title
CC - (1) Approval of Amendment to Existing Professional Services Agreement with California Watershed Engineering for Additional Design Services for Mesmer Low Flow Diversion Project, PR-005 in an Amount Not-to-Exceed $67,505 ($61,368 Base Cost with a 10% Contingency of $6,137); and (2) (FOUR FIFTHS VOTE REQUIREMENT): Approval of Related Budget Amendment
body
Meeting Date: April 13, 2020
Contact Person/Dept.: Kim Braun/Public Works Department
Phone Number: (310) 253-6400
Fiscal Impact: Yes [x] No [] General Fund: Yes [] No [x]
Public Hearing: [] Action Item: [] Attachments: []
Commission Action Required: Yes [] No [X] Date:
Public Notification: (E-Mail) Meetings and Agendas - City Council (04/07/2020);
Department Approval: Charles D. Herbertson, Director of Public Works/City Engineer (03/06/2020)
_____________________________________________________________________
RECOMMENDATION
Staff recommends the City Council approve an amendment to the existing professional services agreement with California Watershed Engineering for additional services for Mesmer Low Flow Diversion Project, PR-005 in an amount not-to-exceed $67,505 ($61,368 Base Cost with a 10% Contingency of $6,137).
BACKGROUND/DISCUSSION
On March 26, 2018, City Council approved a professional services agreement for civil design for the Mesmer Low Flow Diversion Project (Project), PR-005.
The Public Works Department’s Environmental Programs and Operations Division (EPO) Staff is proposing a low flow diversion system that will divert dry weather run-off from Centinela Creek Channel into the Mesmer Pump Station where the run-off will be pumped into an existing sewer main for conveyance to City of Los Angeles’ Hyperion Water Reclamation Plant (Hyperion) for treatment. The Mesmer Sewer Pump Station is located at 5586 Mesmer Avenue, Culver City, CA 90230 adjacent to Centinela Creek Channel.
This required Project is one of three projects approved in the Time Schedule Order (TSO) to comply with the Ballona Creek Bacteria TMDL. The Project is jointly funded by the cities of Los Angeles, Beverly Hills, Culver City, Inglewood, and West Hollywood, the County of Los Angeles and Los Angeles County Flood Control District. The following three regional projects collectively comply with the final water quality based effluent limitations during dry weather as specified by the Ballona Creek Bacteria TMDL:
1. Low Flow Treatment Facility (LFTF) #1 Project at Ballona Creek;
2. Low Flow Treatment Facility (LFTF) #2 Project at Sepulveda Channel; and
3. Mesmer Low Flow Diversion Project at Centinela Creek.
Culver City is taking the lead in managing both design and construction of the Mesmer Low Flow Diversion Project with City of Los Angeles managing the LFTF #1 & #2 Projects.
Conceptual Design
Mesmer Low Flow Diversion (LFD) System was conceptually designed to divert dry weather run-off from Centinela Creek Channel into a proposed inlet constructed along the channel. The inlet will be connected to a new 15-inch diameter pipe that will convey the run-off into a new 13 feet deep concrete receiving sump. From the receiving sump, a new 15-inch diameter pipe will take the run-off via gravity flow into an existing sewer manhole that discharges to the existing sanitary sewer wet well. Both the sewer and dry weather run-off collected in the existing sanitary wet well will be pumped to the sanitary force main for conveyance to Hyperion for treatment.
The LFD System was conceptually designed strictly using gravity flow. However, during design, there were concerns with operational failures to the proposed check valve that is designed to prevent backflow of sewage from the sewer wet well to the creek.
Therefore, to provide added protection from sewer overflows into Centinela Creek, staff is proposing to design a separate low flow diversion pump station upstream of the existing sanitary sewer wet well. The run-off diverted from the channel would gravity flow into the low flow diversion pump station. This would allow the captured run-off to be discharged from the low flow diversion pump station at a higher elevation inside the existing sanitary sewer wet well. The higher discharge point and the pumping system eliminates any potential of sewer overflows from entering Centinela Creek Channel through LFD System.
Request Additional Services
Staff is requesting additional services to perform the Historic Resource Assessment (HRA) and to prepare Drilling Plan. Staff is requesting additional consulting services for a monthly meeting with the USACE and additional coordination efforts.
The HRA will evaluate the historic-period for each of the three regional projects. The HRA is required by the US Army Corps of Engineers (USACE) in compliance with Section 106 of the National Historic Preservation Act (NHPA) since the channels are over 50 years old. The HRA will include an intensive-level historic resources survey of the Area of Potential Effects which is defined as the area within each channel being improved plus 50 feet in each direction, including access path within the channel area worksite.
As requested by USACE, a Drilling Plan for the Mesmer Low Flow Diversion Project will be prepared. The Drilling Plan is for the anticipated jack and bore operations in accordance with the sample drilling plan as provided by USACE.
FISCAL ANALYSIS
The project funding is as follows:
|
PROPOSED PROJECT BUDGET |
|
Funding Source |
Amount |
|
Mesmer Low Flow Diversion CIP (43480000.730100.PR005) |
$180,000 |
|
Total Available Funds |
$180,000 |
|
Amount |
|
|
Design - CWE |
$129,805 |
|
Additional Work - Amendment 1 approved |
$28,582 |
|
Proposed Additional Services |
$67,505 |
|
Total Design Cost |
$225,892 |
The cost of the additional civil design services is in the total amount of $61,368. It is recommended that the City Council authorize the Public Works Director/City Engineer to authorize amendments for additional design work in an amount not-to-exceed $6,137 (10%) if necessary. The additional civil design services exceed the Project budget by $45,892. Funds for this remaining balance are available from the Measure CW fund, Account # 43480000.730100.PZ497.
ATTACHMENTS
None.
MOTION
That the City Council:
1. Approve an amendment to the existing professional services agreement with California Watershed Engineering for additional services for the Mesmer Low Flow Diversion Project, PR-005 in an amount not-to-exceed $61,368; and
2. Approve a related budget amendment (requires a four-fifths vote); and
3. Authorize the Public Works Director/City Engineer to approve amendments to the agreement with California Watershed Engineering in an amount not-to-exceed $6,137 for additional design work; and
4. Authorize the City Attorney to review/prepare the necessary documents; and
5. Authorize the City Manager to execute such documents on behalf of the City.