HomeMy WebLinkAboutAgenda Report - September 20, 2006 E-03AGEMDA ITEM E'3
CITY OF LORI
COUNCIL COMMUNICATION
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AGENDA TITLE: Approve Plans and Specifications and Authorize Advertisement for Bids for
Domestic Outfall Sewer Pipeline Condition Assessment
MEETING DATE: September 20, 2006
PREPARED BY: Public Works Director
RECOMMENDED ACTION: That the City Council approve the plans and specifications and
authorize advertisement for bids for the above project.
BACKGROUND INFORMATION: The Domestic Outfall sewer pipeline currently conveys an average
of 6.5 million gallons per day (mgd) of domestic wastewater flows
from town to the White Slough Water Pollution Control Facility
(WSWPCF). The pipeline is one of the City's most essential and
critical facilities. The 40 -year old pipeline is approximately 33,000 linear feet long and is constructed of
reinforced concrete pipe. The pipeline ranges in size from 36 -inch diameter to 48 -inch diameter and
extends along a diagonal course bisecting roads, vineyard and other croplands.
Concrete pipe used for sewage deteriorates due to hydrogen sulfide reactions. (The City stopped using
concrete pipe for sewers decades ago.) Staff and various consultants have monitored portions of the line
since the late 1970's. In 2003, our consultants recommended a chemical addition pilot test which due to
the pipeline, alignment and wastewater characteristics, proved that chemical addition was not a cost-
effective alternative for controNing corrosion in the pipeline. A short portion of the pipeline near the
White Slough facility failed and was replaced in early 2006.
The proposed rehabilitation project will be separated into multiple phases of work. Phase 1 includes
assessing the condition of the entire outfall pipeline using closed circuit television (CCTV) equipment and
pipe penetration testing. The CCTV assessment will visually document the condition of the outfall pipe
and measure the pipe thickness at selected locations. Since hydrogen sulfide corrosion effectively turns
the concrete pipe into a paste -like consistency and thus compromises the structural properties of the
material, pipe penetration testing will provide information to estimate the actual thickness of sound
concrete that is remaining in the pipeline cross-section. Data collected during the assessment will
facilitate the preparation of pipeline rehabilitation alternatives that would best fit the pipeline condition.
Subsequent work, both in terms of scope and timing, will depend on the results of the Phase 1
investigation.
FISCAL RIIPACT: The FY 06107 Capital Budget has appropriated $430,000 toward Phase 1
and Phase 2. Phase 3 will cost roughly somewhere in the $6 to $10 million
range, depending on the rehabilitation method. Financing this work will be
considered along with the White Slough Treatment Facility Phase 3
improvements.
APPROVED: r
Blair King, My Manager
J:(PROJECTS'LSEWER1DomesticOutfallAssessmentlCPS&A.doc 9/1412006
Approve Plans and Specifications and Authorize Advertisement for Bids for Domestic Outfall Sewer
Pipeline Condition Assessment
September 20, 2006
Page 2
FUNDING AVAILABLE: Estimated Project Cost: $80,000
Wastewater Fund approved in 06107 Capital Budget
/-'�qyPaiste, Financial Services Manager
Richard C. Prima, Jr.
Public Works Director
Prepared by Charlie Swimley, Senior Civil Engineer
RCPiCESlpmf
cc: F. Wally Sandelin, City Engineer
Frank feeler, WaterlWastewaller Superintendent
Del Kerlin, Wastewater Superintendent
Kevin Gaither, Senior Engineering Technician
J:1PROJECTSlSEWEROomesticOutfall Assess nentlCPSBA.doc 9/14/2006