Dewatered Sludge Handling, Storage and Truck Load Out System Fred Hervey Water Reclamation Plant in El Paso, Texas

End User or Owner

El Paso Water Utilities
El Paso, TX

Consulting Engineer

Brown & Caldwell
El Paso, TX

Contractor

Wright Construction Company
El Paso, TX

Plant Name and Location

Fred Hervey Water Reclamation Plant
El Paso, TX

General Description

The Fred Hervey Water Reclamation Plant is located in Northeast El Paso and uses tertiary treatment to produce reclaimed water to drinking water quality levels. Although not used for potable purposes, the reclaimed water is re-injected into the Hueco Bolson Aquifer through a series of injection wells and infiltration basins in northeast El Paso for aquifer replenishment. In 2010, more than 500 million gallons of reclaimed water were returned to the Hueco Bolson Aquifer. The plant is designed to treat up to 12 million gallons per day.

The Fred Hervey plant also supplies the El Paso Electric Company with approximately 900 million gallons of reclaimed water for their cooling towers on an annual basis. The Painted Dunes Golf Course, the second largest customer, uses approximately 200 million gallons of reclaimed water per year for irrigation purposes. The City of El Paso’s Northeast Regional Park uses approximately 25 million gallons per year for ball fields, playgrounds, and landscape. Other customers include the Bowen Ranch and several construction contractors that use approximately 32 million gallons per year.

KWS Environmental supplied and installed a complete dewatered sludge storage and transport system in 2004 for the Fred Hervey Water Reclamation Plant as part of an upgrade and expansion at the facility. The system technologies offered by KWS Environmental were combined on this project to offer complete responsibility for delivery of dewatered sludge from multiple centrifuges to truck loading and landfill. Quicklime was added after the sludge was dewatered and before it was pumped to storage and load out. KWS Environmental supplied a complete conveying system from the point of receiving dewatered sludge from three sludge pumps to the delivery of the dewatered sludge into trucks and included the lime delivery conveyors.

Design Parameters

Product Type: Anaerobically Digested Dewatered Sludge (Thickened, Stabilized, Quicklime Added)
Material Density: 40-65 Lbs. per Cubic Foot
Capacity: 3,240 Cubic Feet per Hour
Capacity: 3,120 Cubic Feet of Storage
Duty: Continuous, 24 Hours per Day

KWS Advantages

The KWS Environmental conveying system included two 304 stainless steel silos, vibrating bin discharge systems, dripless knife gates, controls, lime conveyors, structural steel and two truck-loading stations. The dewatered sludge is stabilized with quicklime before storage in the silos. KWS Environmental designed, delivered, installed, commissioned and tested the complete system. KWS designed the concrete foundation and supplied a complete and fully integrated system. KWS assumed system responsibility for, and coordinated interfaces between, all equipment supplied and worked closely with other contractors on site. KWS performed all start-up activities and trained the Owner’s staff.

Special Features

The KWS Environmental conveying system provided for El Paso Water Utilities had many features that offer advantages over most load out systems on the market. The silos utilized vertical height and gravity to load the trucks. No live bottom screw feeders or additional discharge gates were needed. Bin vibrators and electrically actuated knife gates were located below the silos. Varying the discharge rate of solids was very simple with the control system provided. The shafted screw conveyors had very few maintainable components. The system provided by KWS Environmental was relatively low cost and very space efficient. The number of electrical components was minimized resulting in very low power consumption. The system is so well designed that 20 cubic yard trucks can be filled completely in as little as ten minutes.