- Equipment delivery that supported schedule milestones and construction sequence and re-sequencing when the need arose
- Equipment procurement and installation benefited by operational review for control strategy reconciliation (with main plant control system), training and start-up assistance, as needed to support schedule, spare parts consistent with agency practices, certifications and warranty validation
- In conjunction with agency staff and the design professionals, the control descriptions and screen layouts were developed.
- This project involved the expansion of treatment capacity from 37.5 to 50 mgd
- Implementing Bardenpho technology
- Repairing process units
- Replacing equipment and structures
- Addressing odor control issues and upgrading the facility to be compliant with environmental, regulatory, and building code requirements.
Using a construction management at-risk (CMAR) delivery method, CH2M (now Jacobs) provided design engineering services and Archer Western (dba The Walsh Group) provided pre-construction and construction services to upgrade an existing Pima County pollution control facility. This fast-tracked project was completed and commissioned in September 2013.
The $225M construction project consists of:
- Expanding preliminary and primary treatment facilities from 37.5 to 50 mgd
- Constructing a new 25-mgd ammonia/nitrogen/nutrient removal process system (5-stage Bardenpho) to replace an existing 25-mgd HPO train
- Upgrade modification to existing 12.5-mgd BNRAS process train for additional ammonia/nitrogen/nutrient removal process system
- Constructing a new 12.5-mgd capacity ammonia/nitrogen/nutrient removal process system
- Modifying effluent disinfection facilities using sodium hypochlorite technology followed by de-chlorination
- Constructing interim biosolids digestion and thickening improvements
- Constructing biosolids facilities for additional sludge from an offsite 25-mgd water reclamation plant
- Constructing miscellaneous ancillary support system improvements
- Repairing and replacing wastewater equipment and structures
- Expanding biosolids processing
- Adding odor control measures
- Upgrading the facility to be compliant with environmental, regulatory and building code requirements
The contractor self-performed approximately 50 percent of the work and maintained exclusive control of the entire mechanical process equipment critical path, from procurement through operations. This self-performance strategy focused on the undivided ownership of the most complex aspect of the work, which ensured an on-time startup and completion.
To maintain maximum schedule and quality control, we self-performed the process equipment procurement, installation, instrumentation and control, and commissioning and startup.
The unfragmented control of late phase critical path activities provided the agency with single point accountability at the place in the project most commonly responsible for the largest progress delays.