St. Helena City Council
March 28, 2023

City of St. Helena
Regular City Council Meeting
Tuesday, March 28, 2023 @ 6:00 PM
Vintage Hall Board Room - Second Floor
465 Main Street, St. Helena

PLEASE NOTE: Any person who wishes to speak regarding an item on the agenda or make a comment under the "Oral Communication" portion of the agenda may do so, but please observe the time limit of four minutes.

The City Council meeting will be live-streamed on Comcast Channel 28 and on the City’s website. Public comment for City Council meetings will be accepted via email to [email protected]. All public comments must be emailed three hours prior to the meeting. Emailed public comments will not be read out loud but will be publicly available and attached to the on-line City Council agenda.

The schedule of upcoming meetings and published meeting agendas can be found on the City of St. Helena website at https://sthelena.civicweb.net/portal/.

Simultaneous Spanish interpretation services during meetings can be scheduled upon request.

To ensure interpreters are available, requests must be made at least 72 hours in advance by calling the Office of the City Clerk at (707) 968-2640 or emailing [email protected].

The schedule of upcoming meetings and published meeting agendas can be found on the City of St. Helena website at https://sthelena.civicweb.net/portal/.

Servicios de interpretación en español durante la reunión pueden ser solicitados por el público.

Para asegurar que los intérpretes estén disponibles, los servicios tienen que ser solicitados al menos 72 horas antes de la reunión llamando a la oficina de la Secretaria de la Ciudad al (707) 968-2640 o por correo electrónico a [email protected] .

El horario de las reuniones publicadas y próximas puede ser localizado en el sitio de web de la Ciudad en https://sthelena.civicweb.net/portal/ .

Page

1. CALL TO ORDER

2. ROLL CALL
Mayor: Paul Dohring, Vice Mayor Eric Hall:, City Council Members: Anna Chouteau, Lester Hardy, Billy Summers

3. PLEDGE OF ALLEGIANCE

4. ADOPTION OF THE AGENDA

5. PUBLIC FORUM:

Members of the public are entitled to speak on matters of municipal concern not on the agenda during Public Forum. Each person’s comments shall be limited to 4 minutes. Each person is entitled to speak on any non-agendized item only once at any meeting. Brief questions by Council Members for clarifications may be posed and answered, and Council Members may make requests that items be placed on future agendas, but in accordance with state law, no substantive

discussion or action may take place unless and until the matter properly appears on the agenda.

6. REPORTS BY STAFF AND CITY COUNCIL, FUTURE AGENDA ITEMS, AND AB 1234 REPORTS:

Reports by staff and/or Council Members on items of general interest. Brief questions for clarification may be posed and answered, and Council Members may request that items be placed on a future agenda. Except under certain circumstances, the Brown Act prohibits any other discussion or action by the City Council.

7. PRESENTATIONS AND PUBLIC RECOGNITIONS

7.1. Oath of office for Yosselyn Valencia, Finance Manager administered by Cindy Tzafopoulos, City Clerk

8. STAFF BRIEFING
None

9. CONSENT ITEMS
Members of the Council or the public may ask that any items be considered individually for purposes of considering alternative action, for extended discussion, or for public comment. Unless that is done, one motion may be used to adopt all recommended actions. (Roll Call Vote)

9.1. Consideration and approval of a resolution approving Sanitary Sewer Management Plan version 8 as required by State Water Resources Control Board WQO-2006-0003 Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WDR) and the associated Monitoring and Reporting Program (MRP).

CEQA Determination: Exempt
Prepared By: Clayton Church, Public Works Operations Manager Recommendation:

Adopt attached Resolution.

Staff Report - Pdf
9 - 305

9.2. February 2023 Review and Forecasting of City Water Supply Availability CEQA Determination: Exempt
Prepared By: Ian Dale, Environmental Services Tech
Recommendation:

Receive and File
Staff Report - Pdf
307 - 312

9.3. Consideration and proposed adoption of a Resolution authorizing the City Manager to execute Amendment No. 1 to STH Contract: FY2023- 001 in the amount of $25,000 to the Professional Services Agreement with Regional Government Services (RGS) for finance assistance for a total amount not-to-exceed $50,000.

CEQA Determination: Not a CEQA project
Prepared By: Mandy Kellogg, Administrative Services Director Recommendation:
313 - 331

Adopt the attached resolution.

Staff Report - Pdf

9.4. Review and consideration of the 2022 St. Helena Annual Housing Element Progress Report.

CEQA Determination: Not a CEQA project
Prepared By: Aaron Hecock, Senior Planner
Recommendation:

It is recommended that the City Council review, consider, and file this report recognizing that staff submitted the information to HCD and OPR in keeping with the April 1, 2023 mandate.

Staff Report - Pdf
333 - 347

9.5. Consideration of approval of a Resolution approving out-of-state travel for (1) Administrative Services Director, Mandy Kellogg, to attend the 2023 ICMA Local Government Reimagined Conference to be held April 12-14, at the Hilton Burlington Lake Champlain, Burlington, Vermont (2) Senior Management Analyst, Martin Beltran, to attend the Government Finance Officers Association (GFOA) 117th Annual Conference to be held May 21-24, at the Oregon Convention Center, Portland, Oregon.

CEQA Determination: Not a CEQA project
Prepared By: Martin Beltran, Senior Management Analyst
Recommendation:

Approve the attached resolution
Staff Report - Pdf
349 - 353

9.6. Consideration of a Resolution to execute contract amendment with BKF for design work related to the Main Street St. Helena Pedestrian Improvements Project and authorizing a budget increase of $151,000 to design in CIP Project R18-81 with funding allocated from Gas Tax Funds to Streets Capital Fund 741.

CEQA Determination: Exempt
Prepared By: Eric Janzen, Assistant Public Works Director Recommendation:

Approve Resolution to execute contract amendment with BKF for design work related to the Main Street St. Helena Pedestrian Improvements Project and authorizing a budget increase of $151,000 to design in CIP Project R18-81 with funding allocated from Gas Tax Funds to Streets Capital Fund 741.

Staff Report - Pdf
355 - 372

9.7. Consideration of A Resolution of the City Council of the City of St. Helena to Re-Affirm City Commitment to Housing Element for Regional Housing Need Assessment (RHNA), the Metropolitan Transportation Commission (MTC) adopted Resolution No. 4505 and Comply with State Housing Laws.

CEQA Determination: Not a CEQA project
Prepared By: Eric Janzen, Assistant Public Works Director Recommendation:
373 - 379

Approve A Resolution of the City Council of the City of St. Helena to ReAffirm City Commitment to Housing Element for Regional Housing Need Assessment (RHNA), the Metropolitan Transportation Commission (MTC) adopted Resolution No. 4505 and Comply with State Housing Laws.

Staff Report - Pdf

9.8. Consideration and proposed approval of a Resolution authorizing:
(1) various scope amendments and budget transfers among the Streets Capital Improvement Program Projects, specifically: R21- 02 Crosswalk Improvements on Main Street/Highway 29 at Pratt Avenue and Elmhurst Avenue; R21-04 Pope Street Crosswalk Improvements; R22-79 Pavement Restoration Year 2; R19-05 Grayson and South Crane Rehab which when implemented will have a total FY23 fiscal impact of approximately $798,806.98: (2) staff to execute the appropriate agreements, budget appropriations and transfers to effectuate the various Capital Improvement Program projects noted above; and (3) authorize the Director of Public Works to execute change orders not to exceed $475,000 in addition to the R22-79 Argonaut Construction contract.

CEQA Determination: Class I Categorical Exemption under Section 15301 of CEQA
Prepared By: Mario Traverso, Public Works Assistant Engineer Recommendation:

Staff recommends City Council adopt the attached Resolution.

Staff Report - Pdf
381 - 392
Quarterly Grant Report for FY 2023 Q3, for the period ending March 31, 2023
CEQA Determination: Not a CEQA project
Prepared By: Martin Beltran, Senior Management Analyst
Recommendation:

Receive and file report.

Staff Report - Pdf
393 - 400
Consideration and Proposed Adoption of a Resolution Adopting a list of Projects for Fiscal Year 2023-24 funded by SB1: The Road Repair and Accountability Act of 2017.

CEQA Determination: Exempt from the requirements of CEQA pursuant to Section 15301, Class 1, which exempts the operation, leasing, or minor alteration of existing facilities
Prepared By: Mario Traverso, Public Works Assistant Engineer Recommendation:

Adopt a resolution adopting a list of projects for fiscal year 2023-24 funded by SB1: The Road Repair and Accountability Act of 2017.

Staff Report - Pdf
401 - 405

10. PUBLIC HEARINGS

None
Consideration and proposed adoption of resolutions as follows:

1. Consideration and proposed approval of a resolution accepting the City of St. Helena 2023 Water and Wastewater Cost of Service and Rate Study Final Report; and

2. Consideration and proposed approval of a resolution approving a. Changes to the water base rates, water use rates, fire line rates, and rate structure effective September 1, 2023; and b. Changes to the wastewater base rates, wastewater use rates, and rate structure effective September 1, 2023; and c. Approving Drought Surcharges and rate structure
effective September 1, 2023: and
d. The charges for water, wastewater, and drought
surcharge rates will become effective on September 1,
2023, and a rate increase will occur every subsequent
year on July 1st for the next (5) years as follows:
i. September 1, 2023
ii. July 1, 2024
iii. July 1, 2025
iv. July 1, 2026
v. July 1, 2027
CEQA Determination: Not a CEQA project
Prepared By: Mandy Kellogg, Administrative Services Director Recommendation:

Staff recommends the following to the City Council:

1. By resolution, accept the City of St. Helena 2023 Water and Wastewater Cost of Service and Rate Study Final Report; and

2. Adopt a resolution approving:
a. Changes to the water base rates, water use rates, fire line rates, and rate structure effective September 1, 2023; and b. Changes to the wastewater base rates, wastewater use rates, and rate structure effective September 1, 2023; and c. Approving Drought Surcharges and rate structure
effective September 1, 2023: and
d. The charges for water, wastewater, and drought
surcharge rates will become effective on September 1,
2023, and a rate increase will occur every subsequent
year on July 1st for the next (5) years as follows:
i. September 1, 2023
ii. July 1, 2024
iii. July 1, 2025
iv. July 1, 2026
v. July 1, 2027
Staff Report - Pdf
407 - 574

11. OLD BUSINESS

11.1. 03-28-23 UPDATE *THIS ITEM WILL BE CONTINUED TO A DATE

UNCERTAIN
Consideration and Proposed Approval of a Resolution Adopting the Integrated Master Utility Plan
575 - 616

CEQA Determination: Exempt from CEQA pursuant to Section 15262 Prepared By: Mark Rincon-Ibarra, Public Works Director and City Engineer
Recommendation:

Receive presentation and adopted the attached Resolution accepting the Integrated Utility Master Plan.

Staff Report - Pdf
Public comment - Gene Armstead
Public comment - David Sasson
Public comment - Katie Avery

12. NEW BUSINESS
None

13. ADJOURNMENT
The next Regular City Council meeting is scheduled for April 11, 2023, at 6:00 p.m.

This agenda was posted at City Hall, 1572 Railroad Avenue, and at Vintage Hall, 465 Main Street, St. Helena, California on March 23, 2023. Republished 03-28-23
Cindy Tzafopoulos, City Clerk
In Compliance with the Americans with Disabilities Act, if you need special assistance to participate in this meeting, please call the City Clerk’s Office (707) 967-2792. Notification 72 hours prior to the meeting as required by Section 202 of the Americans with Disabilities Act will enable the City to make reasonable arrangements to ensure accessibility to this meeting.

CHALLENGING DECISIONS OF CITY ENTITIES
The time limit within which to commence any lawsuit or legal challenge to any quasi-adjudicative decision made by the City of St. Helena is governed by Section 1094.6 of the Code of Civil Procedure, unless a shorter limitation period is specified by any other provision, including without limitation Government Code section 65009 applicable to many land use and zoning decisions, Government Code section 66499.37 applicable to the Subdivision Map Act, and Public Resources Code section 21167 applicable to the California Environmental Quality Act (CEQA). Under Section 1094.6, any lawsuit or legal challenge to any quasi-adjudicative decision made by the City must be filed no later than the 90th day following the date on which such decision becomes final. Any lawsuit or legal challenge, which is not filed within that 90-day period, will be barred.

Government Code section 65009 and 66499.37, and Public Resources Code section 21167, impose shorter limitations periods and requirements, including timely service in addition to filing.

If a person wishes to challenge the above actions in court, they may be limited to raising only those issues they or someone else raised at the meeting described in this notice, or in written correspondence delivered to the City of St.

Helena, at or prior to the meeting. In addition, judicial challenge may be limited or barred where the interested party has not sought and exhausted all available administrative remedies.

SUPPLEMENTAL MATERIAL RECEIVED AFTER THE POSTING OF THE AGENDA
Any supplemental writings or documents distributed to a majority of the City Council regarding any item on this Agenda, after the posting of the Agenda, will be available for public review in the City Clerk’s Office located at 1572 Railroad Avenue, St. Helena, California, during normal business hours and by appointment. In addition, such writings or documents will be made available on the City’s web site at https://sthelena.civicweb.net and will be available for public review at the respective meeting.

Report to the City Council
Regular City Council - 28 Mar 2023
Agenda Section: CONSENT ITEMS
Subject: Consideration and approval of a resolution approving Sanitary Sewer Management Plan version 8 as required by State Water Resources Control Board WQO-2006-0003
Statewide General Waste Discharge Requirements for
Sanitary Sewer Systems (WDR) and the associated
Monitoring and Reporting Program (MRP).

CEQA
Determination:

Exempt
Prepared By: Clayton Church, Public Works Operations Manager Reviewed By: Joseph Leach, Public Works Director and City Engineer Approved By: Anil Comelo, City Manager

BACKGROUND
The City’s SSMP (Sanitary Sewer Management Plan) was first developed in 2006 to comply with requirements initially put forth by the San Francisco Bay Regional Water Quality Control Board in July 2005. The SSMP has been updated several times, most recently in August 2010, to comply with State Water Resources Control Board WQO2006-0003 Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WDR) and the associated Monitoring and Reporting Program (MRP). Section D.13 of the WDR requires, at minimum, the City shall conduct an internal audit every two years. The two main topics of the audit were:
• Evaluation of effectiveness of the SSMP
• Evaluation of the City’s compliance with SSMP requirements in the WDR Larry Walker Associates (LWA) was tasked with performing an audit of the City's SSMP and updating it as needed to comply with current regulatory requirements and to reflect the City’s current operating procedures. As a result, this updated SSMP must be Agenda Item #9.1.

approved by City Council. The audit report is kept on file at City offices to be presented to regulatory agencies upon request and is also posted on the City Website.

DISCUSSION
LWA reviewed data related to each of the City’s Sanitary Sewer Overflows (SSOs) from 2007-2022 to evaluate the effectiveness of the SSMP. Between 2007 and 2022 the City experienced a total of 47 SSOs with a volume of approximately 1 million gallons (MG).

Twenty of the 37 were Category 1 with a total of approximately 0.48 MG reaching surface waters. The volume of each spill varies from less than 10 gallons to 811,918 gallons, with 19 out of the total 47 spills at 100 gallons or less. The City averages 3.4 SSOs a year with most spills being minimal and not reaching surface waters except for years with significant inflow and infiltration (I&I) into the sewer collections system. The most frequent cause of spills is the accumulation of fats, oils and grease (FOG) in the system, although, during large rain events I&I is the cause of the largest volume SSOs. I&I-caused SSOs generated

99.2% of the SSO volume that reached surface waters between 2007 and 2021. St.

Helena did not have any reported I&I related spills until 2017. Prior to CIWQS reporting beginning in 2007 the City’s only known I&I spills were from heavy winter storms in 2006.

Since the time of the City’s last SSMP audit the San Francisco Regional Water Board performed a virtual audit of the City’s collection system on August 26, 2021. The objectives of the compliance inspection were to investigate corrective actions taken by the City to address issues at the site of the City’s two largest SSOs (2017 and 2019) at 290 Pope Street, confirm legally responsible officials (LROs) and data submitters for the City’s collection system, and to review/discuss the City’s SSMP.

Issues identified in the inspection report following the August 2021 virtual audit determined the following:

1. Found that the City’s collections system team is understaffed.

2. Need for corrective action at 290 Pope Street.

3. Determine modifications needed to prevent future SSOs at various locations (e.g.

CIP FY 2022-23 to FY 2026-27 WWRR-2 Flow monitoring program, WWRR-3 High Priority Pipeline Replacement, and WWRR-4 Model Update and System Analysis).

4. Update definition of Category 2 spills section 6.2 of SSMP (included in attached updated version 8 of SSMP).

5. Update documentation showing City Council approval of SSMP version 8.

6. Update the LRO information reflecting current City staffing (completed September 2021).

The implementation of the City’s SSMP yields the overall number of spills are low with the highest number of spills and highest volume to reach surface waters occurring in periods of heavy rains in the winters of 2017 and 2019. The largest spills volume SSOs occurring at the same location at 290 Pope Street and that the City will deliver the various CIP (i.e. WWRR-2 through WWRR-4) to take corrective measures.

FISCAL IMPACT
Agenda Item #9.1.

There is no fiscal impact for the adoption of the updated SSMP.

RECOMMENDED ACTION
Adopt attached Resolution.

ATTACHMENTS
Reso SSMP update 2023
St Helena SSMP Audit Memo Nov2022 rev 12-28-22
StHelena SSMP V8 1-31-2023
Agenda Item #9.1.

CITY OF ST. HELENA
RESOLUTION NO. 2023-
Resolution of the City Council of the City of St. Helena Consideration and approval of a resolution approving
Sanitary Sewer Management Plan version 8 as required
by State Water Resources Control Board WQO-2006-0003
Statewide General Waste Discharge Requirements for
Sanitary Sewer Systems (WDR) and the associated
Monitoring and Reporting Program (MRP)
WHEREAS, The City’s SSMP (Sanitary Sewer Management Plan) was first developed in 2006 to comply with requirements initially put forth by the San Francisco Bay Regional Water Quality Control Board in July 2005.

WHEREAS, The SSMP has been updated several times, most recently in August 2010 to comply with State Water Resources Control Board WQO-2006-0003 Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WDR) and the associated Monitoring and Reporting Program (MRP).

WHEREAS, Section D.13 of the WDR requires at minimum the City shall conduct an internal audit every two years.

WHEREAS, Larry Walker Associates (LWA) was tasked with performing an audit of the City of St. Helena (City) Sewer System Management Plan (SSMP) and updating it as needed to comply with current regulatory requirements and to reflect the City’s current operating procedures.

WHEREAS, Larry Walker Associates (LWA) reviewed data related to each of the City’s Sanitary Sewer Overflows (SSOs) from 2007-2022 to evaluate the effectiveness of the SSMP.

WHEREAS, Since the time of the City’s last SSMP audit the San Francisco Regional Water Board performed a virtual audit of the City’s collection system on August 26, 2021.

NOW, THEREFORE BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF ST. HELENA AS FOLLOWS:

SECTION 1. The above recitals are true and correct and are incorporated herein by this reference.

SECTION 2. The City Council approves the Sanitary Sewer Management Plan version 8 as required by State Water Resources Control Board WQOAgenda Item #9.1.

2006-0003 Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WDR) and the associated Monitoring and Reporting Program (MRP).

Approved at a Regular Meeting of the St. Helena City Council on March 28, 2023 by the following vote:

Mayor Paul Dohring: _____
Vice Mayor Eric Hall: _____
Council Member Anna Chouteau: _____
Council Member Lester Hardy: _____
Council Member Billy Summers: _____
APPROVED: ATTEST:
______________________ ________________________
Paul Jamison Dohring, Mayor Cindy Tzafopoulos, City Clerk Agenda Item #9.1.

Memorandum
DATE: Alina Constantinescu, P.E.
2246 Sixth St
Berkeley, CA 94704
510.883.9873 x15
510.883.9890 fax
[email protected]
November 28, 2022,
with revisions on December 27, 2022
TO: Joe Leach,
City of St. Helena
COPY TO: Mark Rincon-Ibarra,
City of St. Helena
SUBJECT: City of St. Helena 2022 SSMP Audit
Larry Walker Associates (LWA) was tasked with performing an audit of the City of St. Helena (City) Sewer System Management Plan (SSMP) and updating it as needed to comply with current regulatory requirements and to reflect the City’s current operating procedures. This memorandum presents the audit report; the updated SSMP incorporating the audit recommendations is presented as a separate document. This audit report should be kept on file at City offices and presented to regulatory agencies upon request. The revised SSMP needs to be posted on the City website.1
Introduction
The City’s SSMP was first developed in 2006 to comply with requirements initially put forth by the San Francisco Bay Regional Water Quality Control Board in July 2005. The SSMP has been updated several times, most recently in March 2019 to comply with State Water Resources Control Board WQO-2006-0003 Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WDR) and the associated Monitoring and Reporting Program (MRP).

This internal audit is required by Section D.13(x) of the WDR:
(x) SSMP Program Audits - As part of the SSMP, the Enrollee shall conduct periodic internal audits, appropriate to the size of the system and the number of SSOs. At a minimum, these audits must occur every two years and a report must be prepared and kept 1 In lieu of posting the SSMP online, an electronic copy of the SSMP and proof of the most recent Council certification can be mail to the State Water Resources Control Board.

Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 2 of 9
on file. This audit shall focus on evaluating the effectiveness of the SSMP and the Enrollee’s compliance with the SSMP requirements identified in this subsection (D.13), including identification of any deficiencies in the SSMP and steps to correct them.

Accordingly, this audit report includes two main topics:
• an evaluation of the effectiveness of the SSMP, and
• an evaluation of the City’s “compliance with the SSMP requirements” in the WDR.

It should also be noted that, at its recent December 6, 2022, meeting, the State Water Resources Control Board (SWRCB) adopted a revised WDR. As of the date of this Audit, the adopted WDR has not been published. When published, the City will need to review the WDR and determine what changes, if any, will be needed to bring its SSMP in compliance with the revised regulation.

Effectiveness of the SSMP
To evaluate the effectiveness of the SSMP, LWA reviewed data related to each of the City’s Sanitary Sewer Overflows (SSOs). From 2007 to 2022 (to date) the City experienced 47 SSOs with a total volume of 1,024,570 gallons. Twenty of the 37 SSOs were Category 1 SSOs. A total of 484,029 gallons from SSOs reached surface waters. A summary of all SSOs is shown in Table 1 below. The volume of each spill varies from less than 10 gallons to 811,918 gallons, with 19 out of the total 47 spills at 100 gallons or less.

Table 1: City of St. Helena SSOs, 2007-2022 (all volumes in gallons) Count Date Category Total
volume
Volume
recovered
Vol. reached
surface water SSO Cause
1 09/07/07 3 40 40 0 Grease
2 09/28/07 3 100 100 0 Grease
3 11/20/07 1 2,000 200 1,800 Grease
4 01/28/08 3 15 15 0 Grease
5 07/31/08 3 40 40 0 Grease
6 03/27/09 3 20 20 0 Grease
7 03/29/09 3 40 40 0 Grease
8 09/12/09 3 20 20 0 Grease
9 03/01/10 3 15 15 0 Grease
10 09/11/10 3 10 10 0 Grease
11 03/14/11 1 500 400 100 Grease
12 03/14/12 1 50 50 1 Grease
13 12/07/12 3 25 0 0 Roots
14 12/12/12 3 50 0 0 Grease
15 01/03/13 3 20 18 0 Roots
16 01/25/13 3 70 60 0 Grease
17 07/02/13 3 10 8 0 Roots
18 09/24/13 3 10 10 0 Built-up
solids
19 06/01/14 3 300 270 0 Roots
20 06/09/16 3 4 4 0 Debris
21 09/12/16 3 255 10 0 Grease
22 01/10/17(1) 1 12,800 0 12,800 High I&I
23 01/11/17(1) 1 3,000 500 2,500 High I&I
Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 3 of 9
Count Date Category Total
volume
Volume
recovered
Vol. reached
surface water SSO Cause
24 02/07/17 1 63,725 0 63,725 High I&I
25 02/07/17 1 13,400 0 13,400 High I&I
26 02/07/17 1 300 0 300 High I&I
27 02/07/17(1) 1 5,205 0 5,205 High I&I
28 02/09/17 1 4,600 0 4,600 High I&I
29 02/09/17 1 220 0 220 High I&I
30 02/20/17 1 3,750 0 3,750 High I&I
31 02/04/18 1 950 0 950 Grease
32 03/01/18 1 880 0 880 Grease
33 05/16/18 3 14 3 0 Blockage in
private line
34 09/23/18 3 390 150 0 Structural
failure
35 10/01/18 3 24 15 0 Grease
36 10/08/18 3 170 110 0 Grease
37 10/17/18 3 230 140 0 Grease
38 2/14/19 1 27,500 7,660 19,840 High I&I
39 2/26/19 1 811,918 529,500 282,418 High I&I
40 2/26/19 1 11,655 0 11,655 High I&I
41 2/26/19 1 34,585 0 34,585 High I&I
42 2/26/19 1 12,425 0 12425 High I&I
43 2/26/19 1 6,950 0 6,950 High I&I
44 2/27/19 1 1,285 0 1,285 High I&I
45 2/27/19 1 260 0 260 High I&I
46 1/14/20 1 270 160 110 Grease
47 2/22/20 1 900 500 400 Grease
Total 2007- 2022
(to date)
Category 1: 24
Category 2: 0
Category 3: 23
1,021,000 540,068 480,159 Grease: 22
High I&I: 17
Roots: 4
Other: 4
(1) Volumes shown here are different than volumes reported in CIWQS. In the course of the data review, LWA noted that the volume for these three SSOs was improperly recorded in CIWQS. The City will work with the CIWQS helpdesk to correct the issue.

Annual SSO totals are shown in Table 2, with a graphical representation in Figure 2 and Figure

3. The annual number of spills vary between zero (2015, 2021, and 2022 to date) and 9 (2017) with an average of 3.4 spills per year (see Figure 1). Except for years with significant inflow & infiltration (I&I) spills, overall SSO volumes have been minimal with most spills not reaching surface waters (see Table 2 and Figure 2).

The most frequent cause of spills is grease, with 22 of the 47 total spills having been caused by grease (see Figure 3). Although grease causes the most SSOs, I&I during large precipitation events causes the largest SSO volumes (see Table 2 and Figure 1). From the time CIWQS reporting began in 2007, St. Helena did not have any I&I spills until 2017. In 2017 nine SSOs occurred in a period of back-to-back storms during January and February. In 2019 eight SSOs occurred in a two-week period of storms at the end of February, with one SSO over 800,000 gallons on 2/26/2019. I&I-caused SSOs generated 99.2% of the SSO volume that reached surface waters between 2007 and 2021. Prior to 2017, the last known I&I spills occurred during heavy winter storms in 2006, which was before CIWQS reporting began.

Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 4 of 9
Table 2: SSOs, Annual Totals, 2007-2022 (all volumes in gallons) Year
Total
Number
of SSOs
Category 1
SSOs
Total
volume
Volume
recovered
Vol. reached
surface water SSO Cause
2007 3 1 2,140 340 1,800 Grease
2008 2 0 55 55 0 Grease
2009 3 0 80 80 0 Grease
2010 2 0 25 25 0 Grease
2011 1 1 500 400 100 Grease
2012 3 1 125 50 1 Grease / Roots
2013 4 0 110 96 0 Grease / Roots / Other
2014 1 0 300 270 0 Roots
2015 0 - - - - -
2016 2 0 259 14 0 Grease/ Other
2017 9 9 131,005 1,000 130,005 High I&I
2018 7 2 2,658 418 1,830 Grease/ Other
2019 8 8 906,578 537,160 369,318 High I&I
2020 2 2 1,170 660 510 Grease
2021 0 - - - - -
2022
(to date) 0 - - - - -
Figure 1: Number of SSOs by category, 2007-2022 (to date) Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 5 of 9
Figure 2: SSO total volume, volume recovered, and volume reaching surface waters, 2007-2022.

Figure 3: Number of SSOs by spill cause, 2007-2022.

The City’s largest SSO, when 811,918 gallons spilled, occurred in February 2019, in the time since the previous SSMP Audit. The rain event that caused the SSO totaled 6.24 inches of precipitation from an atmospheric river event. The SSO location at 290 Pope St was the same location where the second largest SSO due to I&I occurred in 2017.

Also, since the time of the previous SSMP Audit, the San Francisco Regional Water Board (Regional Water Board) performed a virtual collection system inspection on August 26, 2021. 0 1
2 3
4 5
6 7
8 9
10 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Number of spills
Number of SSOs by Cause
I&I roots
other grease
to date
Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 6 of 9
The main objectives of the compliance inspection were to investigate corrective actions the City performed to address issues at 290 Pope St., to confirm the legally responsible officials (LROs) and data submitters for the City’s collection system, and to review and discuss the City’s SSMP.

Issues identified in the inspection report that pertain to the effectiveness of the City’s SSMP, and updates to date, are:
• The City’s collection system team appeared to be understaffed at the time of the inspection; the City has recently hired a Public Works Director and is working on adding additional staff to its Collection System team.
• A need for corrective measures in the area of recurring I&I spills near 290 Pope St. including determining what modifications must be made to the collection system to prevent future SSOs at that location; the City is investigating these issues. • Update to the definition of Category 2 spills in section 6.2 of the SSMP; the revised definition will be included in the next update to the SSMP, SSMP Version 8, expected December 2022.
• Update documentation to show City Council approval of the SSMP; the City plans to obtain Council-approval for the next version of the SSMP (Version 8, expected in December 2022).
• Update to LRO information in CIWQS to reflect current City staffing; the City updated the CIWQS LRO information in September 2021.

Audit Conclusions and Recommendations
Based on this evaluation, the following can be concluded about the effectiveness of the City’s SSMP:
• The overall number of spills is low, with less than 10 spills a year. • The highest number of spills as well as the highest volume to reach surface waters occurred over periods of heavy rains in the winters of 2017 and 2019. The City is working to upgrade the Crinella Pump Station to allow for pumping of higher volumes during storm events. The Audit recommends that the City track the frequency of I&I SSOs following the upgrades; if SSO rates are not improving, additional collection system capital projects may be needed.
• The City’s largest two SSOs by volume occurred at the same location along 290 Pope St.

The Audit further recommends that the City investigate potential design or capacity issues at this location and work to prevent SSOs reoccurrence here. • The most frequent cause of spills is oil and grease, with 22 of the 47 total spills having been caused by grease. Following a 2007 grease spill where 1,800 gallons of sewage reached surface waters, the City implemented proactive weekly checks at system hotspots and FOG-caused spill volumes have decreased since. The Audit recommends the City continue its “hot spot” cleaning program as well as restaurant inspection and outreach program. These programs are discussed in Section 7 of the SSMP. • The City will need to review the WDR and determine what changes, if any, will be needed to bring its SSMP in compliance with the revised WDR order recently issued by the SWRCB.

Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 7 of 9
Compliance with SSMP Requirements
As part of this Audit, each SSMP element was reviewed and compared with WDR requirements D.13(i) through (xi).

A review and summary of recommendations for each SSMP Sections is presented below:

1. Goals
Audit task:

Review stated goals and recommend revisions as needed.

Audit findings:

Goals are up to date; no recommendations made at this time.

2. Organization
Audit task:

Review organization chart, roles and contact information for responsible officials, and recommend revisions as needed.

Audit findings:

The City’s organization chart and roles needed updates to show the current roles and organization of the Public Works Department. The City also updated LRO personnel info on CIWQS.

3. Legal Authority
Audit task:

Review relevant Municipal Code sections (13.20 and 13.24) and their respective descriptions under this section and recommend revisions as needed.

Audit findings:

The Ordinances were found to be adequate; no updates were made since the last SSMP update in March 2019. The City’s Municipal Code is available online; the online records are updated on a regular basis.

4. Operations and Maintenance
Audit task:

Review different subsections, compare against WDR requirements, and recommend revisions as needed.

Audit findings:

Most subsections were found to be up-to-date; revisions were made to note that the City does not use chemical root control (Section 4.2) and to reflect the City’s current Capital Improvement Plan (Section 4.3).

Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 8 of 9

5. Design and Construction Standards
Audit task:

Review relevant section (Section 6 - Sanitary Sewer System) of the Water and Sewer Standards (Resolution No. 93-58, June 1993) and recommend revisions as needed.

Audit findings:

The Standards were found to be adequate. No recommendations made at this time.

6. Overflow Emergency Response Plan
Audit task:

Review the Overflow Emergency Response Plan, compare against WDR requirements, and recommend revisions as needed.

Audit findings:

Per findings in the The Overflow Emergency Response Plan is summarized in Section 6 of the SSMP. The full document is included as an attachment to the SSMP. The Plan was reviewed and the only recommendation was to update the Organization Chart.

7. Fats, Oils, and Grease (FOG) Control Program
Audit task:

Review description of FOG Control Program, compare against WDR requirements, and recommend revisions as needed.

Audit findings:

The City continues to identify and clean sections of the sewer system that are subject to grease blockages. The City continues to distribute materials regarding source control activities to educate local businesses about FOG control. The discussion on the City’s restaurant inspection program was updated.

8. Capacity Management
Audit task:

Review the Capacity Management and System Evaluation and Capacity Assurance Plan subsections and recommend revisions as needed.

Audit findings:

The information in this section of the SSMP was found satisfactory; the only recommendation was to update the current status of CIP projects. See also Section 4.3.

9. Monitoring, Measurement, and Program Modifications
Audit task:

Review the subsections and recommend revisions as needed.

Audit findings:

Once the audit is finalized and audit recommendations incorporated into Version 8 of the SSMP, the SSMP updates will be summarized in this section.

Agenda Item #9.1.

City of St. Helena
SSMP Audit Results (November 2022) Page 9 of 9

10. SSMP Audits
Audit task:

Review section, compare against WDR requirements, and recommend revisions as needed.

Audit findings:

The section was found to be up to date.

11. Communication Program
Audit task:

Review section, compare against WDR requirements, and recommend revisions as needed.

Audit findings:

The section was found to be up to date.

Agenda Item #9.1.

City of St. Helena
Sewer System Management Plan
(SSMP)
Agenda Item #9.1.

City of St. Helena
Sewer System Management Plan Version 8 – January 2023
City of St. Helena
Wastewater Treatment and Reclamation Plant
Sewer System Management Plan
1 Goals..............................................................................................................................1-1 2 Organization...................................................................................................................2-1 3 Legal Authority..............................................................................................................3-1 4 Operation and Maintenance Program ............................................................................4-1

4.1 Collection System Map ...........................................................................................4-1

4.2 Prioritized Preventive Maintenance ........................................................................4-1

4.3 Rehabilitation and Replacement..............................................................................4-2

4.4 Training ...................................................................................................................4-3

4.5 Contingency Equipment and Replacement Inventories..........................................4-4 Attachments:

Collection System Map
Infiltration/Inflow Analysis (2000)
Sewer Flow Isolation Study (2007)
Manhole Surveys
Sanitary Sewer Video Inspection Work Sheet
Sanitary Sewer Maintenance Report
Sanitary Sewer Work Sheet
Outreach to Plumbers & Sewer Contractors
Training Attendance Form
5 Design and Performance Provisions..............................................................................5-1

5.1 Standards for Installation, Rehabilitation and Repair .............................................5-1

5.2 Standards for Inspection and Testing of New and Rehabilitated Facilities ............5-2 6 Overflow Emergency Response Plan.............................................................................6-1

6.1 Notification..............................................................................................................6-1

6.2 Response..................................................................................................................6-1

6.3 Reporting.................................................................................................................6-4

6.4 Impact Mitigation....................................................................................................6-4 Attachments:

Overflow Emergency Response Plan
Attachments:

SSO Event Report From
SSO Water Quality Monitoring Plan
SSO and Backup Response Plan Field Guide
7 Fats, Oils, and Grease (FOG) Control Program.............................................................7-1

7.1 Identification & Sewer Cleaning.............................................................................7-1 Agenda Item #9.1.

City of St. Helena
Sewer System Management Plan Version 8 – January 2023

7.2 Source Control.........................................................................................................7-1

7.3 Facility Inspection...................................................................................................7-1

7.4 Legal Authority .......................................................................................................7-1 Attachments:

Grease Trap Ordinance
FOG Outreach Materials
FOG Inspection Materials
8 System Evaluation and Capacity Assurance Plan .........................................................8-1

8.1 Capacity Assessment...............................................................................................8-1

8.2 System Evaluation and Capacity Assurance Plan...................................................8-1 9 Monitoring, Measurement, and Program Modifications................................................9-1 10 SSMP Program Audits.................................................................................................10-1 11 Communication Program.............................................................................................11-1 Agenda Item #9.1.

City of St. Helena i
Sewer System Management Plan Version 8 – January 2023
Introduction
The City of St. Helena’s (City) sanitary sewer collection system conveys wastewater for the area within the city limits (3,285 acres) to the Wastewater Treatment and Reclamation Plant (WTRP). The system includes 18.8 miles of sewer pipelines ranging in diameter from four to 24 inches, and one lift station located on Crinella Drive. The WTRP has a permitted average dry weather flow design capacity of 0.5 million gallons per day (MGD). The City currently has a population of about 5,500 residents.

The City’s Sewer System Management Plan (SSMP) was initially developed in 2006 to comply with requirements of a 2005 Order from the San Francisco Regional Water Quality Control Board (Regional Water Board). The SSMP was revised several times to comply with a State Water Resources Control Board (State Water Board) Order and subsequent amendments. The SSMP complies with Provision D.13 of State Water Board Water Quality Order (WQO) 2006-0003 Sanitary Sewer System Waste Discharge Requirements (WDR) and the associated Monitoring Reporting Program (MRP). This latest version of the SSMP, Version 8, includes recommendations from Regional Water Board 2021 Collection Systems Inspection findings as well as from internal SSMP audits performed in 2014, 2016, 2019, and 2022.

It should also be noted that, in December 2022, the State Water Board adopted a revised WDR, which will become effective in June 2023. Over the following months, the City will review the WDR and determine what changes, if any, are needed to bring its SSMP in compliance with the revised regulation.

Agenda Item #9.1.

1. Goals
Agenda Item #9.1.

City of St. Helena Page 1-1
Sewer System Management Plan Version 8 – January 2023
1 Goals
The City of St. Helena’s goals include the proper management, operation, and maintenance of all parts of the wastewater collection system, adequate capacity to convey peak flows, minimizing frequency of Sanitary Sewer Overflows (SSOs), and mitigating the impact of SSOs.

Agenda Item #9.1.

2. Organization
Agenda Item #9.1.

City of St. Helena Page 2-1
Sewer System Management Plan Version 8 – January 2023
2 Organization
The City’s organization chart identifies agency staff responsible for implementing, managing, and updating the SSMP. Additionally, it includes the chain of communication for responding to and reporting SSOs. Figure 1 illustrates the organization chart for the City Public Works and roles are further described below.

Figure 1. City of St. Helena Public Works Organization Chart City Council. The Mayor and Council members represent the residents of St. Helena, establish all public policy, and adopt policies responsive to the community. The City Council meets two evenings per month.
• The City Council’s role in the SSMP is as follows:
o Look to the Director of Public Works for reports on any SSOs o Make decisions regarding resolution of collection system problems City Manager. The City Manager is the administrative head of the government of the City of St. Helena responsible for providing general administrative management of the City; providing a liaison between the City Council and Staff; carrying out, on behalf of the City Council, its policies, rules, regulations and laws; supervising the preparation of the annual budget; and overseeing the preparation of council agendas and material for Council Meetings.

City Clerk. Provides information updates to City Council and arranges for emergency meetings if necessary.
• The City Clerk’s role in the SSMP is as follows:
o May, at times, receive phone calls regarding SSOs
o Arrange for emergency meetings, if necessary
Agenda Item #9.1.

City of St. Helena Page 2-2
Sewer System Management Plan Version 8 – January 2023
Director of Public Works (Director). Implement City Council policy, establishes departmental policy, plans strategy, leads staff, allocates resources, delegates responsibility, authorizes outside contractors to perform services, and may serve as public information officer. Prepares wastewater collection system planning documents; manages capital improvement delivery system; documents new and rehabilitated assets; and coordinates development and implementation of SSMP.

The Director is legally responsible for monitoring, compliance and reporting associated with the City’s National Pollutant Discharge Elimination System (NPDES) permit, the State Department of Health Services water purveyor permit, transportation and commercial trucking permits, surface mining reclamation, the safety of the City’s two dams and reservoirs and their operations, and is the City’s primary point of contact with the ecological, environmental, and other water quality and water rights regulatory agencies.

The Director plans, bids, manages and monitors all Capital Improvement Projects (CIP) for each of the Department of Public Works’ functional divisions. For private (non-City) projects, the City Engineer or City Surveyor are responsible for the review of tentative and final parcel and subdivision maps, improvement agreements, inspection of privatelyconstructed public improvements, review of use permits, review and approval of all encroachment permits, staff for the Tree Committee, monitoring of mitigation measures, safety issues of all City facilities, staffing of Napa County Transportation Planning Agency and Water Resources Planning Committee. DPW Administration personnel attend and participate in each Planning Commission and City Council meeting. • The Public Works Director’s role in the SSMP is as follows:
o Prepares wastewater collection system planning documents o Coordinates development and implementation of the SSMP o Reports SSOs to City Council
o Works with Sewer System Supervisor to resolve and report SSOs o Works with Sewer System Supervisor to implement fats, oils, and grease program, and other special collection system programs.

Public Works Operations Manager. Under general supervision from the Director of Public Works, manages the operation services of the streets, storm drain, garage, facilities, wastewater collection, water distribution, and parks maintenance services. Exercises direct supervision over public works supervisors in those divisions, as well as professional, technical and support staff of operations. Performs a wide variety of professional, administrative, human resources, analytical and management support within assigned program areas; develops, implements and administers assigned program responsibilities, including budget preparation, financial management, reviews and processes invoices, conducts research; performs other related duties as required. • The Operations Manager’s role in the SSMP is as follows:
o Assists Director with management of SSMP
o Receives reports of SSOs
o Works with Sewer System Supervisor to resolve and report SSOs Agenda Item #9.1.

City of St. Helena Page 2-3
Sewer System Management Plan Version 8 – January 2023
o Works with Sewer System Supervisor to implement fats, oils, and grease program, and other special collection system programs.

Underground Utilities Superintendent. Under general direction from the Director and Operations Manager, supervises, evaluates and participates in the work of crews responsible for construction, repair, maintenance and operational work in the Sewers operational unit of the Public Works Department; ensures safe work practices, work quality and accuracy; maintains appropriate work records which may include time cards and work orders; serves as a technical resource for assigned work crews, Operations Manager, and the Director; performs other related duties as required.
• The Underground Utilities Superintendent’s role in the SSMP is as follows:
o Manages field operations and maintenance activities
o Provides relevant information to Operations Manager
o Leads emergency response
o Works with Operations Manager and Director to report SSOs to the State o Trains field crews
o Works with Operations Manager and Director to implement fats, oils, and grease program, and other special collection system programs.

Collection System Operation Team. Under the supervision of the Underground Utilities Superintendent performs field operations and maintenance activities, provides relevant information to agency management, prepares and implements contingency plans, leads emergency response, and investigates and reports SSOs. Performs preventive maintenance activities, mobilizes and responds to notification of stoppages and SSOs (mobilize sewer cleaning equipment, by-pass pumping equipment, and portable generators). • The Collection System Operation Team’s role in the SSMP is as follows:
o Perform preventative maintenance activities
o Respond to stoppages and SSOs
o Report equipment needs to Sewer System Supervisor
The names and contact information for each person in the positions described above are kept on file at the Public Works office. The information is updated on an on-going basis as personnel changes are made.

Agenda Item #9.1.

3. /HJDO$XWKRULW\
Agenda Item #9.1.

City of St. Helena Page 3-1
Sewer System Management Plan Version 8 – January 2023
3 Legal Authority
This section demonstrates the City’s legal authority to control infiltration and inflow (I/I) and to require proper construction, testing and inspection of their sewer system.

The City’s Sewer Service System Ordinance, Chapter 13.20 of the Municipal Code, includes information on sewer charges, use of funds, rules for annexation to the municipal sewer, prorated charges for line extensions, installations of adequate capacity, compulsory connections, and standard sewer construction details and specification adoption procedures.

Additionally, the City’s Wastewater Discharge Ordinance, Chapter 13.24 of the Municipal Code, includes prohibitions on discharges, storm drainage, ground water, unpolluted water, and limitations on radioactive wastes, use of garbage grinders, point of discharge, holding tank waste, and wastewater strength. The Wastewater Discharge Ordinance also includes provisions on wastewater volume, administration, user charges and fees, enforcement, abatement, and grease traps. In January/February 2023, the City will be updating the Municipal Code to require the responsibility of ongoing ownership and maintenance of sewer laterals (both on private property and within the public Right-of-Way) lie with property owners. The City’s entire Municipal Code is available online at www.codepublishing.com/CA/StHelena.

Agenda Item #9.1.

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Agenda Item #9.1.

City of St. Helena Page 4-1
Sewer System Management Plan Version 8 – January 2023
4 Operation and Maintenance Program

4.1 Collection System Map
A map of the City’s collection system is maintained and updated periodically based on the Underground Utilities Superintendent’s guidance. The map was updated in November 2014 and closed-caption television (CCTV) inspections of the collection system were completed in May 2015. The collection system map is accessible to City staff in both hard copy and electronic formats. The current collection system map contains the following information:
• Manhole ID numbers
• Manhole locations with reference to streets and property lines • Line size and direction of flow
• Force main size and direction of flow
• Private lines and direction of flow
• Cleanouts
• Lampholes
• Pump stations
• Wastewater treatment plant
• Rivers/creeks
Subsequent versions of the map will include the following additional information:
• GPS coordinates
• Manhole rim elevations
• Manhole invert elevations
• Material types
• Worker safety information
• Pipe slope
• Date built
• Pipe invert elevations

4.2 Prioritized Preventive Maintenance
The City completed an Inflow/Infiltration (I/I) Analysis in July 2000 (attached) and a Sewer Flow Isolation Study in the spring of 2007 (attached). Additionally, the City completed an Integrated Utility Master Plan (IUMP) in April 2021.
1 The I/I Analysis recommended that
the City use smoke testing, flow isolation, manhole inspections, and source defect/cost benefit analyses to reduce the amount of I/I entering the system during wet weather. The Sewer Flow Isolation Study assessed nighttime flows at 32 manhole locations to identify areas of excessive apparent infiltration. Based on this evaluation, subsequent manhole and CCTV inspections were recommended and the City is using this information to prioritize system rehabilitation. Additionally, previous manhole surveys and system CCTV efforts (see attached examples) are evaluated to prioritize maintenance activities. 1 Available at:
www.cityofsthelena.org/sites/default/files/fileattachments/public_works/page/2491/cosh_utility_master_plan_fi nal_draft.pdf
Agenda Item #9.1.

City of St. Helena Page 4-2
Sewer System Management Plan Version 8 – January 2023
The City’s Underground Utilities Division maintains a Sanitary Sewer Maintenance Report which is updated each time maintenance work is performed on a line (see attachments).

Sewer line maintenance is performed as necessary. The City has a planned schedule for cleaning sewer lines that are highly susceptible to root intrusion, grease, and various debris.

The frequency of cleaning a sewer line is determined by the cleaning history needs, with the goal of preventing sewer line blockage and overflows. Areas with previous SSOs caused by grease or roots are reviewed more frequently to ensure that the same problem does not occur again.

The City does not use chemicals for root control in the collection system. Instead, sewer lines are cleaned through other means, using the following equipment:

Rodder
The Rodder is used to remove roots, heavy grease,
and other obstructions from inside the sewer lines by
quickly rotating a hydraulically driven continuous steel cable rod with a cutting blade or saw attached to the
leading cable.

Hydro
The Hydro cleans grit and grease accumulated from
sewer mains with water pressure, scouring the inside
of the pipes. The Hydro is used primarily for cleaning
sewer lines that have the highest potential for
blockage, mostly due to grease being discharged into
the sewer lines. These areas are described as "hot
spots".

4.3 Rehabilitation and Replacement
The overall goal of the City’s SSMP is to maintain the collection system and prevent SSOs.

Currently, 80% of collection system inspections are in response to a problem and 20% are routine inspections in areas which have previously had a problem. Every Friday, all ‘hot spots’ manholes are visited. The Underground Utilities Division completes the attached Sanitary Sewer Work Sheet when performing inspections. Additionally, all manholes are visited systematically.

The City completed a five-year program to CCTV the collection system in May 2015. As a result of this program, pipe lining and repair work was performed in the residential area surrounding and tributary to the Crinella Lift Station. This work was completed in 2015/2016 and is expected to reduce infiltration and inflow, along with the probability of SSOs in that area.

Agenda Item #9.1.

City of St. Helena Page 4-3
Sewer System Management Plan Version 8 – January 2023
As a result of the IUMP, the City will be conducting “Phase 1” cleaning, CCTV and smoke testing during 2023 and funded via General Obligation Bond approved by City residents in June 2022.

The City’s Underground Utilities Division maintains a Sanitary Sewer Maintenance Report which is recorded each time maintenance work is performed on a line (see attachments).

Sewer line maintenance is performed as necessary. The City has a planned schedule for cleaning sewer lines that are highly susceptible to root intrusion, grease, and various debris.

The frequency of cleaning a sewer line is determined by the cleaning history needs, with the goal of preventing sewer line blockage and overflows. Areas with previous SSOs caused by grease or roots are reviewed more frequently and routine maintenance is conducted bimonthly.

The Wastewater Enterprise Fund budget is used to ensure adequate resources are available to maintain and upgrade the City’s collection system. The budget includes funding from the following sources:
• Wastewater Enterprise. Used for day-to-day operations, maintenance, and repair of sewage collection and treatment activities associated with the City’s wastewater system.
• Wastewater Capital Projects. This funds the costs for capital projects that upgrade, improve, or repair/replace portions of the wastewater collection and treatment system.
• Wastewater Impact Fees. This funds the costs for wastewater collection and treatment system capital projects that are needed to serve new development.

The total annual operating budget for wastewater operations is approximately $1,000,000.

The City’s goal is to replace 1% of its sewer mains annually, through $150,000 earmarked annual expenditure.

The City’s current 5-Year Capital Improvement Plan covers Fiscal Years 2022/2023 through 2026/2027 and dedicates $19,000,000 to wastewater projects. The majority of these funds are earmarked for critical WWTRP upgrades that will be complete in 2023. The CIP is reviewed and updated annually, based on current priorities and funding availability. Current and past CIPs are available online at www.cityofsthelena.org/publicworks/page/capital-improvementplan-cip.

It should be noted that the City will be adopting a user rate increase in Q1 2023 for implementation on July 1, 2023. The updated rate structure will fund additional “high priority” and systematic pipeline replacement efforts.

4.4 Training
The “Training Sign-In Form” (attached) is used to keep a log of staff attendance at training events. The Collection System Operation Team is required to participate in several trainings per year.

The City offers the following formal and informal trainings:

Agenda Item #9.1.

City of St. Helena Page 4-4
Sewer System Management Plan Version 8 – January 2023
• Technical training: Training sessions are scheduled periodically by the Chief Wastewater Treatment Plant Operator to address training on routine O&M activities.

Most training is completed as on-the-job training, where knowledgeable staff trains less experienced staff on the O&M of equipment.
• Skills training (for equipment use and maintenance tasks): Staff members learn on the job without the use of standard O&M procedures. If new equipment is purchased, the supervisor requests that the manufacturer offer an informational training on the proper use of the equipment.
• Safety training: Safety meetings are conducted by the supervisor, who selects topics based on needs of staff. American Water Works Association videos are also available.

Through participation with Bay Area Clean Water Agencies (BACWA), the City developed a fact sheet educating plumbers and sewer contractors on preventing SSOs and informing the City if work in private laterals may cause issues in sewer main downstream (attached). This fact sheet is distributed to all plumbers and building contractors who perform work in the City’s service area.

4.5 Contingency Equipment and Replacement Inventories
Recent equipment purchases include updated CCTV inspection camera with internal components, addition of trailer mounted CCTV sewer inspection trailer, and a vacuum excavator purchased in 2018.

Agenda Item #9.1.

Attachments
Agenda Item #9.1.

Collection System Map
Agenda Item #9.1.

Agenda Item #9.1.

Infiltration/Inflow Analysis (2000)
Agenda Item #9.1.

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INFLOW I INFILTRATION

ANALYSIS
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Feb 2000 Date
Prepared For:

THE CITY OF
ST. HELENA
July 6,2000
Prepared By:

EHVIAONM£NW.L SERVICES
ADS Environmental Services
3830-A Charter Park Drive
San Jose, CA 95136
(408) 448-2315
Agenda Item #9.1.

August 5, 2004
Bob Kyle
City of Sarnt Helena
1480 Main Street
Saint Helena, CA. 94574
/j_V a]_ --J ENVIRONMENTAL
SERVICES®
Re: 2000 ADS RDIJ Analysis Report
Dear Mr. Kyle,
ADS Environmental Services is pleased to have the City of Saint Helena (City) as a primary client in the Northern Californian area. ADS makes every a ttempt to provide the City with the most accurate and up-to-date information concerning the wastewater flow system. We take great pride in providing our clients with the best-trained flow monitoring staff in the flow monitoring business.

Please find enclosed a CD containing the report we completed for you in 2000 as requested. The results listed in the report are final. The scattergraphs for Appendix D I had to generate from the only data set we could locate.

One note of caution is that T am not sure if the data we located and I have provided to you in the scattergraphs and in Excel format is the final data set. If the Excel data is to be fed into a model it should be done with caution. If you would like me to review the data set to ensure it is the final one, I am certainly able to do so. but we would have to quote a price for the time required for me to complete the review. T apologize for this inconvenience.

Please do not hesitate to contact me at the ADS Huntington Beach office on (714) 379 9778, if you have any further questions or require any further fl ow metering services.

Sincerely

ADS ENVIRONMENTAL SERVICES
Gillian Woodward, P.E.

Senior Civil Engineer
AN 'IXEL .iOHNSON INC COMPANY
15205 Spnngdale S1, Hunllngton Beach. CA. 92647 • Phone 714·379-9776 • Fax 714·379·9568 Agenda Item #9.1.

TABLE OF CONTENTS
City of St. Helena
Inflow /Infiltration Analysis
1 Project Summary and Recommendations ........................................................... 1

1.1 Project Objectives ................................................................................................. 1

1.2 Project Scope of Work .......................................................................................... 1

1.3 Basin Flow Analysis ................................................................ ........................ ...... 1

1.4 ROll Analysis ........................................................................................................ 3

1.5 Hydraulic Analysis ................................................................................................ 4

1.6 Recommendations ............................................................. ......... .......... ................ 5

1.6.1 Short Term Recommendations: .. ................................................................... 5

1.6.2 Long-Term Recommendations: ..................................................................... 6 2 Project Approach ................................................................................................... 7

2.1 Basin Identification .............................................. ................................................. 8

2.2 Flow Monitoring Equipment ................................................................................ 10

2.3 Installation ........................................... ............................................................... 11

2.4 Data Collection, Calibration, and Quality Assurance .......................................... 12

2.5 Rain Gauges and Rainfall Data .......................................................................... 13 3 Basin Flow Analysis ............................................................................................ 15

3.1 Net Dry Weather Flows ...................................................................................... 15

3.2 Net Wet Weather Flow ....................................................................................... 16

3.2.1 Average-Day Wet Weather Flows ............................................................... 16

3.2.2 Peak-Hour Wet Weather Flows ................................................................... 17

3.3 Net Minimum Flows - Dry vs. Wet Periods ........................................................ 19 4 ROll Analysis ........................................................................................................ 20

4.1 Net ROll Analysis ............................................................................................... 21

4.2 Q vs. i diagrams .. ............ .................................................................................... 23

4.3 Normalized ROll Analysis ................................................................................... 24 5 Monitoring Site Hydraulic Analysis .................................................................... 26

5.1 Peak-hour Wet to Average-Day Dry Flow Evaluation ......................................... 26

5.2 d/0 Ratio Evaluation ......................... .................................................................. 27

5.3 Scattergraph Analysis ......................................................................................... 29 6 Conclusions and Recommendations ................................................................. 31

6.1 Conclusions ........... ............................................................................................. 31

6.2 Recommendations ..................................... ............................................ ............. 32 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
1 PROJECT SUMMARY AND RECOMMENDATIONS
ADS Environmental Services performed an Inflow & Infiltration (1/1) analysis in the City's sanitary sewer collection system. This report contains a summary of the flow monitoring data collected, the study methodology, and the subsequent 1/1 analysis. A hydraulic and capacity analysis was also performed based on the flow monitoring data.

1.1 Project Objectives
The objective of this 1/1 study was to quantify the amount of Rainfall Dependent Inflow and Infiltration (ROl l) entering sub-basins (Basins) within the collection system. Then, these Basins were to be prioritized based on the amount of ROll entering each; with recommendations provided to locate and quantify specific defects that allow the extraneous flow to enter the system.

1.2 Project Scope of Work
The scope of work for the 1/1 Study included the following tasks:
• Develop flow Basins and identify possible monitoring locations. • Investigate flow monitoring sites.
• Install temporary flow monitors at proposed locations. • Perform flow monitoring for a period of one week during the dry weather period and for a period of four weeks during the wet weather period. • Quantify ROll, and make recommendations for further action based on the flow monitoring data collected

1.3 Basin Flow Analysis
The flow monitoring study consisted of dividing the collection system into discrete Basins and simultaneously monitoring the discharge of each Basin during both a wet and the dry weather period. The flow data was used to calculate the amount of ROll entering each Basin.
1 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
The collection system was divided into a total of six (6) Basins; which were comprised of nine (9) flow monitoring sites (monitored using ADS Model 1500 open channel flow monitors). A flow schematic of the Basins is provided in Chapter 2. Two (2) tipping bucket rain gauges were also used to measure the volume and intensity of each rainfall event. Rainfall and flow data was collected at 15-minute intervals for the entire duration of the project.

Flow and rain monitoring was performed during the following two periods:
• Dry Weather:
• Wet Weather:

September 11 I 1999 through September 21 I 1999
February 5, 2000 through March 7, 2000
The average daily flows were calculated for each Basin for both the dry and wet weather periods. A comparison of the dry weather flows and wet weather flows during the largest volume storm event (Storm No. 1) is presented graphically in Figure 1.1.

Figure 1.1 -Average Daily Dry Vs Average Daily Wet Weather Flows As shown in Figure 1.1, wet weather had varying effects on each of the Basins. In Basin No. 6 for example, the average-day wet weather flow was nearly equivalent to the 2 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
average-day dry weather flow. Conversely, in Basin No. 3, the average-day wet weather flow was about fifteen (15) times higher than the average-day dry weather flow.

1.4 ROll Analysis
Net ROll was calculated for each Basin by subtracting average dry weather flows from wet weather flows and compensating for pre existing infiltration. The Basins were then normalized by dividing the net ROll by the total number of inch diameter-miles of pipe within each Basin. The ROll was further normalized by dividing each Basin's computed net ROll for each storm by the inches of rainfall observed during the storm. A summary of the normalized ROll for each Basin (two-storm average) is presented in Figure 1.2. c
a::
"C
Cl)
.!:!
n;
E
...
0 z
Basin No.

Figure 1.2 -Normalized ROll (gal/ idm-inch rain)
As shown in Figure 1.2, the Basins with the highest normalized ROll (averaged over two storm events) were Basins 3 and 1. These Basins accounted for about 68% of the total study ROll normalized volume (in total gallons per inch of rain). ROll in Basins 2 and 4 was slightly below the average for the study Basins and accounted for about 23% of the study ROll volume. ROll in Basins 5 and 6 was less than 1/3 of the study 3 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
average normalized ROll and accounted for only about 9% of the total study ROll volume.

1.5 Hydraulic Analysis
A hydraulic analysis was performed at each flow monitoring location using gross flows to evaluate the pipeline in the immediate area around the flow monitor. The basis of this evaluation was to compare the peak-hour wet flow to average-day dry flow ratios and to compare the depth-of-flow to the diameter (d/0) of the pipe.

The peak-hour we.t to average-day dry flow ratios (peaking factors) were graphed and are presented in Figure 1.3.
-Actual Peak:Average -Design Peak:Average
20 0~------------------------------------------------------,

18.0+----

16.0 -t------
5 14.0 -t------
0 Cll 12.0
u..

C) 10.0 c:
:X 8.0 Cll
8:. 6.0

4.0 2.0

0.0 1 2A 28 3A 38 3C 4 5
Monitor No.

Figure 1.3 - Peak to Average Ratio (Actual Vs Typical Design) 6 As shown in Figure 1.3, the gross flow peaking factors in the immediate vicinity of the flow monitors ranged from 5.6 to 19.5. All of the pipelines associated with the monitors exhibited flow peaking factors that exceeded 3.0 (which is commonly used as a design peaking factor). Therefore these pipelines may be exceeding design capacity. 4 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
The d/0 ratio was graphed for each pipeline associated with the monitors and is presented in Figure 1.4.
0 ~ 3.0
0::
.e 2.0
1:)

1.0 0.0
1 1-Actual d/0 -Design d/0 I
'2A 28 3A 38 3C 4 5 6
Monitor No.

Figure 1.4 - diD Ratio Vs Typical Design
Sewers are commonly designed to handle a diD ratio of 0.75 at peak flows. The graph in Figure 1.4 shows that the d/0 ratio during the study period exceeded 0.75 for flow monitoring sites 1,2A, 3A, 3B, 4, 5, and 6. In fact, five of these s1tes exceeded a d/D ratio of 2.0, which means the p1peline was in significant surcharge conditions with wastewater traveling up the manhole. This indicates that the pipelines in the immediate area of the flow monitors listed above were experiencing backup conditions and may be exceeding design capacity during these periods.

1.6 Recommendations
Based on the ROll analysis, it is recommended that the following short and long term projects be considered.

1.6.1 Short Term Recommendations:
• Perform Smoke Testing on Basins 1, 2, and 3.
• Perform flow isolations on Basins 1, 2, 3, and 4.
5 Agenda Item #9.1.

City of St. Helena
Inflow I Infiltration Analysis
• Conduct T.V. and manhole inspections based on results of smoke testing and flow isolations.
• Perform a source defect/cost benefit analysis based on the results of the manhole inspections and T.V. inspections.
• Begin to rehabilitate defects based on cost benefit analysis.

1.6.2 Long-Term Recommendations:
• Implement long-term flow monitoring. This will help gauge the success of any future rehabilitation work.
• Implement comprehensive infrastructure management system. 6 Agenda Item #9.1.

2 PROJECT APPROACH
City of St. Helena
Inflow /Infiltration Analysis
Rain Dependent Inflow and Infiltration (RDII) consists of extraneous water that enters a sanitary sewer system during or just after a storm event. Inflow is typically described as water that directly enters a system through roof leaders, clean-outs, foundation drains, sump pumps, and cellar, yard, and area drains. Infiltration is typically described as water that enters a sewer system from the ground through defective pipes, pipe joints, damaged lateral connections, or manhole walls.

Most collection systems have -been designed to convey some quantity of ROll.

Excessive ROll however, can have the following impacts on a collection system:
• Reduced collection system capacity
• Increased probability of sanitary sewer overflows.
• Increased treatment and transport costs.

The most cost effective means of identifying, quantifying, and prioritizing ROll entering a collections system is through a comprehensive RDII study comprised of the following major components:

1. Collection system review and Basin identification.

2. Simultaneous flow monitoring and rain gauging.

3. Data analysis and Basin prioritization.

4. Sanitary Sewer Evaluation Surveys (SSES) including smoke testing, manhole inspection, flow isolation, dye water flooding, closed circuit television, etc.

ADS conducted tasks 1 through 3 of the above RDII study; each of which are discussed in detail in this report.
7 Agenda Item #9.1.

2.1 Basin Identification
City of St. Helena
Inflow /Infiltration Analysis
ADS reviewed the City St. Helena sanitary sewer collection system maps. The study area was divided into six (6) separate Basins using nine (9) flow monitors. A map depicting the topographic Basin boundaries is shown in Figure 2.1 .

A Rain Gauge
e Flow Monitor
. ·'
/
Figure 2.1 -Basin Map
/
/
/
,./
'
~---I \
WWTP (
)
8 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
A flow schematic of the monitoring locations and Basins indicating direction of flow is shown in Figure 2.2
............... -..... , .. ,_,, ........................... , .. __ , ......................................................... -·· ··~ ····<-·· .,.--..,.....,--.,---,. ! Overflow Basin 2
Basin 3
Figure 2.2 - Flo.N Schematic
9 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
Basin 1 was hydraulically independent, while the remaining Basins were hydraulically isolated by adding gross sub-basin (e.g. 2A, 2B, etc.) monitor flows, then subtracting measured gross inflow from measured gross outflow of each Basin according to the flow schematic in Figure 2.2. These Basins were considered as the performance units for purposes of conducting the ROll data analysis and evaluation. The Basins and Basin characteristics are listed in Table 2.1 below along with the basis of hydraulic isolation of each.

Table 2.1
Basin Summary
~ ·.~ Len_gtJt of
~!lsin # ''~-;~ Basfs of Hydraulic ~~~tation Pipe;.
l"ch .. MUes, >If',
' ,~,
- "" Cifl (hl...m)
1 SH 01 18,020 22.75
2 SH 2A+ SH2B 15,820 19.02
3 SH 3A + SH 38 + SH 3C- (SH 01 + SH 2A + SH 28) 21 ,645 25.78 4 SH 04 - (SH 3A + SH 38 + SH 3C) 13,430 23.50
5 SH 05- SH 04 13,590 25.38
6 SH 06 - SH 05 16,900 39.61
The individual Basin parameters (linear footage of pipe, inch-miles, and Basin drainage areas) presented in Table 2.1 were obtained from the maps and electronic files provided by the City of St. Helena.

2.2 Flow Monitoring Equipment
The monitor used for this project was the ADS Model 1500 open-channel flow monitor.

This flow monitor consists of depth and velocity sensors and a battery powered microcomputer. The microcomputer includes a processor unit, data storage, and an onboard clock to control and synchronize the sensor recordings. The monitor was programmed to acquire and store depth of flow and velocity readings at 15-minute intervals. A laptop computer was used in the field to retrieve and store data from each flow monitor.
10 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
The ADS Model 1500 uses depth and velocity measurements to calculate the wetted area and average velocity of the wastewater in the pipe. The Continuity Equation (Q=V .. A) is then used to calculate flow.

2.3 Installation
Installation of the flow monitoring included the following four steps:
• Site investigation
• Installation of equipment
• Monitor Start-up
• Monitor calibration
A typical Model1500 flow monitor installation is shown in Figure 2.3.

MANHOLE

PRESSURE
SENSOR

EXISTING PIPE
Figure 2.3- Typical Installation
The installation presented in Figure 2.3 is typical of the configuration used for this study and is customarily used on circular or oval pipes up to approximately 42-inches in diameter or height. In this type of installation, depth and velocity sensors are mounted 11 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
on an expandable ring and installed one to two pipe diameters upstream of the pipe/manhole connection in the incoming sewer pipe. This reduces the affects of turbulence and backwater.

2.4 Data Collection, Calibration, and Quality Assurance During the monitoring period, field crews visited each monitoring location on a weekly basis to retrieve data, verify proper monitor operation, and document field conditions.

The following general quality assurance steps were taken to assure the integrity of the data collected:
• Measure Power Supply: The monitor is powered by a dry cell battery pack.

Power levels are recorded and battery packs replaced, if necessary. A separate battery provides back-up power to memory, which allows the primary battery to be replaced without the loss of data. • Perform Pipe Line Calibrations and Confirm Depth and Velocity: During initial and final site visits (at a minimum), a field crew member descends into the manhole to perform a field measurement of flow rate, depth and velocity to confirm they are in agreement with the monitor. Since the ADS V-3 velocity sensor measures peak velocity in the wetted cross-sectional area of flow, velocity profiles are also taken to develop a relationship between peak and average velocity in the line.
• Measure Silt Level: During initial and final site visits, a member of the field crew descends into the manhole and measures and records the depth of silt at the bottom of the pipe. This data is used to compute the true area of flow. • Confirm Monitor Synchronization: The field crew checks the flow monitor's clock for accuracy.
• Upload and Review Data: Data collected by the monitor is uploaded and reviewed for comparison with previous data. All readings are checked for 12 Agenda Item #9.1.

3.0 2.5
Q)2.0 .J::
g1 .5

1.0 0.5

0.0 Feb
City of St. Helena
Inflow I Infiltration Analysis
consistency and screened for deviations in the flow patterns, which indicate system anomalies or equipment failure.

2.5 Rain Gauges and Rainfall Data
An important part of an ROll study is the collection and analysis of rainfall data (volume and distribution). The rainfall data is the basis for determining the ROll in each Basin being studied. A chart of rainfall during the study is presented in Figure 2.4.

Rainfall
System Wide
-- RGI -- RG2
I~ II • . h II h I II h .. II It II I. .. It
8 Tue 15 22
Date
Figure 2.4 - Rainfall Chart
1 Mar
Wet weather data was evaluated for the two (2) largest volume rain events. These particular events were chosen because they were significant (i.e. greater than 1.0 inch, lasted more than 5-hours) and were followed by little or no measurable rainfall for 3 days.

For this study, two rain gauges were located in the City of St. Helena for the duration of the study period. Rain gauge #1 was located by the water tank on Spring Mountain Road near the Lookout Reservoir. Rain gauge #2 was located at the pump station off College Avenue.
13 8
Agenda Item #9.1.

City of St. Helena
Inflow I Infiltration Analysis
The Theissen polygon rain gauge distribution method was used to assign rainfall amounts from each rain gauge to the respective Basins. A bisecting line was drawn between the rain gauges and effective areas represented by each gauge were drawn.

Each Basin was assigned rainfall amounts in proportion to the percentage of the Basin area falling within the influence area of each rain gauge. The rain gauge distribution used in this study is indicated in Table 2.2.

Table 2.2
Rain Gauge Weighting for Each Basin
~ Ba5J!l # ,!• a .. ln G,aqf18 o/o R~in GaU,ge,.
·'r #1 ~ .. #2
1 90% 10%
2 100% 0%
3 60% 40%
4 0% 100%
5 0% 100%
6 0% 100%
14 Agenda Item #9.1.

3 BASIN FLOW ANALYSIS
City of St. Helena
Inflow /Infiltration Analysis
Basins were monitored during a dry and wet period to determine the impact of wet weather on the system. Dry weather flows were monitored for approximately one week from September 11 , 1999 through September 21 I 1999. Wet weather flows were monitored for four (4) weeks from February 5, 2000 through March 71 2000.

3.1 Net Dry Weather Flows
Dry weather monitoring took place in September after a long dry period with little or no rain. The net average-day dry weather flow for each Basin is presented graphically in Figure 3.1.

0.25 0.20
"0
Cl 0.15
E
ai
-
cu 0.10
0::
~
..Q
u..

Basin No.

Figure 3.1 -Net Average-Day Dry Weather Flows
As shown in Table 3.1 I the average-day dry weather flow ranged from 0.05 mgd which came from Basins 2 and 6 to 0.23 mgd which came from Basin 5. The combined average-day dry flows from all the Basins was 0.64 mgd. 15 Agenda Item #9.1.

3.2 Net Wet Weather Flow
City of St. Helena
Inflow /Infiltration Analysis
Wet weather flows were monitored during the month of February and March, 2000 when there were multiple rain events. The storms used in this study including their dates, quantity, and duration are presented in Table 3.1.

Table 3.1
Storm Events Evaluated
$to ~ ·Pate ·'~· 5 Raiofat((in} . .. . ~. Duratlo~~. .. "~ RG2 .. . « ~ e~~r RG 1 .. ~ :;, · (t.ours ~:1-i.:
1 2/12/2000 5.22 3.55 48
2 212212000 1.95 1.39 48

3.2.1 Average-Day Wet Weather Flows
To show the impact of these storm events with respect to the net average-day dry weather flow, the average-day wet weather flow (averaged over the two (2) storms) was graphed with the average-day dry flow. This graph is presented in Figure 3.2. 2 3 4 5 6

0.05 0.1 0.13 0.23 0.05

0.47 1.37 0.36 0.57 0.05
Basin No.

Figure 3.2 -Net Average-Day Dry Vs Average-Day Wet Flows 16 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
As shown in Figure 3.2, the average-day wet weather flows were substantially greater then the average-day dry weather flows for Basins 1 .2 and 3. This indicates that the rain had a significant effect on average-day flows. To illustrate this further, the ratio of highest average-day wet weather flow to average-day dry weather flow was calculated and is presented in Figure 3.3.
>.
1'0
Q
en
>
~
>.
1'0
Q
~
1'0
Ql

11. •Peak to ave
6 1
Basin No.

Figure 3.3- Net Average-Day Wet to Average-Day Dry Ratio The graph in Figure 3.3 indicates that Basins 1, 2, and 3 greatly exceed a 3:1 ratio for the wet vs. dry daily flows. The WEF manual of Practice FD-6 indicates that an average-day wet weather flow to average-day dry flow ratio that exceeds 2 to 3 is considered significant.

3.2.2 Peak-Hour Wet Weather Flows
Peak·hour wet weather flows were graphed with average-day dry flows and are presented in Figure 3.3.
17 Agenda Item #9.1.

"C
C)
E
a)
-
CIS
0:::
~
..2
IL.

1.6 1.4

1.2 1.0

0.8 0.6

0.4 0.2

0.0 Basin No.

City of St. Helena
Inflow /Infiltration Analysis
Figure 3.4- Net Average-Day Dry Vs Peak-Hour Wet Flows
As shown in Figure 3.4, the net peak-hour wet weather flows were substantially greater than the average-day dry weather flows for all of the Basins; with the possible exceptions of Basins 5 and 6. This indicates that the rain had a significant effect on peak-hour wet weather flows. To illustrate this further, the ratio of peak-hour wet weather to average-day dry weather flows were calculated and are presented in Figure

3.5. B Peak to avera
Basin No.

Figure 3.5 - Net Peak-hour Wet to Average-day Dry Ratio 18 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
The graph in Figure 3.5 indicates that Basins 1, 2, 3 and 4 exceed a 4:1 flow ratio based on comparing net peak-hour wet weather to net average-day dry weather flows. These ratios may indicate that flow peaking factors are similarly high within portions of the respective Basins. The WEF manual of Practice FD-6 indicates that a ratio that exceeds 3 to 4 is considered significant.

3.3 Net Minimum Flows -Dry vs. Wet Periods
The minir:num recorded flows (in the middle of the night - in units of mgd) during the dry period were determined for each Basin and then compared to the minimum flows recorded (in the middle of the night) early into the wet weather study period.- The recorded minimum flows for each Basin are summarized in Table 3.2 for both the dry and wet periods along with the percentage increase in recorded minimum flows from the dry period to the wet period.

Table 3.2
Summary of Minumum Recorded Flows
Dry vs. Wet Periods
BasJn# 1
, ,fJoW r.un. fl9W Mln/:1;. , Per~dt Flow lta~rean :pry Weather Wet Weather (mgd) . (mgd) Dry to Wet W«J.'ather
1 0.01 0.06 500%
2 0.01 0.11 1000%
3 0.04 0.11 175%
4 0.07 0.12 71%
5 0.11 0.11 0%

0.06 0.06 0%
The above data indicates that minimum flows significantly increase in Basins 1, 2, and 3 from dry to wet weather periods. Basin 2 indicated a 10 fold increase in the minimum recorded nighttime flows from the dry to wet weather periods. These data suggest that infiltration comprises a significant portion of the overall ROll volume for these Basins. 19 Agenda Item #9.1.

4 ROll ANALYSIS
City of St. Helena
Inflow /Infiltration Analysis
An analysis was performed to determine the quantity of Rain Dependent Inflow and Infiltration (ROll) produced by each Basin in the study. The analysis involved subtracting the net Average Dry Weather Flow (ADWF) from the net Wet Weather Flow (WWF) using an ADS proprietary software called Sli/icer®. Sli/icer® takes into consideration weekday or weekend flows and accounts for infiltration immediately prior to a storm. Compensation for the pre-storm elevated flows is termed precompensation.

The process of breaking down the hydraulic impact on a Basin associated with rainfall is termed decomposition. The Sli/icer® output for Basin 2 during the 02/22/00 storm event is depicted in Figure 4.1.

0.5 Storm Event- 02/22/00 08:00
02 ~~~~~~~~---;Jtr---1 t-T:AJV"'t-/";;;:::= -:-::- ---;:--- =t- o.25 ?1 s·

0.4 '0
Ol
E0.3
-
~
0 U:0.2

0.1 0.0
~-t---l-fo...--:---t----..:::--.t-.+t--+ f"<:----1---k---tl--H-+---t--• 0.20 ~ r-~-+~-~-r ~~~r+--~ ~- ~~r-~~~~r-~0 05
----+--1- 0.00
21 Mon
Feb 2000
22 Tue 23 Wed 24 Thu
Date
25 Fri 26 Sat
Figure 4.1
Basin 2 Decomposition Hydrograph
The graph in Figure 4.1 shows that Basin 2 produced a significant volume of ROll during the storm event beginning 02/12/00. In Figure 4.1, the gray highlighted time 20 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
period prior to the storm period is the period during which precompensation is determined. The light purple period is the storm period. The two darker purple periods following the storm period are the recovery periods R1 and R2. Each of these periods is set at 24 hours in duration unless they are extended or reduced due to factors including longer storm period, short duration to subsequent storms (reduced R 1 and R2), and short duration from previous storms (reduced precompensation period).

The Sli/icer® hydrographs for each Basin during the two storm events are included in Appendix A.

4.1 Net ROll Analysis
Net ROll from each Basin was analyzed during each of the two (2) storm events. The ROll was broken down into ROll occurring during the storm event and additional ROll occurring during the recovery periods, R1 and R2. The ROll volume for the storm events was calculated and is presented in Table 4.1.

Tal*4.1
SlJTmry d ~ RDI per Starn Evert
,~l;~.~ ·~·~1 ". Storm~!f ". '" '· Stonn~2 · '.ll, J> ". l·,.· ( t;"'
Basin (2/12100) ,- (n'1/(XJ) StormAriodRll
No. NetfUI NltFQI Net lUI Net lUI ~As a Pen:ertdTota
l'i SiOOri Paiod _Rt-+R2 ~Ferfod R'I+.R2 I!!
1 " Evert Rll . '· ... lb, (nW < ~Ci;(t1lD -.;~tl! (lTV) '~i (~ .., . Yi, ;., .. , $;· ~- ";;.. ., . 1 0.68 0.37 0.13 0.25 49% 2 0.31 0.05 0.12 0.16 64%
3 1.01 0.54 0.49 - ffi%
4 0.15 0.04 0.12 0.33 53%
5 0.11 0.17 0.03 0.04 41%
6 0.05 0.05 0.05 0.25 J30/o
s..bTd 231 1.22 094 1.03 57%
Tcta 3.53 1.97
As shown in Table 4.1 Storm No. 1 had the greatest impact in terms of Net ROll.

Basins 1, 2, and 3 generally produced the largest quantity of ROll (up to 87% of the 21 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
ROll volume during storm 1) and Basins 4, 5 and 6 produced the smallest quantity of ROll.

A review of the net flow responses for each Basin during the study period indicates that both the inflow and infiltration components of ROll are prevalent. Based on the percentages of storm vs. total event volumes in Basins 1, 2, 3 and 4 during storm 1, it appears that the ROll component shifts significantly toward inflow with increasing rainfall volume. It is possible that inflow will predominate in these Basins during any storm of significant volume that is accompanied by saturated antecedent soil conditions (as is the case for storm 1 ).

The 2-storm average Net ROll (in mg per inch of rain) for each Basin is presented graphically in Figure 4.2.

0.30 .,...------------------------,

0.25 +--------
41 -c::

E "' 0.20 '- ::I
- .r:.
0 (J 0.15 > c:
-
c -C) 0.10 a:: E
- 0.05

0.00 1 2 3 4 5 6
Ia ROll Volume 0.10 0.06 0.25 0 .06 0.02 0.02
Basin No.

Figure 4.2- Net ROll Volume (2-storm average)
As shown in Figure 4.2, the net average ROll from the two storm events (in mg per inch rain) ranged from 0.02 mg from Basins 5 and 6 to 0.25 mg from Basin 3. This graph shows that, on average, in excess of 80-percent of the net ROll comes from Basins 1, 2 and 3.
22 Agenda Item #9.1.

a;

4.2 Q vs. i diagrams
City of St. Helena
Inflow /Infiltration Analysis
There is generally a linear relationship between volume of rainfall and net ROll in each basin. This correlation between net flows in each Basin to volume of rainfall can be depicted graphically and is termed a Q vs. i diagram. The Q vs. i diagram for Basin 3 is presented in Figure 4.3.

Q vs i- 03
Total Event Net RDU Volume vs. Rainfall Depth
w
All Storms

2.5 - ~
. 02110<\JO) / ~ y--' 4r' '"VUI
~ 00)
~--""'
L ~ ~-21 = 1.0 0.00) c
Q)
>
w A 2/22.<)0)
/' 1§ 0.5
0 f- ~·.00)

0.0 ~ pmymo11 I I I I I I I I I I I I I I I l I I J i I l illl_i 0 2 3 4 5 6 7
Total Event Rainfall Depth (Inches)
Figure 4.3- Q vs. i Diagram for Basin 3
The slope of the best fit line fitted to the (Q,i) data points is an indication of how "leaky" the Basin is. In certain cases where the rainfall response in a Basin is low, this linear relationship to increasing ROll with increasing rainfall may be less discernable. This less defined linear relationship is evident for Basins 4, 5, and 6. The Q vs. i diagram is often a very useful tool for determining degree of success of rehabilitation efforts. Q vs. i diagrams for each Basin are included in Appendix B.
23 8
Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis

4.3 Normalized ROll Analysis
To enable a comparison of ROll between Basins of differing sizes and piping lengths (and diameters), the net ROll volumes for each Basin were also normalized by dividing each Basin's net ROll value by the lineal footage of pipe and average pipe diameter within the Basin to yield ROll values in units of gallons/ inch (diameter)-mile. The ROll values were further normalized by dividing each Basin's computed Net ROll for each storm by the inches of rainfall observed during the storm. This allowed a direct comparison of Net ROll between Basins using a common basis using units of gallons/ inch-diameter per mile per inch-rain. A summary of the normalized Net ROll in each Basin during each storm event is presented in Table 4.2.

As shown in Table 4.2, the normalized ROll ranged from 320 to as high as 10,900. The normalized net ROll values (averaged over the two storm events) for each Basin are depicted in Figure 4.4.

Table 4.2
Summary of Normalized ROll per Storm
8-~~)~. q"t;\~ J' Nomu,l ~ed .RDII (ga Jcil11 .. fnch raft'l) :: ..,., "' ~· .,. '•t'l - Storm t l\ Sfornt,\2 . Average "'~
1 5880 2950 4415
2 3130 3080 3105
3 8580 10900 9740
4 1820 3510 2665
5 1210 690 950
6 320 870 595
Total Average 3578
24 Agenda Item #9.1.

10000
8000
0 l:t
'0 6000
Q)
.~
n:J
E 4000 ....
0 z
2000
0 • Normalized ROll
2 3 4
4415 3105 9740 2665
Basin No.

City of St. Helena
Inflow /Infiltration Analysis
5 6
950 595
Figure 4.4- Normalized ROll (gal/ idm-inch rain)
As shown graphically in Figure 4.4, Basins 1, 2, 3 and 4 produce the highest normalized ROll on an average basis. It should be noted that these Basins also produced the highest average net ROll volume for the two storms studied. 25 Agenda Item #9.1.

5 MONITORING SITE HYDRAULIC ANALYSIS
City of St. Helena
Inflow I Infiltration Analysis
A hydraulic analysis was performed at each flow monitoring site using gross flows to evaluate the pipeline in the immediate area around the flow monitor. The basis of this evaluation was to compare the peak-hour wet to average-day dry ratios and to compare the depth-of-flow to the diameter (d/D) of the pipe throughout the study period.

5.1 Peak-hour Wet to Average-Day Dry Flow Evaluation
The dry and wet weather gross flows were evaluated at each monitor location. These flows were summarized for the study period and are presented in Table 5.1.

Table 5.1
Gross ADWF and WWF Peak Hour
GrossADWF Gross "WWF
Mof!ftor No; ~ Averag4l~ay f ~,ak-ho~r ·,'
I' (mgd) · (mgd) '
SH 1 0.08 1.0
SH2A 0.02 0.4
SH 2B 0.05 0.5
SH 3A 0.14 1.5
SH 3B 0.06 0.8
SH3C 0.14 0.9
SH 4 0.34 3.6
SH 5 0.58 3.6
SH 6 0.62 3.5
Ratios of gross peak-hour WWF to gross average-day dry weather flows were determined from this data. The peak to average flow ratios are presented in Figure 5.1 . 26 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
-Actual Peak:Average -Design Peak:Average

19.0+----

17.0+----
5 15.0 +---- ...
:; 13.0 +----

11..

C) 11 .0
c: :i 9.0 Ia
~ 7.0

5.0 3.0

1.0 2A 29 3A 38 3C 4 5
Monitor No.

Figure 5.1 · Peak to Average Ratio (Actual Vs Typical Design) 6 These flow ratios or peaking factors ranged from 5.6 to 19.5. The pipelines associated with all of the monitors exhibited peaking factors that exceeded 3.0 which is commonly used as a design peaking factor.

5.2 d/0 Ratio Evaluation
Sewers are commonly designed to handle a depth-of-flow over Diameter-of-pipe (d/0) ratio of 0.75 at peak flows. When 0.75 is exceeded, this may indicate that the pipeline has exceeded its design capacity. To illustrate this, the depth-of-flow hydrograph for flow monitor SH 3A is shown in Figure 5.2.
27 Agenda Item #9.1.

-rn
Q)
.r:.
(.)
c:
~
0 LL
-
0 .r:.
-
Q.

Q)
c

30.00 25.00

20.00 15.00

10.00 5.00

0.00 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
-- -- ;::::: (") l() --(j) --...... (") -- I{)
-- --,..._ 0 0 0 0 ...... ...... ..- ...... N
-- C\3 N -- c;::; --
N --

N --N --N
0 0 0 0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
(j)
-- --...... (")
-- --l() --,..._ .,.... N N N N
--N --

N N -- --N N
-- 0 0 0 0 0
City of St. Helena
Inflow /Infiltration Analysis
0 0 0 0 0
0 '0 0 0 0
(j)
-- --
N --'V --(() --co
N 0 0 0 0
C\3 -- -.. (") (") --(") --(")
0 0 0 0 0
Figure 5.2- Depth-of-Flow Hydrograph for Monitoring Site SH 3A The depth-of-flow hydrograph in Figure 5.2 shows that the pipe associated with Monitor SH 3A was surcharged during the largest storm period (storm 1) and very briefly during storm 2. ADS evaluated the depth-of-flow hydrographs for each Basin . . The peak d/0 ratios for each monitor location are graphically presented in Figure 5.3. 28 Agenda Item #9.1.

City of St. Helena
Inflow / Infiltration Analysis
Figure 5.3 - d/0 Ratio Vs Typical Design
1-Actual d/D -Design d/0 I

5.0 4.0
0 .. 3.0 1';1
0::
0 2.0 i3

1.0 0.0
2A 28 3A 36 3C 4 5 6
Monitor No.

The d/0 ratio during the study period significantly exceeded 0.75 for flow monitoring sites SH 1, SH 02A, SH 3A, SH 38, SH 4, and SH 6. In fact for these sites the d/0 ratio exceeded 1.0, which means the pipeline was in surcharge conditions with wastewater traveling up the manhole. This may indicate that the pipelines in the immediate area of the flow monitors listed above have exceeded their design capacity due to the backup condition; particularly during the 5-inch storm event on 2/12/00.

Although the Monitor for Basin 6 indicated a high peak d/0 condition, the d/0 ratio was well within the normal range for the study duration with exception to an apparent backup condition on Friday, 2/11/00. in the evening and again on Saturday, 2/26/00, just before noon. The City may wish to investigate the cause of these isolated backup conditions.

The Depth-of-flow hydrographs for each of the 9 monitoring sites are included in Appendix C.

5.3 Scattergraph Analysis
The flow data for each Basin monitor were reviewed for signs of possible hydraulically anomalous behavior caused by flow restrictions. This included a review of scattergraph 29 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
plots of velocity versus depth data points that are instructive in identifying such hydraulic anomalies.

Review of these scattergraphs suggests that possible SSOs may have occurred at or immediately downstream of monitor SH 1 between the evening of 2/13/00 and the morning of 2/14/00 as well as monitor SH 3A in the late afternoon and evening of 2/14/00. This is particularly notable considering that these monitoring sites were among the five sites exhibiting peaking factors in excess of ten (1 0).

With exception to the above discussed system capacity limitations, no significant hydraulic anomalies (e.g. blockages, displaced pipes, or other unusual hydraulic behavior) were evident based on this review.

The Scattergraphs for each of the 9 monitoring sites are included in Appendix D. 30 Agenda Item #9.1.

6 CONCLUSIONS AND RECOMMENDATIONS

6.1 Conclusions
City of St. Helena
Inflow /Infiltration Analysis
ROll was evaluated for each Basin during the two primary storm events. The following evaluation parameters were used for this study:
• Basin Peaking Factor
• Basin total volume of ROll per storm event
• Basin normalized ROll (average of 2 storms)
• Basin monitor site hydraulic capacity
The total volume of ROll was provided as a means of determining impact on overall treatment and transport. The net peaking factor, normalized ROll, and d/0 parameters were used to priority rank the study basins for future assessment and possible rehabilitation work. A summary of the net Peaking Factor, net ROll. and d/0 evaluation parameters is provided in Table 6.1.

Table 6.1
Summary of ROll and Flow Analysis Parameters
~.:: ' N
NQrmalli'~ et " Pea"k'f Basin No:o!! -. , · Net Ffow ., ~' ~ Pa•klng FaCtor . ROll diD Ratio
' (gal/idm-incb rain)
1 11.9 4415 3.5
2 17.6 3105 3.0
3 15,0 9740 2.4
4 6.2 2665 1.5
5 4.0 950 0.9
6 3.8 595 4.8*
·- high d/0 likely caused by hydraulic backup condition from downstream

1. Each of the above ROll factors yield Basins 1, 2, and 3 as the highest priority Basins for future evaluation. It is estimated that Basins 1 ,2 and 3 are contributing about 84% of the study ROll volume while constituting about 36% of the total dry weather flows. 31 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis

2. Based on evaluating hydraulic capacity (in terms of d/D) of the flow monitoring sites during the largest storm event (5 inches), it appears that flow monitoring sites SH 1, SH 2A, SH 3A and SH 3B are the most susceptible to future SSOs resulting from ROll.

6.2 Recommendations
Based on the analysis discussed above, the City of St. Helena is experiencing significant wet weather inflow and infiltration (ROll) in portions of its sanitary sewer service area. This ROll is causing a reduction in sanitary sewer capacity that could lead to future sanitary sewer overflows.

To reduce the quantity of ROll entering the system, defects must be located and repaired. The process of locating, quantifying and analyzing these defects using a cost benefit analysis is called a Sanitary Sewer Evaluation Survey (SSES). An SSES can include the following:
• Smoke Testing
• Flow Isolations
• Manhole Inspections
• CCTV Inspections
• Source Defect Analysis
• Cost Benefit Analysis
The following SSES work is recommended for the Basins analyzed in this Study and summarized in Table 6.2:
32 Agenda Item #9.1.

Table 6.2
Recommended SSES
Smoke Flow ~- Manh~le Basfn No. ,), Testing m Isolation _,,, . \ " ~ ht\p~ions " ~ ~ '·
1 X X X
2 X X X
3 X X X
4 X
5 6
Short Term Recommendations:

1. Perform Smoke Testing on Basins 1. 2, and 3.

City of St. Helena
Inflow /Infiltration Analysis
Source Oefect/
Cost Benefit
Analy;sls •I'
X
X
X
X
The identified Basins would likely benefit from this type of analysis since the response and recovery signatures of these Basins during rain events suggest inflow is a significant factor influencing overall ROll during heavy rain events.

Smoke testing represents a relatively inexpensive means by which to quickly discover often substantial points of inflow caused by factors including but not limited to illegal storm drain connections (e.g. downspouts, area drains, uncapped service lines, faulty manhole seals, illicit catch Basin connections, etc.).

2. Conduct Flow Isolations within Basins 1, 2, 3 and 4.

This type of analysis helps to isolate segments of Basin piping that are the primary contributors to infiltration. Flow isolations are typically beneficial in Basins suspected of prolonged infiltration or increased base infiltration during the wet season.
33 Agenda Item #9.1.

3. Conduct T.V. Inspections
City of St. Helena
Inflow /Infiltration Analysis
Hydraulically clean and perform T.V. inspections on areas identified as critical during the performance of smoke testing and flow isolations. This task typically consists of examining 10 - 50% of the area previously tested.

Long-Term Recommendations:

1. Conduct Long-Term Flow Monitoring.

Install permanent (and telemetered) flow monitoring devices to obtain long-term flow data for the purposes of trend analysis, verification of rehabilitation efforts, and to provide the basis for on-going investigations and maintenance efforts. It is recommended that the system be divided into 30,000 to 40,000 linear foot Basins. Consequently, up to three (3) monitors would be required.

As an option to the installation of permanently installed and telemetered flow monitors, the City could perform comprehensive temporary flow monitoring studies approximately every 2-3 years depending on the amount of rehabilitation performed. This will assist in focusing SSES and rehabilitation efforts on an annual basis.

2. Implement a Comprehensive Infrastructure Management System It is recommended the City obtain an electronic infrastructure management system for tracking inventory, condition assessment of infrastructure, and work order management. This could be the primary tool with which to track collection system rehabilitation success in terms of ROll reduction.

This type of system can be linked to a GIS system and hydraulic models to assist City personnel in planning, engineering, and maintenance activities. 34 Agenda Item #9.1.

City of St. Helena
Inflow /Infiltration Analysis
This system could also be expanded to include storm drains, water system, streets, pavement management, signs, parts inventory, and fleet and facility management.
35 Agenda Item #9.1.

Appendix A
ROll Analysis Slili cer® Hydrographs
Agenda Item #9.1.

--.
'0
Ol

0.75 .§. 0.50
~
0 u:

0.25 Rainfall
-
11 Fn
Feb 2000
0 5
........
'0
~ 0 3 ......
~
0 u: 0.2
Storm Event- 02/ 12/00 22:00
0 1
Gross
-
a Gross
-
Ill
- -
12 Sat 13 Sun 14 Mon
Date
15 Tue
Storm Event - 02/22/00 08:00
01 16Wed
Gross
-
a
- -
17 Thu
Weekends

0.30 0.25

0.00 o:g f

0.0 ,....+ --1H-.<o+-l---\---fl- -f\-,f---f-'\,\-----+-ll- 0.25 ;:u ::l
~:-1\--t----- 0 .20 ~

0.1 t---t---1'--~-T-------\:-t--t---:-HH-tl-ltrl11-+------l---\f- ..-l, --t H\1-\-~---/--\--t-.... 0. 05 21 Mon
Feb 2000
22Tue 23 Wed 24 Thu
Date
25 Fn
0 .00 ---+--..- o:g f _. __ ... ..-o.o
26 Sat
Agenda Item #9.1.

0.9 0.8

0.7 _0.6 1:1
_[o.5
~ 0.4
u:: 0.3

0.2 0.1

0.0 -
Storm Event- 02/12/00 22:00
02 - - - - F--+-----t----itrlr-t-1~1::;-------t-----+-- ---+---- 0.25 :;{) ::l

0.20 ~
- ~:--::;-""<J'<:>'"'I7'..-+nlt--f-...::>.-""'*k--flttflf-::::..t.;; .-...;:-'k-=f,~~~~'--..p:l"""'-',...--r---t---- 0.15 lf :::;
(I)
(J)
!---+-----+-t11ttttTH+ ...tHli+I+-+H+t++---.+----t-----~------+--+----- 0. 10 - 1---t---tt--- -HtlfHH+Mit:rhtltti+H-HI+H-l+ft,.,..---+-------l---l-- -1--t-_._ 0.05 -+--+- 0.00
--~------ 3:§ !0 .._ __ 0.0 s
12 Sat
Feb 2000
13 Sun 14 Man 15 Tue
Date
16Wed 17 Thu

0.5 0.4
u
Eo.3
.........
~ u:: 0.2

0.1 0.0
-
Storm Event - 02/22/00 08:00
02 - - - - ~-r-----~--~~~~~~-1rt-- ---+-----~~o 25 ~
:;·
F--t--t--T--.--t----..::-htl-+----1"...,..----t--~---\-t---H--\----t---- 0.20 ~ -::l
~--r----\-;J'I-=Jl:mt+¢=~=======+~========~=~-----''1-:r-- 0.15 g.

C!>
(/)
- r--t--t~-...,..;::-+--t-rttttflttrH--t----="'--1:-N'-t- --~.......:-:~t-----""-<:----:;.....:--t--.- 0 .05 - ----+-1- 0.00
----+-~ 3:B ~· _. __ ........ o.o •
21 Man
Feb 2000
22 Tue 23 Wed 24 Thu
Date
25 Fri 26 Sat
Agenda Item #9.1.

3.0 2.5
~2 0
0>
E i' 1.5 0
u:::

1.0 0.5

0.0 - -
Storm Event- 02/12/00 22:00
03 - - - -
:::u
Ol -~=--+--tt-tt-+-----+-t------:1Hf-Ht-l----+---"'=""'r-f--- --+---.... 0.20 s· ~
-J=--+--1trltl--t>oo.-J---=.:>~'id-ih'---~f1Pttttt:-H--P:--L- -+---"""-"-"c'l'v"T--""-o..<-..-.f-+--w- 0. 15 ~ (") =r
ctl
-F---t---tflitt-.H-t----t-ffifHI-- -.tfjlffi-tftHif--f----t-""r-------1f-----i--t---.... 0. 10 ~

0.00 0:8 ~· 0.0 s
11 Fri
Feb 2000
12 Sat 13 Sun 14 Mon
Date
15 Tue 16Wed 17 Thu

2.5 2.0
-g 1.5
.§.
~ iL 1.0

0.5 0.0
Rainfall
-
G
-
Storm Event- 02/22/00 08:00
03 - - - -
:::0
Ol
F---t------t----Ht-+------+------lr-------+---- 0.20 :;· ~
1::--t--f-T---:=--+--t<;:---:IHH'hl-*"-r"'c----l--.,..._.----l--f-\,.----+--.... 0.15 ~ (") =r
ctl
1=--l--------\--1-t=""""'''#lt~~~¥+==--+=~==-===""'i-=t----+---- 0.10 ~ ~-t--- ---+-;-~~~+---4----l-------1--*---+-~0 05
-
---+--tt- 0.00
'--- +---- 0:8 ~· ...---.-.-o.o ·
21 Mon
Feb 2000
22 Tue 23 Wed 24 Thu
Date
25 Fri 26Sat
Agenda Item #9.1.

3 .5

3.0 1.0

0.5 Rainfall
-
Gross
-
Storm Event- 02/ 12/00 22:00
04 Gross
-
Ill
-
Net 1/1
- ~
Weekends

0.0 -t---+-__... ................... '"¥e~--""'--
11 Fri
Feb 2000

2.5 2.0
-
12 Sat
-
13 Sun 14 Mon
Date
15 Tue
Storm Event- 02/22/00 08:00
04 Gross
-
1/1
16Wed
-
17 Thu
Weekends
:;o
Ill
;:)
~~---------~----~~~~ --~--~-----------+----------~~0 15 -Ill \J Ol
g 1.5
~
........
;:)
(")
0 u::: 1.0 ~-r 4rr---~~-+~WHI~1-*-~~--~ --~~--~-+-. -- ~~0 10 ~

0.5 21 Mon
Feb 2000
22 Tue 23 Wed 24 Thu
Date
25 Fri
~

0.00 ----+--..- o:8 r -----~-~~~-- 0.0
26 Sat
Agenda Item #9.1.

3.5 3.0

1.0 0.5
Rainfall
-
Gross
-
Q
Storm Event - 02/ 12/00 22:00
05 Gross
-
1/1
-

0.0 -t--+-.....W.WLLWW!I+-...&,...I..,..,.I.&.I..,-.:-~ 11 Fri
Feb 2000
-

3.0 2.5
~ 2.0
.s
~ 1 .5 0
u::

1.0 0 .5
0 .0
21 Mon
Feb 2000
12 Sat
-
22 Tue
13 Sun 14 Mon
Date
15 Tue
Storm Event- 02/22/00 08:00
05 -
Net 1/1
-
23 Wed 24 Thu
Date
16 Wed
-
25 Fri
~
Weekends
17 Thu
~
Weekends
26 Sat
0 .25
0 .00
o:B I
0 .0

0.25 0.20
;:o
ll>
s·
0 .15 ~
-::;,
()

0.10 ffi
(/)
- 0.05
0 .00
o:B
0 .0
"' I
Agenda Item #9.1.

3.5 3.0
Rainfall
-
Gross
-
Q
Storm Event - 02/ 12/00 22:00
06 Gross
-
1/1
-
Net 1/1
- ~
Weekends

2.5 *--+--~lh-fl:-t------+--ft'dL- Hf---f+--- f>r--1---\:f~---j-- -t---il- 0 .20 ::0 Q!. ~
"0 :::J
Ol 2 iii' .0
_§_ ~-+---&4-~~~~~~~ ~~Hr-+- ~-+-~~~-~~ 4-~0 15 ~
:::J
(") ~ 1.5 ~
u::: E--+--,O~-~ -~---+~~-o#~H¥~~~~-----+---~~~0 10 ~

1.0 0 .5

0. 0 -1--+-~LLLLLW.U.~
11 Fri
Feb 2000
3 .0
Rainfall
-

2.5 ~

2.0 "0
Ol
5 1.5 ~ 0
u::: 1.0

0.5 0.0
21 Man
Feb 2000
12 Sat
Gross
-
Q
22 Tue
13 Sun 14 Mon
Date
15 Tue 16 Wed
Storm Event- 02/22/00 08:00
06 - -
Net 1/1 Precom
23 Wed 24 Thu 25 Fri
Date

0.00 o:g f
0 .0
17 Thu
~
Weekends

0.25 0.20
::0
Q!. :::1

0.15 -
~ ~
:::1
(")

0.10 ~ (/1
._..

0.05 0 .00
3:g "'
~ 0 .0
26 Sat
Agenda Item #9.1.

Appendix B
Q vs. i Diagrams
Agenda Item #9.1.

-C)
E 2
(I)
E
:::J
0 > 1.5
0 0:::
....
(I)
z 1
-
c:
(I)
> w
co
.... 0.5
0 ~
0 1 2
City of St. Helena
Q vs. i for All Basins
3 4 5 6
Total Event Rainfall (in.)
7 8
• Basin 01
• Bas in 02
Basin 03
;t( Basin 04
o Basin 05
• Basin 06
-Linear(Basin 01)
--Linear (Basin 02)
·- Linear (Basin 03)
-Linear (Basin 04)
- Linear (Basin 05)
--Linear (Basin 06)
Agenda Item #9.1.

Appendix C
Depth-of-flow Hydographs
Agenda Item #9.1.

40.00 35.00
-
c:: 30.00 -
~
0 25.00
't; 20.00 '1-
0 I 15.00 .r=.
-
Q.

Q) 10.00
c

5.00 0.00
0 0 0 0 0
0 0 0 0 0
-

1.() -I'- -(j') -
~ -(")
0 0 0 ...-- ..-
-

N -N N - -N -N
0 0 0 0 0

20.00 18.00
- 16.00 c::
- 14.00 ~ 12.00 0
't;
'1- 10.00
0 • 8.00
.r=.
-
Q. 6.00
(I)
c 4.00

2.00 0.00
0 0 0 0 0
0 0 0 0 0
- -

1.() I'- -
0> -
~ -(")
0 0 0 ..- ..-
- -

N N -N -N -N
0 0 0 0 0
Monitoring Site SH 01
Depth-of-flow Hydrograpb
0 0 0 0 0
0 0 0 0 0
- -

1.() I'- -(j) -..- -(")
..- ..- ..- N N
-

N -N -N -N -N
0 0 0 0 0
Monitoring Site SH 02A
Depth-of-flow Hydrograpb
0 0 0 0 0
0 0 0 0 0
-

1./) I'- - -
0> -
~ -(")
...-- ..- ..- N N
N
- -
N -N N
- -N
0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0

1.()
- -I'- -(j') -
N --.::t -CD -
<X)
N N N 0 0 0 0
-
N -N -N -(") - - (") (") -(")
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0

1./)
- I'- - - - 0> N --.::t -
CD -
co
N N N 0 0 0 0
N N
-- -
N -(") -(") -(") -(")
0 0 0 0 0 0 0
Agenda Item #9.1.

10.00 9.00
--=- 8.00 c:
::.=:.. 7.00 ~
0 6.00
...... 5.00 .....
0 I 4.00
r.
..
c. 3.00
Q) 2.00 0

1.00 0.00
0 0 0 0 0
0 0 0 0 0
-l[) -t-- -(J) -
~ --("')
0 0 0 ~ ~
-N -
N -
N N
-- -
N
0 0 0 0 0

30.00 -en
Q) 25.00
r.
0 c: 20.00 -
~
0 - 15.00
L&.
.....
0 10.00
r.
..
c. 5.00 Q)
c

0.00 0 0 0 0 0
0 0 0 0 0
-("') -l[) -t-- (J)
-- --....... 0 0 0 0 .......

N
-- -N -N -
N -
N
0 0 0 0 0
Monitoring Site SH 02B
Depth-of-flow Hydrograph
0 0 0 0 0
0 0 0 0 0
l[)
-- t-- -- -(J) -
~ -("')
'r" ....... ....... N N
-

N N -- -

N -N -N
0 0 0 0 0
Monitoring Site SH 03A
Depth-of-flow Hydrograpb
0 0 0 0 0 0
0 0 0 0 0 0
-("') l[)
-- -t-- - - (J) ~ -("')
~ ~ ....... ....... N N
-
N N
-- -

N -N -N --N
0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
-l[) -t-- (J)
-- N -v -
<D -
<X)
N N N 0 0 0 0
--
N - -N N --(") - - (") ("') -("')
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
-l[) -t-- -(J) -
N -v -
<D --
<X)
N N N 0 0 0 0
--
N - - - N N (") -("') -("') -(")
0 0 0 0 0 0 0
Agenda Item #9.1.

Depth-of-flow (in.)
...... ...... ...... ...... 0 N ~ ()) (X) 0 N ~ ())
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
......
(X)
0 0
~~ 'S.o 7 s.
0 0 7>§ ·
0(1Q
~ {./) ::r: ;:::;: '< (l)
E}{J')
0 ::t
(JQO
..., w
~(] c0
0 0
02/05/00
02/07/00
02/09/00
02/11/00 -
02/13/00
02/15/00
02/17/00
02/19/00
02/21/00 -
02/23/00
02/25/00
02/27/00
02/29/00
03/02/00
03/04/00
03/06/00
03/08/00
Depth-of-flow (in.)
...... ()1 0
0 0
0 0
-" N N
()1 0 ()1
0 0 0
0 0 0
Agenda Item #9.1.

30.00 25.00
~
0 20.00
;;;:
...
0 I 15.00
J:
-g. 10.00 _,
0 5.00

0.00 0 0 0 0 0
0 0 0 0 0
-l() -,..._ -(j) ~ - -("")
0 0 0 ~ ~
-

N -N -N - -N N
0 0 0 0 0

30.00 -:- 25.00
c:
-
~ 20.00
0 c;r
... 15.00
0 I
J: 10.00 -
a.

Q)
0 5.00 -

0.00 0 0 0 0 0
0 0 0 0 0
-l() -,..._ -(j) -
~ -("")
0 0 0 ~ ~
- -

N N -N -N -N
0 0 0 0 0
Monitoring Site SH 04
Depth-of-flow Hydrograpb
0 0 0 0 0
0 0 0 0 0
-l() -,..._ -(j) -
~ -("")
~ ~ ~ N N
-
N N
-- N
- N
-- -
N
0 0 0 0 0
Monitoring Site SH 05
Depth-of-flow Hydrograpb
0 0 0 0 0
0 0 0 0 0
-l() -,..._ -(j) - -
~ ("")
~ ~ ~ N N
-
N N
- -N -
N -N
0 0 0 0 0
0 0
-l()
N
-
N
0 0
0 -l()
N
N
--0
0 0 0 0 0 0
0 0 0 0 0 0
-,..._ -(j) -
N -~ -
co -
CX)
N N 0 0 0 0
-
N - - N ("") - - (") ("") -("")
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
- - ,..._ (j) -
N --.::t -<D -
CX)
N N 0 0 0 0
-
N -N -("") --("") -("") -("")
0 0 0 0 0 0
Agenda Item #9.1.

100.00

90.00 - 80.00 .
r::
- 70.00 ~ 60.00 0
;;:: I 'too 50.00
0 I 40.00
J:
-
Q. 30.00
Q,) 20.00 0

10.00 -

0.00 0 0 0 0 0
0 0 0 0 0
-
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1'- ()')
- -...-- -('f")
0 0 0 ...-- ...--
- - N N N - -N -
N
0 0 0 0 0
Monitoring Site SH 06
Depth-of-flow Hydrograph
0 0 0 0 0
0 - 0
- 0
- 0
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-
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- - -
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N N 0 0 0 0
-
N -N -('f") - - ('f") ('f") -('f")
0 0 0 0 0 0
Agenda Item #9.1.

Appendix D
Velocity vs. Depth Scattergraphs
Agenda Item #9.1.

Intersection of Mitchell and St James
ADS Environmental Services
2/5/2000 12:00:00 AM - 3/7/2000 11 :59:00 PM
St Helena, CA
Pipe Height: 9.75
4----------4----------+----------+----------~--------~--------~~--------4---------~ 4----------+----------+----------r----------r----------r-------- ----------~--------~ 7 -!/)

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3 0 5 10 15 20 25 30 35 40
SH_01\mp1\DFINAL (in)
Agenda Item #9.1.

1445 Oak
~
ADS Environmental Services
2/5/2000 12:00:00 AM- 3/7/2000 11 :59:00 PM
St Helena, CA
Pipe Height: 6.00
10 ----------~V~F~IN~A~L~-~DF~IN~A~L~~~~----------~------------~--~~~~--~------------~ 4--------------+------------~--------------~------------+-------------~------------~ 8~------------~-------------4--------------~------------+--------------r------------~ 74-------------~-------------4--------------~------------+--------------r------------~ -(/)
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20 25 30 Agenda Item #9.1.

1345 Railroad Avenue
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ADS Environmental Services
2/5/2000 12:00:00 AM- 3/7/2000 11 :59:00 PM
St Helena, CA
10 15
SH_02B\mp1\DFINAL (in)
20 Pipe Height: 7.88
25 30 Agenda Item #9.1.

1345 Railroad Avenue
ADS Environmental Services
2/5/2000 12:00:00 AM - 3/7/2000 11 :59:00 PM
St Helena, CA
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20 25 30 Agenda Item #9.1.

-(f)
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ADS Environmental Services
2/5/2000 12:00:00 AM - 3/7/2000 11 :59:00 PM
Intersection of Pope and Church St Helena, CA
Pipe Height: 10.13
10 ~----------~V~F IN L~-=D IN ~~~~----------~------------~--~~i~~==--~------------~ 4-------------~------------~------------~------------~------------~------------~ ~------------~------------~------------~------------~------------~------------~ 7 6
5 4
3 0 5 10 15
SH_03\mp1\DFINAL (in)
20 25 30 Agenda Item #9.1.

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ADS Environmental Services
2/5/2000 12:00:00 AM- 3/7/2000 11 :59:00 PM
Intersection of Pope and Church St Helena, CA
Pipe Height: 8.00
10 ~----------~V~F~IN~A~L~-~D~F~IN~A=L~~~~----------~------------~--~P~i~~~--~------------~ 94--------------+-------------4--------------~------------+-------------~------------~ 84--------------+-------------4--------------~------------+-------------~------------~ 7 6
5 4
3 o. 5 10 15
SH_03A\mp1\DFINAL (in)
20 25 30 Agenda Item #9.1.

940 Hunt Street
ADS Environmental Services
2/5/2000 12:00:00 AM - 3/7/2000 11 :59:00 PM
St Helena, CA
Pipe Height: 12.00
~---------r--------~----------r---------+---------~---------+--------~~------~ 0~---------r--------~----------r---------+---------~---------+---------- ------~

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0.0 2.5 5.0 7.5 10.0 12.5
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15.0 17.5 20.0 Agenda Item #9.1.

ADS Environmental Services
2/5/2000 12:00:00 AM- 3/7/2000 11:59:00 PM
Intersection Of Redondo and Paseo Grand St Helena, CA
Pipe Height: 17.75
[QJ c::=:::::J c:::::::::=J
10 ~--------~V~F~I~N~A=L_-~D~F_ITN~A~L~~~~----------.---------.-------P~i_,~~------.---------. 9~--------~---------+--------~----------r---------+---------~---------r--------~ 84---------~---------+---------1----------t----------+---------,_---------r--------~ 7 -(/)

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Agenda Item #9.1.

Garden Well
ADS Environmental Services
2/5/2000 12:00:00 AM - 3/7/2000 11 :59:00 PM
St Helena, CA
Pipe Height: 21 .00
+--------+--------r-------,_-------+--------r-------,_-------+-------- ------ ------~ ~-------+-------- ------~-------+--------~------ -------+--------~------~------~ 7 -(/)
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Agenda Item #9.1.

Wastewater Treatment Plant
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ADS Environmental Services
2/5/2000 12:00:00 AM- 3/7/2000 11:59:00 PM
St Helena, CA
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Pipe Height: 21 .13
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110 120 Agenda Item #9.1.

Sewer Flow Isolation Study (2007)
Agenda Item #9.1.

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Prepared for:

Summit Engineering, Inc.
463 Aviation Boulevard
Santa Rosa, CA 95403
Sewer Flow I solation Study
Saint Helena, California
Spring 2007
Prepared By:

Agenda Item #9.1.

(' JJ
Table Of Contents
City of Saint Helena
Spring 2007 Sewer Flow Isolation Study
Introduction ................................. .......... ........................ 2 ~C:()J)~ •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• ••••• ~ Flow I so lations
F»LJrJ)()!it! •••••••••••••••••••••••••••••••••• •••••••••••••••••••••••••••••••• ~ Procedure-................................................................ 4 Flow I solation Result-s ................................................... 7 Conclusions and
Flt!C:()rJ1r11t!r1dCiti()Jl!; .......................................................... ll 1 Agenda Item #9.1.

I
Introduction
City of Saint Helena
Spring 2007 Sewer Flow I solation Study
Summit Engineering Inc. contracted with ADS Environmental Services to provide flow isolation services for portions of the sewer system in the City of Saint Helena.

Nighttime flows were isolated at 32 manhole locations within former flow monitoring basins 1, 2, and 3 of the City sewer system. This report presents the results of the flow isolation study indicating areas of excessive apparent infiltration.

The locations of the flow isolations are indicated in Figure 1 with a marker placed on the associated pipe in which the weir was placed.

Figure 1 - Flow I solation Locations
N
Roads.shp
• Flowisolation_locations2007 .shp
N Sh_sewers.shp
D Mcro Basins
0 1000 2000 Feet
-- -
2 Agenda Item #9.1.

t;
SCOPE
City of Saint Helena
Spring 2007 Sewer Flow I solation Study
The scope of this prqject was to perform up to 35 flow isolations at sites selected by ADS in cooperation with Summit Engineering. The flow rate data from these flow isolations was compiled for each area associated with the isolation, and then ranked in terms of relative severity by normalizing the flow rates in terms of flow per associated mile of pipe in gallons per day per mile (gpd/mile) . Although 32 Jocations were selected for flow isolations, four locations were re-measured on different nights to confirm stable flow readings. These include site 104. 105, 110. 112, and 309B.

FLOW ISOLATIONS
Purpose
Flow isolations allow infiltration to be quantified by dividing the previously delineated flow monitoring basins 1 into smaller zones (micro-basins) and measuring the late-night (clear water) flow rate within each of the micro-basins. The process consists of recording flows of micro-basins by taking instantaneous weir readings at the isolation points during periods of minimum sewage contribution - normally between 2 :00AM and 6:00 AM. By subtracting any 'flows from upstream microbasins, net infiltration for a particular micro-basin may be determined. Where applicable, the observed degree of clarity of the flow can be applied as a multiplier to the measured flow to calculate the portion that is considered infiltration. It .is noted that all flows quantified during this study were comprised of "clear water".

Once infiltration rates are established, a determination of Excessive or Non - Excessive infi'ltration rates is determined for each micro-basin. Based on this evaluation, subsequent manhole and TV inspections are recommended. , Inflow/ Infiltration Analysis Report for Saint Helena prepared by ADS. July 2000. 3 Agenda Item #9.1.

City of Saint Helena
Spring 2007 Sewer Flow I solation Study
All sewage collection systems will have a certain amount of infiltration. The joint ASCE-WEF (1982) design guidelines for gravity sewers gives a table of guidelines used by various municipalities for the infiltration that should be used in capacity calculations for a sewer system approaching the end of its design life. These guidelines are expressed in terms of gallons per day per inch diameter mile (gpd/1 OM) and in terms of gpd/mile (assuming 8-inch pipes) and are presented in the following table.

Table 1
ASCE-WEF Infiltration Guidelines
Nwriberand
Percent 1at Allowance iTotal lal AUo•anca
Of Cities (gpd/IDWQ (gpd/mlle)
Reporting
4 (.3.1 %) 1500 12.000
4 (3.1 %) 1000 8,000
1 (0.8% ) BOO 6,400
2 (1.6%) 700 5,600
1 (0.8%) 600 4 800
63 (49.2%) 500 4,000
11 (8 .6%) 450 to 300 3.000
16 (12.5%) 250 to 150 1,600
21 (16 .4%) 100 800
5 (3 .9%) 50 400
Total Cities = 128 Weighted Avg . = 422 Weighted Avg . = 3,200 Procedure
Flow isolations were performed with calibrated volumetric V- Notch weirs and completed between the hours of 2 :00 AM and 6 :00 AM to record infiltration entering each micro-basin . ADS field crews recorded pipe diameter, f low clartty, active leaks and other manhole or line observations while performing the flow isolations. Flow isolation field log forms are included in the Appendix of this report along with flow isolatlon reference maps used during field operations . Flow isolations were conducted at locations selected and evaluated by ADS and Summit Engineering.

It is noted that the intended 8" pipe to be measured at location 111 (the line coming into this manhole from the east) was not found at this location. therefore flow was quantified in the main 1 0" line along Mitchell Drive. This modified the boundary of micro-basin 111 from its original configuration . The actual sewer connection from this area to the east of Mitchell Drive will require field verification. 4 Agenda Item #9.1.

~l I
1' I
City of Saint Helena
Spring 2007 Sewer Flow I solation Study
Based on electronic maps provided by Summit Enginering, ADS mapped locations and linear footage (LF) of each micro-basin. Total sewer pipe lengths for each micro-basin were determined based on computed lengths from the maps provided.

Pipe diameters were measured in the field at t he flow isolations points.

Micro-basins are either hydraulically dependent or independent. The flow quantities generated for an independent micro-basin were based on one or m ore flow isolation locations at the outflow pornt(s) of the micro-basin independent of all other locations. while t he flow quantities generated by a dependent micro-basin include flow from upstream micro-basins. Upstream flows, derived from upstream flow isolations, were subtracted from the dependent micro-basin flow quantities to calculate net flow for the dependent micro-basins.

Weirs are available for standard pipe diameter sizes rang.ing from 6 inches up to 18 inches. Weirs were placed in sewer lines at the outlet locations of each microbasin. Flowrates in gallons per day (gpd) were recorded from the weir readings.

When a weir was installed, the flow was allowed to stabilize for at least five minutes before the first reading was taken. The weir flow rate reading was recorded only after the flow stabilized to the same reading for two consecutive 2 minute intervafs.

A depiction of a stabilized weir at a pipe outfall is shown in Figure 2.

Figure 2 - Depiction of Flow I solation Weir
5 Agenda Item #9.1.

tf
City of Saint Helena
Spring 2007 Sewer Flow Isolation Study
In case where unobstructed dept hs of f low were greater than 1-inch or if backwater disallowed weir readings to be made with confidence, flow quantification was also attempted using direct depth and velocity measurements. The depth of the flow was manually measured with a folding carpenter ruler and velocity was obtained with a portable electromagnetic velocity meter. The flow quantity W{)S then calculated using the continuity equation ·for open channel flow:

Q=A * V
Q =Quantity (gpd)
A = Cross-sectional area of flow (fr2)
V = Average Velocity (ft/s)
Cross-sectional Area for a partially full pipe is a function of measured depth (less any measured silt). Average Velocity is calculated using standard 0 .9 average I measured peak ratio.

The conversion from ft3/s to gpd is 646317.

An example is presented below for Site 3098 comparing weir -based flow to flow rate based on direct open channel measurements.

Example (Site 3098):

Diameter: 1 2"
Depth: 4.38" Peak Velocity : 0 .21 ft/sec
Cross-sectional Area of Flow: 0 .259 (ft2
)
Vavg = --0 .19 ft/sec
Q = A (cross-sect) X v avg X gpd conversion
Q = 0 .259 ft2 x 0 .19 ft/sec x 646317
Q = 31,800 gpd
Qvveir = 35,960 gpd
6 Agenda Item #9.1.

I
Flow I solation Results
City of Saint Helena
Spring 2007 Sewer Flow I solation Study
Tabular results of the flow isolations are summarized in Table 1. The results of the flow isolations are depicted graphically in Figure 3 showing colored gradations associated with worsening classifications of observed infiltration. The primary break point of 4000 gpd/mile was chosen based on the majority of respondents per Table 1.

Figure 3- Flow Isolation Infiltration Results
N
Roads.shp
N Sh_sewers.shp
MicroBasin Infiltration (gpd/mile)
Indeterminate
No Flow Observed
1- 3999
4000 - 12000
>12000
0 1000 2000 Feet
--- -
7 Agenda Item #9.1.

I
f I
City of Saint Helena
Spring 2007 Sewer Flow I solation Study
Three of the micro-basins indicated an imbalance regarding net flows. They were 110, 111 , and 302. This may be the result of flows bypassing the weir through the piping trench (e.g. at 302) or low confidence due to a high degree of upstream subtracted flows (11 0, 111 ), or a combination of both factors . Three micro-basins showed stagnant flow conditions likely due to a downstream obstruction. They were 108, 302, and 310. Consequently, if infiltration flows were present at these locations, it was not quantifiable (i.e. flows may have occurred in the trench and not in the pipe during the night-time minimum flow period). These 5 different locations are highlighted or footnoted in Table 1.

It is notable that flows were re-measured at location 11 o on 3 separate nights (at approximately the same time), each night resulting in different values of infiltration.

The highest measured value is indicated in Table 1 for this location. An explanation for this was not readily evident.

Conclusions and Recommendations
It is generally evident that each of the 3 primary basins appear to worsen in measured degree of infiltration moving downstream. This is likely the result of the groundwater table encompassing more of the sewer trench as the sewer progresses deeper toward the effluent point of each basin .

Given the relatively ubiquitous excessive infiltration m easured in the micro-basins, it is likely that the entire sewer system in these basins becomes inundated with infiltrating groundwater during extended periods of heavy precipitation, The highest rate of inifiltration was measured in the lowest micro-basin within basin 3 (at location 3098) at an estimated net flow rate of 24,000 gpd. This flow rate in conjunctron with the observed gravel and silt in this line suggests that portions of the piping in this m icro-basin may be failing and allowing backfill or even road bed materials to enter the sewer.

ADS recommends that the City of Saint Helena conduct CCTV (video) inspect ion of all the pipes within micro-basin 309 as soon as practicable. Selected other areas should follow, including micro-basins 102, 109 and 206, to determine frequency of defects (e.g. every joint or just at defects such as offsets or broken segments).

Given the age of much of the sewer system and the apparent degree of infiltration and inflow (1/1) as evidenced by this and the previous 2000 study, it Ts recommended that the City adopt a program to rehabilitate the sewer system while continuing to monitor flows in these primary basins to capture progress toward 1/ 1 removal and wastewater flow capacity improvement. It appears that the rehabilitation should begin at the lower reaches of the system (e.g. micro-basin 309) and move upstream
8 Agenda Item #9.1.

c. . -
Table 2 · Micro Basin Flow Isolation Results
Nonnaltzad Net
Net Flow Net Flow Flollll
Sum Pipes Upstream Micro basin PipeOia Weir Gross Flow Mlcrobasin Mlcrobasln MicroBasio 10 (feet) Sites (%of gross) Site 10 (In) (gpd) (g-pd) (gpdlmlle} 101 2062 101 8 2440 2440 6248
102 2421 102 8 4690 4690 10229
103 1615 103 8 0 0 0
104 2196 101+102 I ~~ 104 6 8806 1676 4030
105 1653 103 - 105 6 0 0 0
106 1284 106 8 260 260 1069
107 2545 106 86% 107 6 1916 1656 7000
108' 2559 108 8 o· o• -. 109 2718 107+108 79% 109 8 9243 7327 14233 110' 5058 104+105+112 110 8 9243 -1315 -. 11,. 3899 109 + 110 . 11 1 10 11180 -3223 -. 112 848 112 6 1752 1752 10909 113 831 113 8 0 0 0
201 1003 201 8 0 0 0
202 1268 201 - 202 8 0 0 0
203 1356 203 8 57 57 222
204 3355 202+203 99% 204 6 10512 10455 '1 6454
205 1735 205 6 1458 1458 4437
206 3674 205 86% 206 6 10512 9054 13012
207 2360 207 6 464 464 1038
301 3363 301 8 1916 1916 3008
302. 1722 301 - 302 8 o• 1916 -. 303 637 303 6 115 115 953 304 2888 304 6 0 0 0
305 1641 304 100% 305 6 5160 5160 16603
306 1296 306 6 3196 3196 13022
307 2428 307 6 5553 5553 12076
308A 6 5553
308 2255 307 3088 6 1916 1916 4486
309A 6 0
3098 12 35960
309 2202 306 67% 309U 6 8806 23958 57446
310. 932 310 6 o· o· -. • - micto basin now data inconclusive due to debris & backwater and/or imbalance with upstream sites.

Agenda Item #9.1.

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•
Appendix
Microbasin Flow I solation
Field Logs and Maps
Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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This pipe not observed coming into
manhole. Therefore, 10' line on
Mitchell was flow tested.

Agenda Item #9.1.

Manhole Surveys
Agenda Item #9.1.

City of St. Helena
Man Hole Survey
~- MH # I MH Location ' MH Depth Pipe size In-Out • Type of pipe.. I Distance to downstream MH __ ~:~; I Pope St a_t _P-'op~e_S_t_B __ ri_..dg,_e ______ -+1----+---- ----+--II +-.. ... ~--------==~ -·~1-14--lcollegeAve&PopeSt =t--- -r--~ - - --. 1-15.. • 1 Peppertree Cir & Pope St _______ ··_-~-1·~_-_-_-_-_-~-+. ---.·--.----+ 1 1 • --~ ~-=== ---.; _ _!::.!§__ . Pope St . ------------+---- -~_!:1"7__ !Pope St. 605 . _ ... i l___ _____ ·_·--·---~--- ...... 1-17A ~.. ,Pope St._ & S_tarr A_ve j I · -~-1-18-_=Jfope St 601 east prop. Line +- t==-=--~--===1--:--··-__ ::::::::::::.-.. --~---- _ __ 1-.19 !'Pope St 601 ('Nest Prop, Line in driveway) _ 1 1 _ ~--··- 1
,. . .. ·.-+.--.. -·.-. ----~~----~ t-- . 1-20Pope St 601 (east prop. line in backyard} • L........ _ _ ......).__ _ _ _ _ f-·-·_!-?_1 ---+.Granda Ct ?64 (inside yard next to sidewalk) -+-----------·--\·----·-· i .. . _ r--1-22~--+,;Granda Ct 751 .. __)_.____ I _j__._ ... -~------- r--1-23_~Granda Ct. (couldn1 find) . +--. -· I -\-=:-.-.·--·--·.·--. r----1-24 __ ·~Granda Ct. 763 ___]_ _ 1-----:-1·.:::2':'-5. _Maripo-"'s·a'-';;&-';P,~o.c...p_e-;;;S:-1.-- ! += ' __J __ 1-26 ·~~Granda Ct. &Mariposa · ·---·· r----·-~---· ·-----··--· f-- 1-27 . !Mariposa 932 _ . j I __L ,__ 1-28 _Mariposa 923 (in driveway) ~ ·-·----~-~ · I ······-----· :__._1-28~- \'Mariposa 923 (in driveway) 1 I --r---------------.-~------~-1 , . . . . I . +-----~------~ ~-· 1~;:A . ~~~g~rk~ ~~c;1otle .. -1------+_·---~-~---·--=+. -----+ .. _·_· -··--··--·--·····-- 1--......J-30_ ~llison Ave & Pope St. -~-· ··----··-~--··----· r--- t~}-i~~~~ :tv~;2 Brown St . -+ i ·-··-----:-------··~-·----·- ~:;!. ~~~~~~:~~/!,~orkleAve ' +---···--· ~-----~~:t=-----==---·~ ~~-1-35'----,_McCorkl_e Ave 963__ · i -·r---···-·· i --+--·--·--·------ ~--~:;j ~~~=~~rA~=k&A:~~rt~e~;~o~a;;;:k:_:A:;:v:_:e:::::::::::::::::::::::::_=f-----~~~~--=t--··-··-_ -··-.-=r ·-+--==--=-- - L__ 1 ;:;: .. llg~:~=~~:~~~: ~~~0 . . ·1----· ·i -+---------~--==··---==-·--~---· __ _ ' · 1-38A Charter Oak Ave 1050 · +==. . I ___ ·· -··==4.·------==·-·---~--==--·-····==--= 1---___1_-39~. !Main St. 801 ·-··-----+' ____ j-- 1---___1_:40 _ •
1 Main St. 789 ... t::::~=- ~r--==--t·=====~-::::
f--- . ~:~}- ~~~~:: g~~= & Mobilehome Park 1------+---.. -----T-- -==1:::::::---======= f----=2c.:-0:...:3 __ .Hunt Ave & Starr Ave --------+------ -t----- : ~-~-·--·· . 1-------1----·--------~---+-----+~--- I -r·-··--------
Agenda Item #9.1.

City of St Helena
Man Hole Survey
Agenda Item #9.1.

City of St. Helena
Man Hole Survey
Agenda Item #9.1.

City of St. Helena
Man Hole Survey
MH Location I MH Depth j\ Pipe size In-Out =t'_. Type of p.lpe···+l Distance to do·w·· _nstream M .. ··H··- _ . 3-12A_·--1Main St & Pope St (on Mc.caccinc_S.c..t"-)-------+1-----f---·----- 3-13 Main St 1111 I I ~-----~~------~~------
~---- 3-14 .Main St & Spring St _ L----·---- I--------··--·- f--3-15_ jMain St & Mitchell Dr_ I l I ~ 3-16 :Mitchell Dr between Main St 7 Oak Ave · 1 · ·r-----·----t-I'- -- r-------3:17 J Mitchell Dr between Main St 7 Oak Ave I ---+ ± l -_____ _____::__--::
1---__ 3-18 ___ -~Mitchell Dr & Oak Ave . . . I .. J : T -i---------------1 f---____1::~--- Mitchell Dr 1340 -+---------- . I --··· . . 3-20 . jMitchell Dr & StJames Cir --+-·--·-t= ). J---- __ -+------. ____ _ 1--- 3-21 -~Oak ave 1111 _ 1- :- . .... \_----- ----~ -----------i __ 3-220akAve & Spring St I · + 3-23 --frakAve&TainterSt +----=±=--. ----. · ----. . ---_--···----- f--_Ili ~~:~~~Ys~:! ~ainterst _ 1 -f-·· I ±=-===-:-
r-- 3-26 -
1 TainterSt1550 ··------- , + _$= __________ _ f-----~-27 ____ 'oak Ave & Spring St (@10' west of oak) =t= . .. .. . __ f---3=cc·:o:27.._A 1 Kearney St & Spring St ~- T I - - -------~ f----- 3-28 ___ !Spring St 1515 . t=. ----------1 f-----;o3-..::;:27
9 __ ]spring St & Stock!. on St _ 1------- ~ . I_ .. . .. -·-. . i1t iiE~o;:~!~~~icleano~-) ------- ~- +-~ --_ -···· r---_ --==t---===-. . .. f-___:_3:33 I Stockton St i240 (cleanou1) -l--=-= . ·--· · 1 ---- I______ ----- __ 3-34 ,Stockton St & Tainter . =t' r-· . . __j___________ _ __ 1--- 3-35 eockton St 1318 (cleanout) .. . . -_r---_____ L-..--··-__j_. . _ 3-36 Stockton St. 1334 (cleanout) =r- I I
~=£F= ~~~r;:~ ~:~~~!Manhole on Stockton I · ·=t=--===:=--t - +----- - ~- 4-01 _ Mitchell Dr & StJames Cir I _-+_---. --------=:r--· 1 ------ - 4-02 _=:]Mitchell Dr. at bridge. I _j_ _______ _J._ --t--1 _____ -------J f- ::~---+Mitchell Dr & Voorhees Cir T +--- 1 +-_______ _ !--------~--------·-··· =t=---~------ . -r--------·---- f----~---· ~::~~~~~ ~~~:~~sti~yard) :
1 +---=--=-_____ J=-=- . --::
1---- 4-07 J Voorhees Cir ( in Baldwin Park) _. _ l _ . I _______ _ 4-08 -I Mitchell Dr & North Crane Ave _L ! _ ~ _________ _____, 1---- 4-09 North Crane Ave 969 - I · I r-----
4-10 Birch St & North Crane I i r----
Agenda Item #9.1.

City of St. Helena
Man Hole SuNey
Agenda Item #9.1.

City of St. Helena
Man Hole Survey
Agenda Item #9.1.

City of St. Helena
Man Hole Survey
Agenda Item #9.1.

Manhole II
Location
C ll,I\.2..:Tt:: t:.. Df\ I(_
MA.~rJ. 1-~q CHAt. ic""K DAK.
'lfA {.6.w~ ,.~e,
C~:tl\ e.:rcf.. OA 1.::
lDZ-7 l·"3S A.
0\A.ll:i-=.R. oAK
cwz 1·37 Ct\f}~IC:K.. CA \(::.
llL lot! 1--::6
p.,j..Ll '>C~ ~
&Co~Ls 1-~s
'~e...Cc~KLC
(.)(;,.2 I V&':>
A._U...\ <;,a ~ ~
O/(ow ,j \-31 ~U..,.So>l ~
J:t,?e- t-;o Pope~
MAI(I ?os..\ 1-Zt:.:>
'M.ttl(, ?o s4
6RAN. A()r:r- 1-.Z.b
6RArJA\>A
751 1-24
1"\fl £J fo ::.1\
_9_~S I·Z7
Ji.ARI Po~(\-
}1 (_ &RK.L.~ l· z '1
New
M~./b~£.; I· .zq 1. s-:l>c- U.A ~-~~ J>oPc
blO H8 17cV~:::
bto H7
PoPe
bots He':.>
1=t:)"Pe
~'±SG HS
CITY OF ST. HELENA

SANITARY SEVER MANHOLE SURVEY
Date
3-1~-'il
" ..
.. ,,
" ,.
,, ,.
u .,
,, II
\I ll
.. ..
.. ..
.. ..

I• ..
.. ..
•• ..
lo ..
.. ,,
\I II
•• II
1• •
~ •
MARCH 1991
Depth of
Manhole
Line Size Flow in Flow to
In OUt Inches Street Level
~· I 4" l.o ,, 1
•• 1.1
~z" 0' 211 (o ~
b" K" " b" 'Z ~-9
b .. ~~~ t' ~·6 ..
bll bu Ill ~~~~~
b'' b'' z" &'
4'' 4'1 ~ z411
{;;' b'' ~·· ~·~..{''
&~ It' ~- q'
12'' rt' , .. 8'
8" ~- '&'' 5 i.j. ,,
~-t .Af'' I 6). 4
8" 8'' I
~ Jf
8" e:;· & b'
~ .. f..o" -& c...kA.J oul
IZ11 IZ" ( 7'6.,
,z,·· II I It
ll~ z 7Z
tZ." 12" 2'' 7'z_''
IZ" IZ" z~ 7'
Jl" 1211 z·· £'3"
Condition of
Manhole
{,()0 u
6ooV
Goo/)
6~i)
ftool)
6c::o 0
GDOj)
6ocb
6ct::lb
6~oi)
Goo))
Gooo
~ooD
6ooJ)
6()oP
6co'P
6ooP
ftr:>c~
tico!)
l'1oo0
Agenda Item #9.1.

Manhole II
Location
'tbPE -1\C..I<.D~S
Ko ~ • L.c: ·-;:>K
l'Oi>t::

GQ.AIJ ()E 'lj~. 1-14
S':JL...tArJef(..
.lt::A~ 4-Zb
S'jl...v'AN t:ll
lc7~ ~z':>
SPI<Jr-1l1 J, lJv4
SP12AM-\ >i 4-2~
$1"1(1~1..\ .:il
~'-1Lv1Jefl.. ~z:s
flt~u. 51 ~. f:::.D I lZ ~'PR.• ~b ~· f
CJ.hJ A~\/ 6\vt< .. l~ S,VI<_('Io-)0,. Yi
?..'l.l-2
SP"-' wL1 i3~ot>l4. c.-.
\l.~o
~~~ Nb1 ~eoK, Cj
~?Q\~'-"
l~R.I~l\ t
k" V:ew 421
VA f.D:;_\.1 V. B vJ
\\~- 4-~ v A. lli:j vi C:\1'1
loC?4 </-1'1
VALle.:r VtC.~...!;:!
99~ 1 C>L..IVC '-1-18
VA u.e-~ ~e-vJ 4- 4~r; ~ • 1e.ul ·I :S
Ol...i'-lc
Zc11 4t? ~,a..,LI-(
2o2o
'"''' z Hv'U ~ON
1-lb
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
3-1~-~ I
lt If
I( II
II ••

1.< " ... ..
h l•
h "
.. ..
h ..
.. •
\I ..
.. ..
"' It
/I ,,
,, .,
.. ..
ll u
• ..

KARCH 1991
Line Size
In OUt
ll~ rt' II • IL tn
&'' b"
b" b.
~· &14
to'' 6"
b/ 6'1
{~;/ b~
6" b''
b,, b~
bb b"
6'' b/' .. b b'1
(:;,'' t./
b" t/
b .. t:/'
~ .. ~~~
Depth of
Manhole
Flow in Flow to
Inches Street Level
z " bl
!:.>" 2o'
Z'' ~·~"
2" t:s'
~" ~·?II
~ (I 2- ~·
~~ ?'
(z_4 bl

12.h ~'7::>''
4-" r::,'~H
~·, ~I
L-J-" 1'6/' .. 41
~ 6"
3" {Z" ,, 1 It 2 4-~
I
Cl t.f'
z._" +'
Condition of
Manhole
6oo0
~~\> -1EPS
bcoP
6ob~
M._AtJ f1e1ES
UJ{Ef.tii)
,, .. ••

6.oo\
L'1<Jt:> v
f?ooV
6oo!)
G'oeb
6co1>
6oob
Gooi)
Gboi)
G ooY
~~0
6~a()

6.oob
~~ Hot.£
&.I~ feb
Agenda Item #9.1.

Manhole II
Location
t\u'b)b,J
ll_ts.':>
Hv bSt>r-l t
_QL\'l'E
1-\v"t;l~~f
~tlt.Ui
~tJE"f
~.({c..~
O(AtJG ~
<i'?D I
~'<r,~c~
Mt'\C.~€l.L I !)!1 (}{ eU- t
YooRHe~s.

M.'1c.gru.. A<. OS5. ~;e-L-0
4-t5
~,4
--I~,,
4-10
1~9
-/~5
4~
4~ ~' lUte Ll- "'-
YmRdc:E<. de: -~ ~i<.rt~L.L <..R...o $..S. C.ii <:6~ ~z M•iWEU- ~I A.c.fLO~!.
vo~;u..l s <:'I· 1-\t'T<..I-Iti~L
Sr. 5A~e-s C-r: 3-21:::>
MtT<..HcL-L
l~"fD 31~ M'1U-\c.L.L ~
OAK. 3-18
M_ll(.t-fc L-l.. 3-17
3-!6
H.tl U{ e: LL1-'\.1\IN .=,-} !:>
1-\b ,,J
}b?c- ~;-1Z
'Fbi:>6t c.l,{ull.l.f
C)C)C) 5'S6.. ~PE {Ciivll.LH
1J2.0 ~-~
~eve: 17 3·.3
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
~-13~ 9r
.. (I
<I ..
l• ,,
It ll
II u
l• ,,
.. "
\1 u
II II
... u
lr lt
l\ •
\\ "
... "
~-1~·91
\\ "'
" ,,
.. ..
~· "
KARCH 1991
Depth of
Manhole
Line Size Flow in Flow to
In Out Inches Street Level
6" 611 I" ~I
,, bll (f r II
b I 3l)
b" 0 I( I ,,
6 3 310
8" 6" !:>'' 42~
8~ 8" .. b' ..3
o" B' J..t 6'{11
b" !() " ~II b' .. ll
10 lD 4' 4~(
I(::J'' y..'' ti? It
lb"
•• 5' ;./." </-'J_ ,, !D
8'' 8>" 1" 6'611
8 .. 514 4" ~I
s· .. B 6" ~·
0 .. o" 6(t ~·
804 II II sf4 5 3'7
o" B~ It" b I
s .. E:>" ~·~ I ., 3~
~ .. [)4 c. I It
-3 55
()u ~ .. I J.r 3'':>''
Condition of
Manhole
6oo0
6ce1>
6oab
6oo'l::>
qco~
ttooD
6ooD
6oo1>
qooo
6oc()--kP>
6oo1>
6co0
6ooD
6oo.D
~itt-\ 'A.tr.i~ ~
6ooD
6:o0
6~ol>
6oo!)
6ooi)
Agenda Item #9.1.

Manhole II
Location
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
3-1~-91
.. ..
••
.. ••
..

II
,,
..
..

I' II
t./-33A ..
•• ..
... ,,
KARCH 1991
Depth of
Manhole
Line Size Flow in Flow to Condition of
In Out Inches Street Level Manhole
II 15'' 6~ "
6'' ~I
{ ,,
b'' I
.,
~··
lr
b /(
I
6''
6'
Z''
~·
trociJ (
I
., 0'7''
Agenda Item #9.1.

Manhole II
Location
SPR.,rlb f
CizA~-JE
CJ2..ArJc
173~
O{AtJE'
}()~
Sc..oif
1761
Sc.o11
i-\ ,LLvu:w
t6~ SCJ::>-zr t
MA"DRo,~A
~~~RoJA 'I'\ t-Ic
-p,~.::

IB':>3
AJ./..~,.1 \-
'))/tJt
AJ~N
1416
A-91\M.~
A.,U.'j ,J ~
,~'l).v.\s
A!)AMS.

A_~~,.J i361
Y, N € -~~~{(_f) iq(.)4
~z.J¥~>
Yo.J t:/ 1\ R.J>
~etsAVc
V11w .::~A 12. I)
~-l4
L(J.,fb
~-Z7
~-tf~
tf-'-/8
~1
J-L/6
4~s
t/.1o
4'12
J391r
1-3~
~-'S7
'-~-~
4-38>
~-3SA
S-3D
~ z'1
~l~
13·26
CITY OF ST. HELENA
SANITARY SEYER KA.NBOLE SURVEY
Date
3-J~-q I
II lA
l• ,.

II II
lo ..

I• "
" ,.
" II
" II
u II
u Jl
II II
L< •
If ..
" II
" ..
/I t(
• 0(
.. ,.
,. •
KARCH 1991
Depth of
Manhole
Line Size Flow in Flow to Condition of
In OUt Inches Street Level Manhole
S" B" II
eo· 7" LeA-k.
4 EJ} sl J, 0 <::
6~ o" 3" 7
I
6ocD
8'-' 6~ '-!" 11:/ L<::'FTK/1
/cASI I wesT
B" B" ~: 8' Gc(:).D
61f E:J" I. I
I 6 6oof)
B" ~u
~· I
8 6oon s~ a'' ii II
~3'' bco])
8(/ B~ 1 ~, ~lr h
(tt>DO
6'' (:::/' & 2' L7oo])
ES 6u 211 1' 6cob
b., t:/ 211 'o u 3o 6~o
bt( bll z If
~'8'' baeD
bq (;/ ZCJ q~u (-. ()I~ s
toDP P1 ?e
At 1:1! Ji~ 1 (I
37 &oob
Jju 61f h" •L {-' {roof)
6~ b>f ~~· s·~fl 66~0
6'1 6" [q 55'' 6rPD
Agenda Item #9.1.

Manhole II
Location
ViNE\/Af'-')
. f.LL[:;tt:vJ 5-2~
1 V;gJArtfJ -S~23 t:'t.A oRe..! 1\
~r.IE~/Afl.l> S-22A
s 00 c...l( 1\:> .J.
176~ S-.<.c
S1o<..KTo..{
~l,LLv,sw ~-19 Mf\ l) !<eN: ASroc.~t-oJ !)-1 e:,
1)E'A.tJ)Jc.R.I(
174D 3-11 1)::1\~oe..K
17D4 !s-tb

1.);::-AI-lj{z:.I\K
lbco 5-15
'\)i A._.,.!.( o £..1(
\15. -o 1 s-H- S'?~l-kl M• "-.1>
,Zt~D
~ Pi<.IIJ, 1:1 t-\'1 llD
"!)e-A.N \)C t.K ~-~~
c.>PI<..t..st, ~ 1 C.{
l~'t3 .S-IC
~P12JIIIb ~~ c...f
1'0co ..s-q SIJ12.t~Jb 1-\) A~~ ...,;]'
I':>Z.I 5-~
SPQ..tt-1.6 1-\T ~<:.t>
IQ,fc( S-IZ ~?il1t-ll\ l-4.\ ~i>
lB'SD S-It
S"P{(I t-1 l\ IJ.i ll--1,)
E U..\\l. 1.) ~SI S·?
S?R.uJ.l. 1'\"T 1£..\:7
1115 .S-b
<,;?Q.. .... h ~ i<:.l>
17cli ;-s
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
~-,J-0t
(I tl
I>\ ,,
II If
It IJ
It ..

If "
'i u
ll "
'-\ II
u i
l• u
\j lt
u ..

II ~·
.. ~
ll ,,
I• "
{I ,,
II ..

KARCH 1991
Line Size
In Out
6'' 6'' 6~ (;:/
6 .. 6H
J-r 4''
+It b''
6b 611
6 .. 8''
0~ 8Q
8" 8"
0~ ou
c; 6"
~:/ 6''
6~ t/
6- b''
b" b ..
8k 04
~ .. B"
~u 8"
4-1( ~·
e; 6"
Depth of
Manhole
Flow in Flow to
Inches Street Level
li(f 6'
5" 16''
~4 s' ~" 2... 4~'
" I '-I'S'' II
z 4'
~ 9'
'& C)'
I
&. q
'& 12 I
~ ::,'
• 12. I I
Yz" S'bt·
~·· z.. 5 ·_rs •·
/6..~ s I'-+ I(
z_'' s'qt·
2" 8'L/4
.. ?'z" I
"&. z'
z·· '·/t''
Condition of
Manhole
G{)()])
6CC>D
~oo0
6<3cr)
6co.D
6oa_0
(--,coJJ
6aol.)
bocJJ
bociJ
br;oo:\J
6~oJ)
6e:,e.t)
Go0v
~oo})
bcc.D
6tt>b
bt>oD
6oo.D
btoof)
Agenda Item #9.1.

Manhole II
Location
SPf(.uJl-. lA\ ~I)
lli Lbt1e w S~t./ A
SP'<.1I'l<=> f-11 ~~
Jb56 s-'i
<;f?etl'\{,. ~IIC-\>
M.A teo,..\ 1\- S-3 ~Aul<.tl-lA
142.c s~z
~A;\)1\MI\
k'r:Ae..t.J'-1 s~1
MA !) R.ty;i 1\
1~30 Z..'3>~ 1-'\~DI't:>t-l~
DA-K 'l-3Z
MAD£.01'tlf
Z.31
'FuL!c~
1136 2-3o
Fvt..'"Tc>1J
0\ IU'<D l\ ~ 2-Z1
i<A.1LRoAD
\~'47 2-Zh
i(_f\1LRPAD
l>t.JIS 2-Z7 ~,LRol\1) ~~~1.\l::.

McR.luAI2ll Z.Z6
~L(.cA b
•AHS 2-Z'"=> ~,lJCc,Al)
13+5:> 2-14
1'l?Ai>
ut->l zzz
S!oc...K/oN
1'!>16 2-52..
91b<...K'ib,J
A.'l)AMS Z-5\ -p,~~
1"5Zs- Zr'-f7
)>IN.c- "u.:cy ,.,..

P..bA'"'S 2-%
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
3/J+/~1
lr "
II II
\1 "
II "
p "
\.f "
\I "
l• Ll
" ..
,, II
" ..
\\ w
.. •
I• ,,
\I "
.. '"'
It ,,
It II
tl "
MARCH 1991
Depth of
Manhole
Line Size Flov in Flov to
In Out Inches Street Level
b'' b" ~v ~'1 II
b" b" Yz" 4-'711
b" It ,,
b I 3'6"
c; II L{ ;.{ Co
&:," (o~ 4
II 4'5"
b" L~., L( '-('q''
fo '4 &~ " I..-" 4 5~
b~ bll tf II $'~ If
6" b:.lf ,, ;./'7 ,, 3
t;' t;' 3" 3t-:>11
6' 6'' ,, 7Jj,~ I( 3
b. blr ~ .. J{/"
" 6'' ~,, 6 ~r,'·
b~ bit .. 3,~t, 3
&/ 6' ,.
3'7
,,
5 e:," (a~ '·
3 3'1~'·
+'' ~..( '$ LJ.'(oll
+" It
6 ~~ 4-'
'-( t{' t. • s .. " ~[I + zYz" (_p
Condition of
Manhole
L-"" P, ..... ';;>
11-tJoe.Tt{ /we.s(
t., oou
~ r>t>l>
~ocD
L1ooD
&oJJ
6ooo
6oo.D
6ooD
~ocP
6oon
~oc.D
t{ce-1
6oDb
~tt>JJ
booJ)
bt>D 7)
booo
6oo!)
&.~o
Agenda Item #9.1.

Manhole 1/
Location
1<..~:<; ~IZ..l'Jj
Kc-ttt.N~
~1MG
'JS....."D'AM.S'
:\~\~;
A..bAM.S.
14-ID
1\l:>AM.S
K~412J.JI.}
A..'f>A-~s
JZ.'l c.t ftAtN~
111'4
5-.oc...l<.lo..l
r~-+B
'Ill. I oJ I c::Q,
~~~
fiA1.-JT~~
1'-1-1~
'IA•!ol~ (A.l'i-\t>l.sc... ~ •
S?i2uJq
Sroc..trC-ro,.\
Si>RuJq
15l.D
~?R.lrJb
l'ic\
~PR.tt-..~~
DAI<.

KE4R...I'J;J
-ro
CAl-<.

Ko-A(UJ'j
oiH~
DM<
l7'fs
Dt\-K
_lb_tl
OAK
153Z.
2- '+~
Z-'1~
2-::0
z.-'fs
Z.-t.!-1
2-~4
3~8
'5·37
3'2Cc
3·ZS"
~-z~
~-l'l
3-:z..cb
3-Z1A
3-27
.2.-61
2-bl
2-&::>
2-stt
2-58
CITY OF ST. HELENA

SANITARY SEYER KANBOLE SURVEY
Date
3~1~-~~
II If
\1 It
ll •
, II
" v
•• . \I •
• ..

H •
II II
.. ..

L• ...
.. II
.. "
I• ,,
Vt ••
c. ..
[.1 ,
LA u
KARCH 1991
Depth of
Manhole
Line Size Flow in Flow to
In Out Inches Street Level
It
r..o· 1-}. 'li" 2' ... ~'< .. ~ l I
?..... c9.-
6'' b. ~~ q'J'' .. " .. ~/~ (J b 6 3
b .. bw II /./6 t, 3
~· &,' 3
.. G'l"
t.J-" " It
4- 3'z.'' J
' .. 'fl.c,
·~
~1 I v/:;' 2 '5.

A!' 4 ;,. z· ~ .. I
4 ;f J" 'i Z.'~ II
~, I
&,v ~1.1 ~ 7''2-,.
~ .. to" d... II
7'~"
&,'- to"' 2.-" 42.~
to .. By 2, 3~v
4 ,, b" ~lr 2'
+4' ~ ~~~
~ g7
b" bq !Z~
,
i
6u ,, ,, 6 I 1~~
be. b" ~N {I
s'~
Condition of
Manhole
~cob
G~
boo])
6t>O £>
boob
booD
6ccb
'&LL
&,oo'b
trooP
G,ooD
6t>oj)
6U1)!>
tzoob
L')pO 0
(._,DoD
6ceD
tlMJD
!-tooj)
Lc Pt K..
vJ. ~t.1fbp.

Agenda Item #9.1.

Manhole II
Location
OAK
\)11-J.E
OAK
14{$"
OAI<.

AbAt--\ s
U4K
'IA,~k'"l..
of\ K...
<\?12.\Jb
OAK
II 1 l
M..PtltJ
JGl5
M.._A-t/1...1
M(f(1l
MAtl-J
~If
AR.t<
·~~~
IJA~K
11tf7
i~f~ Ci?JAlE~
10'15
{J6tJc/.J....Pr
IOLJ-5
c._{?_1,.JcLL/\
11Zb
CR.:tJ.EUJt
175<1
C..R..tJeUJt
J~o8
~e, tJ"'" L.LA1~7
C.R..1 N E U.-lt
17RZ
zs~
~:H
2-A/D
3--23
3~zz
3-:21
6-ZZ.
&Zt
&zo
&lq
{..,-11
&1~
b--1~
b--B
6--?
&-&.
(§5
t?IZ
6-Jo
b-1
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
MARCH 1991
Depth of
Manhole
Line Size Flow in Flow to Condition of
Date In OUt Inches Street Level Manhole
3-1 ~~~! b" bll z" !3 I~ II 6Do0
II (I b" bv 3'' ':J'(c/ bcob
t\ II 6{' b' 1-" :s 'zrt bctlJ II bq 1'' 3'7" 6cDIJ \1 • 6 •I 'I &" 811 Z'' .3'4 ([ 6rx:)J
•• .. B~ ~II J.( Z'~u 60C>b
\• .. E/ B'' 2..11 IS' 6cob I' 14
tbvte~
Bv 8/ 1" I GooD II /0 II
~~~ II
If L(-" b's H 0 cSoo])

6. 6~ tJ
~~~(I u:.AI(. .S . .::,ll)t:. ,, 1/ 3 Sr€Ps

6. 611 1/ I 1/ /..E. ArK. 2 . St Dt:. If II 2 (o3 $-;£Ps I' It b~ 6~ ,,, ~;.(' LeAK w. s.t !JC::
<;;;'csP~
.. 6l! 6'' rzll 3P/ tzmiJ .. .. 611 6u ~/1 ;,/2. It tt<PD (' " /# biA bu ~~~ 3b" ~])
~ u 6'' 6. '-I (f 1~~ 6oCJb
" .. ~It J./'9 4 II .. jL£M< 1-l· ~!>c 6 b ~ ~LS:Ps
,. b(• 6. ~~~ 1' lirPiJ I'
' - 6~ b~ ,, 3bv f /...E.41'( ~ . ;>I ~
.. It I s~fs
Agenda Item #9.1.

Manhole II
Location
~l..EX AN. \)E' f. V,
ID~S (,.,-Z
3-t3
/I
~I
I•
~-h fl
tluN'T
/017
'lt8 tJ
I'
II
CITY OF ST. HELENA

SANITARY SEYER MANHOLE SURVEY
Date
,,
..

If
I'
(I
I'
(I
II
MARCH 1991
Depth of
Manhole
Line Size Flow in Flow to Condition of
In OUt Inches Street Level Manhole
~·· 2'
~'7"
Lj'' )'
6''
1'' h
3 'c. {( _)-.)
tj''
If
10 1-'
6 ,, 6'' I H
35 6"
JO ,,
" /0 v ;D 11 t2 II 6''
,, !2" !2''
Agenda Item #9.1.

Manhole II
Location
qurJI
?Z-:s Z-7
.70 Hv~~ i-6
/10 ,.,.rf ~ND 2-S
HuN/
eND 2-3
1-\ufo>\
S\fcwr;"l Z-t~ ~~ - :?f .. J£,,.1.4>/ Z.-13
tlutv'f -\qoe:,
~FEvJA'.f Z-tl t uiJ/ ---~
~ll 2-10
l-jvr-J) ~ f.IIDJ.iic ~L+ 2-8 ~{c'(ts.TA- 2,-~
0~~E:f
AbAMS
loo 1
~~~
&Wt~b VolTtror:
-
\j~N 1A!.\C'-IJ,..)lO'-.M
""f'At.M s
Vu,(f'f!r(\ c
iltfA'Ik
L-A 'f'A1A- _. I'{ E\A( (of-.) t; I
MAII-l s:l pj; Z.OJ..tw ,-
J-1,4.-lrJ
VIPt>Vlc.l'f 1-~()
CITY OF ST. HELENA
SANITARY SEYER MAJ\'BOLE SURVEY
KARCB 1991
Depth of
Manhole
Line Size Flov in Flov to Condition of
Date In OUt Inches Street Level Manhole
3-1~-11 !2 v !Zv 011 7~ {/ 6-,~b
II II /ZIA 12 ~, to" 8'ou 6(JtJ]J
!2ll II
tl 0'' 71-{J tl !2 6r4J
II It ;Z'' 12~ 6~ 8~(' bq()j)
l/ ,, 8u 8" h_q 1~t' b(J()ZJ
D(' Bv " tf II I 1'::/ ~y
II II 8& 8' ( ~I &rev
" ,. 8u 8v !'' 55~ ~]J
8if 8v z~~ I If
&DO-D (J /1 37
tl II 6& Bp Q s¥lt GDoD
lt {f 6u B& ~ ¥'7q &ai>
I• <I 6'1 6'' ~<I 2'5" 6coJJ b~ 'I ;il' z3 4
u 6oeJJ Lf 6
II <I 6" 61' (£" !3'2- 11 6tr:dJ
o" 5" !i" 6'3 II 6oon {I t I
,, " ou fS' %~ 5's" 6aoj)
1-i. "' 8"' s~ & t~s4
trco!J
11 I• 8M B- G ~-~q 6~
I< lA 8~ B" ~I q/(:/ !1oeb ,, ,, (p" 0'~ ~~ 2'7" ~j
Agenda Item #9.1.

Manhole II
Location
J}w~~~
1>CMJ'DCLL /0~5
1DJJ~LL 11.50
'fl:u,./VwJ S, £N.b oP . Lt-tflotC.s-r
6R.A td.:t ef._
LI··H-H;t SJ
CiVA-IL ~
L~t<AI?..~ u
1'1-0clLB~AR--i w!
llloo
CITY OF ST. HELENA
SANITARY SEYER MAl\'llOLE SURVEY
KARCH 1991
Depth of
Manhole
Line Size Flow in Flow to Condition of
Date In Out Inches Street Level Manhole
3-fs,,q { 3" t/ 6< B lt{l firpjj
11 u tt/ (r/ Q ~ '{{( 6xxJJ
I' I" 6/ 6/t 'CY s;11' G(JOJJ
/1 II 6* 6u ~ 5t_;v &P!)
II 4 b'i 6/t & 3 I 6oo.P
tl II 61' 6t. & --~~~~ 6o:;D .. "' 64 6~ z~ IZ" &ot>!)
"' ... b" 614 ~~ 3 ' 6cc.O
I
Agenda Item #9.1.

Sanitary Sewer Video Inspection Work Sheet
Agenda Item #9.1.

®) '-ALII-UKNIA flt't !>URVEY CITY St. Helena
(415) 883-3676 AREA TAPE NO.
2 POST OFFICE BOX 3415 • SAN RAFAEL, CALIFORNIA 94912 MAP SHEETDistrict 2 QUADRANT Nos SANITARY SEWERS--WORK SHEET STREET Oak
' MANHOLE N0.2-55 TO NO. 2- 11:
4 40
CLEANED T.V. INSPECTION REPAIRED
CREW LEADER REMARKS LEAK DISTANCE QUADRANT PHOTO REMARKS DISTANCE AND DATE NO READING I 2 3 4 NO AIR TEST SEAL 8/8~85~ Televise 1' X X Cracked 'oi:pe, offset jo nt
Mark p. 4• X II II
19' X II II
24 1 X Latera 1 w:ve
33' Roots ' .
35 1 X I X Cracked nipe ;
39' Roots ...
41 1 ' II .. ' .....;,--ift.
-"" 52 I X r X II cracked p tpe
54' II l '
79' X l ,, Lateral wye
82' X II I tap
86 1 ' X 11 wye
89' X l II tap .. '
" . 103' • X Crasked nipe
114 1 X X 11 II 4
PIPE ~ CONDITION Fair, .~, roots, cracks, bad taps, slip" line or replace - MANHOLE CONDITION Fati GRADE Fair, up and down
REMARKS TV from MH 2-55, downstream through l'1H 2-54 to MH2-40 DIRECTION OF MEASUREMENT --+• 111 .. · _, FROM CENTER OF MANHOLE PIPE SIZE· 6tr

TYPE OF PIPE VCF

TYPE OF JOINT
CUES SECTION LENGTH 2 I
Agenda Item #9.1.

~ QUADRANT T.V. INSPECTION ~ QuADRANT
32 Nos Nos T.V. INSPECTION

LEAK DISTANCE QUADRANT PHOTO REMARKS LEAK DISTANCE QUADRANT PHOTO NO READING I 2 3 4 NO NO READING REMARKS I 2 3 4 NO
111 1 X Lateral w:ve 361 1 X Lateral w_ye
135' X 11 tap 375' X II II
149' X " wye 408 1 X X Cracked pipe
15B' . X X Cracked pipe 410 1 X X II II
159' Roots 444• X X Lateral wye
173' Bad roots ~
* 445' X X II tap. w:aaer running
179' Roots 446• X " wye
187' X Lateral wye, roots 447 1 X X X Cracked pipe -
203' X X II tap .. 466• Offset joint
208 1 X X Cracked pipe 467• X • . Lateral wye
258' X f::ateral . 4<3&>' X II wye X tap
260 1 482' ... X " II X X II "
272' X II tap, bad roots * 491' X n· II water ru.p.ning . 273' X Cracked pipe 499' X X II " 276' Bad roots 506 1 X X Cracked pipe
271' X Lateral tap 514' X X ll II
283. X X tl tl 517' X lateral wye
284• 521 1 X II II Bad roots ' . 523' Dip .i' 11 · 287' X Lateral wye, bad roots "'i'- 288• X X Bad roots, cracked Pi"Pe Y; 52 8t II end ;.\!- 539' " - ·t" ;;;::
290' II II
295' MH 54. roots 543 1 II e.nd
Roots 564• II 3/4" 299' ~
302' II 568• II end
317' . . J.1; ~,..!; . "· 578' " .. . . ' . -- -- ~II
326' X Lateral wye, roots 581 1 II end
338' X I X II tap .. - ...... · ra·.:ked . . 584• X ~ X Cracked pipe ' ' . 342 I X ;::T~ ~li ?..1 ·"' 602 1 1•1H 2-40
354' X X \ Cracked pipe, roots
Agenda Item #9.1.

~ CALIFORNIA PIPE SURVEY CITY st. Helena
(415) 883-3676 AREA TAPE N0.3
2 POST OFFICE BOX 3415 • SAN RAFAEL, CALIFORNIA 94912 MAP SHEET n1 ~t:,.'i l".t: 2 QUADRANT Nos SANITARY SEWERS--WORK SHEET STREET Oak
&64
.., MANHOLE NO. 2-32 TO NO. 2 -55
CLEANED T.V. INSPECTION REPAIRED
CREW LEADER REMARKS LEAK DISTANCE QUADRANT PHOTO REMARKS DISTANCE AND DATE NO READING I 2 3 4 NO AIR TEST SEAL 8/8/85 Thread and Televise 12 t X X Cracked nine 1
.fvia.rk P. 28' X X Lateral wye
58' X X Cracked pipe
62 1 X X II u
80' X X Broken joint
100- X X Lateral wye, ws~er runn ng
101' X X Cracked pipe . :-5.
122' X· X II " I
- ~ 140' Dip i" !
146 1 X X lateral tap, dip end I
151' X X Cracked pipe joint .
166• X X ·Lateral wye
167' X X , tap
180 1 X X II wye ,_
200 1 X X Cracked joint ~
-~:"c· 217' ,»'', MH '58
PIPE CONDITION Fair, bad taps, cracked pipe-, lbpen joints, slip line or replace.

MANHOLE CONDITION Fair
GRADE Fair
REMARKS TV from HH 2-32, downstream through MH 58 to MH 2-55· DIRECTION OF MEASUREMENT _ ___,.. .....,.-..,...~ FROM CENTER OF MANHOLE PIPE SIZE 6n

TYPE OF PIPE VCP

TYPE OF JOINT
CUES SECTION LENGTH 2'
Agenda Item #9.1.

@B QUADRANT T.V. INSPECTION ~ QUADRANT 32 Nos Nos T.V. INSPECTION _EAK DISTANCE QUADRANT PHOTO REMARKS LEAK DISTANCE QUADRANT PHOTO NO READING I 2 3 4 NO NO READING REMARKS I 2 3 4 NO
227' Lateral tap. bad into main lt" root
234' X X II wye
238' X X " tap
243' Offset joint
244~' X Possible lateral tap or hole
250' X De Lateral W1fa
252' X X It tap or hole
252' X It wye
258' X X X X Cracked pipe joint
316' X Lateral wye. possible 6"
" 337' X ;, II tap \
339' X II wye .. . .~
348• Change to Tape 4 _,\t
,: )
380. X I.e. teral wye :
.~~!
'383' X 11 It
416. M.H 55 :

I
\
·'"
~:_ ' ~';:.f
.
~ .
.. .

I ...

Agenda Item #9.1.

(iJ CALIFORNIA PIPE SURVEY CITY ~,- .1~~ ,,4
(415) 883-3676 AREA TAPE N0.1
2 POST OFFICE BOX 3415 • SAN RAFAEL, CALIFo.!tNIA 94912 MAP SHEET.:k~~- .,-i,. ;}.. ~ :J OUAORANT Nos SANITARY SEWERS--WORK SHE~T STREET ~
. ~ ' .d!._ "").._ :)...._..;;.&>.A. MANHOLE N0 • .,2 ~tt~ TO NO. 1~~ "" !/ CLEANED T.V. INSPECTION REPAIRED

CREW LEADER REMARKS LEAK DISTANCE QUADRANT PHOTO
A~D DATE REMARKS NO READING -- NO DISTANCE AIR TEST SEAL -- I 2 3 4
/)</~5 . ~ ' l.
~, y /~ \ ~
~L4t..(... -'i tJ r £.--' rr c. .Lo f~ - ?tO' v ?------ • .. '-"- '~ qq' tlA...
lo~' '-'-
/ /I /0 "'
~ JIG I j/ ~~)-h~. ,, Jf11 - " ,.._
/;)..5" l
;::; ._, ·- /4L-1' ·- '-'- ~
- /5;1.1 y~ .
-' ,. ./ _5? I j)~_~-1_
" / G2- 1 ~1;:_ ' .
'
'l- I e,·?'t. '"\
.h
~~cg I j/ -~Y~ /7/' .v· iJ
\.. ' "'\ t:<-1>'
MANHOLE CONDITION t:fa0 I ·Cf""
GRADE :; ~
PIPE SIZE tJ'
TYPE OF PIPE vcf'

TYPE OF JOINT
~l='r.TI nN I I='NtlT~ ""\ '
Agenda Item #9.1.

"==~=-
~ T.V. INSPECTION • w
~ QUADRANT
Nos Nos T.V. INSPECTION --- -~----
- --
"EAK DISTANCE QUADRANT PHOTO REMARKS LEAK DISTANCE QUADRANT PHOTO NO READING I 2 3 4 NO NO READING REMARKS I 2 3 4 NO
/'1~ I?' M- hA.t.e SLJq s (/ - "~ f-- ~;,-a.o.-· 9~w ::;2.6)7( }" v v 5"70' t- 1.?-- v ~ {/ v (/
~LJP~~ ,...._ ,_ - 2/c:?' D_ ~-h s? J' -

I( )---I-
'...._ ~<O(AL ,
;). "3.2. ' v !Yf- ~w~ ~o3' lv V' ,, ,I' .......... ..... ,, /:J 3Cl ' I~ v- I?--' v ,, T~~ \.~ v
C..Js-' y -y v .... , "'- ... - ;). I-/ I \ .P' ~ f- fl r-...~ C;.;)G,. \ )--I- -- -, u,__.,):l i {/ v-_vV -- -. C.,;)_~\ v I-" )). J-j? "' '- ,,' ~ ,L - ;).. ~q'' llr lv .v
v --~ ,, ~'?I 'J -- -g \
~ Gl.f<:?' J. v It-....-- ' ;L(p I \. ...._ -'i ......... ,, ;2c.,.,-' t/ ,....... l '- """- ....... [:;rps' ,, ........... \-. ~p
:J...rt/.& I
"'
\, 0?s- \ IJ.-- f.-- \.......,_ ,,
.:::L'1Lll -~ ~ • G'Jt/ v .....- ~..n_-;i. .._, (~~
3o 1' v 1-- )/"" _.-
'-.._\a-t)_ ~~~ \· ... ~ l f :..-- \.- w~~ ~ \ ... , ?o& ~ "?11 t:::l I }.-- _.- / ?o~' v ....-- v
"'-'- Vt.~..t. '- ,,
'-3 7:3 4 I IV ~v #
6 U{J~ ?Is' v v- /,r v
"' '- \a../.)_ \.. .... ... , '1~~~ y v v ?;'7' IV / ,( {2..+b ...... ..._ ....... , C/ ...__ '-'- ....... q {DCj I ~Acf ?..2)' If" !---' ir 1- v .....:..--,.
\ ' ~...__
3 :7(9' v 1-- ~ 'V'-' ?;;)- 'f ) v v lt' .....- 1.., \ .... '""' ,, ..._~ --:s /~I ~""\. tlr ;!) 7-:3C:, I & ·v v ~ ...... ._ ,;.." ,, l..f{)?' {/ v '-'- "'- ?3&.<3 v 1-- lv ~ ........ '- ,..,_ -j-~r? k 1-- C.\... ,, ~~ ~,, 7.s-4" y !--"" '-'-.. T~
;yG~' ~ 1-h ~ ,_:2 ""3 ~
/Cb~' IV {/ t- ...... '- ....... L / 0"\.. )~~
-9?'1' v <-'
CAM~~ I(J_, .AA ?~;J' JY I/ IYV '- ...... I a.,. --b '\Vv,_p ~ ,, p ~Cf) I v v ~.~ G I' ). ).A-u-, a. _,.. A'..- J
?G<7 1 i- ~ ~ r-- ....._, ,! ......__ / !l_l ~~
5J£"' .).-vy v I &.a .1::6..{1~ .b euvrk~£~ /&Z(b' It/ v ........ \.._ w-4'2-- " CJI..f41 -y " J 9_ :; ....._v ?9q' r !.?-- ~ CJu.JJ& y ........... ' -- I I ~k.4.r~ I )So7 1 l ' ( \Cit2-~~ " 6'4S ~~ ·v '- [..?- - b'Cf~\ II a.~ <f? I() I v v t-- I
" - .... , --"' \\.

S'iq I :.---- 1?;7<2' IY lr ~ ,...._ y '-..- \' ,,
Agenda Item #9.1.

~ CALIFORNIA PIPE SURVEY CITY ~. 1~~~
(415) 883-3676 \ . AREA TAPE NO • ..y~ 5 2 POST OFFICE BOX 3415 • SAN RAFAEL, CALIFOlNIA 94912 MAP SHEET<:>::..~_-!,.,. .Q -f. 3 QUADRANT Nos. SANITARY SEWERS -- WORK SHEET STREET 0~
~ 1L :l. JJ"\ ~ .. P'fl~JUl. MANHOLE NO. ~-*' TO NO. 3-~ CLEANED w
T.V. INSPECTION (;.1

REPAIRED
CREW LEADER REMARKS LEAK DISTANCE QUADRAN __ PHOTO REMARKS DISTANCE . AIR TEST AND DATE NO READING I 2 3 4 NO SEAL 'f< 3~' ~~h~G-AA~ ~~f~ ? j) ~~~ _I_ "
~~~ I 10. 1-L 3 - :;. ;;).. . v (/
~ -
...
.) ~
-
-
-
PtPE CONDITION

MANHOLE CONDITION
GRADE ·

REMARKS
- DIRECTION OF MEASUREMENT ----+•- ••- - FROM CENTER OF MANHOLE PIPE SIZE ·

TYPE OF PIPE

TYPE OF JOINT -- - -
Agenda Item #9.1.

Sanitary Sewer Maintenance Report
Agenda Item #9.1.

STREET DEPARTMENT

SANITARY SEWER MAINTENANCE REPORT
DATE: ________________
START WORK ____________ END WORK _____________ EMERGENCY CALL: Yes___ No___ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ RODDED ____________ L.F. on ___________ From _____________ To _____________ DATE ___________ MANHOLES # ___________ on ___________ From ____________ To ____________ DATE ___________ REPAIR _________________________________________________________________________ DATE ___________ REPAIR _________________________________________________________________________ DATE ___________ STOPPAGE LOCATION ______________________________________________________________________________ Cause of stoppage, unusual conditions or added information ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ Equipment Hours Labor Hours

STREET FOREMAN
Agenda Item #9.1.

S T R E E T D E P A R T M E N T

SANITARY SEWER
DATE: 19 MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
Yes No
RODDED L.F. on From To DATE
RODDED L.F. on From To ,DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To -DATE
RODDED L.F. on Frpm To DATE
RODDED L.F. on From To .DATE
RODDED L.F. on From To DATERODDED L.F. on From To -DATE RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
'"'0DDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To ."DATE
RODDED L.F. on From To DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

S T R E E T D E P A R T M E N T
-----------~~ ---

START WORK

SANITARY SEWER

MAINTENANCE REPOIT
END WORK __________ __ EMERGENCY CALL
Yes No
DATE
RODDED ~ 5 1 - .L. F. on __ 11
____ From ,DATE
AI":~ RODDED £ '"'fl L.F. on ____ From
RODDED2 ~ 9 L.F. on
RODDED ________ L.F. on .DATE
RODDED_~-'~q ______ L.F. on .DATE-
< I A•'' RODDED : ,, ~ L.F. on
/Juri RODDED L I I L.F. on DATE
From ·nATE
From DATE
From
From DATE
MANHOLES # ------- on ____ _ From To PATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

S T R E E T D E P A R T M E N T

SANITARY SEWER
-· '\TE: - 19 -- MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
I' Yes No
/4'-{t( J
. ~} 3 ~
RODDED L.F DATE . on From 4 ".z To ,. ,
RODDED ~6s-· · on {))J :.s~ From L.F. i!-JRow .... To Pot. .._ ,DATE &. J'-/-0~ RODDED ~ql')._ L.F. on ~ \1, (s<>t;J F~om Ph\c.l!t?rt.e...r~ o (\ R I 'AJ -,.) DATE 6 -/l./ bl..f RODDED 'J-3~ L.F. on AJJ, \~ From ~ L t 01\ tX /"'Fa ~ "!.t.&. ATE t - J'f-et~ RODDED lf'-/C, L.F. on lk/a.;,. From I y 1/ , &:(~ ..! To I ,..)_.. $ )- 'DATE 9/t/}o1 37h thlt~ 1£, 't(q L.F. From ~rlQ .. To P.•tt <L RODDED on .DATE ~/o6 /OJ/ RODDED .3 ) 'l L.F . on ,., ;~"1 < From 14~...., To o-r--_ lA '\ ~I. .DATE - I ;~-;_A;r:,
RODDED L.F. on From To .DATE
RODDED L.F. on From To :DATE
RODDED L.F. on From To DATE
"ODD ED L.F. on From To ·nATE
RODDED L.F. on From To DAT]l:

RODDED L.F . on From To .'DATE
RODDED L.F. on From To DATE
MANHOLES # on From To DAT~

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

S T R E E T D E P A R T M E N T

SANITARY SEWER
l)ATE: 19 -- MAINTENANCE REPORT j

START WORK END WORK EMERGENCY CALL
Yes No
RODDED L.F. on From T~ DATE
RODDED L.F. on From To ,DATE
I RODDED i L.F. on From To -DATE
RODDED / .C( 0 I
L.F. on From To .DATE
RODDED '333 L. F1 • on From To D~TE
RODDED 65 L.F. on From To DATE
RODDED L.F. on From To .DATEI
RODDED L.F. From ~ To - on DATE
RODDED L.F. on From To DATE
RODDED L.F. on To DATE
-~ODDED I a~ JtJ L.F. on To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To :DATE
RODDED L.F. on From To DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

·
RDdded
LF .....
qb I I 'I r1 f\.t \ \P
3,<4 I C W...Q.,r oa.. t
!
STREET n 'ABTMENT

SANITARY SEWER MAINTENANCE REPORT
fromxltl• ........ .,... J· I
7 ~ l , UM\} \ k~. 1 j,q Jo7 ~
'" ·-,
Info
Hv&.ro
l OtX? 1 f ~ \}, a.u_ 3)36}07 'X I rh.Jc\fa \1c ~ l .t!..f\1() ..... , Agenda Item #9.1.

yATE:

START WORK
RODDED ~#< ,"J t:j L.F.

RODDED ""<"7 j
.,. ') { {z L.F.

RODDED \J.•1 L.F.

I
RODDED cfb L.F.

RODDED L.F.

RODDED j2 z' L.F.

RODDED J L.F.

RODDED 3::/2 L.F .

RODDED . l:t l I L.F.

RODDED L.F.
··RODDED L.F.

RODDED L.F.

RODDED L.F.

RODDED L.F.

MANHOLES #
REPAIR
REPAIR

STOPPAGE-LOCATION
on
on
on
on
on
on

S T R E E T D E P A R T M E N T

SANITARY SEWER

MAINTENANCE REPORT
END WORK __________ __
From
From
From
From
From
From

EMERGENCY CALL
Yes No
To DATE
To DATE
To DATE
To DATE
To _"DATE
To DATE
To DATE
DATE
DATE
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

s T R E E T D E P A R T M E N T

SANITARY SEWER
1ATE: 19 MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
Yes No
L.F. on From To
RODDED L.F. on From lOll To
RODDED L.F. on From To A ~~~2 l
RODDEncJS,~ L.F. on From To
RODDED L.F. on From To
RODDED L.F. on From To
RODDED JSlf L.F. on From To
RODDED l~J-"~l L.F. on From To -DATE
RODDED L.F. on From To DATE
RODDED 2 L.F. on From To DATE
g L.F. on :From To DATE
RODDED ?_ (o L.F. on From To DATE
RODDED L.F. on From To :nATE
RODDED L.F. on From To DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

R~
LF 8trMt
212 J \-tu ('\ r '25"3/ o~-t
STREET n >ARTMENT

SANITARY SEWER MAINTENANCE REPORT
-
I " 1.:
fromxlb..t toxltiMt~ a.

Qa. \ \ ~ oec.l • t'Y\cc.. \ (\ 12/1q /o~ X
I c 17 HvV"l-r ( .)_ \\ ((Y \ ., 12/1~/oto
~
Info
Hv&ro
HydLrc
Agenda Item #9.1.

S T R E E T D E P A R T M E N T

SANITARY SEWER
""''TE: 19 MAINTENANCE .REPORT --

START WORK END WORK EMERGENCY CALL
Yes No
')
RODDED ~ L.F. on From To DATE
RODDED L.F. on From To ,DATE
RODDED L.F. on From To DATE
RODDED :) L.F. on From To .DATE
~ODD ED L.F. on From To DATE
RODDED 2 IZ I L.F. on From To DATE
RODDED L.F. on From To DATERODDED L.F. on From To -DATE RODDED L.F. on From To ·nATE
RODDED L.F. on From To DATE
:OODDED L.F. on From To DATE
l
RODDED L.F. on From To DATE
RODDED L.F. on From To _"DATE
RODDED L.F. on From To DATE
MANHOLES # on From To PATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
---------::-----------"'!vi; Street Foreman
Agenda Item #9.1.

s T R E E T D E P A R T M E N T

SANITARY SEWER
DATE: MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
Yes
RODDED :}'6q L.F. on From To DATE
} =;e ·"~ RODDED J ~:~ L.F. on From To ,',DATE
RODDED L.F. on From To -DATE
RODDED L.F. on From To -DATE
RODDED L.F. on, From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To _'DATE
RODDED L.F. on From To DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foremar.;
Agenda Item #9.1.

START WORK
RODDED L.F.
/
'~} § -.-
RODDED I ( I L.F.
17 2 /
RODDED L.F.

RODDED l~.-'1
1 I I L.F.

RODDED 1~1
J l L.F.

RODDED
,.,__,
f I I L.F.

RODDED " 7 L.F.

RODDED ll] L.F.

RODDED L.F.

RODDED L.F.
~ODD ED L.F. ~
RODDED L.F.

RODDED L.F.

RODDED L.F.

MANHOLES #
REPAIR
REPAIR

STOPPAGE-LOCATION
on
on
on
on
on
on
on
on
on
on
on
on
on
on
on

S T R E E T

SANITARY SEWER

MAINTENANCE REPORT
END WORK __________ __
From
From
From
From
From
From
From
From
From
From
From
From
From
From
From
Cause of stoppage,

EMERGENCY CALL
Yes NO
To DATE
-
To ,DATE
To -DATE
To ·nATE
To DATE
To .DATE
To .DATETo -DATE
To "DATE
To DATE
To "DATE
To DATE
To _:DATE
To DATE
To PATE
DATE
DATE
or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

STREET n 1

ARTMENT

SANIT ART SEWER MAINTENANCE REPORT
I' ~-.:- ~ . h -
I . .

Rodded
LF ..... fromxlttMt , toxlll..t DMII I ..!I Info
13 5 ,I !(a\\r~ H-uY)+ I bt hit\~ r t:~ltD.r 4( l"'fHJ~ )( ' )\.-./If; fb
'
Agenda Item #9.1.

Rodded
u: StiNt
( {?I ~ TN 'n ""'
97 ~ 1 S.o( '(" ~
:;_so" s .v f/f'\() •
-.J
I
STREET n 'ARTMENT

SANITARY SEWER MAINTENANCE REPORT
' I C"
;,
tromxlbMt toxltiMt 011111 I
I J I ).( ""NNWD..V 1r1 ,J, ... ; I •
N t'1 tt l t\ cs t I /3 I/() 7 c;nJ_ " w~ J y
rYl DYtP_ y Wav Oak: t/31 / ol ><
I
._ - .

Info
.<s .:.":i.- , D ~'$
(-lydro
}-/ y dora
Agenda Item #9.1.

s T R E E T D E p A R T M E N T

SANITARY SEWER
\ATE: 19 -- MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
Yes -No
Spring 1781 1709
ROOD ED DATE 2/9/95 ] 56 I L.F. on :t::it Bd From s :t::1 B To s :t::1 E (
RODDED L.F. on From To ,DATE
RODDED L.F. on From To DATE
ROOD ED L.F. on From To
RODDED L.F. on From To
RODDED Is b L.F. on From To
RODDED 3 :)-7 ' L.F. on From Z.(, To .DATERODDED / z~ ~' L.F. on From To X(, -DATE / ,',, ' ROOD ED "'i ,}; L.F. on From ~·':.-s i, "1:j To ~DATE RODDED 3'J7 L.F. on From To DATE
12 %,
!ODD ED lt:Jo L.F. on From To ~DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To .:DATE
RODDED L.F. on From To .DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

s T R E E T D E P A R T M E N T

SANITARY SEWER
'\>ATE: -1± '! "-- MAINTENANCE REPORT

START WORK END WORK EMERGENCY CALL
Yes No
RODDED L.F. From To DATE
RODDED ;2(£?Q L.F. From To ,DATE
RODDED;) L.F. From To -DATE
RODDED L.F. From To -DATE
4e::rz RODDED v L L.F. From To DATE
}!
RODDED Lj L.F. From To DATE
U'
RODDED '' L.F. From To DATERODDED L.F. on From To DATE RODDED L.F. on From To DATE
RODDED L.F. on From To DATE
~ODD ED L.F. on From To DATE
RODDED L.F. on From To DATE
RODDED L.F. on From To _"DATE
RODDED L.F. on From To DATE
MANHOLES # on From To DATE

REPAIR DATE

REPAIR DATE

STOPPAGE-LOCATION
Cause of stoppage, unusual conditions or added info.
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

S T R E E T D E P A R T M E N T

START WORK ----------

SANITARY SEWER

MAINTENANCE REPORT
END WORK __________ __ EMERGENCY CALL
Yes No
RODDED_'.''uq..J: __ ' L. F. on " VI M lit,# From
.. ) RODDED :. I -
lf uq RODDED 1
RODDED lfi'J
RODDED If L/~
RODDED 1_ 7 7
RODDED LtO t
RODDED 44q
RODDED '-fLf ~ '
RODDEnL14 q .

L.F .

L.F.

L.F.

L.F.

L.F.

L.F.

L.F.

L.F.

L.F.

RODDED ~ 1 L.F. :--'-'----
RODDED -'- j L. F.
i
on l); ,J.t n:-t 't...i From
on vl~,{_~(J F~om
on V ~~/.~~From
on v""' '7' ,. f-rom
. on 1,l t •t 1""\._ "r<f'rom
on l
lf2. ~r rom
on ·rl::. -~ w From I
on ll•.-7l•,.4From
on IJ,tll.~c.Q.~ From
on V,-,.~y.c.tL:I From
on v.( I J ljt ,J)From
~1..._ / __ To \hl 1)~j DATE
. Do,... ' > r-c To I 7 i:f 7 .DATE
/vf~ r;~..ct r it;~d,
V !!~"'~"'' "~ To (}~r· t'"t'"'S .DATE -
To ~,... ...... 1 ~ .. d')( iDATE
To f I, I VffW ·nATE
l)q"/ To HI~ "1'!-W DATE
-t
To -·-~,.. r ·nATE
1-;_.~.., To -~-----
RODDED ____ ~ __ L.F. on , -., From To --------
RODDED Q.!..: ~
MANHOLES # _______ on _______ From __________ To ___ _ DATE

REPAIR DATE

REPAIR --------------------------------------------------- DATE

STOPPAGE-LOCATION
..- /c 1
7 .) : ij ~ ""\ -:\ (
?Vu?~
IO/o7
10 /z. -~ /03
. 0-?..7-03
f -;:t)~t1t
~-f3· 0~
~ ... /f-a i
/'l G C;LJ
Cause of stoppage, unusual conditions or added info .
~I \.... J l -
3 ruTI~r- I
======================================================================== Equipment Hours Labor Hours
Street Foreman
Agenda Item #9.1.

Sanitary Sewer Work Sheet
Agenda Item #9.1.

Street
Manhole Id. #
From:

To:

Date
Pipe size in: out:

City of St. Helena
Sanitary Sewer Work Sheet
Type of pipe in: out:

Distance Quadrant Manhole
reading 1 2 3 4 REMARKS Type
Condition

REMARKS & REPAIRS NEEDED
Direction of Measurement
From Center of Manhole

No. # of Laterals:

No. # of Lots
4 1
3 2
Quadrant Nos.
manhole
Id. #
manhole
Id. #
Agenda Item #9.1.

&tJ
'ZE7
Quadrant Nos.
' City of St. Helena
Sanitary Sewer Work Sheet out
out

REMARKS
Type
Condition
-· ·----- - -... -- REMARKS & REP AIRS NEEDED
Direction of Measurement
From Center of Manhole
manhole
~------------ Id. # _/
No.# of Laterals;
No.# of Lots
Agenda Item #9.1.

~
\T7
Quadrant Nos.
istance c uadra t
cead:in2 l 2 3 4
4'3 .2 X
7fo, 0
4z,o
IX ~4.?
·~,.-
- l .;. . (
BG,.o X ..
. '.<.
~52. I
1r '
/0.0 IX ..
-y..· ..
u street 0 a. ~ c:-· I
,. City of St. Helena
Sanit:ary Sewer Work Sheet in out
L
L ,. _L.
.•
, .. C:-
Ac·
/1l..

HaL~ t 1 , .,. ""
_,
~
\"' r
Let.
le+er~ I
c;:

A-c+~r
\ .
/~
.
{._

REMARKS & REPAIRS NEEDED
o v\..J Oo... ~.:::: <::: '- -· .._ .

Direction of Measurement
From Center of Manhole
No.# of Laterals;
No. II of Lot:s
manhole
Id. # _/
Agenda Item #9.1.

~
'ZV
Quadrant Nos.
11 Street
' City of St. Helena
Sanitary Sewer Work Sheet
Type
Condition
-· ~----- - -.... --·

REMARKS & REP AIRS NEEDED
Direction of Measurement
From Center of Manhole
manhole
~~~~------ Id. # _/
No.# of Laterals;
No.I! of Lots
Agenda Item #9.1.

~
\T7
Quadrant Nos.
stance c uadra
eading 1 z 3
_I~
IL, Y I ,a) 7. X.
11 - y
~( )
152.1 X
,' 7. I 'X
9{ ~ .. J J -
I 711. I
; L{), Lf . -, :'.{ I -
\\\; .I..\
-\"\ \J I,
-\-\-:.\
'',. n"""' '-)_ ·-? tJ, ..1 '-l: 'i
I' "lll -\ '
\'I) j "' - .IV . I \11~ . .
~u.s
. .
1 .,
I
I I
' I I
I
\ I· .
..

I I
I
I
.• i i I
i I
i i I i ' '
I l
11 Street
\ c , r .. (.
~)/,1
_, .-C-=:1-.tz~o.;;..f ... s-.t.._ • ..;:;;B;.;:;;el_.,=• _ _. ~L I ~
· Manhole Id. I . from ,,: r- , ••
' !to· -
Sanitary Sewer Work Sheet
-- --~<(
t . Type
4 REMARKS fl~t_ ' •
Condition
x· 'I' -c: ~
i'i_ I A-~OL/1 ( 4t, . .; -· ·-- - . -· .; kn(l I'} ; .. REMARKS & REPAIRS NEEDED . · c ;') . l ~{ J ' 1 lA ~ ~l_lf l 1 t'L> /l .
' ,.) ~ ('llt; ' ' J.:n, ( - L;1 ~c.,! J;. \ If'). ~
ll'j ·~1'-1 II I JJ, (.! :/" rna4.,. Hd!L I f.?. .<\ A..~_J ~ l {i L. r.t•·
I l'7L. <.- 191J
X I • I ~ ~ {"~ ~. ;)7v. I
_'j.. ' _,: • .!_· (l ~. ?L/},t-/ 1 •
rn.\, I r: tl ~'.~ \ i{\~··(,, ~,t, N\ t+JJ_
J-1-0 LC. - ~· L t\-\--t .. ,.-> ~!!4.t{
~:. ·lr r-:_!.; I '•~
. \ J' ,,, \~ ~-\.( I r -. _.- , ?') Lltl') / ' ....... ., . " ~· 'L,/\ ~ I I I . L/l ~, :· J. I I ... ' ( c ~ ~ "' 11 r ~ I
•,J; r \1~ - 'JJ ·\· l -t
/ ~~-
I'\- ../ ~ ..
·i . !'t"; f( ·,?1 u •. r ,; ~~·. # qn ,I)
. I I ' , . . . .
[. ~ v ,_ . ,_. '• t. • .. ~ -.. , - . . . . . ~ .
.. - . . .. • • t . ~ . . . . . . . . . .. - . . .. . . . . . . . - . . . . . ... . .. .

Direction of Measurement - From Center of Manhole
-
€ manho~e
I d. u -;; D
No. II of Laterals;
. .

No ./1 of Lots
I
Agenda Item #9.1.

~
\T7
Quadrant Nos.
.stance uadra
adin~ 1 l 3
I n
I
lO ~

7.5 I
I
I
I
I I .
! I
I
I I
I
r
i
. l
I r
i I
j i I I
I
l
t
7i
I
'· Ciey of St. Helena
SaAit&lJ' s..,.r Vork Sb~t
. ll!MAIXS . L• ... ~ -1..11 w6ieli
,...,_Jr ~J ... £..vi-' ~ -( - . ~ , ,
· ?
' I
1 Street !'riA ~~
Mahole Id. -~ .. J Itt ... m~.t . froa
.to"
out
out
Couditi.OD
. .
- ·- - ---- 1U'JWtXS & REPAIRS H!EDBD
-
-
-
--. ...
-
-
-:'
.. . . . . . . . . . . . ..
. .

Diract1on of Measuremen t
From Center of Manhole
I€ manho1 e
I d. I ,; IJ
No. IJ of Laterals; ,
. . . . - . . -
No./1 of Lots
...
.l .

Agenda Item #9.1.

~
\T7
Quadrant Nos.
.stanc el c uadr
eadin~t 1 z
l (
I I ...
-
.), (
'_, . c.
~ -J . ) 0
I
I
I
I 'I
I
I I .
! I I I
! I .

I
'
I I
I
I
. i ;
i l
I j I i ' '
I ~
a'lt'
3 4
J
j
J
' I
'
'
i .

I
'· City of. St. Helena
San1Ury Sever Wor~ Sheet
. Type
JlEM1R1tS Conclition
J.t tc..JtJ #
I
~JI J 2. '2... -· . . ( )(J .t - · -·· _ ,
L I .../ ~f REMAlUCS & REPAIRS NEEDED
" C.JI ~ J lUJ _, ' flll5} A. I 1
(• """' 1('# ct. w~ . ~
-
'
. . . . ... . . . . . . . ' . . . . . ... .... . . . ... .. . . . . . . < • . . . . . . . . . . . .

Direction of Measurement
From Center of Manhole
1€ manhole
I d. {) -/ n
No .II of Laterals;
. .. .. . ' -
No./1 of Lots
Agenda Item #9.1.

11 Street
Quadrant Nos.

J-":_) . 11" _,~,, .-- !)fjl.#
istance c uadra t ' Type /- -.b.n· -
reading 1 2 tiJ 4 REMARKS Condition- > -
~5--·- I Wes-4 I~ rca t e ;-
57 ~ ..; Lt:\'TI~ L F ~"I "' ,_, lb; -- -- - --· -
21·" 0 ., JSS-;.b\e t-'c " tl' - REMARKS & REPAIRS NEEDED Iff' .
f-""
I . i .
. ' ' ' . .. """' - . . . . . . . . ~ . '
. . .. . ' . . . . . . . . . . .
. '
- l Direction of Measurement ., From Center of Manhole
l
I
' . I -l 1€ I . manhole
I II !d. !J -;~
!
• No .11 of Laterals;
I I
I - ' • .. . . . ~ .. . . ' ' '
! l / ;;, No.I! of Lot:s
i I
i I - ' i - ! . I
'
' i
li I .. '@
!
Agenda Item #9.1.

~
\IT7
Quadrant Nos.

Lstance c uadra~t
:eading 1 2 3 4
) - X ~
1"\ \ ~
(;, :"\
c;l
tc C[ '
I j 1 X
..J I 1tc r--·
} LjJ I
I
I ·I
~ '
~.J ~
. .
-I
I
I I
! ·1- . I
I)
I I : .
• I
~ I I if r
I
..,.
' t l ~, I . I I j
• ... I i
l
.. ~
I
I !
. ~J ..

J
I 'II
f\'Kr.ILt.
.II.

I
J ..L
LA
fi...LI_
LA~ C' retA
r .

I
'
'· City of St. Helena
1 Street
f)lt>-·~-·
· Manhol e . fr !)m
·Io
in out Sanitary Sewer Work Sheet in out
I Type
REMARKS Conditi on ,, .
. l
r -- . ·- -· -- REMARKS & REPAIRS NEEDED
' • j
t, I
J
Ji.n
X
.
.
.I
. . . - - . 0- . ' .
. . . ·- ~ . . . .. . . . - - . .
• 4 ~ •
Direction of Measurement
From Center of Manhole
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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

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Agenda Item #9.1.

Outreach to Plumbers & Sewer Contractors
Agenda Item #9.1.

Plumbers & Sewer Contractors:

Your Actions Can Prevent
Sanitary Sewer Overflows!
What are Sanitary Sewer Overflows or SSOs?
SSOs discharge untreated or partially treated human and industrial waste, debris and disease-causing organisms
from the sanitary sewer onto the ground near and into
homes and potentially into creeks, rivers, lakes or streams.

What are the impacts of SSOs?
SSOs may result in property damage, environmental
damage and/or potential liability to you or your company.

Allowing sewage to discharge to a gutter, storm drain or waterway may subject you to penalties and/or out-of-pocket costs to reimburse cities or public agencies for clean-up efforts and regulatory penalties.

How can you prevent SSOs?
and avoid associated penalties & fines
When clearing plugged sewer laterals:
; Whenever possible, remove root balls, grease
blockages and any other debris; don’t push debris
from the lateral to the sewer main.
; If you can’t prevent a root ball or other debris from entering the sewer main when working in our service
area, please call us at (707) 968-2658, so we can
work with you (free of charge) to remove the root ball
from the sewer main to prevent blockages further
downstream.
; Use plenty of water to flush lines.
; Don’t open manholes. Hazardous sewer gases from
manholes are odorless, undetectable and can be
deadly. Call us to open manholes for you and please
note that discharge into a publicly-owned manhole
requires a permit. Contact us at (707) 968-2658, for
an application.

When constructing sewer laterals:
; Check your work area. Gravel, backfill material and
test plugs can become lodged in the sewer line and
cause blockages. Make sure no debris is left in the
sewer line before you backfill.
; Avoid offset joints – offset joints make sewer lines
vulnerable to root intrusion & grease accumulation,
cause debris hang-ups and make lines harder to
clean. Properly bed your joints and don’t hammer tap.
; In the City of St. Helena service area, contact us for the appropriate construction specs at (707) 968-2658.

Who Do I Call to Avoid an SSO?
Help us help you…
If you require our free assistance to help clear
root balls, grease blockages and other debris
from a main sewer line to prevent an SSO or
to open a manhole in our service area, please
call us at:
(707) 968-2658
Agenda Item #9.1.

Training Attendance Form
Agenda Item #9.1.

City of St. Helena
Collection System Staff DATE: ________________
Training Sign-In
TITLE OF TRAINING SESSION: _____________________________________

NAME SIGNATURE
INSTRUCTOR: ________________________________________
INSTRUCTOR SIGNATURE: ___________________________________ Agenda Item #9.1.

 Design and Construction Standards
Agenda Item #9.1.

City of St. Helena Page 5-1
Sewer System Management Plan Version 8 – January 2023
5 Design and Performance Provisions

5.1 Standards for Installation, Rehabilitation and Repair Section 6 (Sanitary Sewer System) of the City of St. Helena Water and Sewer Standards (Resolution No. 93-58, Adopted June 22, 1993) includes design criteria as outlined below.

These Standards are periodically reviewed, and updated as necessary. These standards are available online at www.cityofsthelena.org/publicworks/webform/forms-and-documents . 6-1.01: Materials 6-2.01: Permits
6-1.02: Acrylonitrile-Butadiene-Styrene (ABS) Pipe 6-2.02: Pipe Size 6-1.03: Polyvinyl Chloride (PVC) Pipe 6-2.03: Grades and Alignment 6-1.04: Ductile Iron Pipe (DIP) 6-2.04: Backflow Device 6-1.05: Excavation and Backfill 6-2.05: Independent Systems 6-1.06: Existing Manholes 6-2.06: Cleanouts
6-1.07: Pipe Laying 6-2.07: Fittings
6-1.08: Sewer Structures 6-2.08: Proximity to Wells
6-1.09: Testing of Sewers 6-2.09: Connecting to Existing Buildings 6-1.10: Trench Resurfacing 6-2.10: Connection to Existing Sewers 6-1.11: Mandrel Test 6-2.11: Material
6-2.12: Pipe Cover and Clearance
In addition to written specifications for the design and construction of the sanitary sewer system, standard drawings are included for the Sewer Division, as listed below:
201 - Standard 48” diameter precast concrete manhole sanitary sewer 202 - Standard 60” diameter precast concrete manhole sanitary sewer 203 - Inside drop in sanitary sewer manhole
204 - Outside drop in sanitary sewer manhole
205 - Temporary mainline cleanout
206 - Temporary mainline cleanout
207 - Abandoned pipe plug detail
208 - Abandoned manhole detail
209 - Standard precast concrete manhole reducer slab sanitary sewer 210 - Standard manhole frame and cover
211 - Sewer service lateral
212 - Sewer service lateral
213 - Pipe-structure crossing detail
214 - Plastic sewer pope deflection mandrel
215 - Precast grease interceptor
216 - Sand and grease interceptor
217 - Sampling manhole exterior use
218 - Sampling box building interior
219 - Cleanout detail at building
220 - Typical service sewer connection details
221 - Backwater check valve installation
222 - Service sewer trench detail
223 - Sewer separation requirements
Agenda Item #9.1.

City of St. Helena Page 5-2
Sewer System Management Plan Version 8 – January 2023

5.2 Standards for Inspection and Testing of New and Rehabilitated Facilities
Inspection and testing of new facilities is important to ensure that the City’s established standards are implemented in the field. Using the legal authority described earlier in the SSMP, completed construction is not accepted by the City until inspection and testing have been completed. This approach helps ensure proper operation and maximum life expectancy.

The City has added to their Sanitary Sewer System Standards a requirement for a CCTV inspection prior to accepting a lateral or issuing a Certificate of Occupancy for a new connection.

The City’s process for testing Public Sewer Mains and Private Laterals is as follows:

1. Video inspection is required of all construction to ensure proper construction and to confirm connections and fit is as required.

2. Test by other means is also required using one of the following methods:
a. Pressure Test: Pressure testing is required under 4 pounds per square inch (PSI) for a minimum of 4 minutes with a maximum allowable pressure drop of 0.5 PSI. If the pressure drops more than this amount, then re-pressurize to 3.5 PSI and hold for additional 4 minutes. Pressure must not drop below 3 PSI during this retest. b. Hydrostatic Test: All manholes and isolated laterals shall be tested by plugging at the main connection(s) and then filling structure or lateral with water. The water shall not exceed the allowable loss (for a four hour period), as determined by the City Engineer.

Inspection and testing of new wastewater collection facilities may be conducted by Wastewater Collection staff or by the contractor while an inspector representing the City makes sure the installation and testing meets the City’s standards. Inspections are performed during and at the completion of construction.

Agenda Item #9.1.

. Overflow Emergency Response Plan
Agenda Item #9.1.

City of St. Helena Page 6-1
Sewer System Management Plan Version 8 – January 2023
6 Overflow Emergency Response Plan
A copy of the City’s Overflow Emergency Response Plan (ERP) can be found as an attachment to this section and was developed in 2014. The ERP protocols are summarized below. The ERP is to be used in conjunction with the Sanitary Sewer Overflow & Backup Response Plan, a field guide developed in 2008 (also attached). In 2023, the City plans to update the ERP and the field guide, to address new applicable regulatory requirements expected from the State Water Board’s adoption of the revised WDR.

6.1 Notification
This section includes information on how the City is to be notified of an SSO through a complaint or a report. Additionally, this section includes the chain of communication leading up to the response to the overflow.

The City has an emergency on-call service 24-hours a day, every day of the year with a goal to respond to all calls within 30 minutes. The City will clear all plugged sewer laterals from the property line and all City main lines. If the problem is in the homeowner's section of the lateral, the City crew will inform them of the situation. The homeowner is responsible for any issues with the upper lateral and house plumbing. As listed on the City’s website, anyone wishing to report an SSO should contact the Department of Public Works:

Address: 1480 Main Street, St. Helena, CA 94574
Hours: 8:00 a.m. - 5:00 p.m.

Phone: 707-968-2658
After Hours Phone: 707-967-2850 or 911
Fax: 707-967-2806
Email: [email protected]
Immediately upon receipt of a notice of a SSO, the following actions take place:
• Public Works Director (or nights and weekends sewer standby person) is notified of SSO.
• Public Works Director notifies Collection System Operation Team. (Nights and weekends standby person responds and identifies need for additional personnel). • Collection System Operation Team mobilizes to location of SSO to assess overflow.

6.2 Response
Once the Collection System Operation Team is notified of a SSO, the chain of events is as follows:

It is the responsibility of the first St. Helena wastewater (STHWW) employee arriving at the scene of the sewer overflow location to protect the health and safety of the public by immediately beginning the necessary steps to mitigate the impact of the overflow.

Agenda Item #9.1.

City of St. Helena Page 6-2
Sewer System Management Plan Version 8 – January 2023

1. Initial Assessment and Response. General, quick steps to mitigate the situation can be taken once an employee becomes aware of the sewer overflow:
• Determine the cause of the overflow, e.g., line blockage, line breakage, pump mechanical or electrical failure, etc.
• If possible, take immediate steps to stop the overflow by rectifying the line blockage, isolating a pipeline breakage, restoring power, putting another pump into service, etc.
• Identify what, if any, resources can assist with the mitigating the cause of the overflow, including additional personnel, materials, supplies and/or equipment.

2. Spill Containment and Control. The primary objective of the responders to a sewer overflow incident is to protect the public’s health. Therefore, if it is at all possible that the public may come into contact with any sewage material from an overflow event, the responders should remove that possibility by isolating the surrounding area. The perimeter of the sewer overflow site can be controlled with cones, barricades, vehicles or some other barrier that restricts access.

After the public has been isolated from the spill area, containment and clean-up can proceed. The spill should be contained within the smallest possible area, and every effort should be made to prevent the discharge of sewage into any receiving waters.

The following are containment suggestions:
• For spills that occur within the Wastewater Treatment facility, every effort should be made to keep the spill from leaving the facility’s property. • Determine the immediate destination of the overflow, e.g. storm drain, street curb gutter, body of water, culvert, landscaped area, etc.
• Identify and request the necessary equipment to contain or isolate the overflow if not readily available. Take immediate steps to contain the overflow, e.g. block or bag the storm drain inlet, recover the overflow by pumping, construct a containment pond, divert into a downstream manhole, etc. • In the event of a prolonged line blockage, breakage or collapse, a determination must be made to set up a portable by-pass pumping operation around the problem area. If this becomes the case, personnel will be required to continuously monitor the by-pass pumping operation until it can be terminated.

3. Spill Cleanup. SSO sites are to be thoroughly cleaned as soon as possible after the overflow incident is mitigated. No residue will be left for future rains to carry away or for public contact to occur. The following steps should be taken to ensure that the overflow sites are returned to their former conditions:
• Where possible, the area is to be thoroughly flushed and cleaned of any sewage or wash-down water. Solids and debris are to be flushed, swept, raked or picked up by hand and properly disposed of.
• Where appropriate, the overflow site is to be disinfected with HTH (hydrated calcium hypochlorite) and water or liquid bleach (aqueous sodium hypochlorite).

Never flush any disinfectant into a storm drain or body of water. • If sewage has ponded, the pond should be pumped dry and the residue and site cleanup managed as previously mentioned.

Agenda Item #9.1.

City of St. Helena Page 6-3
Sewer System Management Plan Version 8 – January 2023

4. Spill Classification and Quantification. There are three general classifications of SSOs:
• Category 1 SSO – Spills of any volume that reach surface water without being fully recovered.
• Category 2 SSO – Spills over 1,000 gallons or greater that do not reach surface water or that are completely recovered from a municipal separate storm sewer system and disposed of properly.
• Category 3 SSO– Spills less than 1,000 gallons that do not reach surface water.

No matter what the SSO classification or its volume, the need for containment, control and recovery procedures by STHWW employees and our responsibility to understand and comply with the reporting requirements remains.

Spill quantification requires careful documentation and close observation of discharges. Staff should make every effort to maintain a careful chronology of the events during a spill and make every attempt to conduct linear measurements of the discharge streams and flow velocities in order to effectively quantify the spill volumes. If possible, photo documentation of the spill event should also become a routine procedure in the spill documentation process. Official estimates of the spill volume will be the responsibility of the Director of Public Works. A few other types of spills, and the compliance requirements, are outlined in the next couple of sections.

5. Spill Documentation. Aside from the “SSO Event Report” Form, STHWW employees may also (at the discretion of the Director of Public Works) compile, document and report an “Official Spill Record” which can assist in providing a record of the events of the incident. The Spill Events Record may include:
• Event times (failure, discharge start and stop)
• Personnel on site
• Arrival and departure time of all personnel
• Equipment on site
• Milestone events (if any)
• Photo and video documentation
• Spill volume estimates and the method used to determine the estimates • Arrival time of outside resources (and list of the resources) • Regulatory agency representatives on site (obtain their business cards) • Spill recovery volume estimates

6. Posting. Posting contaminated water signs is required downstream of the location of an SSO. Posting should be implemented under the following guidelines:
• Wetlands or creek beds shall be posted at 50 foot intervals for high use areas and 600 foot intervals for low use areas. Both sides of creek beds must be posted.

7. Spill Sampling and Monitoring. If more than 50,000 gallons reached waterways, sampling of the body of water is mandatory. Sampling procedures are included in the Agenda Item #9.1.

City of St. Helena Page 6-4
Sewer System Management Plan Version 8 – January 2023
Water Quality Monitoring Program (attached to the ERP). At the direction of the Director of Public Works, sampling of lower volume spills may also be performed.

Conducting sampling at the appropriate locations allows staff to establish and monitor the levels of contamination as well as to establish or compare with the natural background levels of bacteria in the receiving waters.

All final sampling and monitoring results will be uploaded into CIWQS at http://ciwqs.waterboards.ca.gov.

6.3 Reporting
The Public Works Director or his/her designee is responsible for completing, or overseeing the completion of the SSO Event Form (attached) and CIWQS online reporting (http://ciwqs.waterboards.ca.gov). In addition, the Office of Emergency Services will be notified of SSOs where 1,000 gallons or more reach waterways or are likely to reach waterways when not fully recovered from a drainage channel or a storm drain system.

Depending on the SSO classification, CIWQS reporting procedures are as follows:
• Category 1 (all spills that reach waterways without being fully recovered):
 Submit draft report within 3 days of becoming aware of SSO  Finalize report and certify within 15 days of the end of the SSO  If more than 50,000 gallons reached the waterways:
o Submit all water quality results to CIWQS as soon as they become available o Develop and submit an SSO Technical Report within 45 days of the end of the SSO
• Category 2 (spills of 1,000 gallons or more that do not reach waterways or that are fully recovered):
 Submit draft report within 3 days of becoming aware of SSO  Finalize report and certify within 15 days of the end of the SSO • Category 3 (spills less than 1,000 gallons that do not reach waterways or that are fully recovered):
 Submit certified report within 30 calendar days of the end of month in which the SSO occurred.

6.4 Impact Mitigation
When an SSO results in release of sewage into the street, the following procedures are used to remove the wastewater and clean the affected area as soon as possible after the overflow incident is mitigated. No residue will be left for future rains to carry away or for public contact to occur. The following steps should be taken to ensure that the overflow sites are returned to their former conditions:

Agenda Item #9.1.

City of St. Helena Page 6-5
Sewer System Management Plan Version 8 – January 2023
• Where possible, the area is to be thoroughly flushed and cleaned of any sewage or wash-down water. Solids and debris are to be flushed, swept, raked or picked up by hand and properly disposed of.
• Where appropriate, the overflow site is to be disinfected with HTH (hydrated calcium hypochlorite) and water or liquid bleach (aqueous sodium hypochlorite).

Never flush any disinfectant into a storm drain or body of water. • If sewage has ponded, the pond should be pumped dry and the residue and site cleanup managed as previously mentioned
When an SSO results in release of sewage into a surface water, efforts are made to remove the wastewater and minimize negative impact on the affected area using pumps and manually collecting solids. Posting “contaminated water” signs is required downstream of the location of an SSO. Posting should be implemented under the following guidelines:
• Wetlands or creek beds shall be posted at 50 foot intervals for high use areas and 600 foot intervals for low use areas. Both sides of creek beds must be posted. If 50,000 or more gallons reached waterways, sampling of the body of water is mandatory. Sampling procedures are included in the Water Quality Monitoring Program (attached to the ERP). At the direction of the Director of Public Works, sampling of lower volume spills may also be performed. Conducting sampling at the appropriate locations allows staff to establish and monitor the levels of contamination as well as to establish or compare with the natural background levels of bacteria in the receiving waters.

Agenda Item #9.1.

. Overflow Emergency
Response Plan
Attachments
Agenda Item #9.1.

Overflow (PHUJHQF\Response Plan
Agenda Item #9.1.

CITY OF ST. HELENA WASTEWATER ENTERPRISE
Overflow Emergency Response Plan
Department of Public Works
1480 Main St
SAINT HELENA CA 94574
Phone 707-968-2658 • Fax 707-967-2806
Revised April 2014
Agenda Item #9.1.

1.0 Purpose
The City of St. Helena Wastewater Enterprise (STHWW) has developed this Overflow Emergency Response Plan (ERP) in order to fulfill requirements in its National Pollutant Discharge Elimination System (NPDES) and in the Sanitary Sewer System Waste Discharge Requirements (WDR) and the associated Monitoring Reporting Program (MRP). The procedures described in the ERP ensure that the protection of the environment and of the public’s health and safety remains a concern with a high priority.

This document provides the necessary guidelines for the STHWW staff when they must respond to a sanitary sewer overflow event (spill or SSO) in the STHWW service area. It contains the following elements:
• General information
• Basic spill definitions
• The spill response organizational matrix
• Guidance for spill containment and/or control
• Spill monitoring
• Proper notification protocols and forms
• Training
• Phone Directory
• Attachments:
• SSO Event Report Form (3 pages)
• SSO Water Quality Monitoring Plan (27 pages including appendices) Agenda Item #9.1.

2.0 General Information

2.1 Background and Regulatory Requirements: STHWW operates its wastewater collection, treatment and reclamation facilities under California Regional Water Quality Control Board, San Francisco Bay Region (Regional Water Board) Order No. R2-2010-0105 and Order 87-090. In addition, the STHWW is covered under Regional or Statewide General Permits issued by the Regional Water Board and the State Water Resources Control Board (State Water Board). With Regional Water Board Resolution R2-2003-0095 a collaborative effort between the Regional Water Board and the Bay Area Clean Water Agencies (BACWA) was initiated to develop and implement regional sewer system management planning assistance for individual wastewater system operators.

With Resolution 2004-0080, the State Water Board required the development of a Sanitary Sewer Overflow Reduction Program. This ERP, initially known as a Sewer Overflow Response Program or SORP, was first developed to comply with that program. Later on, the State Water Board issued the WDR (Order 2006-0003-DWQ) and associated MRP. The WDR requires development of a Sewer System Management Plan (SSMP), with the ERP as one element of the SSMP. The State Water Board revised the MRP several times since first issuing it; the latest MRP amendment was issued in July 2013 through WQ 2013-0058-EXEC. The current version of the ERP (April 2014) was revised to comply with the 2013 MRP amendment.

2.2 Overflow Emergency Response Plan: The WDR requires development of an ERP to establish procedures for responding to spills to protect public health and the environment.

Provision D.13(vi) of the WDR requires that each ERP include, at a minimum, the following elements:
(a) Proper notification procedures so that the primary responders and regulatory agencies are informed of all SSOs in a timely manner;
(b) A program to ensure an appropriate response to all overflows; (c) Procedures to ensure prompt notification to appropriate regulatory agencies and other potentially affected entities (e.g. health agencies, Regional Water Boards, water suppliers, etc.) of all SSOs that potentially affect public health or reach the waters of the State in accordance with the MRP. All SSOs shall be reported in accordance with the MRP, the California Water Code, other State Law, and other applicable Regional Water Board WDRs or NPDES permit requirements. The SSMP should identify the officials who will receive immediate notification;
(d) Procedures to ensure that appropriate staff and contractor personnel are aware of and follow the Emergency Response Plan and are appropriately trained; (e) Procedures to address emergency operations, such as traffic and crowd control and other necessary response activities; and
(f) A program to ensure that all reasonable steps are taken to contain and prevent the discharge of untreated and partially treated wastewater to waters of the United States and to minimize or correct any adverse impact on the environment resulting from the SSOs, including such accelerated or additional monitoring as may be necessary to determine the nature and impact of the discharge.

Agenda Item #9.1.

2.3 Civil Monetary Remedies and Penalties: The California Water Code provides for fines for violations of the NPDES and Order 87-090 of up to $25,000 per day for each day in which a violation occurs. Additional fines for spills which were not, or cannot be cleaned up, may also be imposed. These additional fines may be up to $25 per gallon for each gallon in excess of 1,000 gallons discharged to a receiving water. Intentional negligence or repeated violations may be subject to higher penalties. Significant fines may also be imposed for failing or refusing to furnish technical or monitoring reports or for falsifying information in these reports.

Agenda Item #9.1.

3.0 Definitions

3.1 Sanitary sewer system: The wastewater collection system including sewers, pipes, pumps or other conveyances that convey wastewater (e.g. domestic, commercial, and industrial sewage) to the wastewater treatment plant.

3.2 Sewer overflows: Each instance of a surface discharge from a sanitary sewer system at any point upstream of the sewage treatment plant. Sewer overflows often contain high levels of suspended solids, pathogenic organisms, toxic pollutants, nutrients, oxygen demanding organic compounds, oil and grease and other pollutants. Sewer overflows can cause a temporary exceedance of applicable water quality objectives, pose a threat to the public heath, adversely affect aquatic life, and impair the public recreational use and aesthetic enjoyment of surface waters in the impacted areas. This expression is interchangeable with the terms “spill” or “sewage spill”.

3.3 Surface waters: Surface waters include (1) the Napa River, (2) Sulphur Creek, (3) York Creek, (4) ephemeral streams, (5) lagoons, (6) dry creeks, (7) wetlands, (8) lakes, (9) natural ponds, (10) man-made canals and (11) storm drains.

3.4 Reportable event: Sanitary sewer overflows (SSOs) of any volume resulting from the STHWW system’s failure or flow condition are reportable – those that are 1,000 gallons or more that reach surface waters, or are likely to reach surface waters, must be reported within 2 hours to the California Governor’s Office of Emergency Services (OES). All SSOs must be electronically reported to the California Integrated Water Quality System (CIWQS); there are different timeframes for CIWQS reporting depending on the SSO’s severity (see discussion on SSO categories in Section 5.4). Note that overflows or backups into buildings caused by blockages or other problems in private facilities are not SSOs.

3.5 Initial receiving waters: The surface water body that is first impacted by the spill.

3.6 Secondary receiving waters: The final surface water body that is impacted by the spill.

3.7 Informal enforcement: The types of actions taken by the Regional Water Board that may be characterized as “less serious” in nature. Actions may include a (1) Notice of Violation, or (2) Request for Information.

3.8 Formal enforcement: The types of actions taken by the Water Board that may be characterized as “serious” in nature. Actions may include (1) Cleanup and Abatement Orders, (2) Cease and Desist Orders, (3) Referral to the Attorney General or District Attorney, (4) Administrative Civil Liabilities.

Agenda Item #9.1.

4.0 Spill Response Organization
The STHWW Spill Response Organization provides a clear organizational structure designed to facilitate an understanding of the responsibilities of each staff member in the agency with regards to spill events.

4.1 Director of Public Works / City Engineer – The primary role of the Director of Public Works is to take responsibility for effectively coordinating the overall response to the sewer overflow event once it has occurred. His/her responsibilities include:
• Assume primary management and coordination of all SSO response actions • Request assistance or resources from other agencies if necessary • Assess the SSO situation and establish action priorities • Perform an initial assessment of the extent of the onsite and off-site impacts (if any) • Direct immediate spill control and containment measures • Advise the City Manager as soon as possible
• Delegate staff to begin the spill record documentation and spill notification protocols. • Ensure that all oral and written reports are completed within the time allotted requirements • Oversee contractor work (if needed) and cleanup activities • Reviews the preliminary and final spill reports to CIWQS, for accuracy. • Ensures that the details of the spill event are accurately entered into the STHWW Spill Overflow Report Log
• Documents, by photo, all spill response and abatement activities (as necessary) • Provides media and public information whenever the City Manager is unavailable • Updates the Overflow Emergency Response Plan and provides staff training (as necessary)

4.2 Sewer Supervisor (or first responder) – The duties of the Sewer Supervisor consist of providing coordination, under the direction of the Director of Public Works, to mitigate the sewer overflow event, by directing resources and staff to contain, control and clean up the spill. His/her responsibilities include:
• Mobilize staff and equipment for spill abatement activities • Delegate assignments to staff members in order to achieve spill containment and control • Turn on/off all necessary equipment or utilities as needed • Dike and contain spill areas as directed
• Assist in the evacuation of personnel if necessary
• Set up emergency power sources if needed
• May conduct the initial notification to OES and the initial reports to CIWQS • Maintain security control at the spill site

4.3 Maintenance Workers – The duties of this position are to assist the Sewer Supervisor in whatever manner is necessary to secure equipment, coordinate the repair and/or replacement of equipment, coordinate the efforts of the maintenance staff, procure supplies and equipment if necessary, etc.

Agenda Item #9.1.

SPILL RESPONSE ORGANIZATION
Agenda Item #9.1.

5.0 Overflow Response Procedures
It is the responsibility of the first STHWW employee arriving at the scene of the sewer overflow location to protect the health and safety of the public by immediately beginning the necessary steps to mitigate the impact of the overflow.

5.1 Initial Assessment and Response – General, quick steps to mitigate the situation can be taken once an employee becomes aware of the sewer overflow:
• Determine the cause of the overflow, e.g., line blockage, line breakage, pump mechanical or electrical failure, etc.
• If possible, take immediate steps to stop the overflow by rectifying the line blockage, isolating a pipe line breakage, restoring power, putting another pump into service, etc. • Identify what, if any, resources can assist with the mitigating the cause of the overflow, including additional personnel, materials, supplies and/or equipment.

5.2 Spill Containment and Control
The primary objective of the responders to a sewer overflow incident is to protect the public’s health. Therefore, if it is at all possible that the public may come into contact with any sewage material from an overflow event, the responders should remove that possibility by isolating the surrounding area. The perimeter of the sewer overflow site can be controlled with cones, barricades, vehicles or some other barrier that restricts access.

After the public has been isolated from the spill area, containment and clean-up can proceed. The spill should be contained within the smallest possible area, and every effort should be made to prevent the discharge of sewage into any receiving waters. The following are containment suggestions:
• For spills that occur within the Wastewater Treatment facility, every effort should be made to keep the spill from leaving the facility’s property.
• Determine the immediate destination of the overflow, e.g. storm drain, street curb gutter, body of water, culvert, landscaped area, etc.
• Identify and request the necessary equipment to contain or isolate the overflow if not readily available. Take immediate steps to contain the overflow, e.g. block or bag the storm drain inlet, recover the overflow by pumping, construct a containment pond, divert into a downstream manhole, etc.
• In the event of a prolonged line blockage, breakage or collapse, a determination must be made to set up a portable by-pass pumping operation around the problem area. If this becomes the case, personnel will be required to continuously monitor the by-pass pumping operation until it can be terminated.

Agenda Item #9.1.

5.3 Spill Cleanup
SSO sites are to be thoroughly cleaned as soon as possible after the overflow incident is mitigated.

No residue will be left for future rains to carry away or for public contact to occur. The following steps should be taken to ensure that the overflow sites are returned to their former conditions:
• Where possible, the area is to be thoroughly flushed and cleaned of any sewage or wash- down water. Solids and debris are to be flushed, swept, raked or picked up by hand and properly disposed of.
• Where appropriate, the overflow site is to be disinfected with HTH (hydrated calcium hypochlorite) and water or liquid bleach (aqueous sodium hypochlorite). Never flush any disinfectant into a storm drain or body of water.
• If sewage has ponded, the pond should be pumped dry and the residue and site cleanup managed as previously mentioned

5.4 Spill Classification and Quantification
There are three general classifications of SSOs:
• Category 1 SSO – Spills of any volume that reach surface water or are likely to reach surface waters because they entered the storm drain system or a ditch and were not fully recovered • Category 2 SSO – Spills over 1,000 gallons that do not reach surface water • Category 3 SSO – Spills less than 1,000 gallons that do not reach surface water No matter what the SSO classification or its volume, the need for containment, control and recovery procedures by STHWW employees and our responsibility to understand and comply with the reporting requirements remains.

Spill quantification requires careful documentation and close observation of discharges. Staff should make every effort to maintain a careful chronology of the events during a spill and make every attempt to conduct linear measurements of the discharge streams and flow velocities in order to effectively quantify the spill volumes. Photo documentation of the spill event should also become a routine procedure in the spill documentation process. Official estimates of the spill volume will be the responsibility of the Director of Public Works. A few other types of spills, and the compliance requirements, are outlined in the next couple of sections.

5.5 Spill Documentation
Aside from the “SSO Event Report” (attached), STHWW employees may also (at the discretion of the Director of Public Works) compile, document and report an “Official Spill Record” which can assist in providing a record of the events of the incident. The Spill Events Record may include:
• Event times (failure, discharge start and stop)
• Personnel on site
• Arrival and departure time of all personnel
• Equipment on site
Agenda Item #9.1.

• Milestone events (if any)
• Photo and video documentation
• Spill volume estimates and the method used to determine the estimates • Arrival time of outside resources (and list of the resources) • Regulatory agency representatives on site (obtain their business cards) • Spill recovery volume estimates

5.6 Posting
Posting contaminated water signs is required downstream of the location of an SSO. Posting should be implemented under the following guidelines:
• Lagoons, wetlands, or creek beds shall be posted at 50 foot intervals for high use areas and 600 foot intervals for low use areas. Both sides of creek beds must be
posted.

5.7 Spill Sampling and Monitoring
If more than 50,000 gallons reached waterways, sampling of the body of water is mandatory. Sampling procedures are included in the Water Quality Monitoring Program
(attached). At the direction of the Director of Public
Works, sampling of lower volume spills may also be
performed. Conducting sampling at the appropriate
locations allows staff to establish and monitor the levels of contamination as well as to establish or compare with the natural background levels of bacteria in the receiving
waters.

All summary sampling and monitoring results will be uploaded into CIWQS at http://ciwqs.waterboards.ca.gov.

Agenda Item #9.1.

6.0 Reporting
It is the responsibility of the Director of Public Works or the Sewer Supervisor to make the initial notifications to OES and to prepare the preliminary written report for review.

6.1 Notification to the Office of Emergency Services (OES) The Office of Emergency Services will be notified of SSOs where 1,000 gallons or more reach waterways or are likely to reach waterways when not fully recovered from a drainage channel or a stormdrain system. Procedures are as follows:
• Notification will be made by phone at (800) 852-7550 within 2 hours of becoming aware of the SSO. The caller will record the OES notification control number. • The caller shall report the following information:
• The name and phone number of the caller reporting the spill • The responsible owner of the sewer system (STHWW)
• The location of the overflow
• The estimated total overflow amount
• The surface water(s) that may be affected by the overflow • Whether or not the spill is still occurring at the time of the notification • If the flow volume or other information is significantly revised at a later point, the caller (or a supervisor) will call back to update OES on the spill volume.

6.2 CIWQS Notifications
All SSOs must be electronically reported to the California Integrated Water Quality System (CIWQS) at http://ciwqs.waterboards.ca.gov. The State Water Board provides screen-by-screen CIWQS reporting instructions in the Discharger Workbook available at:
http://www.swrcb.ca.gov/water_issues/programs/sso/docs/discharger_workbook.pdf Depending on the SSO classification, there are different timeframes for CIWQS reporting:

Category 1 (all spills that reach waterways or are likely to reach waterways when not fully recovered from a drainage channel or a stormdrain system):
• Submit draft report within 3 days of becoming aware of SSO • Finalize report and certify within 15 days of the end of the SSO • If more than 50,000 gallons reached the waterways: • Submit all water quality results to CIWQS as soon as they become available (see Section 5.7 and attached Water Quality Monitoring Program) • Develop and submit an SSO Technical Report within 45 days of the end of the SSO (refer to requirements in Provision B.5 of the MRP WQ 2013-0058-EXEC).

Category 2 (spills of 1,000 gallons or more that do not reach waterways or that are fully recovered)
• Submit draft report within 3 days of becoming aware of SSO • Finalize report and certify within 15 days of the end of the SSO Agenda Item #9.1.

Category 3 (spills less than 1,000 gallons that do not reach waterways or that are fully recovered):
• Submit certified report within 30 calendar days of the end of the month in which the SSO the occurred.

6.3 Notification to other recipients
OES will notify Napa County Department of Environmental Management in the event that an SSO is reported to OES. In any area where an SSO has the potential to imminently and substantially affect human health the public must also be notified through posting (see Section 5.6). Beyond that, at the direction of the City Manager, STHWW will forward a copy of the spill report, depending on the nature, location and volume of the spill, to other public agencies, local interest groups or the media as warranted.

6.4 Reporting Responsibilities
The Sewer Supervisor has the authority to make the Initial Notification to OES. The electronic reporting to CIWQS can be made by the Sewer Supervisor or the Director of Public Works, but shall be reviewed for completeness and accuracy before being certified.

6.5 Report Forms
All spill information must be recorded using the STHWW “SSO Event Report” Form (attached).

6.6 Retaining Records
All spill reporting records, including the STHWW Overflow Reporting Log, will be retained for a period of five (5) years from the date of the final report in the Administrative Office files. The records shall be filed in the “NPDES, Spill Report Records” file.

Agenda Item #9.1.

7.0 Revisions & Employee Training

7.1 ERP Revisions
The STHWW Overflow Emergency Response Plan shall be reviewed and revised, as necessary, after each overflow event. The Director of Public Works will conduct an annual review of the ERP in order to maintain a document that remains up-to-date.

7.2 Annual Training
The Director of Public Works, or his/her designee, shall schedule annual training designed to identify resource shortcomings, clarify roles and responsibilities, improve response performance and reveal any response weaknesses. The training may consist of:
• Response training –An annual awareness training meeting will be conducted with respect to the details of the ERP and the responsibilities of each employee. All employees will attend this meeting. Additional training sessions may also be conducted by the Sewer, Wastewater Treatment and other divisions to further familiarize employees with the response procedures. • Tabletop exercise – A simulated spill event may be scheduled, according to need, to allow the exercise participants to discuss and understand the necessary response actions, test equipment and gauge the response ability of the employees. Scheduling a simulated Tabletop exercise will be at the discretion of the Director of Public Works.
• Spill Review Committee – After each SSO, STHWW’s will convene a Spill Review Committee to review the event’s cause, the procedural response of the employees, the regulatory and compliance documentation and whether additional issues and/or resources have to be addressed.

Agenda Item #9.1.

8.0 Phone Directory
The following phone, fax and email directory provides STHWW personnel with the current contacts for regulatory agencies and resources:

REGULATORY AGENCIES
Governor’s Office of Emergency Services (OES)
(800) 852-7550
(916) 262-1677 Fax
Regional Water Quality Control Board (Regional Water Board) (510) 622-2460
(510) 622-5633 Fax
Napa County Department of Environmental Management
(707) 253-4471 (business hrs.)
(800) 540-5306

CONTRACTOR SERVICES
Montelli Construction Harold Smith & Son M&M Sanitary
436 St. Helena Hwy 800 Crane Ave. American Canyon
944-1167 963-7977 224-4548

OTHER CONTACTS
PG&E
(800) 743-5000 (Emergency number)
REMIF (City Insurance Company)
(707) 938-2388
(707) 938-0374 Fax
Napa County Public Works
(707) 253-4351
(707) 944-0196 Roads
Upper Valley Disposal
(707) 963-7988
Railroad Police
(707) 477-5955 (Emergency)
Caltrans
(707) 224-8684
Agenda Item #9.1.

No. Question
1 Address *
City
State
ZIP
2 Estimated Spill Volumes
a) Estimated spill volume that reached a separate storm drain that flows to a surface water body? * in gallons
b)
Estimated spill volume recovered from the separate
storm drain that flows to a surface water body? (Do not include water used for clean-up) *
in gallons
c) Estimated spill volume that directly reached a drainage channel that flows to a surface water body? * in gallons d) Estimated spill volume recovered from a drainage
channel that flows to a surface water body? * in gallons e) Estimated spill volume discharged directly to a surface water body? * in gallons
f) Estimated spill volume recovered from surface water
body? * in gallons
g)
Estimated spill volume discharged to land? (Includes
discharges directly to land, and discharges to a storm
drain system or drainage channel that flows to a storm
water infiltration/retention structure, field, or other non-surface water location. Also, includes backups to
building structures) *
in gallons
h) Estimated spill volume recovered from the discharge to land? (Do not include water used for clean-up) * in gallons 3 Did the spill discharge to a drainage channel and/or
surface water?*
4 Did the spill reach a storm drainpipe that is not part of a combined sewer system? *
SSO Event Report
City of St. Helena
Office of the Director of Public Works
1480n Main Street } St. Helena, CA } 94574
Phone: 707.968.2658 | Fax: 707.967.2806
www.cityofsthelena.org
Multiple Choice Response Circle One
(if blank provide written response)
Physical Location Details
St. Helena
CA
Yes | No
94574
Yes | No
* Denotes required response
Agenda Item #9.1.

No. Question
SSO Event Report
City of St. Helena
Office of the Director of Public Works
1480n Main Street } St. Helena, CA } 94574
Phone: 707.968.2658 | Fax: 707.967.2806
www.cityofsthelena.org
Multiple Choice Response Circle One
(if blank provide written response)
5 If spill reached a separate storm drainpipe, was all of the wastewater fully captured from the separate storm
drain and returned to the sanitary sewer system? *
6 Spill location Name
7 Latitude of spill location *
8 Longitude of spill location *
9 County
10 Regional Water Quality Control Board
11 Spill location description:
(Use attachment if location description is more than
2000 charaters)
12 Number of apperance points *
13 Spill appearance point *
14 Spill appearance point explained for "other"
15 Final spill destination *
16 Explanation of final spill destination:
(Required if final spill destination is "Other")
17 Estimated spill start date/time *
18 Date and time sanitary sewer system agency was
notified of or discovered spill *
19 Estimated Operator arrival date/time *
20 Estimated spill end date/time *
_____ /_____ / 20_____ | _______:_______ AM/PM
_____ /_____ / 20_____ | _______:_______ AM/PM
_____ /_____ / 20_____ | _______:_______ AM/PM
_____ /_____ / 20_____ | _______:_______ AM/PM
Beach | Building or structure | Combined storm drain (combined CS only) | Drainage Channel | Paved Surface | Separate storm drain | Street/curb and gutter | Surface water | Unpaved surface | Other (specify below)
Napa
Region 2 - San Francisco Bay
Combined sewer D.I. (combined CS only) | Force main | Gravity Mainline | Inside Building or Structure | Lateral Clean Out (private) | Lateral Clean Out (public) |Lower Later (private) | Lower Lateral (public) | Upper Lateral (private) | Upper Lateral (public) | Manhole | Other sewer system structure (explain below) | Pump station
Agenda Item #9.1.

No. Question
SSO Event Report
City of St. Helena
Office of the Director of Public Works
1480n Main Street } St. Helena, CA } 94574
Phone: 707.968.2658 | Fax: 707.967.2806
www.cityofsthelena.org
Multiple Choice Response Circle One
(if blank provide written response)
21 Spill cause *
22 Spill cause explanation:
(Required if spill Cause is "Other")
23 Where did failure occur? *
24 Explanation of Where Failure Occurred:
(Required if Where Failure Occurred is "Other") *
25 Was the spill associated with a storm event? *
26 Diameter of sewer pipe at the point of blockage or spill cause (if applicable) inches
27 Material of sewer pipe at the point of blockage or spill cause (if applicable)
28 Estimated age of sewer pipe at the point of blockage or spill cause (if applicable) months
29 Explanation of volume estimation methods used:
(describe how you developed spill volume estimates for
this spill) *
30 Name and Title (Contact person who can answer
specific questions about this SSO) *
30b Contact Person Phone Number *
Cleaned up (mitigated effects of spill) | Contained all or portion of spill | Inspected sewer using CCTV to determine cause | Restored flow | Returned all or portion of spill to sanitary sewer system | Other (specify below)
Air Relief Value (ARV)/Blow-Off Valve (BOV) Failure | Construction Diversion Failure | CS Maintenance Caused Spill/Damage | Other (specify below) Damage by other not related to CS Construction/Maintannce (specify below) | Debris from Construction | Debris from Lateral | Debris-General | Debris-Rags | Flow exceeded capacity (Separate CS only) | Grease deposition (FOG) | Inappropriate Discharge to CS | Nautral Disaster | Non-Dispersables | Operator error | Pipe structural problem/failure | Pipe structural problem/failure installation | Pump station failure-controls | Pump station failure-mechanical | Pump station failure-power | Rainfall exceeded design (separate CS only) | Roof intrusion | Siphon Failure | Surcharged pipe (combined CS only) | Vandalism Air Relief Valve (ARV)/Blow-Off Valve (BOV) | Force Main | Gravity Mainline | Lower Later (public) | Mainhole | Upper lateral | Main | Lower Lateral | Other (specify below) | Pump station failure-controls | Pump station failure-mechanical | Pump station failure-power |Siphon | Upper Lateral (private)
Yes | No
Agenda Item #9.1.

February 2014
CITY OF ST . HELENA
Sanitary Sewer Overflow
Water Quality Monitoring Plan
Agenda Item #9.1.

Table of Contents
A PROJECT MANAGEMENT................................................................................................................ 1 A.1 PROJECT ORGANIZATION .......................................................................................................................... 1 A.2 BACKGROUND........................................................................................................................................... 1 B DATA GENERATION AND ACQUISITION .................................................................................... 3 B.1 SAMPLING PROCESS DESIGN..................................................................................................................... 3 B.1.1 Sampling Event Timing.......................................................................................................................... 3 B.1.2 Monitoring Site Locations ..................................................................................................................... 3 B.2 EQUIPMENT PREPARATION........................................................................................................................ 3 B.2.1 Sampling Containers.............................................................................................................................. 4 B.2.2 Field Meter Calibration......................................................................................................................... 4 B.3 WATER QUALITY MONITORING ................................................................................................................ 4 B.3.1 Spill Travel Time.................................................................................................................................... 5 B.3.2 Sample Collection Methods................................................................................................................... 6 B.4 SAMPLE HANDLING AND CUSTODY .......................................................................................................... 7 B.4.1 Sample Bottle Labels ............................................................................................................................. 7 B.4.2 Transport ............................................................................................................................................... 7 B.4.3 Chain of Custody Form.......................................................................................................................... 8 C REPORTING ......................................................................................................................................... 8 List of Tables
Table 1. Project Contact list........................................................................................................................................... 1 Table 2. Monitoring Equipment List ............................................................................................................................. 3 Table 3. Constituents to be Analyzed, Sample Volume Required, and Sample Type ................................................... 4 Table 4. Constituent Hold Times and Analytical Methods............................................................................................ 7 Table 5. Site Names for Sample Handling..................................................................................................................... 7 Table 6. Analytical Laboratories ................................................................................................................................... 8 Table 7. Notification and Reporting Timeline............................................................................................................... 8 List of Figures
Figure 1. SSO Action Flow Chart.................................................................................................................................. 2 List of Appendices
A Field Forms
B Calibration Logs
C Chain of Custody Forms (CoCs)
Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 1 February 2014

A PROJECT MANAGEMENT
A.1 PROJECT ORGANIZATION
This monitoring program will be conducted under the direction of the City of St. Helena (the City) with guidance provided by Larry Walker Associates (LWA). Caltest Analytical Laboratory of Napa (Caltest) will serve as the primary laboratory, but alternatives might be used due to logistics and timing. The Project Contact list is provided in Table 1.

Table 1. Project Contact List
Name Role Agency/Company Phone Number Email
Michael
Sample
Monitoring
Coordinator/Field
Crew
City of St. Helena
Kristine
Corneillie
MRP Technical
Advisor
LWA 408.261.3996 (o) [email protected]
Todd
Albertson
Laboratory Project
Manager
Caltest 707.258.4000 (o) [email protected]
A.2 BACKGROUND
In 2006, the State Water Resources Control Board (State Water Board) adopted Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (SSS WDRs), Order No. 2006-0003-DWQ. The Monitoring and Reporting Program (MRP) established monitoring, record keeping, reporting, and public notification requirements.

On September 9, 2013, Order No. WQ 2013-0058-EXEC became effective that clarified and expanded requirements of the original MRP and defined new sanitary sewer overflow (SSO) categories. The SSO definitions, as well as the notification, monitoring, and technical reporting requirements are shown in Figure 1.

This monitoring plan addresses water quality monitoring requirements for Category 1 SSOs that are greater than or equal to 50,000 gallons. As defined by Order No. WQ 2013-0058-EXEC, the following elements must be included in an SSO Water Quality Monitoring Plan to comply with subsection D.7(v) of the SSS WDRs:

1. Protocols for water quality monitoring.

2. Account for spill travel time in the surface water and scenarios where monitoring may not be possible (e.g. safety, access restrictions, etc.).

3. Water quality monitoring analyses for ammonia and bacterial indicators to be performed by an accredited or certified laboratory.

4. Procedures for proper maintenance and calibration of monitoring instruments and devices used to implement the SSO Water Quality Monitoring Program and documentation of maintenance and calibration, as necessary, to ensure their continued accuracy.

5. Water quality sampling within 48 hours of the City becoming aware of the SSO, for, at a minimum, the following constituents:
a. Ammonia
b. Total Coliform
Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 2 February 2014
Figure 1. SSO Action Flow Chart (Based on Order No. WQ 2013-0058-EXEC) Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 3 February 2014

B DATA GENERATION AND ACQUISITION
B.1 SAMPLING PROCESS DESIGN
B.1.1 Sampling Event Timing
The Monitoring Coordinator will determine when the field crew will be mobilized to sample the receiving water.

Sampling must be conducted within 48 hours after initial Category 1 SSO and spill volume notification. The monitoring coordinator will target daylight sampling within the first 24 hours of the SSO notification, but sample timing may be shifted due to safety and logistical issues.

Sampling will not be conducted if there are any concerns regarding field crew safety. These concerns may include heavy rain events, which compromise access points through flooding and swift currents. Thunderstorms will also be avoided when lightning is occurring. Sampling will only be conducted if there are at least two members of the field crew team available.

B.1.2 Monitoring Site Locations
Upon notice of a Category 1 SSO, the Monitoring Coordinator will determine where the field crew will sample. The Monitoring Coordinator will be responsible for determining the sampling locations. At a minimum, sampling will occur where the SSO enters the surface water body, 100 feet upstream of the entry point, and at least one point downstream of the entry point. The downstream location(s) will be determined from visual monitoring and estimated spill travel time (see Section B.3.1). The Monitoring Coordinator will provide a detailed description of potential monitoring site locations to the Field Crew.

Upon arrival at the monitoring sites, the Field Crew will determine the best locations to sample by assessing the hydrology of the receiving water and any safety precautions. The Field Crew should look for locations where the receiving water can easily be entered or sampled mid-channel by a grab pole. Once the sampling site location is selected, but before sampling starts, the Field Crew will record the latitude and longitude of the sampling location into the Field Form (APPENDIX A).

B.2 EQUIPMENT PREPARATION
The Field Crew shall maintain a sampling kit with the necessary supplies to conduct a monitoring event. Table 2 lists the equipment and supplies that will be included in the sampling kit.

Table 2. Monitoring Equipment List
Storm Kit
Spare batteries for field meter (6)
Spare sample labels
Pencils (2) and waterproof pens/markers (2)
Diagonal clippers
Electrical tape
Cable ties (assorted sizes)
Utility knife
Zip-lock baggies (assorted sizes)
Powder-free nitrile gloves
Rubber bands, heavy duty
Camera
Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 4 February 2014
Duct tape
GPS Device
Camera
SSO Water Quality Monitoring Plan
Log books/ Field forms
Chain-of-custody forms
New sample bottles
Intermediate containers
Flow meters
Coolers and ice
Cellular phone
Any necessary safety gear
Grab pole
Umbrella
Paper towels
Trash bags
B.2.1 Sampling Containers
The Field Crew will maintain a supply of sampling bottles for at least 4 events. The Field Crew will order bottles directly from the laboratory and will reorder bottles if they are unused for six months. Table 3 includes the required bottle types, sample volumes, and preservatives for ammonia and total coliform samples.

Table 3. Constituents to be Analyzed, Sample Volume Required, and Sample Type Constituent Optimum Vol.
(L)
Min. Vol.
(L)
Collection
Method
Bottle
Type Preservation Analytical
Lab
Ammonia (NH3) 0.500 0.100 Direct Fill 500mL
Plastic H2SO4, <6° C Caltest
Total Coliform 0.100 0.100 Direct Fill
100mL
Sterile
Plastic
<6° C Caltest
B.2.2 Field Meter Calibration
All field meters will be properly calibrated and maintained by the Field Crew. Calibrations will be performed according to the methods and frequency recommended by the equipment manufacturer. When calibrating the instruments, the Field Crew will document all pertinent information in a Calibration Log (APPENDIX B) and keep it with the rest of the project documentation.

B.3 WATER QUALITY MONITORING
The Field Crew will be responsible for the following tasks upon arrival at the monitoring location:

1. Determine best sampling locations and record latitude and longitude readings for the upstream, SSO entry point, and downstream sampling sites.

2. Calculate spill travel time at the downstream monitoring site.

Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 5 February 2014

3. Collect water quality samples in the following order: first at the SSO entry point, second at the downstream site(s), and third at the upstream monitoring site.

4. Complete all field forms and prepare the samples for delivery to the laboratory.

The following sections outline the necessary steps the Field Crew must take when performing the above actions.

B.3.1 Spill Travel Time
When the Field Crew arrives at the downstream monitoring site, they will estimate spill travel time by calculating travel time within enclosed storm drains (distance traveled ∕initial spill rate) and within open surface waters. Travel time within the open surface waters can be determined two different ways depending on the accessibility and safety of the monitoring site.

B.3.1.1 Velocity Probe
Using a velocity probe is the preferred method of spill travel time calculation, but it requires extra safety precautions, since the Field Crew will have to wade and cross the surface water body.

1. The Field Crew must first ensure that the receiving water body is flowing at a safe rate and its span can be crossed by wading.

2. One Field Crew member will be responsible for using the velocity probe and the other will stand on the shore and record the readings.

3. The Field Crew member with the velocity probe will enter the surface water at the shore and begin to take a velocity measurement, roughly six inches below the surface. The Field Crew member will wait for the reading to stabilize before reporting the value to the recording Field Crew member.

4. The Field Crew member will then move the velocity probe two feet further into the surface water body and make another measurement. This will continue until the entire span of the receiving water body has been measured.

5. The Field Crew will not cross into any unsafe portions of the receiving water body and will note on the Field Form if the measurements are only for a portion of the channel.

B.3.1.2 Visual Velocity Estimation
If the receiving water body is unsafe to enter, the velocity can be measured by observing floating debris.

1. The Field Crew members will stand on the edge of the channel, 30 feet apart.

2. The Field Crew member standing upstream will indicate when a large piece of debris passes their point. At this time the Field Crew member standing downstream will start timing.

3. Once the same piece of debris passes the downstream Field Crew member, they will stop timing and calculating the velocity (ft/sec) by dividing 30 feet by the number of seconds it took for the debris to travel that length.

If there isn’t any large debris floating in the surface water, the upstream Field Crew member can use a nearby stick or other buoyant object.

Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 6 February 2014
B.3.2 Sample Collection Methods
Sample collection methods will vary depending on the surface water and the safety of the Field Crew. Clean, powder-free, nitrile gloves will be worn for all bottle handling. The direct fill sample collection method is the preferred sampling method, since it does not use an intermediate container. In cases where the direct fill method cannot be used due to accessibility or safety an intermediate bottle and a grab pole can be used.

B.3.2.1 Direct Fill Sample Collection
The direct fill sample collection method will be used in cases where the surface water can be entered safely by the Field Crew. Field Crew will wear waders and ensure that the water level and velocity of the surface water are low enough to provide a safe entry and sampling environment.

Ammonia and bacteriological sample bottles will be filled by direct submersion to approximately mid-depth as follows.

1. Wade to approximately the area of the water body with the highest flow rate and face upstream. This will most likely be midstream, but can be in a different portion of the stream, depending on the hydrology.

2. Submerge the sample bottle with its cap on to approximately mid-depth at a location of significant flow (avoid stagnant water). Hold the bottle upright under the surface while it is still capped.

3. Open the lid carefully just a little to let water run in. Fill the bottle and screw the cap tightly while the bottle is still underneath the surface.

4. Remove bottle from stream and place on ice.

B.3.2.2 Intermediate Container Sample Collection
If the flow, water level and/or access point are deemed unsafe then an intermediate bottle attached to a grab pole will be used for sample collection. A clean, new intermediate bottle will be used for each sampling event and sampling site.

Ammonia and bacteriological sample bottles will be filled by intermediate container sample collection as follows:

1. Attach the intermediate bottle to an expandable pole using tape or cable ties and remove lid.

2. Submerge the intermediate bottle, attached to expandable pole, to approximately mid-depth at a location of significant flow (avoid stagnant water).

3. Remove bottle from water and empty contents. Repeat this twice more.

4. Once the intermediate bottle is properly rinsed, return it to approximately mid-depth at a location of significant flow (avoid stagnant water).

5. Using the intermediate bottle, fill the bacteriological sample container and then the ammonia bottle. Ensure that neither bottle overflows and that the preservative stays in the sample container.

6. After bottle fills, replace bottle lid, remove bottle from pole, and place on ice.

Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 7 February 2014
B.4 SAMPLE HANDLING AND CUSTODY
The Field Crew will ensure that all samples are collected and submitted to their respective labs by the maximum hold times listed in Table 4. If timing or logistics prevent a hold time being met, the Field Crew will contact the Monitoring Coordinator.

Table 4. Constituent Hold Times and Analytical Methods
Constituent Analytical
Method1
Maximum Hold
Times
Analytical Lab
Ammonia (NH3) SM 4500-NH3-G 28 days Caltest
Total Coliform SM 9221-B/E 6 hours Caltest
B.4.1 Sample Bottle Labels
The Field Crew will label all sample bottles with a waterproof label, which will contain the agency name, sample collection date, analyte, analysis method, station number and name and Field Crew names. The analytes and analysis methods are shown in Table 4 and the station identification protocols are shown in Table 5.

Table 5. Site Names for Sample Handling
Station Number Station Name
US-001 Surface Water Upstream
ENTRY Surface Water Point of Entry
DS-001 Surface Water Downstream 1
DS-XXX1 Surface Water Downstream XXX1
1 Additional downstream monitoring sites will be labeled in sequential order starting from the SSO surface water point of entry.

Example sample bottle label:

Direct Fill Sample Bottle Label
City of St. Helena
Station Number - ____
Analyte – Analysis Method ________________
Date & Time:________ Collected by:__________
B.4.2 Transport
All samples will be kept on ice from the time of collection to the time of receipt by laboratory personnel. It is imperative that all samples be analyzed within maximum holding times (see Table 4). Samples will be shipped/delivered as specified in Table 6.

Agenda Item #9.1.

City of St. Helena
SSO Monitoring Plan 8 February 2014
Table 6. Analytical Laboratories
Analytical Laboratory Analysis Shipping Method
Caltest
Attn. Todd Albertson
1885 North Kelly Road
Napa, CA 94558
707.258.4000
Ammonia and bacterial Hand delivered/courier
B.4.3 Chain of Custody Form
Chain-of-Custody (CoC) forms will be filled out by the Field Crew for all samples submitted to the laboratories.

CoCs will contain the following information:
• Sampler name
• Address (where the results will be sent)
• To whom the laboratory results are being sent
• Sample collection date and time
• Sample location
• Analysis method requested
• Sample container type and number
• Comments/special instructions
• Samples relinquished by (signature, print name, date) • Samples received by (signature, print name, date)
An electronic data deliverable will be requested for all sample reports. Example lab specific CoCs are included in APPENDIX C.

C REPORTING
A Category 1 SSO in which 50,000 gallons or greater are spilled to a surface water requires multiple stages of notification and reporting. The City will adhere to the required timeline outlined in Table 7, which begins when the City becomes aware of an SSO. The specific requirements for notification and reporting are specified by Order No.

WQ-2013-0058-EXEC and detailed in the City’s Sanitary Sewer Management Plan.

Table 7. Notification and Reporting Timeline
Time Period Requirement
<2 Hours Notification to CalOES
Within Three Business Days Draft Category 1 SSO Report to CIWQS Within 15 Calendar Days Certified Category 1 SSO Report to CIWQS Within 45 Calendar Days SSO Technical Report with water quality results to CIWQS
Agenda Item #9.1.

Appendix A
Field Forms
Agenda Item #9.1.

SSO Water Quality Monitoring Plan Field Log
General Information
Event ID: Date: SSO Time:

Sampling Personnel:

SSO Description
Time of Notification: Size: Location:

Weather (fog, rain, wind, etc):

Total precipitation during previous 5 days:

Monitoring Sites
US-001
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity:

Odor:

POINT of ENTRY
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

DS-001
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

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Agenda Item #9.1.

SSO Monitoring Plan Field Log (Additional Downstream Sites) DS-____
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

DS-____
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

DS-____
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

DS-____
Arrival Time: Departure Time:

GPS Coordinates Latitude: Longitude:

Sample Location Mid-Channel Bank
Sample Time: Total Coliform: Ammonia:

Floating Material or Debris:

Water Color/Turbidity/Odor:

Estimated Spill Travel Time to Monitoring Site:

Page __ of ___
Agenda Item #9.1.