Where some see wastewater, we see a vital source of nutrients, energy and aquifer recharge. In this era of resource resilience and zero waste, it’s all about knowing what you’ve got and making the absolute most of it. Which is our approach to everything, from new plant design to rehabs and expansions, from regulatory compliance to process, performance and life cycle optimization. As demands on California’s systems change and intensify, we’re helping agencies and municipalities anticipate, adapt and find the wealth in waste.
Our Wastewater Treatment expertise includes:
Headworks and Grit System Improvements and Rehabilitation of Primary Sedimentation Basins, Point Loma Wastewater Treatment Plant
LEE + RO provided studies, engineering, design and construction phase services for a $22 million major improvements project at the 240 mgd Point Loma Wastewater Treatment Plant. LEE + RO constructed two physical models (for the headworks and aerated grit removal tanks) and conducted tests to find ways to optimize the flow distribution to the grit tanks and to determine the most efficient grit tank cross-sectional configuration. The project included modifications to flow distribution channels, reconfiguration of the south aerated grit tank, the addition of a new two-story grit dewatering building, and modifications to the odor control system. The new grit dewatering building is 40-feet wide, 140-feet long and 49-feet high and houses seven SlurryCup grit separators/grit washers, seven grit storage bins, an electrical room, foul air fans and a grit trucking facility. A temporary grit building was constructed to facilitate construction. An extremely congested site with heavy water-bearing concrete channels required extensive constructability analyses.
LEE + RO was also the design engineer of record responsible for engineering, design and construction support services for a $7 million design/build project to rehabilitate 12 primary sedimentation basins at Point Loma. The 12 basins were constructed under five separate contracts from 1962 through 1996. As a result, there were substantial differences in the sludge/scum collectors, such as differences in shaft diameters, drive motors, sprockets and installation layout. This project replaced a total of 36 longitudinal and 12 cross collectors with new standardized units. The project also included detailed inspection and condition assessment of each drained basin, repair of damaged concrete and/or coatings and linings, modification of scum spray actuators, and installation of a new 8-inch diameter water main connected to the plant’s industrial water system.
Wastewater Treatment Plant Improvements
LEE + RO provided the City of Brawley with engineering analysis, final design, construction management and resident engineering/inspection services for the $25 million Brawley Wastewater Treatment Plant Improvements project. The existing 5.9 mgd plant consisted of a headworks, three primary clarifiers, five facultative lagoons, UV disinfection, sludge pumping, and drying beds. LEE + RO prepared a detailed project report presenting a systematic approach for the requisite improvements. LEE + RO also analyzed the potential for water reclamation based on Title 22 requirements, consulted with the Regional Water Quality Control Board (RWQCB), and assisted the City of Brawley in successfully obtaining $15 million from the Clean Water State Revolving Fund (CWSRF) and a $10 million federal grant under the American Recovery and Reinvestment Act of 2009 (ARRA). Wastewater and sludge handling processes designed and constructed included three Biolac® WaveOx aeration basins and secondary clarifiers, gravity thickening, centrifuge sludge dewatering, solar greenhouses producing Class A Biosolids, an operations building, and rehabilitation of the headworks and other support facilities. Since the project construction was complete in May 2012, the upgraded plant has been producing an effluent quality that exceeds the NPDES permit requirements. This project received “Project of the Year” award from the San Diego / Imperial County Chapters of the American Public Works Association in 2012.
Wastewater Treatment Plant Phases 1, 2, and 3 Expansion and Upgrading Projects
LEE + RO provided planning, engineering, design and construction management / resident engineering services for plant expansion and modification projects that was implemented in three phases. The $5 million Phase 1 project in 2003 increased the plant capacity from 0.5 to 1.3 mgd and the $11 million Phase 2 project in 2007 further increased the capacity from 1.3 to 2.0 mgd with nitrification + denitrification capability. The $14 million Phase 3 project in 2015 increased the plant capacity to 2.75 mgd and improved process reliability. These projects replaced the pond treatment systems. The upgraded plant processes consist of the influent pump station, headworks, oxidation ditch activated sludge, centrifuge dewatering, and percolation ponds.
Wastewater Treatment Plant Expansion and Improvements, Valley Sanitary DistrictLEE + RO provided process analysis and a plant master plan, prepared final design plans + specifications, and provided construction management + resident engineering services for a $46 million plant expansion and improvements that was implemented in two phases. The $26 million Phase 1 project increased the activated sludge capacity from 5 to 10 mgd, and added new hypochlorite / bisulfite chlorination + dechlorination, a 54-inch diameter outfall, belt-press sludge thickening + dewatering, and drying beds. The $20 million Phase 2 project added two primary clarifiers, anaerobic digestion with a gas management system, odor controls, and administration + laboratory buildings. Both projects included extensive electrical work.