Water Management Services
Engineering | Planning | Operations | Rate Studies
Water Management Services
Waste Water Treatment Plants
Horse Cave Wastewater Treatment Plant Additions
Caveland Environmental Authority, Inc.
Water Management Services, LLC. provided planning, design and construction inspection for a plant improvement project at the Horse Cave, KY Wastewater Treatment Plant. The 0.28 MGD treatment plant was experiencing solids carry over from the clarifiers at peak flow. In order to continue using the existing two clarifiers along with the proposed new clarifier, a flow proportioning hydraulic splitter was installed upstream of the clarifiers. The flow splitter also provided for a future clarifier addition.
The project’s primary improvement was to construct a 40 ft diameter by 12 ft depth center-flow clarifier and associated feed, sludge, scum and effluent piping. This new clarifier has eliminated the permit limit violations that initiated the project.
The project included other equipment to enhance the plant operability. This included a mechanical fine screen to replace a comminutor at the headworks. Also included was a new ultraviolet disinfection unit to increase peak flow disinfection capacity. The UV is an innovative where effluent flows through clear plastic tubes with UV lamps housed in a dry box. The unit reportedly operates for over six months without needing any cleaning. The UV was installed in a newly constructed vault adjacent to the existing unit.
Lastly, the project included a trailer mounted sludge dewatering centrifuge. The centrifuge was designed at 400 lbs/hr loading at 45 GPM and 2% feed solids. CEA’s intention was to use the centrifuge to eliminate the use of sand drying beds at this plant and at their Cave City WWTP. The dewatering trailer was fully equipped with polymer feed, flocculation tank, centrifuge, controls and discharge conveyor. The trailer had heavy duty sliding curtains that can be closed for weather protection. The dewatering system has worked out well for both plants, and for a time at the Marzetti plant.
Wastewater Treatment Plant Additions and Modifications
City of Lebanon, Tennessee – Department of Public Works
Water Management Services LLC, provided planning, design, and construction inspection services for the Lebanon Wastewater Treatment Plant expansion. This project as in response to Lebanon receiving an Agreed Order to eliminate overflows. It was determined that the most expedient way to eliminate the major overflows at the treatment plant was to increase the plant’s peak flow capability. The goal was to increase the peak flow of the plant from 12 MGD to 22 MGD.
To accomplish this, raw pumping capacity was increased, headworks screen and grit removal were doubled, aeration basins’ depth was increased 2 feet, aeration capacity was increased, anoxic mixers were installed and (2) 90 foot clarifiers were added. To improve operational control, a flow control chamber was installed, allowing varying the flow to each of the five clarifiers. Disinfection was converted to ultraviolet light. New, variable speed pumps were added to increase effluent pumping capacity. To carry this extra effluent flow, a parallel five mile 30-inch force main was added.
Provisions were included in the design that allows operators to convert the operation from extended aeration to a modified contact stabilization mode during peak flows. Operators can shunt all or any percentage of incoming flow to the downstream aeration basin while sending all or a portion of the return activated sludge to the upstream basin. This operational change reduces the solids loading on the final clarifiers and allows for a more reliable peak flow operation.
The project included conversion of anaerobic digesters to a second generation Autoheated Thermophilic Aerobic Digestion (ATAD) sludge treatment system. This system destroys 60% of the volatile solids and generates Class A biosolids. Centrifuge dewatering was added to the existing belt press. A biofilter odor control system that was also designed to collect and treat foul air from the ATAD and other plant odor sources.
The project successfully eliminated overflows that regularly occurred at the wastewater treatment plant. Along with the existing 20 MG equalization tank, these modifications allow the plant to treat or store 32 MGD during a peak rainfall event. The sludge improvements have reduced the amount of sludge to be land applied, and eliminated operational problems with the old treatment system.
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