- Orange County Sanitation District
- Project of Merit
- Additional Files
Rendering In Word
Selected Photos of Completed Project in Word
Selected Photos of Completed Facility
SELECTED PHOTOS OF COMPLETED FACILITY2
CWEA Hydraulics Presentation
- Additional Information
New Secondary Activated Sludge Facility 2 at Plant No. 1 (Project No. P1-102)
- Project Location:
Fountain Valley, California
- Project Description:
Orange County Sanitation District’s (OCSD’s) New Secondary Activated Sludge Facility 2 at Plant No. 1 (Project No. P1-102) is a $202M 60 million gallons per day (mgd) activated sludge facility – one of the largest in California to incorporate the biological nitrogen removal (BNR) process. Completed in July 2012, the Project is a culmination of more than a decade of work associated with OCSD’s commitment to take their facilities to full secondary treatment while keeping existing plants in operation and meeting discharge permit requirements. The Project also has enabled OCSD to exceed its commitment to provide high quality effluent to the Groundwater Replenishment (GWR) System Project, an internationally-recognized cooperative effort between OCSD and Orange County Water District (OCWD). Project design began in April 2004 and included preparation of a 2,000 page Preliminary Design Report with 100 drawings over an 8 month period and 1,000 final design drawings with specifications over a 22 month period. Construction was completed in 5 years on schedule with 2.5% change orders. Because of the high quality effluent being produced, OCSD staff diverted flow to the GWR System only one day after wastewater was introduced to the new activated sludge facility, enabling successful delivery 8 months before a December 31, 2012 Consent Decree deadline.
- Project Justification:
Project P1-102 embodies a unique combination of sustainable environmental benefits and innovative, practical approaches to engineering, construction, and commissioning.
Sustainable Environmental Benefits. With the successful completion of Activated Sludge Facility 2, the facility serves as the main OCSD secondary treatment facility and source of water to the GWR Advanced Water Purification Facility (AWPF). Sustainable environmental benefits include:
• Higher qualify effluent translates to reduced energy and chemical usage resulting from the reduction of required backwash cycles and chlorine dosage in the GWR System feed water. This allows more water to be produced, conserving local clean water resources and improving local reliability. With P1-102 in operation and enhancements underway at AWPF, full use of the 100 mgd GWRS capacity will be realized providing enough water for 850,000 people.
• Secondary effluent discharged to the ocean is reduced 100 mgd which eliminates chlorination and dechlorination chemicals for that volume and results in improved environmental stewardship of the Pacific Ocean and the Southern California Coast. When discharge to the ocean is required due to periodic GWR System maintenance events, a higher quality effluent is discharged and less chorination and dechorination chemicals will be needed as compared to prior to operation of Activated Sludge Facility 2.
Engineering, Construction, and Commissioning. The critical need to reliably provide high quality effluent to the GWR System by the Consent Decree date of December 31, 2012 while addressing OCSD’s exhaustive design requirements resulted in an extremely challenging project. Several innovative approaches were implemented:
• Selection of the BNR process allowed for removal of nitrogen biologically, rather than chemically; resulted in higher quality effluent due to removal of ammonia and other pollutants as well as nitrogen; and optimized oxygen use for reduced operational costs.
• Innovative design features enhanced process reliability and maximized process flexibility. The top three innovations were: 1) The aeration basins were designed to prevent the accumulation of foam on the tank surface. The top the internal wall levels were set to allow foam unobstructed passage toward the end of the basin. Installed ahead of the basin discharge weir is a rigid surface baffle that captures and diverts surface foam to a sump where it is removed from the system. A chlorine spray system is incorporated at the baffle to spray on the foam to reduce filamentous organisms. 2) Providing high quality effluent to GWR was one of the primary goals of the design. As designed the new P1-102 facility would treat both primary effluent and internal solids processing return flows, such as dewatering centrate. The latter flows are high in ammonia and contain polymer that could potentially degrade the membranes used at GWR. Structures were put in place to isolate flows that contain polymer residual and treat them separately. This effluent would not be discharged to GWR for water re-use and instead directed to the ocean outfall. The high ammonia concentrations would be spread at multiple feed points in the aeration basin oxic zone to better assimilate the ammonia loading. 3) Clarification systems are all designed to promote the development of solids that have excellent settling characteristics. In this case the development starts in the aeration basin effluent channel which is a vertical channel that directs the mixed liquor downward into the splitter channel and flows upward through grid that reduces the velocity prior to discharging through the splitter box. Given an even clarifier flow split the energy is further reduced at clarifier influent by the clarifier energy dissipation baffles to reduce the potential of short circuiting and promote settling. A horizontal baffle is located along the outer clarifier wall that redirects solids back down to the clarifier bottom.
• Features to reduce operation and maintenance costs include choosing to construct six circular clarifiers rather than 26 rectangular clarifiers, elimination of a primary effluent pump station through hydraulic modeling, and a highly automated energy saving blower control system. Although 60 mgd of treatment capacity was added, no additional Operations or Maintenance personnel was added to the staff because of the automated features and control system.
• Construction planning allowed the existing facilities to remain operational 24/7 in spite of the enormity of the construction effort. Construction at the 13.2 acre site required an average excavation depth of approximately 23 feet with a deepest structure excavation depth at 41 feet. Two tower cranes and crawler crane served the Project. During the 5 year construction period over 50,000 haul, concrete, and delivery trucks served the plant site, and over 5,700 piles were driven over an 18 month period.
• Commissioning, start-up, and performance testing of the 60 mgd facility was flawless due to the coordination and exhaustive pre-planning effort between OCSD and the B&V project team. The actual commissioning process began in the design phase. A year before wastewater was to enter the P1-102 facility orientation training was provided to prepare staff for changes that would be required to incorporate the new P1-102 facility into the other plant process systems. So successful was the transition that the plant Supervisor instructed the team to divert the high quality effluent flow effluent (less than 10 mg/L BOD and TSS, and turbidity between 0.5 and 2.0 NTUs) from the ocean outfall to GWRS only after one day of introducing wastewater into the new activated sludge facility. Performance testing of the new facility revealed performance better than the design capabilities including turbidities less than 2.0 NTU at a 2.0 peak factor.
- Special Circumstances:
At the outset of design, a project office housing the project design team (Black & Veatch in association with CDM and SPEC Services) was establish near the Plant No. 1 site. The local project office facilitated face to face coordination between all team members and disciplines resulting in comprehensive and coordinated contract documents and between the design team and OCSD staff. Frequent discipline meetings and over the shoulder reviews were performed to ensure OCSD staff concerns and requirements were heard and addressed. As a result of these meetings, consensus on issues was made more quickly and confidently at the larger workshop meetings allowing the project to move forward.
The partnering of OCSD and B&V through this 8 year project has resulted in open communication, and trusted relationships between staff in these organizations from top to bottom. Most importantly, it has resulted in an understanding of each company’s and each staff members concerns, interests, and responsibilities in producing a quality project. This has allowed OCSD and B&V to effectively move through project issues from preliminary design to final performance acceptance testing.
- Project Attachments:
No additional information.
- Award Citation::
The Orange County Sanitation District’s (OCSD) $202M 60 mgd New Secondary Activated Sludge Facility 2 at Plant No. 1 (Project No. P1-102) is the cornerstone project of OCSD’s $2.2B Capital Improvements Program. Black & Veatch served as the lead consultant providing preliminary design, final design, and construction phase services.
- Suggested Award Summary:
The Orange County Sanitation District’s (OCSD’s) $202M New Secondary Activated Sludge Facility 2 at Plant No. 1 (P1-102) is the cornerstone project of OCSD’s $2.2B Capital Improvements Program (CIP), one of the most comprehensive public works programs in the nation. Black & Veatch is the lead consultant providing preliminary design, final design, and construction phase services. The P1-102 project was initially developed to (1) meet Consent Decree requirements of full secondary treatment by December 31, 2012, (2) meet increasingly stringent OCSD NPDES objectives, and (3) meet OCSD’s commitment to provide high quality secondary effluent to the award-winning Groundwater Replenishment System (GWRS), a joint effort of OCSD and Orange County Water District. Preliminary design for P1-102 developed an 80 mgd activated sludge treatment train. Reduced flow projections resulted in final design of a 60 mgd facility. Variations on the original project planning that the consultant team has suggested include: (1) a hydraulic design that eliminated the need of a new primary effluent pump station; (2) a secondary treatment process for nitrogen removal which will reduce operation costs and improve treatment efficiency, and (3) changes in clarifier configuration that reduce life-cycle costs and increase ease of operation and maintenance.
Project challenges included:
• Developing the 2,000 page Preliminary Design Report within 8 months, including over 100 preliminary drawings. A local Project Office was established to enhance communications and expedite the schedule.
• Producing more than 1,100 drawings within a time frame of 30 months. A comprehensive resource loaded schedule was created to ensure adequate staffing throughout the design effort.
• Providing process enhancements to allow OCSD operations staff system flexibility to address changes in flow and quality conditions. This was essential to meeting GWRS start-up goals.
• Developing construction packaging and sequencing to maintain other CIP projects and minimize system disruption and construction cost and impacts. This includes addressing a myriad of underground piping and utility tunnels on and adjacent to the project site.