Village of Verdigre Wastewater Treatment Plant Facility Plan and Design

Verdigre, Nebraska In April 2007, the Village of Verdigre, Nebraska was faced with drastic changes to their wastewater treatment plant NPDES permit. Along with these changes, all of the engineering planning that was completed to this point was not usable to address the changes in the treatment plant. WLA was retained to develop a facility plan, complete final design to address the new permit limitations and provide assistance with regulatory and funding coordination. New ammonia limits for year-round discharges were being proposed by the NDEQ that included a summer effluent limit of 0.64 mg/L, and limits for spring and winter. In addition to ammonia, continuous disinfection of the effluent would be required. The receiving stream, Verdigre Creek, is classified as a Class "A" stream, which is capable of supporting trout fish species. WLA prepared the facility plan and proposed a treatment process that will meet all of the new effluent limitations. The facility plan included significant upgrades to the existing mechanical wastewater...
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Wastewater Force Main Relocation Project

City of Lincoln, Nebraska Biosolids from Lincoln's Northeast Wastewater Treatment Facility (WWTF) are pumped to a location 1.5 miles north of the plant prior to land application.  The pipeline must pass below Interstate 80.  With the widening of the Interstate 80 corridor between Omaha and Lincoln, the relocation of this pipeline became a priority.  Based on the new Interstate design, the existing force main will no longer have sufficient cover.  In addition, the force main casing would not provide sufficient protection to span the entire width of the proposed six lanes of the interstate.  The depth of bury and span of the steel casing did not meet Nebraska Department of Roads (NDOR) minimum standards.  This deficiency required the City of Lincoln to reconstruct the undercrossing and WLA was tasked with the engineering design services. During pre-design, a topographic survey, wetland delineation, and geotechnical soil investigation were completed.  Preliminary design consisted of pipe route selection, analysis of sludge pumping head conditions, material selection,...
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Papillion Creek Wastewater Treatment Plant Primary Clarifiers Replacement

Bellevue, NE WLA was selected by the City of Omaha to evaluate alternatives for replacement of the primary clarifier mechanisms at the Papillion Creek Wastewater Treatment Plant. This plant operates eight primary clarifiers that are 115 ft in diameter and have a side-water depth of 6 ft-10 in. Each clarifier is covered with an aluminum dome for odor control. After presentations from numerous clarifier mechanism manufacturers, a Basis of Design was developed. The concept will then be applied to all future primary clarifier mechanism replacements. Primary Clarifiers No. 5 and 8 were selected to be replaced in 2009. The clarifiers were drained and inspected for concrete deterioration. The top 26 in. of the tank walls will be repaired and re-coated with hydrogen sulfide resistant materials. Fiberglass materials will replace the severely corroded aluminum weirs and baffle plates. WLA prepared drawings and specifications that will be used to describe mechanism replacement....
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Missouri River Wastewater Treatment Plant Ohern Street Grit Basin Cover

Omaha, NE The City of Omaha, Nebraska has experienced significant odors from its Ohern Street grit basin which removes grit from wastewater influent at the Missouri River Wastewater Treatment Plant. WLA was contracted to research and identify alternatives for covering the grit basin. Due to the complexities of the clam shell structural steel, many traditional cover systems were eliminated from consideration. The new cover system was required by the City of Omaha to accommodate the existing clam shell grit removal process, be fully retractable by cables and winches without significant manual cover opening, and be constructed of compatible materials for the severe wastewater environment. A Technical Memorandum was prepared that addressed various design issues and established requirements for this project. Working with a cover manufacturer, WLA prepared a cover system design that will cover the grit basin and meet City requirements. In addition to the cover system, an odor control unit was designed that generates a hydroxyl ion fog to oxidize hydrogen...
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Duncan Aviation Paint Hangar 4 Wastewater Treatment Facility Design

Lincoln, NE In December 2010, WLA Consulting permormed a Life Cycle Cost Analysis (LCCA) at Duncan Aviation for the wastewater treatment equipment anticipated for three treatment scenarios and three economic scenarios, resulting in nine total life cycle options. The final analysis revealed taht the most cost effective solution included a wastewater evaporation system with both a primary and secondary evaporation system that ultimately reduces wastewater to solid waste. Duncan Aviation decided to build a new paint hangar, Paint Hangar 4, at its facility in Lincoln, Nebraska at the Lincoln Municipal Airport. This project consisted of approximately 54,400 square feet of paint hangar bays, office support spaces and other necessary operational equipment areas. (WLA Consluting, Inc. designed an evaporator for Duncan Aviation's wastewater.) The Wastewater Treatment Area provides operational support by receiving and treating the wastewater produced during the aircraft painting process. Wastewater entering the wastewater treatment area is contained in a collection pit and will flow into one of three 3,000 gallon storage...
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