HydroScience Engineers

The City of Hayward needed to improve their water distribution and sewer collection systems to fix pipe sags, cracks, and deformations, improve maintenance access, and increase capacity and O&M capabilities. HydroScience was hired to design these improvements and provide engineering services during construction. Spread over 32 different locations, the design improvements included 5 miles of water and 3 miles of sewer pipelines ranging from 8 to 15 inches in diameter.

Project challenges included Caltrans, UPRR, and BART permitting, constructing pipelines in easements, and pavement moratoriums. Trenchless repair was needed in four locations where the pipelines crossed railroad tracks and a gas transmission main. Construction bids came in on a very tight spread, with the low bid being within 0.5% of the engineer’s estimate.

Memorial County Park is a family and group campground facility. Wastewater generated within the park was collected in a 1.8-mile gravity sewer pipeline system, then flowed into a 30,000 gpd extended aeration WWTP, where it was treated to secondary standards, disinfected, and discharged to a spray field with an unlined retention lagoon. The system was over 50 years old and had poor performance, reliability concerns, and high maintenance requirements.

HydroScience planned, designed, and oversaw construction for a new, modern WWTP, along with significant collection system improvements, including a new sewer force main and pump station. HydroScience developed a collaborative, forward-looking project approach that provided reliable operation and permit compliance and reduced operations and maintenance costs, all within in a small, low-impact footprint.

HydroScience prepared a design report, developed detailed plans and specs, and provided construction phase engineering support for Granular Activated Carbon (GAC) treatment systems on four groundwater wells in the City of Manteca. The GAC treatment systems address concentrations of the synthetic organic chemical 1,2,3-trichloropropane (TCP) in the groundwater.

This was a progressive design-build project, where HydroScience worked with a general engineering contractor in a highly collaborative process that optimized cost, constructability, reliability, flexibility, and long-term operations and maintenance.

This project was selected as ENR California’s 2022 Best Project in the Water/Environment category.

HydroScience developed the City’s Water and Sewer Master Plans, using Innovyze InfoWater and InfoWorks ICM software to calibrate the models, and conducting site visits and operator interviews to document all major facilities and to identify any noted physical wear and deficiencies. An essential element of the Water Master Plan included a comprehensive water demand assessment and used fire flow and pressure data to reflect actual system demand, operation, and response. For the sewer system, HydroScience used both existing wet and dry weather data to establish unit sewer flow factors for various land use types. The model was used to assess existing and future system capacity including impacts of future development. The results of both the water and sewer system analyses formed the basis for phased Capital Improvement Programs to address the respective system deficiencies.

HydroScience provided engineering services to SacSewer to rehabilitate the Mission Trunk Sewer, a 34,000 LF unlined reinforced concrete pipe (RCP) ranging in diameter from 36- to 75-inches. This critical trunk sewer had severe corrosion with exposed aggregate and rebar. HydroScience developed rehabilitation alternatives that included open-cut and trenchless rehabilitation techniques, new manholes and a junction structure, and sewer flow management during construction. Following the alternatives evaluation, HydroScience performed detailed design with cured-in-place piping (CIPP), repair and installation of new manholes to improve trunk access, and replacement of a key junction structure. This highly successful rehabilitation was one of SacSewer’s largest ever capital projects.

HydroScience planned and designed a new wastewater treatment and recycled water storage and pumping facility that now serves an all-new tribal residential community in Sonoma County. As part of a design/build effort, HydroScience developed the design in close collaboration with the Tribe, owner’s representative, and the general contractor.

The treatment facility consists of a prepackaged membrane bioreactor (MBR) facility. HydroScience also designed all recycled water infrastructure downstream of the treatment facility, including two large seasonal storage reservoirs, a transfer pump station, inline filtration, and piping to the distribution system. HydroScience also designed the development’s drinking water wells, storage tanks, booster pumps, and arsenic and manganese filtration systems.

HydroScience developed a Water Master Plan for the City of Manteca with the objective to develop capital improvement projects to address supply and system capacity deficiencies in the water system. Work included conducting a comprehensive water demand assessment, then using the General Plan and GIS land use files to incorporate planned future development and system expansion. The hydraulic model was calibrated using existing conditions and real-time hydrant flow testing data, then used to assess system capacity under scenarios including peak demand, fire flow conditions, and future development. HydroScience also conducted a water infrastructure condition assessment to create a prioritized rehabilitation and replacement program. The results were translated into a comprehensive and phased Capital Improvement Program and water rate study that addresses the system deficiencies and plans for future growth.

HydroScience provided engineering and design services to improve the District’s Water Pollution Control Plant. The existing plant’s treatment primary clarifier was severely corroded. HydroScience designed improvements to renew the facility, including replacement of scum skimmer wipers and bottom sludge scrapper blades, replacement of the existing bridge, platform and handrail above the clarifier, epoxy protective coatings for all bridge support beams, miscellaneous concrete surface repairs, and replacement of all electrical conduits and conductors with PVC coated rigid steel conduit, as well as installation of a new light post on the bridge.

HydroScience provided on-call planning, evaluation, detailed design, and construction support services under a multi-year Master Services Agreement with the City of San Jose. The Regional Wastewater Facility (RWF) is a 167 MGD secondary and tertiary wastewater treatment plant serving 1.4 million residents and businesses across 8 cities in Santa Clara County. It is the largest advanced wastewater treatment facility in the western United States. It discharges advanced tertiary treated effluent to the sensitive southern end of the San Francisco Bay and delivers 14 MGD of recycled water to customers in the South Bay. HydroScience worked directly with RWF Operations and Maintenance (O&M) staff to plan, design, and implement urgent improvements on an on-call basis throughout the facility.

HydroScience worked closely with the City of Davis to design improvements to their aging WWTP, including replacement of aged and oversized influent pumps, influent channel hydraulics and bar screen improvements, and grit and primary clarifier improvements. HydroScience utilized innovative approaches to maintain treatment capacity while minimizing costly bypass facilities.

As part of a design-build team, HydroScience also provided design, engineering services during construction, and facility commissioning for secondary and tertiary wastewater treatment improvements. This $71M comprehensive upgrade modernized the WWTP to bring it into compliance with current discharge regulations. The project included design and construction of BNR activated sludge secondary treatment facilities, tertiary disc filters, chlorine disinfection, post-aeration, effluent pumping, flood control facilities, and a new administration building.