San Diego Pure Water Construction Management Program — San Diego, CA

The City of San Diego developed the Pure Water Program to reduce its dependence on imported water and unique regulatory requirements for regular permit renewal at the Point Loma Wastewater Treatment Plant. At full implementation in 2035, the program will provide 83 million gallons of water per day (mgd), nearly one half of San Diego’s water supply. It will reduce the City’s treated wastewater ocean discharges by half. As the lead firm in a joint venture, Parsons is providing program construction management services for treatment plants and related facilities for the San Diego Pure Water Program.  

North City Pure Water Projects: Phase One

North City Pure Water projects make up the first phase of the Pure Water Program. The North City projects are scheduled to be operational by the end of 2025 and are designed to augment the City’s Miramar Reservoir with approximately 30 mgd of purified water.

From the NCPWF, purified water will be pumped to Miramar Reservoir via the North City Pure Water (NCPW) pump station and pipeline. Miramar Reservoir is a source of drinking water for the Miramar Drinking Water Treatment Plant (DWTP), which provides drinking water to the northern portion of the city’s service area. 

Key Projects And Parsons’ Role

Parsons is currently providing CM services for the following projects: 

• North City Water Reclamation Plant Expansion: The existing NCWRP located at Eastgate Mall, and l-805 has an existing capacity of 30 mgd and delivers non-potable reuse water to irrigation and industrial customers throughout the northern San Diego region. The NCWRP will be expanded and upgraded to produce 42 mgd of tertiary-treated water to meet non-potable reuse water demands and generate source water for the NCPWF. Treatment at the expanded NCWRP will feature preliminary treatment, chemically-enhanced sedimentation, primary effluent flow equalization, biological nutrient removal using the 4-stage Bardenpho process, secondary clarification, coagulation followed by deep bed anthracite filtration, and chlorine disinfection. The project scope also includes the 30 mgd pump station needed to convey the tertiary-treated water from the NCWRP to the NCPWF. 
• North City Pure Water Facility and Pump Station: Located just north of the NCWRP, across Eastgate Mall, the new NCPWF will be a state-of-the-art advanced water treatment facility designed to produce up to 34 mgd of purified water. The new treatment facility will include the following processes: ozonation, biological activated carbon (BAC) filtration, membrane filtration (MF), reverse osmosis (RO), ultraviolet light/advanced oxidation (UV/AOP), stabilization via carbon dioxide and lime addition, and chlorination. The new treatment facility will have the most advanced controls and monitoring systems to ensure treatment reliability. The NCPW pipeline will be built under a separate project. A pump station at this facility was initially planned as a separate project to occur later, but as an innovative solution to the client’s schedule delays, a new pump station with a capacity of up to 32.8 mgd was added to this project to send the purified water produced at the NCPWF to the Miramar Reservoir. The City will also build a 48-inch-diameter force main approximately 8 miles long to convey the water. 
• Metro Biosolids Center Improvements: The MBC is the City’s regional solids processing facility, which receives digested biosolids from the Point Loma Wastewater Treatment Plant and undigested biosolids from the NCWRP. Because of the NCWRP expansion, the quantity of solids sent to the MBC will increase, which may impact the quality of the biosolids treated at the facility. To accommodate these additional flows and potential changes in biosolids quality, the following upgrades and improvements will be implemented at the MBC: expansion of grit removal building; new feed pumps; grit separators and clarifiers; new thickening centrifuges, sludge pumps, and pipeline; equipment upgrades and replacements at the existing digesters; and centrate pump station upgrades. 

• Miramar Drinking Water Treatment Plant: The project consists of improvements to the existing 100-mgd Miramar Reservoir Pump Station (MRPS) and the addition of 1 megawatt (MW) of photovoltaic panels on Clearwell 1 at the Miramar Water Treatment Plant. The improvements at the MRPS include the rehabilitation of six 200-horsepower (hp) pumps, assessment and rehabilitation of the existing pump cans (if needed), replacement of approximately 200 feet of 66-inch potable water pipeline, rehabilitation of the 48-inch pump discharge pipeline (if required), replacement of the existing emergency generator, site improvements, electrical improvements, and HVAC improvements. The photovoltaic project includes phase 2 of a two-phase installation of a commercial roof-mount solar photovoltaic power system on Clearwell 1. This phase 2 installation will increase the capacity of the existing system by 1.24MW-AC. 

• Central Area Small Scale Facility (CASSF): The CASSF will treat wastewater from the City’s Point Loma Wastewater Plant (PLWTP). It will consist of water reclamation plant processes (preliminary to tertiary treatment) and advanced water purification process trains. The CASSF will be tested and operated to demonstrate compliance with recycled water objectives and to determine parameters for the full-scale design of the Pure Water Program Phase 2 facilities. 

Program Challenges And Solutions

• The program was impacted by a legal injunction between 2017 and 2019. The team has overcome the delay, and the San Diego Pure Water Program is actively moving forward with the construction phase. This challenge was partly overcome with the work of Parsons’ project labor agreement team to secure a sizeable skilled labor workforce. These shortages were an anticipated challenge in the program due to the volume of work happening simultaneously on North City projects and other ongoing work in Southern California. 
• A creative innovation implemented to compensate for lost time was combining the North City Pure Water Facility Project with the North City Pure Water Pump Station. These two combined projects currently total $358 million.