18 - Project #201 - Rehabilitation of Four Force Mains Costa Mesa Sanitary District
…an Independent Special District
Protecting our community’s health and the environment by providing solid waste and sewer collection services.
www.cmsdca.gov
Memorandum
To: Board of Directors
Via: Scott Carroll, General Manager
From: Rob Hamers, District Engineer
Date: September 26 , 2013
Subject: #201 Rehabilitation of Force Mains – Proposed Methods and
Project Budget
Summary
The purpose of the project is to rehabilitate four critical force mains (pressurized sewer
lines) prior to the force mains experiencing failure. The District Engineer presented three
options for each force main to the General Manager; installing a liner; dig and i nstall a new
line, or directional drilling (underground drilling from one end to the other to install a new
line ). Each option was evaluated for cost, complexity, and level of disturbanc e to the
public and the General Manager and District Engineer agree with the conclusions shown
below. An important point to consider are the merits of a new force main compared to a
60 -year old force main with a new liner; a newly installed force main is considered
superior.
Staff Recommendation
That the Board of Directors approves the following:
1. Alternative IV for rehabilitating Harbor, Mendoza , South Coast Plaza and Victoria
force mains.
2. Transfer $180,868 from the Asset Management Fund to fund the enti re proposed
project.
Board of Directors
September 26, 2013
Page 2 of 5
Analysis
Force mains carry high flows under pressure and a fracture or break normally results in a
large sewer spill. The four pumping stations under consideration have high pumping rates
and old force mains and the District has prio ritized these four as the next four force mains
needing rehabili t ation or replacement. A proactive force main rehabilitation program is an
essential element in a comprehensive sewer system management program.
In 2012, the District undertook an electronic analysis of the Santa Ana force main and the
23 rd force main using Pipeline Inspection and Condition Analysis (PICA ) technology and
the results indicated both force mains had little to no remaining pipe wall thickness, the
leading indicator for potential f ailure. In order to utilize the PICA technology, the District
had to first send a “cleaning pig” through each line. Because the pigging operation was
very complicated and included dismantling piping inside the pumping stations, separate
operations were r equired for the pigging and the PICA analysis. These two costly and
time consuming steps were reevaluated for these four force mains based on the age of the
lines as shown below. All six force mains shown below are either cast iron pipe or ductile
iron p ipe.
The force mains at Santa Ana and 23 rd that had little to no remaining pipe wall thickness
were originally installed as follows:
Santa Ana 1977
23 rd 1984
The four force mains under c onsideration for this project were installed as follows:
Harbor 1956
Mendoza 1963
South Coast Plaza 1966
Victoria 1974
Because the four force mains under consideration are older than the two force mains that
had little to no remaining pipe wall thickness, staff believes pigging and PICA analysis are
not necessary.
Board of Directors
September 26, 2013
Page 3 of 5
The four force mains wer e further analyzed as follows:
I. Costs for Lining Only
Harbor $ 422,600
Mendoza $ 235,500
SCP $ 280,360
Victoria $ 297,425
$1,235,885
II. Least Expensive
Harbor Dig & Install $ 275,500
Mendoza Dig & Install $ 100,000
SCP Dig & Install $ 100,000
Victori a Dig & Install $ 244,750
$ 720,250
III. Least Disruptive
Harbor Dir. Drilling $ 345,500
Mendoza Dig & Install $ 100,000
SCP Dig & Install $ 100,000
Victoria Dir. Drilling $ 648,000
$1,193,500
IV. Engineer’s Recommendation (a new line is superior to lining)
Harbor Dir. Drilling $345,500
Mendoza Dig & Install $100,000
SCP Dig & Install $100,000
Victoria Dig & Install $244,750
$790,250
A few other p oints to consider are as follows:
Item IV above provides the ability to reha bilitate the old force main either
now or at a later date to become a secondary, backup, force main.
Lining the force mains requires 24/7 bypassing of pump station flows until
the lining is complete, but installing new lines allows the old lines to stay i n
service until the final tie -in.
If item IV is chos en, both Victoria and Harbor could be designed with two
options: dig and install new, and directional drilling, and CMSD can select
the options when bids are opened.
Board of Directors
September 26, 2013
Page 4 of 5
Item IV (with the options shown in t he bullet point above) le nds itself to
designing all 4 force mains as one project. Lining poses timing challenges
due to coordination, installation time, curing time, etc.
Strategic Plan Element & Goal
This item complies with the objective and strategy of Strategic Plan Element 1.0, Sewer
Infrastructure , which states as follows :
“Objective: Our objective is to collect and transport wastewater to meet the needs of
existing and future customers.
Strategy: We will do this by th e careful management of the collection infrastructure using
prudent planning and maintenance, with financial strategies to maintain sufficient capacity
and respond to changing regulatory demands.”
Legal Review
This report does not necessitate District C ounsel review.
Financial Review
The total project cost for Alternative IV, which includes design, construction, contingency,
contract administration and inspection is $1,030,868 , as shown below.
Design $ 82,593
Construction $ 790,250
Contingency $ 79,025
Contract Admin/Insp $ 79,000
Total $1,030,868
There is a total of $850,000 in the CIP budget for this project, so if the Board wants to
proceed with the entire project, then $180,868 will need to be transferred from the
District’s Asset Management Fund, which curren tly has a balance of $5,1 4 0 ,2 92.
Board of Directors
September 26, 2013
Page 5 of 5
P ublic Notice Process
Copies of this report are on file and will be included with the entire agenda packet for the
September 26, 2013 regular Board of Directors meeting at District Headquarters and on
the District website.
Alternative Actions
1. Stay within the CIP budget of $850,000 and d o not rehabilitate Mendoza and S outh
Coast Plaza force mains
2. Direct staff to report back with additional alternatives for consideration
3. Direct staff to report back with more information.
Reviewed by:
Stacey Cuev as
Finance Manager