Duffield Associates participated in the construction of the first two cells of a new municipal solid waste Class 1 landfill facility encompassing an initial geosynthetic lined footprint area of 30 acres plus ancillary support facilities.

acms2This landfill is being constructed in karst terrain where sinkholes are problematic.  Most states will not permit any landfill project to be situated in karst, adding to the uniqueness of this project in our experience.  Essentially the landfill is being constructed on beach sand which deflects under foot traffic, similar to walking at the beach, with occasional intercepts of the native limestone bedrock.

Duffield Associates’ role was to provide resident GCI (Geosynthetic Certification Institute) certified technicians (as required by the site permit and Florida DEP regulations) to lead and manage the field team during the installation of all geosynthetics including dual geomembranes, a geosynthetic clay liner and geocomposite layers..  Our team was also involved with the installation of all leachate collection and management facilities including piping, pumps and slope riser conveyances.  We were acms1a sub consultant to Civil Design Services, the Florida based CQA firm responsible for certifying the overall project construction.

This was a 4-month-long project that included significant rain delays as the year’s tropical storm season arrived early in Florida.  A solution channel was discovered within the rock of one of the deep cell sumps which prompted much discussion and concern, and was ultimately remediated utilizing a grouting program.

Further exacerbating the project construction, Tropical Storm Debbie rolled thru the Gulf in June 2012 and dropped 15” of rain at the site within a 48-hour period creating 30 acres of impounded storm water as deep as 15 feet in some portions of the site.  Two 6” pumps were operating round the clock and could not keep up.  Perimeter berms were overtopped in some regions and storm water canals looked like moats.  The entire 30 acres of the site had been lined with the initial 2 layers of geosynthetics just prior to the storm hitting.  Fortunately, the site weathered this storm with  no damage to the liner system nor evidence of water under the liner to saturate/hydrate the GCL and erode the subgrade.