Inclined Sludge Load Out System for Louisville Wastewater Treatment Plant Louisville, CO

General Description

The City of Louisville is a Home Rule (citizens decide the framework of the local government) Municipality in Boulder County, Colorado. The city population was 18,376 at the 2010 United States Census and the city has been ranked in the top ten of “The 100 Best Places to Live in the U.S.” many times in recent years.

The Louisville Wastewater Treatment Plant (WWTP) is located in eastern Boulder County on the east side of Louisville. The facility discharges into Coal Creek, which is approximately ¼ mile east of the plant. The initial WWTP was constructed in 1952 and consisted of a settling pond followed by an aerated lagoon.

Beginning August 1, 2017, effluent released to Coal Creek must comply with new discharge limits for ammonia. To meet the new limits, the existing secondary process was replaced with new facilities capable of nitrification, denitrification, and biological phosphorus removal. The new solids handling facilities included new equipment for aerobic digestion, sludge pumping, and sludge storage.

KWS Environmental provided a new dewatered biosolids load out system to replace a belt conveyor to sludge drying bed that was inefficient, messy, and unreliable. The new system consisted of an incline shaftless screw conveyor with a single discharge to a truck. KWS also designed a new transition chute and flexible connection to mate to the existing centrifuge.

Design Parameters

KWS Advantages

KWS Environmental engineered, manufactured, delivered and commissioned a load out system that included an inclined shaftless screw conveyor along with a transition chute and flexible connection after the centrifuge. KWS engineers used 3D Autodesk Inventor to model the system and show exact details for the new KWS inclined screw conveyor, accessory equipment, egress and the truck load out area. The KWS team assisted the consulting engineer when the scope of supply after the centrifuge was not clearly defined. KWS took the lead and designed the complete load out system including the flexible connection and transition chute so the centrifuge would be isolated and easily able to discharge into the conveyor. KWS frequently and clearly communicated with the consulting engineer and contractor throughout the project so that no dimension or feature was missed.

Special Features

KWS Environmental provided a complete biosolids load out system including a 31-feet long inclined shaftless screw conveyor with an abrasion resistant AR-235 spiral for long screw life. The shaftless spiral is supported by ½-inch thick UHMW trough liners that are easily replaceable. A flexible rubber connection before the inlet transition chute of the shaftless screw conveyor protects the conveyor from the vibration of the centrifuge. The transition chute after the centrifuge was designed to match the centrifuge discharge and inclined screw conveyor inlet and includes an inspection port. The inclined screw conveyor was constructed from 304 stainless steel for corrosion protection. KWS Environmental designed and manufactured a special cantilevered floor support for the discharge end of the conveyor so no supports would interfere with the truck bay.