Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Bear Trap Water Treatment Plant Design-Build

 

Contract: $1,558,500

Design-Build Team Members
Owner: Tidewater Utilities, Inc.
Engineer: Green Stone Engineering, LLC
Electrical Designer: Optimum Controls Corporation

Design-Builder: Johnston Construction Company

Key Accomplishments:

• Johnston Construction Company assembled a design and construction team that provided a reliable and economical new water treatment facility that was completed within the Owner’s specified timeframe.
  
• The water treatment plant building includes: interior walls and ceilings covered with corrosion resistant fiberglass reinforced plastic panels for ease of maintenance; an open floor plan for easy access to all equipment; an air conditioned office and electrical room for operator comfort; and, an insulated rolling door to maximize accessibility for moving equipment.
  
• The pre-cast concrete backwash holding tank has a sloped floor and center sump to efficiently draw off settled sludge solids in the bottom of the tank. Grating was installed over half of the tank area for easy access and to eliminate confined space entry concerns.
• Confined space on the job site required close coordination with several subcontractors that worked simultaneously in the same areas.
• The electrical subcontractor provided telemetry equipment for an off site elevated water storage tank so that the new water treatment plant can operate based on water levels at the on site or off site water storage tanks.

Johnston Construction Company was the lead design-build team member providing engineering, construction, and commissioning services for the $1,558,500 lump sum contract.

The project involved the design and construction of a new water treatment facility to serve areas of Frankford, Sussex County, Delaware. The water for the project is supplied from two on-site wells with pretreatment facilities for iron oxidation, iron removal, and disinfection prior to discharging the treated water to the on-site elevated water storage tower for delivery to the water distribution system.

Water supply is provided by two wells and pretreatment includes a variety of equipment. An 8-inch diameter well and 10-inch diameter well are anticipated to produce 550 GPM and 700 GPM respectively. Well pumps are sized at 30 HP and 50 HP to provide sufficient pressure through the treatment units and accomplish the head required to pump the treated water to the elevated water storage tower prior to flowing into the distribution system. A 75’x 40’x 35’ high water treatment plant building houses most of the pretreatment equipment for the project. Chemical storage and feed systems for sodium hypochlorite and potassium permanganate are provided to pre-treat the groundwater before it enters the three 10-foot diameter green sand pressure filters manufactured by Roberts Water Technologies for iron removal. Filter backwash will be conveyed to a 60,000 gallon concrete backwash holding tank. Settled sludge solids from the backwash holding tank will be withdrawn for disposal and a decant pump will withdraw clear water from the top of the tank that will return to the head of the plant for treatment. Following the filtration process, a chlorination point for disinfection is located prior to the treated water flowing into the elevated water storage tower. A 250 kW outdoor emergency power generator was installed on site.

Several improvements were integrated into the project by Johnston Construction Company. The grinder pump station was relocated next to the water treatment plant building to eliminate the need for deep gravity piping. The use of a metal building for the water treatment building and a pre-cast concrete backwash storage tank saved overall construction time during the winter on the project. Johnston Construction Company coordinated the process and instrumentation drawings and electrical design to integrate supplied equipment and instrumentation with the owner’s Main Control Panel. The HVAC installation was also integrated with the architecture of the building.

The project was started in November 2007. Final design, construction, and performance testing was completed in May 2008.