Project Listing - Whitley Burchett

PLANNING

DSRSD – WWTP Master Plan Update
WBA managed and participated in preparation of Dublin San Ramon Services District’s wastewater treatment plant master plan. The treatment plant has a current average dry weather flow capacity of 11.5 mgd. Projections for rates of growth in the service area indicate that this capacity will be exceeded. Since capacity is projected to be reached in a short time frame, the master plan update was completed on a fast-track basis. WBA prepared an implementation plan for the planning, detailed design and construction of improvements to meet the short timeframe and worked in conjunction with another engineering firm to complete the necessary technical work for the master plan. WBA is also the program manager for all the improvements necessary at the DSRSD treatment plant. There are many distinct projects which require planning, design and construction to satisfy the necessary expansion and improvements. WBA has prime responsibility in ensuring that the various projects are properly coordinated.

Town of Yountville – WWTP Master Plan Update
The Town of Yountville, located in the Napa Valley, required a complete evaluation of its wastewater treatment and disposal systems at current and projected future flow rates. This study was required because the existing land disposal area, then used to grow hay, was in the process of being converted to a new golf course. The study involved evaluating current wastewater flows and characteristics and projecting future flows and characteristics based on Town planning and population projections. The capacity of the existing wastewater treatment plant was evaluated and recommendations were made to optimize O&M costs now and in the future. Because the Town is permitted to discharge treated wastewater to the Napa River only during winter months, it must store effluent for winter discharge or use the treated water for irrigation. A major portion of this project involved optimizing the use of storage for later discharge to the river and effluent reuse. WBA prepared and used a mathematical model to simulate river flows, allowable dilution ratios to the river, precipitation, multiple crop requirements, and storage requirements. The final report included recommendations, cost breakdowns, and schedules for implementation. WBA continues to assist the Town with implementing the recommended improvements.

City of Morgan Hill – Water Reclamation Feasibility Study
The City of Morgan Hill retained WBA to evaluate alternatives to upgrade and expand a regional wastewater system. As the need to commit to the regional system was fast approaching, the City needed a thorough evaluation and preliminary feasibility study with an associated cost estimate quickly. WBA developed a model to determine system needs and unit costs. A key element in the project involved estimating the size of the reservoir required to store reclaimed water for irrigation. The model developed by WBA enabled estimation of the size of the required reservoir, the volume of earthwork required, and the construction cost of alternative reservoirs to accommodate changing wastewater flows and irrigation requirements. Based on this work, the City found that it could implement its own wastewater reclamation program at nearly the same cost as its share of the regional plant.

SKF – Sludge Dewatering Study
WBA conducted a Sludge Dewatering Study for SKF to estimate the onsite sludge drying bed dewatering capacity and to evaluate a supplemental mechanical dewatering system to handle the sludge production in the winter months when the onsite sludge drying beds are not operational. The study concluded that a supplemental mechanical dewatering system is a viable and cost effective means for the District to effectively manage the sludge production during the winter months.

Based on one of the recommendations as adopted by the District, WBA developed an onsite pilot study program and coordinated with two sludge dewatering equipment manufacturers, one for a belt press system and one for a centrifuge system, to perform onsite sludge dewatering pilot studies. Based on the results of the pilot studies, WBA prepared a “Sludge Dewatering Pre-engineering Study” to define the general requirements of the sludge dewatering system and to evaluate the life cycle costs of the belt press and centrifuge systems. The study concluded that a centrifuge system is the recommended alternative for the District.

DESIGN

Livermore Water Reclamaion Plant –Plant Expanion
WBA led the design f a 2.25 mgd, Phase 5 expansin of the Livermore Water Relamation Plant. This project involved expansion or upgrading of the major treatment units and the associated process and utility piping and pumping system. In addition, the project included the planning and design of a completely new digested sludge system with high-rate facultative sludge lagoons and two-stage paved drying beds. Finally, the project included the design of a new administration and control building, a new maintenance building, retrofit of the original operations building to serve as a laboratory, and a new entrance road surrounded by a park-like area featuring ornamental and irrigation uses of reclaimed water. Team architects assisted in gaining acceptance of the project by the City design review commission.

City of Millbrae –Plant Improvements
The city of Millbrae selected WBA to design several major improvements to their wastewater treatment plant. The improvements consisted of modernizing the headworks and influent pumping facilities, rehabilitating the primary and secondary sedimentation units and replacing the sludge dewatering centrifuges. The headworks and influent pumping facilities modifications consisted of replacing the single, variable speed pump, two fixed speed horizontal centrifugal pumps and outdated comminutors and screening devices with three vertical pumps and three hydraulically operated comminutors. The primary sedimentation units modifications included new roofs, new chain drives and temporary structural supports to hold the tanks in place while the roofs were being replaced. WBA designed the replacement of the rotating screens in the secondary sedimentation tanks with fiberglass baffles. Modifications to the tilting weir skimmers in the cells of the chlorine contact tank enabled the rotating skimmer to be eliminated, thereby increasing the hydraulic capacity of the entire plant from 7 mgd to 10 mgd. The sludge dewatering centrifuges were replaced with a belt filter press, and the building housing the centrifuges was modified to accommodate the new equipment as well as to shield the operators from the weather and freeway noise. Heavy rainstorms that occurred during the 1992-93 rainy season were a major test of the improvements. The success of the improvements was proven by the fact that, for the first time, the City did not experience any NPDES violations during a heavy rainstorm.

FSSD –2002 Maintenance Project
WBA designed numerous wastewater treatment plant and pump station modifications for the Fairfield Suisun Sewer District as part of the 2002 Maintenance Project. Modifications included installing a second pH meter with associated control improvements to control influent pH, analyzing and upgrading the variable speed RAS pumping system, replacing existing raw sewage pumps and installing new VFDs, analyzing and modifying the sludge holding tank mixing system, locating and repairing leaks in a buried aeration header, and installation of a security system at the WWTP site.

SKF –Sludge Dewatering Facility
WBA completed a sludge dewatering study for SKF that recommended the installation of a centrifuge. Based on this study, WBA prepared the procurement documents for the District to pre-purchase a centrifuge unit with a capacity to dewater 200 gpm of feed sludge at 2% solids concentration. The selection and award of the purchase order was based on the evaluated costs which accounted for the equipment cost, the projected system performance, and the 10-year projected O&M costs. SKF purchased and took delivery of the centrifuge based on this procurement process.

WBA designed the facilities needed to complete the sludge dewatering system using the prepurchased centrifuge. The facilities include a new centrifuge building, a sludge feed pump, a polymer preparation and feed system, a sludge cake pump system and associated civil, mechanical, control and elecctrical systems. The design of the system includes allowance for installation of a second centrifuge unit in the future.

The above projects are representative of our experience in this area.
If you would like additional information on these, or other projects that
we have completed, please contact us.