious (h)1 $3,000 Nitrogen
10/31/22 4th Quarter 2022 Monthly Average Ammonia 22 2.4 mg/L 1 817% Serious (h)1 $3,000 Nitrogen
11/06/22 4th Quarter 2022 Daily Average Turbidity 3.1 2 NTU OEV 55% Chronic (i)1 $3,000 11/07/22 4th Quarter 2022 Daily Average Turbidity 3.7 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter 2022 Daily Average Turbidity 3.6 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter 2022 Daily Maximum Ammonia 30.6 3.3 mg/L 1 827% Serious (h)1 $3,000 Nitrogen
11/08/22 4th Quarter 2022 Daily Maximum Ammonia 1,761 167 lbs/day 1 954% Serious (h)1 $3,000 Nitrogen
11/11/22 4th Quarter 2022 Daily Average Turbidity 2.3 2 NTU OEV 15% Chronic (i)1 $3,000 11/16/22 4th Quarter 2022 Daily Average Turbidity 2.9 2 NTU OEV 45% Chronic (i)1 $3,000 11/17/22 4th Quarter 2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/17/22 4th Quarter 2022 Daily Maximum Ammonia 42.6 3.3 mg/L 1 1,191% Serious (h)1 $3,000 Nitrogen
11/17/22 4th Quarter 2022 Daily Maximum Ammonia 2,345 160 lbs/day 1 1,366% Serious (h)1 $3,000 Nitrogen
11/21/22 4th Quarter 2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/22/22 4th Quarter 2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 19 11/22/22 4th Quarter 2022 Daily Maximum Ammonia 40.8 3.3 mg/L 1 1,136% Serious (h)1 $3,000 Nitrogen
11/22/22 4th Quarter 2022 Daily Maximum Ammonia 2,348 167 lbs/day 1 1,306% Serious (h)1 $3,000 Nitrogen
11/23/22 4th Quarter 2018 Daily Average Turbidity 2.9 2 NTU OEV 368% Chronic (i)1 $3,000 11/24/22 4th Quarter 2018 Daily Average Turbidity 2.7 2 NTU OEV 131% Chronic (i)1 $3,000 11/25/22 4th Quarter 2018 Daily Average Turbidity 2.6 2 NTU OEV 7,500% Chronic (i)1 $3,000 11/26/22 4th Quarter 2022 Daily Average Turbidity 2.5 2 NTU OEV 25% Chronic (i)1 $3,000 11/27/22 4th Quarter 2022 Daily Average Turbidity 2.2 2 NTU OEV 10% Chronic (i)1 $3,000 11/28/22 4th Quarter 2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/29/22 4th Quarter 2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter 2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter 2022 Daily Maximum Ammonia 42 3.3 mg/L 1 1,173% Serious (h)1 $3,000 Nitrogen
11/30/22 4th Quarter 2022 Daily Maximum Ammonia 1,856 128 lbs/day 1 1,350% Serious (h)1 $3,000 Nitrogen
11/30/22 4th Quarter 2022 Monthly Average Ammonia 39 2.4 mg/L 1 1,525% Serious (h)1 $3,000 Nitrogen
12/6/22 4th Quarter 2022 Daily Maximum Ammonia 23.4 3.3 mg/L 1 609% Serious (h)1 $3,000 Nitrogen
12/6/22 4th Quarter 2022 Daily Maximum Ammonia 1,366 169 lbs/day 1 708% Serious (h)1 $3,000 Nitrogen
12/15/22 4th Quarter 2022 Daily Maximum Ammonia 170 164 lbs/day 1 4% Chronic (i)1 $3,000
Nitrogen
12/31/22 4th Quarter 2022 Monthly Average Ammonia 3.2 2.4 mg/L 1 33% Chronic (i)1 $3,000 Nitrogen
Total: $162,000
20 CITY OF SIMI VALLEY
September 15, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFIC ATION OF NON-COMPLIANCE UNDER NPOES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

The SVWQCP Effluent Daily Average for Turbidity equaled 2.3 NTU on September 11, 2022. The SVWQCP Effluent Daily Average for Turbidity equaled 2.6 NTU on September 12, 2022. The Effluent Daily Average Limit for Turbidity is 2 NTU. The SVWQCP was> 5 NTU for 390 minutes on September 14, 2022. The limit is> 5 NTU no more than 5 percent of the time (72 minutes).

The suspected causes of the exceedances are;
• The record breaking heat wave.JN�jq�, .��sed the plant to go through multiple power transfers from Edison to generator. 1,
• A malfunction on RAS pum'@.#3 on Se
1 ptember 10, 2022.
• Plant construction which leaves us with only two secondary clarifiers and two RAS pumps available for treatment.
• The Enviromix system failed on September 12, 2022 due to a power surge.

SCADA system did not alarm and notify plant personnel.

On September 13, 2022 at approximately 7:00 am plant personnel discovered the Enviromix failure and began diverting flow to the lagoon and halted flow into the Arroyo Simi. Turbidity began to improve on September 14, 2022 and at approximately 9:00 am plant personnel resumed effluent flow into the Arroyo Simi. The turbidity coming out of the tertiary filters was< 2 NTU, yet the water remaining in the chlorine contact chambers during the diversion was > 5 NTU, which cause the plant to exceed > 5 NTU for more than 72 minutes. Keith L. Mashourn, Mayor Dee Dee Cavanaugh, Mayor Pro Tern Mike Judge, Council Member Ruth Luevanos, Council Member Elaine P. Litster, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2 7 99 805.583.6700 www.simivalley.org 21 Plant personnel have begun to remedy the �ituation by adjusting process controls such as RASNVAS rates, replacing RAS pump #3, programming alarms to functioning properly, and remain on mechanical mixing until the Enviromix system can be proven to be reliable.

If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sexton, Deputy Public Works Director - Sanitation at (805) 583-6462 or [email protected].
sr1e�y, �,, �
A�rr��Manager
_;1 I
22 CITY OF SIMI VALLEY
October 6, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

VALLEY WATER QUALITY CONTROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221, ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedances of the Effluent Daily Average Limitation for Turbidity September 29th Through October 4th, 2022. Initial notification calls were made to Jeong-Hee Lim on October 4th & 6th, 2022.

The SVWQCP Effluent Daily Average for Turbidity equaled 2.7 NTU on September 29, 2022, 2.8 NTU on September 30, 2022, 2.8 NTU on October 1, 2022, 4.2 NTU on October 2, 2022, 3.5 NTU on October 3, 2022 and 3.2 NTU on October 4, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU.

The suspected causes of the exceedances are;
• The SVWQCP is still recovering from the Enviromix system failure on September 12, 2022 due to a power surge.
• The SVWQCP is still going through construction and treatment is available at limited capacity with only two secondary clarifiers.

Plant personnel are continuing to remedy the situation by adjusting process controls such as WAS/RAS rates, DO set points, and remain on mechanical mixing. Plant personnel is also continuing to perform maintenance on the BNR diffusers. The SVWQCP has also hired a consultant (Bioalchemy) to help improve treatment by adding more nitrifying bacteria.

Sincerely,<?' J�
,:;,... �
c:-
'
Arthur Fishel, Plant Ooerations Manaaer ..

Keith L. Mashburn, Mayor Dee Dee Cavanaugn, Mayor Pro Tern Mike Judge, Council Member Ruth Luevanos, Council Member Elaine P. Litster, Council Member 2929 Tapo Canyon Road, Si�iVal/ey, CA 93063-2199 805.583.6700 www.simivalley.org 23 CITY OF SIMI VALLEY
October 13, 2022 Home of The Ronald ReQgan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

VALLEY WATER QUALITY CONTROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221 1 ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedances ofthe Efffuent Daily Average Limitation for Turbidity October 8, 2022 and > 5 NTU more than 5 percent of the time on October 7th & 8th, 2022. Initial notification call was made to Jeong-Hee Lim on October 9, 2022.

The SVWQCP Effluent Daily Average for Turbidity equaled 3.5 NTU on October 8, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU. The SVWQCP was> 5 NTU for 120 minutes on October 7, 2022 and > 5 NTU for 350 minutes on October 8, 2022.

The limit is > 5 NTU no more than 5 percent of the time (72 minutes).

The suspected cause of the exceedances are;
• The SVWQCP had a water leak inside the MCC building which caused the power to be shut down at the West BNR from 7am to 2pm on October 7, 2022.

Plant personnel was able to repair the leak in the water line and are continuing to remedy the situation by adjusting process controls such as WAS/RAS rates, DO set points, and remain on mechanical mixing. As of October 9, 2022, the SVWQCP is back in compliance with Effluent Turbidity limits.

If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sexton, D,eputy Public Works Director - Sanitation at (805) 583-6462 or [email protected] .. · '' ' .. , I • • ,
Keith L. Mashburn, Mayor Dee Dee Cavanaugh, Mayor Pro Tern Mike Judge, Council Member Ruth Luevanos, Council Member Elaine P. Litster, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 B05.SB3.6700 www.simivalley.org 24 CITY OF SIMI VALLEY
November 1, 2022
Home of The Ronald Reagan Presidential Library
Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

The SVWQCP Effluent Monthly Average for Ammonia equaled 22 mg/L for October 2022.

The Effluent Maximum Daily for Ammonia equaled 19 mg/L and 1030 lbs/day on October 11, 2022 and equaled 25 mg/L and 1376 lbs/day on October 31, 2022. The Effluent Monthly Average Limit for Ammonia is 2.4 mg/L. The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, 172 lbs/day (10/11/22), and 160 lbs/day (10/31/22).

The suspected causes of the exceedances are due a plant upset caused by; • The record breaking heat wave which caused the plant to go through multiple power transfers from Edison to generator during September 2022. • The Enviromix system failure on September 12, 2022 due to a power surge. • The water leak outside the west blower building that infiltrated electrical vaults which caused the power to be shut down at the West BNR October 7, 2022.

The compounded system power failures likely killed off most of our nitrifying bacteria.

The SVWQCP has hired consultants in bio-augmentation for microscopic analysis of the plant's mixed liquor, and we are in the process of purchasing nitrifying bacteria to seed the BNR system.

Sincerely, /J1,1 f/.1 � r , /1
Keith L. Mashburn, Mayor Dee 6!��%�e Judge, Council Member Ruth Luevanos, Council Member Elaine P. Litster, Council Member Arthur Fishel, Plsnf O]Seffl'ffi:Mf·�Vf�s1-93o63-2199 805.583.6100 www.simivat1ey.o,9 25 CITY OF SIMI VALLEY
November 10, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board, ,t,. ·,,
Los Angeles Region 1 ,;-- : ·y�p:9 . i1.i �
320 West Fourth Street, Suite 200r c- ·
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

VALLEY WATER QUALITY CONTROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221, ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedances of the Effluent Daily Average Limitation for Turbidity on November 6th, 7th, & 8th, 2022 and Maximum Daily Limit for Ammonia on November 8, 2022. Initial notification call was made to Jeong-Hee Lim on November 8th & 10th, 2022.
' : '\�. I I
The SVWQCP Effluent Daily Average, for,.Turbl�ity equaled 3.1 NTU on November 6, 2022, 3.7 NTU on November 7, Z022, anci�L6 NTU on November 8, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU. The Effluent Maximum Daily for Ammonia equaled 30.6 mg/L and 1,761 lbs/day on November 8, 2022.The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, 167 lbs/day.

Plant personnel are continuing to remedy the situation by adjusting process controls such as WAS/RAS rates and DO set points. The SVWQCP also started adding supplemental nitrifying bacteria to the BNR system on November 3, 2022. On November 9, 2022 flow was diverted.

Sincerely, /
j l / (/_ N�-
Keith L. Mashburn, Mayor Elaine P. Litst�/Uktrem Mike Judge, Co1.1ncll Member Dee Dee Cavanaugh, Council Member Ruth Luevanos, Council Member Arthur Fishel, PlaAftl�&tmIB'��aMw,i�� 93063-2199 805.583.6700 www.simlvalley.org 26 CITY OF SIMI VALLEY
November 18, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

Initial notification calls were made to Jeong-Hee Lim on November 14th & 17th, 2022.

The SVWQCP Effluent Daily Average for TurbidiW equaled 2.3 NTU on November 11, 2022 and 2.9 NTU on November 16, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU. The Effluent Ammonia equaled·40:2 mg/L and 2145 lbs/day on November 17, 2022.The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, and 160 lbs/day. The Effluent Total Coliform equaled 920 MPN on November 10, 2022. The Effluent Maximum Daily Limit for Total Coliform is 240 MPN.

The suspected causes of the exceedances are;
• There is the ongoing problem with growing our nitrifying bacteria up to an acceptable range which we are trying to expedite by the continual addition of supplements. We are also continuing to troubleshooting our oxygen transfer uptake which could be a possible issue.
• After diverting flow to the lagoon on November 9, 2022, the SVWQCP began to discharge back into the Arroyo Simi on November 10-, 2022 at approximately 12:00 pm, staff sampled for coliform testing shortly after at 1 :50 pm.

Plant personnel are attempting to remedy the situation by adjusting process controls such as WAS/RAS rates, and DO set points. The SVWQCP are also continuing to add supplemental nitrifying bacteria to the BNR system.

Keith L. Mashburn, Mayor Elaine P. Litster, Mayor Pro Tern Mike Judge, Council Member Dee Dee Cavanaugh, Council Member Ruth Luevanos, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805.583.6700 www.simivalley.org 27 If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sexton, Deputy Public Works Director - Sanitation at (805) 583-6462 or [email protected].
28 CITY OF SIMI VALLEY
November 23, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO. CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI VALLEY WATER

QUALITY CONTROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221, ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedances of the Effluent Da.lly Average Limitation for Turbidity on November 17th, 2Pt, & 22rid, 2022 and MaximLim Daily Limit for Ammonia on November 22, 2022. Initial notification call was made to Jeong-Hee Lim on November 22nd & 23rd, 2022.

The SVWQCP Effluent Daily Average for Turbidity equaled 2.1 NTU on November 17, 2022, 2.1 NTU on November 21, 2022, and 2.4 NTU on November 22, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU. The Effluent Maximum Daily for Ammonia equaled 40.8 mg/L and 2,348 lbs/day on November 22, 2022.The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, 167 lbs/day.

The suspected causes of the exceedances are;
• There is the ongoing problem with growing our nitrifying bacteria up to an acceptable range which we are trying to expedite by the continual addition of supplements. We are also troubleshooting our oxygen transfer uptake which could be a possible issue. • Lowered the Mixed Liquor Return Rates:and HAS rate on 11/22/22. • Lowering the WAS by 10% 11/23/22 .. ·: 'i i ,_ \,:

Arthur Fishel, Plant Operations Manager
Keith L. Mashburn, Mayor Elaine P. Litster, Mayor Pro Tern Mike Judge, Council Member Dee Dee Cavanaugh, Council Member Ruth Luevanos, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805.583.6700 www.simivalley.org 29 CITY OF SIMI VALLEY
December 1, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI VALLEY WATER QUALITY CQNJ"ROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221, ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedances of the Effluent Daily Average Limit for Turbidity on November 23rd through 30th, 2022, November Monthly Average Limit for Ammonia, Maximum Daily Limit for Ammonia on November 3'�, 2022, > 23 MPN Limit for Total Coliform on November 22nd and 24th, 2022, and Median Monthly for Chronic Toxicity in October 2022. Initial notification calls were made to Jeong-Hee Lim on November 28th & 30th and December 1st 2022.

I
The SVWQCP Effluent Daily Average1or Turbidity equaled 2.9 NTU on November 23, 2022, 2.7 NTU on November 24, 202 , 2.6 NTU on November 25, 2022, 2.5 NTU on November 26, 2022, 2.2 NTU on November 27, 2022, 2.4 NTU on November 28, 2022,

2.4 NTU on November 29, 2022, and 2.4 NTU on November 30, 2022.The Effluent Daily Average Limit for Turbidity is 2 NTU. The Effluent November Monthly Average equaled 39 mg/L. The Effluent Monthly Average Limit is 2.4 mg/L. The Effluent Ammonia equaled 42 mg/L and 1856 lbs/day on November 30, 2022.The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, and 128 lbs/day. The Effluent Total Coliform equaled 130 MPN on November 22, 2022, and 130 MPN on, November 24, 2022. The Effluent Limit for Total Coliform is 23 MPN in more than one sample within any 30-day period. The October Effluent Monthly Median Chronic Toxicity yielded a "Fail" result.

The suspected causes of the exceedances are;
• There is the ongoing problem with growing our nitrifying bacteria up to an acceptable range which we are trying to expedite by the continual addition of supplements. We are also continuing to troubleshooting our oxygen transfer uptake and mixing system which could be possible issues. • Plant personnel also began cleaning the chlorine contact chambers on November 21, 2022, which is the likely cause of the Total Coliform exceedances. • The high ammonia in the effluent is the likely cause of the Chronic Toxicity failure.

Accelerated monitoring will begin December 5 2022.Keith L. Mashburn, Mayor Elaine P. Litster, Mayor Pro Tern Mike Judge, Council Member Dee bee Cavanaugh, Council Member Ruth Luevanos, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805.583.6700 www.slmivalley.org 30 CITY·OF SIMI VALLEY
December 8, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Bqard,
Los Angeles Region · ·
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

The SVWQCP Effluent Ammonia equaled 23.4 mg/L and 1366 lbs/day on December 6, 2022.The Effluent Maximum Daily Limits for Ammonia are 3.3 mg/L, and 169 lbs/day.

Plant personnel have turned off the Enviromix system and switched back to the old mechanical mixing system, which is having a positive effect on treatment. The SVWQCP is also continuing to add supplemental nitrifying bacteria to the BNR system.

If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sexton, Deputy Public Works Director - Sanitation at (805) 583-6462 or [email protected].
·oArthur Ishel, Plant Op rations Manager
Keith L. Mashburn, Mayor Elaine P. Litster, Mayor Pro Tern Mike Judge, Council Member Dee Dee Cavanaugh, Council Member Ruth Luevanos, Council Member 2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805,583.6700 www.simival/ey,org 31 CITY OF SIMI VALLEY
December 19, 2022 Home of The Ronald Reagan Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

VALLEY WATER QUALITY CONTROL PLANT (SVWQCP)
Dear Ms. Purdy,
As required under NPDES No. CA0055221, ORDER R4-2019-0135 and Cl-3021, this is written notification on the exceedance of the Maximum Daily lbs/day Limit for Ammonia on December 15th, 2022. Initial notification call was made to Jeong-Hee Lim on December 15th 2022.

The SVWQ,CP .Effluent Ammonia equaled 170 lbs/day on December 15, 2022.The Effluent Maximum Daily Limit for Ammonia is 164 lbs/day.

The suspected cause of the exceedance is;
• There is the ongoing problem with growing our nitrifying bacteria up to an acceptable range which we are trying to expedite by the continual addition of supplements. We are also continuing to troubleshooting our oxygen transfer uptake and mixing system which could be possible issues.

Plant personnel have turned off the Enviromix ./system and switched back to the old mechanical mixing system, which is having a positive effect on treatment. The SVWQCP is also continuing to add supplemental nitrifying bacteria to the BNR system.

If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sexton, Deputy Public Works Director - Sanitation at (805) 583-6462 or [email protected].
2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805 583 6700 www.simivalley,o1g 32 CITY OF SIMI VALLEY
December 29, 2022 Home of The Ronald Reagan'Presidential Library Renee Purdy, Executive Officer
Regional Water Quality Control Board,
Los Angeles Region
320 West Fourth Street, Suite 200
Los Angeles, CA 90013
Attention: Xiaofei Cui,
Water Resources Control Engineer
SUBJECT: NOTIFICATION OF NON-COMPLIANCE UNDER NPDES NO.

CA0055221, ORDER R4-2019-0135, Cl-3021 FOR THE CITY OF SIMI

The SVWQCP December Effluent Monthly Average Ammonia equaled 3.2 mg/L. The Effluent MonthlyAverage Limit is 2.4 mg/L.

Plant personnel have turned off the Enviromix ·�ystem and switched back to the old mechanical mixing system, which is having a positive effect on treatment. The SVWQCP is also continuing to add supplemental nitrifying bacteria to the BNR system.

If you need any additional information, please contact myself at (805) 583-6443 or by email at [email protected] or Al Sex�q,:i,.-Deputy Public Works Director - Sanitation at (805) 583-6462 or [email protected];
1 :.::··;· ·
o '• I '-' �
2929 Tapo Canyon Road, Simi Valley, CA 93063-2199 805.583.6700 www.simivalley.org 33 At 4:23pm on 9/12/22 the Plant began to experience power fluctuations. The Historian sample rate is once per second and was able to catch three instances when the voltage was low during the event. (Low voltage drives motor current high.) 9/12/2022 4:22:59 PM v .;i, 9/12/2022 4:24:59 PM v 0 days and 00:02:00 a. a.
�

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9/12/2022
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----------- -------�-------
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Value: 212.50 amps
Time: 9/12/2022 4:23:42.000 PM
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9/12/2022
Most Blowers and pumps rode through the power fluctuations. Several PLCs did not. - .
n
n
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:24:59 4 p M
9/12/2022
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The Enviromix failure event happened at 4:23 PM on the 12th. The sludge transfer pump discharge pressure alarm came in at 4:24 pm. Belt Presses 1 and 2 were probably in a washdown and the power glitch dropped out the E-Stop relays and shut them down. We didn't get any alarms but this is when the major fault shut down the Enviromix system. The filter turbidity alarms started to come in at 8:44 PM but did not callout. 35 T.s:_1i@b'
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9;1)'2022 7 37 32. AM
Finer J Section 8 Effluen1 VJlve Fail To Pos1t1on 9n3/2022 7 35 2� AM Tuesday S,
The Plant overview screen does not convey the large number of active alarms within the Plant. The diversion structure is the only place that displays the Alarm Shield. 36 --- ... ...._, � --- �..... --- ,..-
9/11/2022 7:43:36 AM v � ,..9_/_13_/"JJJ_22_7_:◄-3-:36-AM-- v� � 6.00
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9/12/2022
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llaR: 9/12/'21l22 5:54:1D3n PM
Quality: Good: lnll!llJOlattd
7:13:36 11M
9/13/2022
The graph above shows two spikes when the primary and redundant meters were cleaned. The graph shows the final effluent turbidity, red dashed line, and the Filter Effluent turbidities.
37 While I was working on the issues at dewatering I was called at 8:17 AM and operations could not get the Enviromix Master Control Panel to reset. l&E staff went to the West Blower building and I instructed him to cycle power on the panel. This did not resolve the issue. I went to the l&E office and used the l&E Plant Laptop to connect to the Enviromix PLC. I discovered it had a Major Fault and was stuck in the program mode instead of the run mode. The fault description said it couldn't communicate with some piece of equipment, it didn't specify which one. I reset the fault and placed the device in run mode. It was 8:48 AM. 9/12/2022 3:00:00 PM v 9,1!)12022 10:00:00 AM v a days and 19:oo:oo Custom [Sample and Ho
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38 ENVIR ,.,,,.._,ZYME�

MICROSCOPIC EXAMINATION RESULTS
Company: I City of Simi Valley
Contact Person: I Art Fishel
City State: I Simi Valley, CA
Sample Date:

Sample Description:

Morphology of Floe*:
[gl Dense
D Weak
Floe Size (µm):
(% in range)
I 10/26/22
I Mixed liquor
< 150
I 20% I
Overall Filament Abundance*
□ □ □
I Date: I 10/27/22
I Rec'd: 10/27/22
[gl Round, Compact
D Irregular, Diffuse
150- 500
I 70% I
□ □
> 500
�
□
0 None
1 Few
2 Some
3 4 5 6
Common Very Abundant Excessive
Common
Filament Effect on Floe Structure*:
[gl Little or None D Bridging
Filamentous Organism Identification*:

Major Organism(s): S. natans (3 abundance)
Type 1701(3 abundance)
Minor Organism(s): Thiothrix sp. (2 abundance)
D Open Floe Structure
Type 0675, Type 0041 (1 abundance)
Bulk Water Clean � Turbid 0
Group ✓ Comments
,.

Amoeba I .• �, rfil. X Present and active
Flagellates f�_,.,,_ X Present and active
ns Free-Swimming Ciliates , X Present and active
0 X .9 Crawling Ciliates !,(�Ii Present and active
0 �a.. Carnivore Ciliates '
Stalked Ciliates _,JI> X Present and active
Suctoria
·�
39 Rotifers � _,••IT..:Ji:' � X Present and active
ro Tardigrades v�
0 � ,:

N
Nematodes ro
� Aeleosoma Worm �¼��-,.!��"J
Other
Features*
India Ink Test <10% encapsulated Spirochaetes None _..;...._ ____ _ Zoogloeal Matter .....;...;.N..;;...on'-'-e ______ _ Free cells in suspension Some present Particulate Matter Present ---------- Loosely Bound EPS _N--'-on_e ____ _ Sulfur Granules Present in Thiothrix sp Other -------
* All characterizations are based upon guidelines set forth in Manual on the Causes and Control of Activated Sludge Bulking and Foaming and Other Solids Separatrons Problems (3rd Edition) by D. Jenkins, M. G. Richard and G. T. Daigger. Lewis Publishers. 2003.

Discussion points:
-The sample contains primarily medium size floe. (150-<500 microns) The shape is mostly round. Every floe had very good density. This is ideal floe and will settle well and dewater. -The overall filament abundance rating is a "3". This is based on a scale of "0" to "6" with a "6" being the worst possible condition. There were a few that showed signs of damage or stress. This rating includes both viable and non-viable.
- The filaments present are all found extending from the floe and not negatively impacting floe formation.
- The dominant filaments are S. natans, Type 1701 (both associated with Low D.O.), Type 1851 and Thiothrix sp.
- Type 0675, Type 1851, Type 0581, and Type 0041 are present in a lower amount and generally associated with a Low F /M.
- Thiothrix sp have been found in a number of environments including the presence of organic acids, sulfides, and/or nutrient deficiency.
- Higher life forms are both diverse and abundant indicating a stable biomass. -The bulk water is very clean and only has a small amount of free bacteria. - Overall the biomass looks very good. The floe size and density are ideal and even though there are plenty of filaments they are only found extending from the floe.

Pictures below
40 Fig. 1 100 X Darkfield Fig. 2 1 00X Phase
Primarily medium size floe and filaments extending
Fig. 3 1 00X Phase Fig. 4 1 00X Phase
Medium sized floe (150-<500 microns)
Fig. 5 400X Phase
Dense floe
Fig. 6 400X Phase
Tight floe transition to bulk water
-\00 V,111 C=rrrrp l�0<1CI I Dol'llrr1CJ Crc,:·11, 01110 4]·lCQ I 800-232-28•171,:·11v1101y111,� co111 41 •
Fig. 7 1 000X Phase
Planktonic bacteria (Rods and cocci)
Fig. 9 1 000X Phase
Type 1701 filament
Fig. 11 100X Phase
India ink stain
Ink is penetrating floe indicating
very low EPS presence
Fig. 8 1 000X Phase
S. natans filament
Fig. 1 0 1 000X Phase
Thiothrix sp. filament
Fig. 12 1 000X Phase
Type 1851 bundling
400 V,rn Cc1mp Roc1cl I Bowl1mJ Groen, 01110 43402 I 800-232-2847 I P11v1rozyme com 42 Fig. 13 1000X Brightfield Fig. 14 1000X Brightfield
Gram-stained slide
Type 0041 (G+) Streptococcus (G+)
Fig. 15 1000X Brightfield Fig. 16 1000X Brightfield
Neisser-stained slide
Fig. 17 400X Phase
Active colonial stalk ciliates
(N-) filaments
Fig. 18 400X Phase
Active crawler ciliate
400 V,111 Ci1111p l�o,HI I Bmvl111�J c;,l't :11 01110 4:!402 I 800-2 32-2847 I e11v11ozyrllt' com 43 ENVIR ZYME ®

MICROSCOPIC EXAMINATION RESULTS
Company: I City of Simi Valley
Contact Person: I Art Fishel
Citv, State: I Simi Vallev, CA
Sample Date:

Sample Description:

Morphology of Floe*:
� Dense
0 Weak
I 12101122
I MLSS
< 150
I Date: I 12/08/22
I Rec'd: 12/08/22
� Round, Compact
0 Irregular, Diffuse
150 - 500 > 500Floe Size (µm):
(% in range) � � 1 20% I
Overall Filament Abundance*
□ □ □
0 None
1 Few
2 Some
□ □ □
3 4 5 6
Common Very Abundant Excessive
Common
Filament Effect on Floe Structure*:
� Little or None D Bridging D Open Floe Structure
Filamentous Organism Identification*:

Major Organism(s): Thiothrix sp (3 abundance) Some wl sulfur granules Type 1701, S. natans (3 abundance)
Minor Organism(s): Type 0675, Type 0041 (1 abundance)
Bulk Water Clean � Turbid □
Group
Amoeba
Flagellates
cu Free-Swimming Ciliates
Crawling Ciliates
0 .... a.. Predatory Ciliates
Stalked Ciliates
Suctoria
f'.j . I l��-�•111:.
•: ..... �- ----··
,
� ..
�
�
�
�
✓ Comments
X Present and both active and inactive
X Few present and active
X Few present and active
X Present and active (Most abundant)
X Few present and active
44 Rotifers :, .. ..,,..;;;,lg
co Tardigrades i¾��t0 - . ;.:.

N
Nematodes co -,-·· - �-
Aeleosoma Worm
-'••·
��:) -..... �·
Other
Features*
India Ink Test <10% encapsulated
Zoogloeal Matter None ---------
Pa rt i cu I ate Matter Present ---------
Su If u r Granules Present in Thiothrix sp
X Present and active
Spirochaetes None -------
Free cells in suspension Some present
Loosely Bound EPS None -------
Other -------
* All characterizations are based upon guidelines set forth in Manual on the Causes and Control of Activated Sludge Bulking and Foaming and Other Solids Separations Problems (3rd Edition) by D. Jenkins, M. G. Richard and G. T. Daigger. Lewis Publishers. 2003.

Discussion points:
-The sample contains primarily medium to large size floe. (150->500 microns) The majority of the floe is very dense and rounded. Some floe has heavy filament growth extending and a few have very little filament growth.
-The overall filament abundance rating is a "3". This is based on a scale of "O" to "6" with a "6" being the worst possible condition. This rating includes both viable and non-viable. - The filaments are found extending and except for a very few, not free in the bulk water. - The dominant filaments are Thiothrix sp., Type 0675, Type 0041 and Type 1851. - Thiothrix sp are noramlly associated with the presence of organic acids, sulfides, and/or nutrient (N&P)deficiency. There are quite a few with sulfur granules. - Type 0675, Type 1851, and Type 0041 are// generally associated with a Low F/M. - Higher life forms are both diverse and abundant indicating a stable biomass. It's dominated with Stalk ciliates and rotifers indicating an older sludge age.
-The bulk water is very clean and only has a small amount of free bacteria. - Overall the biomass looks good and contains an ideal floe (Size and density). The unusual piece is there are some floe's with little to no filaments while the majority are covered in them. The filaments are indicating Low D.O. and low F/M, long sludge age. I found no hyphomicrobium (denitrifying bacteria) which is uncommon for a BNR system.

Pictures below
400 Vc111 U1111p Po,1cl I flmvl111q C1('t:11. 01110 43402 I 800-232-)847 I t;o11V11ozy1ntc.co111 45 Fig. 1 100 X Darkfield Fig. 2 1 00X Phase
Medium size dense (tan eolor)floe and filaments extending Fig. 3 1 00X Phase Fig. 4 1 00X Phase
Various size dense floe
Fig. 5 100X Phase Fig. 6 100X Phase
Floe with filaments extending Floe with almost no filament growth ¥JO V,111 C,1nip l"<(,,HI I F.lc,,-,l111�J C,1,2c11. 01110 -1:M02 J 800-2:l2-28-17 J e11v11,-,7.y111e,co111 46 Fig. 7 400X Phase
S. natans filament false branching
Fig. 9 1 000X Phase
Thiothrix sp w/ sulfur granules
Fig. 11 1 00X Phase
India ink stain
Ink is penetrating floe indicating
very low EPS presence
Fig. 8 1 000X Phase
Type 1701 filament
Fig. 10 1 000X Phase
Thiothrix sp with some sulfur granules
Fig. 12 1 000X Phase
Fungal growth
40U V,111 C ,1111p l<,i<1cl I flov1l111q (;1cc11. 0111 0 ,J"l,!02 j 800-2 -32-7.847 I (:'11v1101.y111,!.co111 47 Fig. 13 1000X Brightfield Fig. 14 1000X Brightfield
Gram-stained slide
Type 0675 (G+)* Type 1701 (G-)
Fig. 15 1000X Brightfield Fig. 16 1000X Brightfield
Fig. 17 400X Phase
Active suctoria
Neisser-stained slide
(N-) filaments
Fig. 18 400X Phase
Active stalk ciliate dividing (Vorticella)
400 V,111 Ci1111p Ro,1cl I l3owl111�J G1l.'C•11. 01110 4J402 I 800 232-2847 I C'llV11ozy11w corn 48 Fig. 19 400X Phase
Empty testate amoeba
Fig. 21 1 00X Phase
Smooth rounded floe edge
Fig. 20 400X Phase
Active testate amoeba
Fig. 22 400X Phase
Floe containing inerts
49 Los Angeles Regional Water Quality Control Board
November 7, 2024
Al Sexton
Deputy Public Works Director - Sanitation
City of Simi Valley
600 West Los Angeles Avenue
Simi Valley, CA 93065
Via Certified Mail
Return Receipt Requested
Claim No. 9589 0710 5270 0590 4679 83
RESPONSE TO REQUEST FOR ALLEGED VIOLATION REVIEW – CITY OF SIMI VALLEY, SIMI VALLEY WATER QUALITY CONTROL PLANT, 600 WEST LOS ANGELES AVENUE, SIMI VALLEY, CALIF ORNIA (ORDER NO. R4-2019-0135, NPDES PERMIT NO. CA0055221, CI NO. 3021)
Dear Al Sexton:

Thank you for your submission dated June 27, 2024 (Response Letter), regarding Settlement Offer No. R4-2024-0176 (Settlement Offer) for the City of Simi Valley (Permittee), regarding mandatory minimum penalties (MMPs) for effluent violations. This letter addresses your comments in this regard.

Issue:

The Permittee asserts that the turbidity and ammonia effluent limit violations from September 12, 2022 to December 31, 2022, as included in the Settlement Offer, were the direct result of a single operational upset (SOU). According to the Permittee, an SOU occurred after work hours on September 12, 2022, and into the morning of September 13, 2022 at the Biological Nutrient Removal (BNR) treatment stage when a newly installed compressed gas mixing system for the BNR, referred to as Enviromix, failed and shut down unexpectedly on September 12, 2022, without triggering a Supervisory Control and Data Acquisition (SCADA) warning or alarm. The non-operation of the BNR mixing system lasted for over 17 hours. As a result, the majority of the biomass, largely the sensitive and slow growing autotrophic bacteria responsible for removing ammonia and ensuring a clear (not-t urbid) effluent, were killed. T he prolonged lack of mixing also caused an accumulation of solids in the BNR aeration tanks that reduced the efficiency of the air diffusion and possibly damaged the air diffusers, prohibiting efficient air diffusion to support nitrification and regrowth of the biomass. The Permittee asserts that the SOU was not caused by operator error or negligence. The Permittee emphasizes that if the biological treatment process had not failed and alarms worked properly, no violations would have occurred because the Permittee has the flexibility to divert discharge from EFF-001 to a lined lagoon for storage and future treatment. In addition, on-call, standby personnel would have responded in 30 minute s or less to reactivate the system. The Permittee stated that it took immediate and timely actions on September 13, 2022, by

ATTACHMENT C
50 Al Sexton November 7, 2024
City of Simi Valley
diverting over 28 million gall ons of EFF-001 discharge to the lined lagoon storage and made appropriate operational adjustments to create an environment best suited for the biomass and slow growing nitrifying bacteria to regrow. Therefore, the Permittee requests that the mandatory minimum penalties for the turbidity and ammonia effluent violations listed in the Settlement Offer, which totals $162,000, be expunged or treated as a single violation to limit the liability of the settlem ent offer to no greater than $33,000. In the Response Letter, the Permittee provided a series of Notification of Non-Compliance letters, graphs related to plant operations and notifications, and microscopic examination results to support the claim that the Enviromix failure is the root cause for the alleged September 12, 2022, SOU.

Response:

Regional Water Board staff evaluated the Permittee’s response. California Water Code (CWC) Section 13385 (f)(2)(A) states that an SOU in a wastewater treatment unit that treats wastewater using a biological treatment process shall be treated as a single violation, even if the operational upset results in violations of more than one effluent limitation and the violations continue for a period of more than one day, if certain conditions are met. CWC Section 13385(f)(2)(B) further limits that CWC Section 13385 (f)(2)(A) only applies to violations that occur during a period for which the regional board has determined that violations are unavoidable, but in no case may that period exceed 30 days.
1 CWC Section 13385(f) corresponds to Clean Water Act section 309(c)(5). The United States Environmental Protection Agency (U.S. EPA) Memorandum “Issuance of Guidance Interpreting Single Operational Upset” (September 27, 1989) (SOU Guidance) defined SOU as an “exceptional incident which causes simultaneous, unintentional, unknowing (not the results of a knowing act or omission), temporary noncompliance with more than one Clean Water Act effluent discharge pollutant parameter. Single operational upset does not include…noncompliance to the extent caused by improperly designed or inadequate treatment facilities.” In addition, U.S. EPA’s SOU Guidance elaborates that the “upset” event must be exceptional (i.e. a non-routine, unusual malfunction, breakdown, or disruption of a facility’s usual proper and adequate operation). The U.S.

EPA’s SOU Guidance further states the “SOU provision shall not be construed to provide relief to regulatees who fail to take timely mitigative or corrective measure to minimize the effects caused by the SOU nor shall continuing days of violations, originally caused by an SOU, be equitably attributable to the SOU if the violator has not taken whatever corrective or mitigative actions are necessary to prevent the continuing violations.” The State Water Resources Control Board’s 2017 Water Quality Enforcement Policy (Enforcement Policy) includes examples of SOUs such as upsets caused by a sudden violent storm, a bursting tank, or other exceptional event. (Enforcement Policy, section VII.C., p. 27.) The Enforcement Policy also makes it clear the SOU defense is not a defense to liability, but rather relates to the amount of penalties that may be imposed and permittees bear the “burden of demonstrating that the violations were caused by a [SOU].” (Ibid.) U.S. EPA’s SOU Guidance states that if an SOU event has occurred, all exceedances on any single day that are attributable to that event will be counted as only 1 Note, if an SOU had occurred on September 12-13, 2022, it legally could not impact the amount of penalties for violations that occurred more than a maximum of 30 days after the event. 51 Al Sexton November 7, 2024
City of Simi Valley
one exceedance for the purposes of calculating mandatory penalties. If the exceedances attributable to the same event continue for two days, two exceedances will be counted, and so on.
2 In the Response Letter, the Permittee requests that the MMPs for the multiple turbidity and ammonia effluent violations from September 12, 2022 to December 31, 2022 be expunged or treated as a single violation to limit the liability of the settlement offer to no greater than $33,000. As previously mentioned, the SOU claim is not a defense to liability.

Regional Water Board staff disagree with the Permittee’s claim that the turbidity and ammonia violations between September 2022 through December 2022 were the direct result of an SOU caused by the Enviromix failure. In further examining the supporting documentation included in the Response Letter, the Enviromix failure was not the only failure the Facility experienced, but rather part of a series of failures and treatment limitations at the Facility, that resulted in the turbidity and ammonia violations between September 2022 through December 2022. The Permittee’s September 15, 2022, Notification of Non-Compliance letter, which addressed turbidity violations from September 11 through 14, 2022, listed four suspected reasons for the turbidity exceedances. The letter stated the suspected causes of the exceedances include: a record-breaking heat wave prior to the Enviromix failure led to multiple power transfers from Edison to the generator; malfunction of RAS pump #3 on September 10, 2022; treatment plant running with only two secondary clarifiers and two Return Activated Sludge (RAS) pumps for treatment due to construction activities; and failure of the Enviromix system on September 12, 2022 due to a power surge and the SCADA system did not alarm nor notify plant personnel. The information provided did not sufficiently explain the cause of the alarm failure. Additionally, the reduction in available secondary clarifiers and RAS pumps coul d have prolonged the Facility’s inability to return to compliance, and a malfunction in one of the available RAS pumps could have affected the biomass in the BNR prior to the Enviromix failure. Hence, when the Enviromix failure occurred, the Facility was already in a position with limited treatment capacity, recovering from a RAS pump malfunction, and a malfunction in the SCADA alarms further delayed the Facility’s ability to promptly respond to the Enviromix failure. Based on the information submitted, the impact of the Enviromix failure is mainly attributed to how long the failure went unnoticed. The delayed mitigation efforts affected the active biomass in the BNR and promoted solids accumulation which could have affected the regrowth of the biomass and impacted the BNR diffusers. The Enviromix failure was resolved when treatment plant staff connected to the Enviromix Programmable Logic Controller (PLC) after not being able to get the Master Control Panel to reset.
3 Once resetting the fault and placing the
equipment in run mode, the Enviromix was back online on September 13, 2022. 2 Note, for many of the alleged violations between September 12, 2022 through December 31, 2022, only one violation occurred on an individual day, meaning if a SOU had occurred, it would not impact the amount of penalties for the alleged violations.
3 When connected to Enviromix PLC, treatment plant staff were noticed that a Major Fault was stuck in program mode rather than run mode. The fault description was that it could not communicate with an equipment piece, but it did not specify which.
52 Al Sexton November 7, 2024
City of Simi Valley
The October 6, 2022, Notification of Non-Compliance letter, which addressed the turbidity violations from September 29 through October 4, 2022, stated that the Permittee had hired a consultant to help improve treatment by adding more nitrifying bacteria and the Permittee was still working on adjusting process control such as waste activated sludge (WAS)/RAS rates, dissolved oxygen (DO) set points, and remaining on mechanical mixing. An October 6, 2022 email from a Facility staff stated that the Facility was back into compliance with the turbidity effluent limit as of October 5, 2022, cleaning and maintenance in each BNR channel would be completed in one week, and that a third secondary clarifier would be operational by the end of the month. The information provided indicated that the treatment plant was overcoming the biomass regrowth issue towards compliance.

However, in an October 13, 2022, Notification of Non-Compliance letter, which addressed the October 7 and 8, 2022 turbidity violations, the Permittee indicated the Facility had suffered a water leak inside the MCC building that caused the power to be shut down at the West BNR from 7am to 2pm on October 7, 2022; the letter also noted as of October 9, the Facility was back in compliance with turbidity limits. This failure occurred while the treatment plant was still working on adjusting process control. Additionally, the West BNR suffered a 3-line break on October 7, 2022 as documented in the Los Angeles Water Board staff’s March 29, 2023, inspection report. The November 1, 2022, Notice of Non- Compliance letter and the March 29, 2023, inspection report, noted the Enviromix system failure and power transfer to generator during September 2022, compounded by the October 7, 2022 failure, most likely killed off most of the nitrifying bacteria and led to a delay in regrowing the biomass. The Permittee hired a consultant for microscopic analysis of the Facility’s mixed liquor; the microscopic examination results for an October 26, 2022 mixed liquor sample indicated “overall the biomass looks very good”, while the December 7, 2022 microscopic examination results of the mixed liquor indicated the biomass looked good and contained an ideal floc but confirmed that no denitrifying bacteria were found, which was noted to be uncommon for a B NR system. Notifications of non-compliance letters submitted by the Permittee between November 10, 2022, through December 29, 2022, consistently stated that the suspected cause of the ammonia and turbidity exceedances were related to the ongoing problem of growing the nitrifying bacteria to an acceptable range and noted that the Permittee were also continuing to troubleshoot their oxygen transfer uptake and mixing system which could be possible issues. During this time, treatment plant personnel continued to address the nitrifying bacteria issue by adjusting WAS/RAS rates, DO set points, continual addition of supplemental nitrifying bacteria to the BNR system, adjusting the oxygen transfer uptake, lowering the mixed liquor return rates, and eventually turning off the Enviromix system and switching back to the old mechanical mixing system which prompted a positive effect on treatment and suggested that the system was not providing the adequate effect on the treatment process.

Based on the above, the turbidity and ammonia violations that occurred between September 12, 2022, and December 31, 2022, were not solely due to the Enviromix failure that occurred from the power surge, but instead could be attributed to multiple factors, including: power surges at the facility, limited treatment capacity due to construction 53 Al Sexton November 7, 2024
City of Simi Valley
activities and a pump failure which affected nitrification and proper solids management, SCADA alarm failures which delayed mitigation efforts, West BNR failures (i.e., power outage due to flooding and pipeline break), effectiveness of the Enviromix system, oxygen transfer update and mixed liquor return rates, and the slow regrowth rate of the active biomass (more importantly the nitrifying bacteria) in the BNR phase of the treatment plant, not all or none of which were unavoidable. Therefore, based on the information provided in the Response Letter, Regional Water Board staff determined that the Permittee did not provide sufficient information to demonstrate the occurrence of a single operational upset that would meet the requirement set forth in the CWC for the exception. The contested MMPs for the turbidity and ammonia violations between September 12, 2022, and December 31, 2022 remain valid.

Since the City of Simi Valley requested an additional review of these violations, the Regional Water Board has established new deadlines. If you intend to participate in the Expedited Payment Program, you must sign and return the Acceptance of Conditional Resolution and Waiver of Right to Hearing form by December 9, 2024 . By signing the revised Acceptance and Waiver, City of Simi Valley agrees to pay the penalty of $195,000 as indicated on the Exhibit “1” – Notice of Violation and waives the right to a hearing.

If you do not elect to sign the Acceptance and Waiver, you will be contacted regarding formal enforcement action that will be initiated with regard to the contested violations.

Should you have questions regarding this matter, please contact Enforcement Unit staff John Salguero at (213) 620-2273 / [email protected] or Ching-Yin To at (213) 620-6370 / [email protected].

Sincerely,
______________________
Russ Colby
Acting Assistant Executive Officer
Enclosures
Exhibit “1” - Notice of Violation
Acceptance of Conditional Resolution and Waiver of Right to Hearing; (proposed) Order Russ
Colby
Digitally signed by
Russ Colby
Date: 2024.11.07
11:10:57 -08'00'
54 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 1 of 6 ends

EXHIBIT “1” – NOTICE OF VIOLATION
Effluent Limit Violations
Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
04/30/20 2nd Quarter
2020
Monthly
Average Nitrate N 9.3 9.0 mg/L 1 3% Chronic (i)1 $0
04/30/20 2nd Quarter
2020
Monthly
Average
Nitrite Plus
Nitrate 9.6 9. 0 mg/L 1 7% Chr onic (i)1 $0
02/09/21 1st Quarter
2021
Daily
Maximum
Ammonia
Nitrogen 189 172 lbs/day 1 10% Chronic (i)1 $0
09/11/22 3rd Quarter
2022 Daily Average Turbidity 2.3 2.0 NTU OEV 15% Chronic (i)1 $0 09/12/22 3rd Quarter
2022 Daily Average Turbidity 2.6 2.0 NTU OEV 30% Chronic (i)1 $0 09/14/22 3rd Quarter
2022
Time
Concentration Turbidity
> 5 NTU
f or 390
mi
ns
> 5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $0
09/16/22 3rd Quarter
2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/17/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/18/22 3rd Quarter
2022 Daily Average Turbidity 3.4 2.0 NTU OEV 70% Chronic (i)1 $3,000 09/19/22 3rd Quarter
2022 Daily Average Turbidity 3.3 2.0 NTU OEV 65% Chronic (i)1 $3,000 09/20/22 3rd Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 09/21/22 3rd Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 55 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 2 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
09/22/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/23/22 3rd Quarter
2022 Daily Average Turbidity 2.5 2.0 NTU OEV 25% Chronic (i)1 $3,000 09/26/22 3rd Quarter
2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/27/22 3rd Quarter
2022 Daily Average Turbidity 2.4 2.0 NTU OEV 20% Chronic (i)1 $3,000 09/28/22 3rd Quarter
2022 Daily Average Turbidity 2.3 2.0 NTU OEV 15% Chronic (i)1 $3,000 09/29/22 3rd Quarter
2022 Daily Average Turbidity 2.7 2.0 NTU OEV 35% Chronic (i)1 $3,000 09/30/22 3rd Quarter
2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/01/22 4th Quarter
2022 Daily Average Turbidity 2.8 2.0 NTU OEV 40% Chronic (i)1 $3,000 10/02/22 4th Quarter
2022 Daily Average Turbidity 4.2 2.0 NTU OEV 110% Chronic (i)1 $3,000 10/03/22 4th Quarter
2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 10/04/22 4th Quarter
2022 Daily Average Turbidity 3.2 2.0 NTU OEV 60% Chronic (i)1 $3,000 10/07/22 4th Quarter
2022
Time
Concentration Turbidity
>5 NTU
f or 120
mi
ns
>5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $3,000
10/08/22 4th Quarter
2022 Daily Average Turbidity 3.5 2.0 NTU OEV 75% Chronic (i)1 $3,000 56 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 3 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
10/08/22 4th Quarter
2022
Time
Concentration Turbidity
>5 NTU
f or 350
mi
ns
>5 NTU
f or 72
mi
ns
NTU OEV N/A Chronic (i)1 $3,000
10/11/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 19 3. 3 mg/L 1 476% Seri ous (h)1 $3,000
10/11/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,030 157 lbs/day 1 556% Serious (h)1 $3,000
10/31/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 25 3. 3 mg/L 1 658% Seri ous (h)1 $3,000
10/31/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,376 160 lbs/day 1 760% Serious (h)1 $3,000
10/31/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 22 2. 4 mg/L 1 817% Seri ous (h)1 $3,000
11/06/22 4th Quarter
2022 Daily Average Turbidity 3.1 2 NTU OEV 55% Chronic (i)1 $3,000 11/07/22 4th Quarter
2022 Daily Average Turbidity 3.7 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter
2022 Daily Average Turbidity 3.6 2 NTU OEV 85% Chronic (i)1 $3,000 11/08/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 30.6 3.3 mg/L 1 827% Serious (h)1 $3,000
11/08/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,761 167 lbs/day 1 954% Serious (h)1 $3,000
11/10/22 4th Quarter
2022
Daily
Maximum
Total
Coliform 920 240 MPN/100
mL OEV 283% Chronic (i)1 $3,000
11/11/22 4th Quarter
2022 Daily Average Turbidity 2.3 2 NTU OEV 15% Chronic (i)1 $3,000 57 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 4 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
11/16/22 4th Quarter
2022 Daily Average Turbidity 2.9 2 NTU OEV 45% Chronic (i)1 $3,000 11/17/22 4th Quarter
2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/17/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 42.6 3.3 mg/L 1 1,191% Serious (h)1 $3,000
11/17/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 2,345 160 lbs/day 1 1,366% Serious (h)1 $3,000 11/21/22 4th Quarter
2022 Daily Average Turbidity 2.1 2 NTU OEV 5% Chronic (i)1 $3,000 11/22/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/22/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 40.8 3.3 mg/L 1 1,136% Serious (h)1 $3,000
11/22/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 2,348 167 lbs/day 1 1,306% Serious (h)1 $3,000 11/22/22 4th Quarter
2022
30-Day
Per iod
Tot al
Coliform 130 23 M PN/100
mL OEV 465% Chronic (i)1 $3,000
11/23/22 4th Quarter
2018 Daily Average Turbidity 2.9 2 NTU OEV 368% Chronic (i)1 $3,000 11/24/22 4th Quarter
2018 Daily Average Turbidity 2.7 2 NTU OEV 131% Chronic (i)1 $3,000 11/24/22 4th Quarter
2018 30-day Period Tot al
Coliform 130 23 M PN/100
mL OEV 15,614% Chronic (i)1 $3,000
11/25/22 4th Quarter
2018 Daily Average Turbidity 2.6 2 NTU OEV 7,500% Chronic (i)1 $3,000 11/26/22 4th Quarter
2022 Daily Average Turbidity 2.5 2 NTU OEV 25% Chronic (i)1 $3,000 58 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 5 of 6 ends

Violation
Date
Monitoring
Period
Violation
Type Parameter Reported
Value
Permit
Limit Units Pollutant
Category
%
Exceeded
Serious/
Chronic
Water
Code
Section
13385
Penalty
11/27/22 4th Quarter
2022 Daily Average Turbidity 2.2 2 NTU OEV 10% Chronic (i)1 $3,000 11/28/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/29/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter
2022 Daily Average Turbidity 2.4 2 NTU OEV 20% Chronic (i)1 $3,000 11/30/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 42 3. 3 mg/L 1 1,173% Seri ous (h)1 $3,000
11/30/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,856 128 lbs/day 1 1,350% Serious (h)1 $3,000 11/30/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 39 2. 4 mg/L 1 1,525% Seri ous (h)1 $3,000
12/6/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 23.4 3.3 mg/L 1 609% Serious (h)1 $3,000
12/6/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 1,366 169 lbs/day 1 708% Serious (h)1 $3,000
12/15/22 4th Quarter
2022
Daily
Maximum
Ammonia
Nitrogen 170 164 lbs/day 1 4% Chronic (i)1 $3,000
12/31/22 4th Quarter
2022
Monthly
Average
Ammonia
Nitrogen 3.2 2. 4 mg/L 1 33% Chr onic (i)1 $3,000
01/30/23 1st Quarter
2023 Daily Average Turbidity 2.8 2 NTU OEV 40% Chronic (i)1 $3,000 02/01/23 1st Quarter
2023 Daily Average Turbidity 3.2 2 NTU OEV 60% Chronic (i)1 $3,000 02/02/23 1st Quarter
2023 Daily Average Turbidity 3.4 2 NTU OEV 70% Chronic (i)1 $3,000 59 Settlement Offer No. R4-2024-0176 City of Simi Valley CI No. 3021

Page 6 of 6 ends

60 Settlement Offer No. R4-2024-0176
CI No. 3021, NPDES Permit No. CA0055221

The Permittee understands that this Acceptance and Waiver does not address or resolve liability for any violation that is not specifically identified in the NOV.

Upon execution by the Permittee, the completed Acceptance and Waiver shall be returned to:

If no comments are received within the notice period that causes the Regional Water Board Assistant Executive Officer to question the Expedited Payment Amount, the Acceptance and Waiver will be presented to the Executive Officer for consideration and adoption of a stipulated order.
61 Settlement Offer No. R4-2024-0176
CI No. 3021, NPDES Permit No. CA0055221
The Permittee understands that if significant comments are received in opposition to the Expedited Payment Amount, the offer on behalf of the Regional Water Board to resolve the violations set forth in the NOV may be withdrawn. In that circumstance, the Permittee will be advised of the withdrawal and an administrative civil liability complaint may be issued and the matter may be set for a hearing before the Regional Water Board. For such a liability hearing, the Permittee understands that this Acceptance and Waiver executed by the Permittee will not in any way be binding or used as evidence in that hearing.

Please mail the check to:

City of Simi Valley
B y :
(Signed Name)
(Printed or Typed Name)
(Date)
(Title)
IT IS SO ORDERED PURSUANT TO CALIFORNIA WATER CODE SECTION 13323 AND GOVERNMENT CODE SECTION 11415.60
B y :

Susana Arredondo
Executive Officer
(Date)
62

Simi Valley City CouncilDecember 2, 2024

Simi Valley City Council
December 2, 2024