msdgc.org
MSD Receives Trenchless Technology Award
The
North American Society for Trenchless Technology
(NASTT) selected MSD to receive NASTT's 10th Anniversary Award Recognition
for contributions to the development of trenchless technology. NASTT recognized
companies and institutions in North America that have made significant
contributions to the development of trenchless technology and the growth
of the industry. Ralph Johnstone of MSD Wastewater Collections accepted
the award on behalf of the Metropolitan Sewer District at the 10th Anniversary
Gala Dinner at the 2001 No-Dig Conference in Nashville on Tuesday, April
3, 2001.
Trenchless Technology consists of the techniques for utility and other line installation, replacement, renovation, inspection, location and leak detection, with minimum excavation from the ground surface.
"The Metropolitan Sewer District of Greater Cincinnati continues to be proactive in advancing and challenging the limits of various Trenchless Technologies. The direction that the District is taking regarding product selection and procurement, sewer lining, directional drilling, and manhole rehabilitation is truly unique and effective," explained MSD's Ralph Johnstone.
MSD's Program
In 1997, the District developed a comprehensive report addressing the procurement of trenchless technologies. The advisory panel that performed the research was made up of various private and government experts in the field of trenchless technology, procurement, and contract management. The panel's final submittal included: a well-defined product approval process, establishment of a separate Trenchless Review Committee to promote trenchless applications, a bid matrix for awarding contracts to "lowest and best" bidders in lieu of simply low bid, a decision tree for reviewing products, and various other procurement changes to include unit price requirement contracts. The District is currently in the test and evaluation phase of using cured-in-place point repair linings and remote lateral lining (no excavations required). The intent is to develop as-needed term contracts to supplement the District's current sewer maintenance and repair efforts.
Internal Pipe Rehabilitation (Small Diameter)
The District has developed an aggressive 6 million dollar per year lining program. The current specification clearly defines the final product and includes a chart of acceptable repair methods. This eliminates many unknowns that contractors have to deal with in managing a contract with the District. The District promotes the use of pipebursting though emergency and non-emergency procurement. We developed criteria for the use of pipebursting to ensure that the final product would be acceptable and ensure the success of the installation. In addition, we are continuing to work with interested plumbers on the use of pipebursting to replace house laterals. The District wants to ensure that the final product meets governing regulations covering acceptance and protect the interests of the affected building owner.
Directional Drilling
Directional drilling has been effectively used to install force mains, house laterals and gravity sewers. Some gravity sewer installations have reached lengths of 1100 lineal feet through steep terrain and heavily developed areas. Detailed design criteria and specifications are used to ensure that proper horizontal and vertical alignment is maintained and no sudden alignment changes are accepted in the final installed product. The overall result is minimal disturbance of environmentally sensitive areas, less risk to other utilities, reduced traffic disruption, and a major reduction in construction and social costs.
Manhole Rehabilitation
In the past year and a half, the District has tested and evaluated over 35 different manhole rehabilitation products installed as demonstrations by the manufacturers' representatives. After substantial completion of these demonstrations, the District used what they learned to develop a specification and then awarded a pilot project consisting of over 150 infiltrating brick and concrete manholes. This project was designed to provide the District with the opportunity to evaluate, in a side-by-side comparison, both the performance and cost of three basic manhole rehabilitation systems: cementitious coatings, spray-on epoxy coatings, and cured-in-place manhole liners. The project area has pre-rehabilitation flow monitoring data so the effectiveness of the rehabilitation in eliminating infiltration should be able to be determined. The manhole rehabilitation evaluation program adopted by the District is one of the most comprehensive programs in the nation.
More Information
For further information on this program, please contact Phyllis Calhoun at (513) 244-5122.
Story by Maria Turner.
