Star Hill Road

February 17, 2015

starhillroad2This $13.6 million project will provide better access from SR 60 to the community of Starlight’s popular attractions as well as a safer, more efficient route for truck traffic through the County’s rolling terrain. Lochgroup’s construction engineers began by reviewing the plans to suggest cost-saving alternatives. Lochgroup is now overseeing construction of the 2-mile road that requires a significant amount of blasting through bedrock. Given the steep grades, careful attention is being paid to the proper placement of excavated soil and rock for embankments. Ongoing monitoring of temporary and permanent erosion control measures was key to protecting environmentally sensitive resources nearby.

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Constructed Wetlands for CSO Treatment

September 24, 2014

The city of Washington, Indiana had a serious combined sewer overflow (CSO) problem. Worse yet, the city’s CSOs mostly flowed through open ditches, and all five eventually discharged into Hawkins Creek, which ran dry most of the time apart from when the untreated CSO discharged. In between rains, the water pooled and then dried up, concentrating pollutants.

Add to that the fact that Washington’s system, most of it dating from the 1930s, had little storage capacity. As little as one-tenth of an inch of rain produced CSOs. The city struggled with this problem for decades. Early attempts to abate it simply enclosed drainage ditches and creeks in large pipes, but didn’t address water quality. Facing federal mandates to clean up its water, the city was stuck.

With a population hovering just under 12,000 and a median household income of $34,000, costs were a critical concern. A 2002 study found that it would cost $39.9 million to properly capture and treat runoff, or $7,500 per household, roughly one-quarter of the average household income. By 2009, the cost had escalated to $53 million.

Washington Wetland During ConstructionLochmueller Group (Lochgroup) worked with Washington and the Indiana Department of Environmental Management to develop a solution that captures the CSOs, transports them to a storage basin, and then treats them using a constructed wetland. The Preliminary Engineering Report showed that the capital costs, when compared to the next lowest present worth alternative–Chemically Enhanced High Rate Clarification – reduced costs to $26.4 million, saving Washington’s residents $26.6 million. In addition, the city will save over $1.6 million annually in operations and maintenance. Diversion of stormwater will also reduce flooding of nearby residences and roadways.

Lochgroup’s design captures the first flush, up to the volume associated with a 1-year/1-hour storm event, in a 5-mg storage tank, pumping this to the wastewater treatment plant. Overflow from the tank— up to a 10-year/1-hour storm event—travels via two 84-inch pipes to a 21-mg, 27-acre constructed wetland for treatment. After treatment in the wetland, the effluent passes through a UV disinfection system before being discharged into Hawkins Creek.

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Hamburg Pike Widening

September 10, 2014

Lochmueller Group (LochGroup) provided construction inspection services for the widening and rehabilitation of Hamburg Pike in Jeffersonville, Indiana. The improved roadway has two 12-foot lanes with a 14-foot center turn lane. Improvements also included widening and rehabilitation of a bridge, installation of a new storm sewer system, curb-and-gutter, asphalt pavement, sidewalks, landscaping, signage, and traffic signal upgrades. Sightlines were also improved, including at the intersection near the Thomas Jefferson Elementary School. Lochgroup met with school officials to coordinate re-routing school drop-off and pick-up traffic as part of traffic maintenance efforts.

The plan called for re-profiling the road to update it to current standards. This re-profiling was accomplished primarily via milling and HMA wedge and leveling. While the plans called for a significant depth of HMA in some areas; many others had proposed overlay depths as little as 1.5 inch. Lochgroup also noted that the existing roadway was severely deteriorated and that the existing roadway depths might be less than anticipated in some areas. In addition there were a number of trenches present in the existing roadway, and the extensive utility relocations required for the project would mean significantly more trenches and patching.

Given these conditions, Lochgroup raised concerns regarding future maintenance costs as a result of issues like differential settlement and crack mitigation. Since a full-depth reconstruction was considered too expensive, Lochgroup recommended that the minimal depth of HMA overlay be increased as a cost-effective alternative. After weighing cost vs. benefit considerations, the city decided to increase the minimal depth of HMA overlay to 6 inches throughout the corridor.

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West Side Wastewater Treatment Plant Improvements

The City of Evansville, Indiana needed to make improvements to the West Side Wastewater Treatment Plant (WWTP) to provide additional capacity for both growth and to treat wet-weather flows. Lochmueller Group used phased construction to make improvements that nearly doubled the plant’s NPDES permit capacity of 20.6 mgd.

One of the major improvements involved the addition of a new Biological Aerated Filter, which is ideal for urban WWTPs with limited space for expansion as it requires no settling tanks and no return sludge system.

The West Side project increased the average design flow from 10 mgd to 30.6 mgd. The average design peak flow for the whole plant is 39 mgd with the average design peak flow of the biofiltration process at 20 mgd. The biofiltration process is operated in parallel with the existing activated sludge system. Other improvements included:

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Bridge 207 over Big Eagle Creek

September 8, 2014

Bridge 207 is a single-span (112’) Pratt Through-Truss steel bridge that carries O’Neal Road over Big Eagle Creek. The bridge originally had a timber plank deck and the steel superstructure was supported on a steel caisson abutment and a concrete wall-type abutment. According to the available records, this steel truss bridge was originally built around 1900.

At the start of this project, the truss bridge had a 3-ton load limit posted. However, the significant deterioration observed on several steel members below the deck made it necessary for Boone County to close the bridge to all vehicular traffic.

Lochmueller Group (Lochgroup) prepared comprehensive bridge restoration plans, specifications, and bid documents. Since original bridge plans could not be located, the rehabilitation included a detailed field inspection and survey to measure the existing bridge framing components and dimensions and to document the existing structural conditions. Restoration plans detailed removal of superstructure members with insufficient load-carrying capacity and replacement with new, high-strength steel members that matched the appearance of the original members. The removal and replacement of these select components increased the load-carrying capacity of the bridge and allowed the county to remove all load-limit postings.

The plans also detailed repairs to damaged bridge components and sections of the bridge railing with replacement pieces closely matching the original appearance. The existing timber plank deck was replaced with a new timber deck capable of supporting the higher vehicular load demands. Project specifications further detailed a full cleaning and repainting of the entire steel truss structure to lengthen the life of the bridge.

Following the completion of the bridge rehabilitation design, Boone County retained Lochgroup to provide construction engineering services. These services included shop drawing reviews and periodic site visits to observe and review construction efforts.

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