Guam Water works Authority

Gwa1

GWA Wells Rehabilitation project consisted of the drilling and development of five potable water wells at five sites in northern Guam. The work consisted of the drilling and testing of pilot holes, reaming the holes to 24”, installation of 16” steel casing with pump and column and decommissioning of the existing wells. New water piping and connections to the existing mains at the street required new chlorination systems, PLC control systems with SCADA support, upgraded power services, water piping, mechanical improvements with building and site improvements. Well depths amounted to between 300 feet to over 500 feet. Funded by EPA, the wells needed to meet both local and federal requirements for the work and water quality. GWA Highwater Alarms was installation of high sewage wet well level alarms to 19 remote wastewater pump station sites on Guam. The alarms were installed with both radio and cellular transmitters that were incorporated into a GPA SCADA system. The USEPA grant funded project was completed in 150 days, which required extensive coordination, design, permitting, airfreighting materials, DPW inspection of all 19 sites and associated challenges at the control panels and equipment were specially fabricated, tested and programmed for this particular project. Asan Sewer Rehabilitation consisted of the replacement of approximately 400 linear feet of existing asbestos cement piping with new 14” to 18” PVC piping at depths of 7’ to 18’ below grade. Work was completed while the existing roadways remained open, between existing operating utilities and included several 24-hour sewage bypass systems to remain operational. Shoring of existing trenches, traffic control, dewatering, sewer lateral connections and abatement work in confined spaces added to the challenges. Permanent improvements consisted of new asphalt, striping, signage, sidewalks and curb and gutter on this Federally funded project.

KEY FEATURES:

  • Wells Rehabilitation – first well project completed on Guamin decades
  • 5 separate locations, each with their own unique challenges
  • Well design that is unique to Guam
  • Pilot wells were drilled, evaluated and approved prior to the ordering, drilling and development of the wells
  • Unique geological conditions at each well created design and construction challenges
  • Highwater Alarms – working in existing wet well facilities
  • Fast track project that required procurement of all materials and control system design to be completed prior to award
  • 2017 GCA Excellence in Construction Project Award Category Recipient
  • 2017 GCA Excellence in Construction Merit Award Winner
  • Asan Sewer – Existing asbestos sewer line condition was not fully understood until excavation was underway and site assessment could be conducted
  • This emergency repair project required 24 hour monitoring and round the clock work at key periods
  • Significant safety challenges were overcome such as abatement, shoring, confined space, traffic control, environmental and maintaining existing adjacent utility services

  • CLIENT: GUAM WATERWORKS AUTHORITY
  • LOCATION: Islandwide, Guam
  • SECTOR: Public Works / Environmental
  • VALUE: US$6M Well Rehabilitation
    US$1.4M Highwater Alarms
    US$2.5M Asan Sewer Rehabilitation
  • SERVICES CARRIED OUT: General Contractor