Platte West Water Production Facility
- Related Projects: Water
The city of Omaha has been operating two water treatment facilities on the banks of the Missouri and Platte rivers since the 1960s, including the first one that's been operating since the 1920s at the northeast end of the city. Together these facilities—along with the peak shaving wells—have a capacity of 234 million gallons per day (mgd), enough to serve Metropolitan Utilities District (MUD) customers with high quality drinking water for more than four decades.
As Omaha's western boundary continues to move outward, (MUD) officials determined that a third water treatment facility was needed to keep up with the increased needs of its expanding customer base.
MUD selected HDR to provide the required engineering services for the planning, design and construction of the Platte West water production facilities. This facility will add 100 mgd of potable water capacity – enough to accommodate the anticipated needs of Omaha residents for the next 30 years or more.
When completed, Platte West will be a highly visible facility, in part because of the nearby residential developments and major roads that border the site on its eastern and southern edges. Utility officials also have decided to make this facility available for public tours and educational activities.
Because this will be a high-profile plant, MUD's board of directors established specific design requirements to include features such as a pitched roof system, natural lighting for basins and outbuildings, a central control room and a strong identity for entry.
HDR's services for the project are being provided through a series of four task orders – a well field, raw water main, treatment plant and finished water main.
The Platte West well field covers approximately 1,900 acres and is designed with a minimum firm pumping capacity of 104 mgd. The well field consists of 42 gravel-packed vertical wells approximately 100 feet deep; piping that includes Platte River crossings (two 48-inch diameter directional-drilled crossings each about 2,800 feet in length); well structures that include valve/meter vaults; pumping equipment with drives; and electrical distribution, instrumentation, roadway and security systems.
Platte West's raw water transmission main connects the well field with the southwest corner of the treatment plant site. The main—which includes a crossing of the Elkhorn River—is a 72-inch diameter pipeline about 22,000 feet long. The design and coordination of a 16-inch diameter backwash water drain line within the raw water main easement also is included.
The 100 mgd water treatment facility will include pre-treatment basins; split-treatment lime softening for hardness, organics reduction and iron/manganese removal; filtration and disinfection using free chlorine as the primary disinfectant; and chloramines as the secondary disinfectant.
This facility also will incorporate necessary ancillary facilities including:
- Finished water storage (15 mg) and 130 mgd of pumping capacity to three separate zones
- Backwash treatment systems
- Administrative, maintenance and personnel areas
- Stand-by generators (3,200 KW)
- Chemical storage and feed systems (lime, powdered activated carbon, permanganate, ferric, fluoride, polymer, chlorine and aqueous ammonia)
- Instrumentation and control systems
- Security systems
Future treatment was considered in the design and facility layout and includes 100 percent softening, recarbonation and UV disinfection. Residuals handling and treatment includes solids pumping, solids thickening and dewatering with plate and frame presses, pH control facilities, solids storage facilities and pipeline facilities.
Platte West's finished water transmission main will connect the treatment plant site to the north side of West Center Road, a major west Omaha thoroughfare. The main is 54 inches in diameter, approximately 10,000 feet long and includes a crossing of West Center Road.