Sludge Storage and Loadout System for Central Davis Sewage District Dewatering Facility Kaysville, UT

General Description

The Central Davis Sewer District (CDSD) is an award-winning, publicly-owned collection system and treatment plant serving the Farmington, Fruit Heights and Kaysville areas near Salt Lake City. The CDSD Dewatering Facility, which is designed for up to 12 million gallons per day (MGD), was upgraded to include a sludge storage and loadout system. The facility provides beneficial reuse of treated biosolids to fertilize alfalfa hay crops and for turf production. Biosolids are also mixed with wood and composted to create a quality soil amendment. The facility is within a few miles of the Great Salt Lake. The facility has been highly awarded in recent years for their management, operations, collection, quality, and biosolids program.

Filter presses dewater sludge that is conveyed via a serpentine belt conveyor up to a KWS hopper and slide gate. Sludge is then loaded out to trucks. The presence of the KWS hopper and slide gate allow for the filter presses to run continuous between truck loads. The hopper and slide gate are mounted on load cells that indicate to the operator the weight of material stored in the hopper above the truck bay. Each truck load contains several thousand pounds of dewatered sludge that is mixed with other composting materials to produce the quality soil amendments. The slide gate is electrically actuated either by the operator or automatically via the control system.

Design Parameters

1. Product Type: Dewatered Biosolids
2. Material Density: 55 to 65 Lbs. per Cubic Foot
3. Hopper Capacity: 3.4 Cubic Yards Active, 5.6 Total Volume
4. Duty: 5 Days a Week, 8 Hours per Day

KWS Advantages

KWS Environmental assisted the consulting engineer during the initial design phase with bin sizing and component selection. The load cell selection was of particular importance so trucks could be loaded accurately from the hopper. KWS communicated effectively though out the project with the contractor and engineer to resolve any issues. As a complete manufacturer of storage equipment, KWS Environmental tested the load cells and slide gate at our facility before shipment to ensure proper operation.

KWS also provided onsite supervision and assistance during the installation and testing phases of the project. KWS is committed to providing high quality service before and after shipment. Training was also conducted with the plant staff.

Special Features

Both the hopper and slide gate were designed and constructed from 304 stainless steel for long-term robustness. The slide gate was designed for drip-proof and reliable operation. The slide gate was equipped with an electric multi-turn actuator, sized to open and close under calculated thrust load of a full bin of biosolids. The rising-stem design of the electric actuator provides efficient and effective response to operator input.

The storage hopper, being mounted on a special mezzanine above the truck bay, was designed with the load cells mounting in mind. Each of the four hopper feet were outfitted with a load cell and provided with a display unit to provide a working system. The hopper side walls maintained a suitable angle to prevent material accumulation.