Pima County Water Reclamation Facility (AZ)

Highlights

  • Innovative treatment process using DAF clarification and 5-stage Bardenpho, enhanced with step-feed capabilities. This process is then followed by deep tank secondary clarification.
  • The DBO contract was awarded to CH2M on December 7, 2010, for $164 million (32 percent lower than the budget cap of $240 million).

The initial capacity of the new Facility will be 32 MGD based on annual average daily flow. Provisions will be made for an ultimate capacity of 48 MGD.

CH2M HILL will operate the facility for 20 years. The Pima County Water Reclamation Facility (PCWRF) Project consists of the design, construction, acceptance testing, operation and maintenance (including all capital maintenance) of a new 32 MGD Water Reclamation Facility at the new PCRWRD Water Reclamation Campus. In addition to the Facility, the Project capital improvements include:

  • an Influent Pipeline from the Facility to the County’s Plant Interconnect,
  • an Effluent Pipeline from the Facility to the County’s existing Santa Cruz River Outfall,
  • a Primary Sludge Line from the Facility to the County’s existing Sludge Transfer Pipeline,
  • a Bypass Sludge Line from the Facility to the Plant Interconnect, and
  • all related capital improvements.

The initial capacity of the new Facility will be 32 MGD based on annual average daily flow. Provisions will be made for an ultimate capacity of 48 MGD.

CH2M HILL is delivering a treatment process using DAF clarification and 5-stage Bardenpho, enhanced with step-feed capabilities. This process is then followed by deep tank secondary clarification. Our odor control solution consists of two separate systems, a centralized odor control biofilter system and a dual bed carbon absorption system. This solution will treat odors to an expected level of 5 D/T and offers low lifecycle cost and exceptional performance.

The site layout allows room for expansion for improvements to support future growth of Pima County and the corresponding increase in customers served by the County’s wastewater system. The County has chosen to use a design-build-operate (DBO) project delivery approach to secure substantial benefits for its customers. These expected benefits include:

  • timely, efficient and cost-effective scheduling,
  • optimal risk allocation,
  • competitive design selection,
  • clear assignment of performance responsibilities to a single contracting entity,
  • long-term Project operations and maintenance efficiencies, and
  • cost savings beyond those anticipated using the traditional design-bid-build project delivery method with operational responsibility maintained by the County under its operations program.

CH2M has 100 percent responsibility for delivery of the PCWRF project. CH2M is delivering the PCWRF using our industry unique, single-entity, integrated design-build-operate (DBO) approach. CH2M will be the lead design professional engineering firm, the firm primarily responsible for the construction of the Facility and the long term operator of the Facility.

Project status

As of November 2012, the project is 70% complete, with over 150 personnel working onsite. All major process equipment has been delivered to site with the majority of concrete work completed. Safety performance has been excellent, with over 515,000 hours delivered with only a single recordable incident. The PCWRF is projected to be operational in September 2014.