State of Technology Report for Force Main Rehabilitation, Final ...

Capital Costs
The TTC collected bid tenders from all over the US on various trenchless installation methods and
published a report in 2003 highlighting the results. The report compared installation costs for open cut
replacement for pipes and manholes with pipe rehabilitation or replacement including CIPP, sliplining,
fold-and-form, deformed and reformed, spray-on linings, pipe bursting, HDD, microtunneling, pipe
jacking, localized pipe and joint repairs and manhole rehabilitation including cementitious and polymer
spray coatings, preformed manhole inserts, and manhole liners. Although the cost data are from 2003, it
is still one of the best documented reports on installed costs of trenchless technologies.
The Office of Water Service (OFWAT), which is the UK Water Services Regulation Authority, has also
collected information from the UK water industry on rehabilitation costs for water mains (OFWAT,
2005). This includes close-fit liners, polymer spray-on linings, sliplining, HDD, and pipe bursting.
OFWAT surveyed 13 water utilities and obtained installed cost data on these various rehabilitation
methods. A benchmark cost was then determined based on the mean value. The open cut replacement
data were further broken down into rural, suburban, and urban segments. Figure 4-2 is a summary chart
comparing the cost of four rehabilitation options to open cut replacement. “Insert” is a close-fit
polyethylene liner. The data do show the favorable cost impact of carrying out epoxy lining and insertion
of a close-fit PE liner versus open cut replacement. When compared to an urban environment, all of the
rehabilitation methods are more cost-effective than the open cut replacement option.
Pd Sterling/meter
250
200
150
100
50
0
Cost For Rehabilitation - OFWAT
4 8 12 16 20 24
Diameter, Inches
Figure 4-2. UK Water Rehabilitation Costs (OFWAT, 2005)
Open Cut Grass
Open Cut
Rural/Suburban
Open Cut Urban
Epoxy
Slipline
Bursting
Insert
O&M Costs
One potential difference in operational cost would be pumped energy requirements. Reduced diameters,
associated with sliplining and liners, means higher velocities to maintain the same flow quantities.
Higher velocities translate into higher head loss (proportional to the square of the velocity). This can be
offset to some degree by a lower friction factor, which many of these new polymer products possess. The
bottom line is energy requirements for pumping operations may be increased to overcome the additional
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