State of Technology Report for Force Main Rehabilitation, Final ...
State of Technology Report for Force Main Rehabilitation, Final ...
State of Technology Report for Force Main Rehabilitation, Final ...
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8.0 FINDINGS AND RECOMMENDATIONS<br />
Partly because <strong>of</strong> the difficulty in assessing the condition <strong>of</strong> sewer <strong>for</strong>ce mains, leaving a lot <strong>of</strong><br />
owners with questions about the integrity <strong>of</strong> these critical assets, and the limited amount <strong>of</strong><br />
rehabilitation technologies available <strong>for</strong> renewing a deteriorated main, there has not been a significant<br />
amount <strong>of</strong> renewal work in the past. Most <strong>of</strong> the renewal activity has been outright replacement <strong>of</strong> the<br />
<strong>for</strong>ce main, either by open cut or trenchless means. As the nation’s <strong>for</strong>ce mains age further, greater<br />
emphasis will be placed on finding cost-effective ways to renew these critical assets. Fortunately,<br />
new products and technologies are now emerging <strong>for</strong> carrying out a direct condition assessment on a<br />
buried <strong>for</strong>ce main, as well as rehabilitation methods <strong>for</strong> those found in distress. Many <strong>of</strong> these<br />
rehabilitation methods originated in the gravity sewer market or water market, but have been adapted<br />
to meet the special needs <strong>of</strong> sewer <strong>for</strong>ce mains.<br />
One method <strong>of</strong> assisting owners in their ef<strong>for</strong>ts to apply some <strong>of</strong> these emerging technologies will be<br />
in the publication <strong>of</strong> demonstration projects and case studies. Also, setting up a decision support<br />
system that helps a utility ask the right questions so that a viable rehabilitation solution emerges is<br />
paramount. Utilities also need to consider implementing maintenance programs that can<br />
demonstratively extend the useful life <strong>of</strong> their current mains, deferring the cost <strong>of</strong> renewal or<br />
replacement to a future date.<br />
This section reviews a number <strong>of</strong> these subjects and <strong>of</strong>fers suggestions <strong>for</strong> technologies that might be<br />
considered in some demonstration projects.<br />
8.1 What Systems Would Benefit Most from Being Demonstrated in Field Settings?<br />
Systems that would benefit from demonstration in field settings fall into two categories: data<br />
collection (inspection) systems and rehabilitation systems. The scope <strong>of</strong> this review is rehabilitation<br />
rather than inspection. Nevertheless, the demonstration <strong>of</strong> certain inspection systems was considered<br />
to be valuable because they can provide data that drive rehabilitation decisions. Referring to Table 7<br />
1, the technologies <strong>for</strong> which field demonstration would yield greatest benefit would be the following:<br />
• External data collection: Screening method to identify high risk locations. Potentially<br />
LPR or over line potential surveys.<br />
• Internal data collection: Live insertion and retrieval <strong>of</strong> inspection tool. Pipe Diver (PPIC,<br />
Canada) <strong>for</strong> PCCP and See Snake <strong>for</strong> ferrous mains.<br />
• Internal data collection: Acoustic technologies <strong>for</strong> leak detection and location <strong>of</strong> air<br />
pockets. Sahara ® (PPIC, Canada) and SmartBall ® (Pure Technologies, Canada).<br />
• Internal lining: CIPP (nonwoven felt/polyester resin and woven fiberglass/UV-cured);<br />
sliplining (PVC and HDPE); and close-fit lining (PVC and HDPE).<br />
• Structural spray-on lining with fast cure: polyurea-based material.<br />
8.2 Key Parameters <strong>for</strong> Evaluation in Demonstration Projects<br />
Table 8-1 identifies the key parameters to be evaluated in demonstration projects.<br />
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