Detroit Arsenal Garrison D/B Water Distribution System
LOCATION: Warren, Michigan
CLIENT: USACE Louisville and Detroit Districts
PROJECT DESCRIPTION
CTI, as Prime Contractor and in partnership with OHM, was responsible for the design, oversight, and general contracting performance of all phases of the Detroit Arsenal Garrison Base-Wide Water Distribution Replacement project.
The objective of this project was to replace the existing water distribution system with a modern water distribution system for the entire 177 acre military installation. The new system was sized to handle domestic and fire needs, within a single pipe network, for the current demand as well as considering the impacts of the future master plan. The new design included all new distribution mains as well as service lines to within 5 feet of each building.
PROJECT RELEVANCE
- Water distribution and fire protection system design and construction.
- Geotechnical investigation and design.
- Extensive subsurface utility investigation.
- Construction and materials testing.
- Traffic control and H&S monitoring.
- Construction QA inspections and reporting.
- Maintaining project budget and schedule.
- Resolution of design issues with contractor and facility engineer.
During the initial stages of the design process, CTI performed a base-wide geotechnical investigation consisting of over 40 soil borings along the proposed water main alignment. Geotechnical analysis included groundwater monitoring for both short and long term conditions, corrosivity testing for pipe protection design and allowable bore pressure calculations for horizontal directional drill installation methods.
During the design process and prior to any excavation, an extensive subsurface utility investigation was conducted to properly identify and document all existing utilities potentially impacted by the project. All underground utilities were located via the use of as-built information in combination with utilizing ground penetrating radar, electromagnetic survey arrays and magnetometry locating equipment. The utilities were exposed by completing ‘soft dig’ exploratory excavations utilizing hydro-excavation equipment and a detailed existing utility map created for use in the design and construction.
The new water distribution system for the Detroit Arsenal was constructed of predominately ductile iron (DI) pipe ranging in diameter from 4” to 12”. The water main crossing beneath Bear Creek was installed with high-density polyethylene (HDPE) DR 9 piping material. The majority of the water main network was installed via a trenchless installation method known as horizontal directional drilling (HDD). Two (2) City roadway crossings included jack & bore techniques for installation of a cased water main. In areas where HDD installation method was not appropriate, traditional open-cut installation of the water main was performed. Domestic water line service leads to the various buildings consisted of 2-inch diameter “Type K” copper material.
New water main appurtenances installed included gate valves, curb stops, post indicator valves, and fire hydrants. All appurtenances were comprised of cast iron materials and meet applicable AWWA standards. The new building fire protection lines installed consisted of 6”, 8”, and 10” ductile iron piping materials. Cathodic protection consisting of double polywrap was installed on all of the water main piping. Pressure and leakage testing was performed required to verify that the installed water main piping and appurtenances were installed properly. The disinfecting procedure is in order to sanitize the public water system before allowing use by the general public.
CTI also performed analytical testing of excavated soils resulting from the open cut water main installation for determining proper off-site disposal options and beneficial re-use. We developed an Asbestos Hazard Abatement Plan and executed the removal of asbestos containing water pipe materials during decommissioning of the old water line in accordance with OSHA regulations for Class II asbestos work.
Traffic control measures were taken throughout the project to maintain site safety and keep an active work barrier, and soil erosion controls were implemented to ensure that sediment would not leave the work zone on site. Overall, the project included the installation of approximately 19,000 linear feet of new 8” to 12” ductile iron pipe with over 16,000 linear feet of that being horizontally drilled to minimize site disruptions. In total, 57 precast gate wells with valve operators were installed along with 35 hydrant assemblies to provide the distribution needed to the base.
In addition to CTI’s construction work, the construction and materials testing division was involved in asphalt density testing of HMA and concrete slump, air content and compression strength testing, per ASTM standards.
PROJECT HIGHLIGHTS
- Design/Build of +19,000 linear feet of 4-inch to 12-inch ductile iron water main
- +50 gate well structures with valve operators
- +30 hydrant assemblies
- Directed extensive geotechnical investigations
- Utility mapping and overall water main infrastructure installation including all water line testing operations.