WithersRavenel, Land Development and Environmental Services
WithersRavenel’s environmental engineers, geologists and environmental scientists performed a rigorous program of services to help M/I Homes transform a distressed brownfields site into a beautiful new community in Raleigh’s historic Five Points district.
Nestled inside the Beltline in the historic Five Points neighborhood is a 10-acre tract that, since 1952, had served as a bus parking, fueling, and maintenance facility for Wake County Public Schools. In 2012 the school district declared the property surplus and sought to divest it. The school district estimated the sale would net a profit sufficient to offset future costs associated with leasing an office building in Crossroads Corporate Park in Cary, NC, where it had consolidated most of its administrative functions in 2010.
The Environmental Services people at WithersRavenel have demonstrated a command of their profession and a buttoned-up approach to their work that continue to impress us. When you are converting unusable space into a beautiful new community, you need to cross every ``t`` and dot every ``i`` — as far as we are concerned, WithersRavenel met and exceeded our expectations.
— Jeremy Medlin, M/I Homes
M/I Homes, which was ranked as the third largest builder in the Triangle in 2012 and has homes under construction in 14 Triangle neighborhoods, purchased the property in 2013. The veteran national developer planned a signature community of 83 Energy Star® Certified townhomes. Because the property had previously been used as a fueling center, M/I Homes wanted to take every precaution to make sure that construction workers and future residents and visitors would be kept safe. They turned to WithersRavenel, their partner on several other successful projects in Wake County, to provide land development and specialty environmental services for converting the site to residential use.
During a Phase I Environmental Site Assessment (ESA) in April 2012, WithersRavenel noted approvingly that Wake County Public Schools had pursued extensive investigation and cleanup efforts relating to the petroleum underground storage tank (UST) system and the remnants of the maintenance buildings since the early 1990s. Between May and September 2012, WithersRavenel completed several Phase II ESA activities, including soil, soil vapor, and groundwater assessments, to supplement work completed by Wake County in order to determine whether residential development of the property was feasible. At the same time, Wake County completed work to remove several in-ground hydraulic lifts at one of the remaining garage buildings.
But although Wake County had obtained site closure letters for each petroleum UST system closure initiated on the property, M/I agreed to pursue a Brownfields Agreement for the project with the North Carolina Department of Environment and Natural Resources to ensure that the property was safe for reuse. The data from WithersRavenel’s ESAs became the basis for a successful application to include the property and the proposed residential development project in the NC Brownfields Program; M/I Homes of Raleigh, LLC became the official applicant for the project in February 2013. As part of the agreement, WithersRavenel prepared an Environmental Management Plan (EMP), which outlined monitoring protocols and materials handling specifications for all grading and utility installation functions during the project, and provided environmental monitoring services to see that it was properly implemented.
To provide an added level of protection for the residents of the development, WithersRavenel designed an innovative soil vapor mitigation system that involved the first residential application of an aerated floor system using CUPOLEX® in North Carolina. An aerated floor is effective at controlling vapor intrusion, humidity levels, and temperature ranges; it also eliminates the costs of importing and compacting the fill or gravel typically required to bring a slab to finished grade, grants maximum control over the concrete curing process to prevent curling or cracking, and providing a ready-made space for running cables and pipes. Working with the manufacturer, the M/I Homes design team, the concrete foundation and plumbing contractor, and the City inspections office, WithersRavenel spearheaded the integration of the mitigation system design and the development of best practices for this project.
In addition to extensive environmental support, WithersRavenel assisted M/I Homes through all stages of the land development. When an initial survey of the impervious surface area did not align with earlier records, WithersRavenel did in-depth research of area photos and determined that overgrowth had hidden some of the former paved areas. A second survey after the ground cover was cleared revealed a total impervious surface area of 64.3%. Through judicious planning, WithersRavenel was able to propose a design that reduced the impervious surface area to 53.7%, which obviated the need for active stormwater controls. It also preserved the impervious surface over the critical root zone of many existing trees, thereby complying with the City of Raleigh’s tree conservation requirements while allowed M/I Homes to take advantage of the maximum available area.
Water and sewer service to the new community were originally designed and approved as private facilities, but changes in the Raleigh City Code during the course of project development rendered the design out of compliance. In response, WithersRavenel adapted the original design, converting it to a public system by retrofitting additional connection points to the public water distribution system during construction. Modifying the design in this way saved M/I Homes from considerable expenses and delays while connecting homeowners to Raleigh’s robust utility infrastructure.
To help residents take advantage of the historic scenery, exceptional schools, and thriving local businesses of Five Points, WithersRavenel encouraged a pedestrian friendly design that makes walking to the nearby elementary school or the City park pleasant and safe.
Construction on the first townhome units began in June 2014, and completed units are available for sale. To date, WithersRavenel has performed inspection services for 35 of the proposed 83 townhomes, and will continue to provide sub-slab soil vapor mitigation system inspections until the development is completed.