Cleghorn Farms

Closure of Dairy Waste Storage Ponds (WSPs)

As a part of the South Florida Water Management District’s effort to reduce nutrient loadings into Lake Okeechobee, Cleghorn Farms’ dairy operation was bought out in 1992.  After the dairy was closed, the site was converted to a sugarcane farm.  For twenty years, the dairy barns and WSPs remained unused.  Wastewater in the WSPs remained high in phosphorus and nitrogen.

RCS provided engineering services, permitting services, nutrient management and construction management services for the closure of two dairy WSPs.  RCS obtained an environmental resource permit exemption from the Florida Department of Environmental Protection for this work pursuant to Section 373.406(9), Florida Statues.  RCS designed a temporary irrigation system that allowed the nutrients in the wastewater to be land applied to Cleghorn Farms’ sugarcane fields.  This allowed the wastewater to be removed from the ponds while following NRCS standards. 

As the ponds were being dewatered, all solid waste in the ponds was removed and land applied at agronomic rates.  After all waste was removed from the ponds, the ground water that refilled the ponds and the ponds bottom were treated with aluminum sulfate (alum) to bind any remaining soluble phosphorus.  The dosing rate of alum to the ponds was established by a series of jar tests to obtain the minimum phosphorus concentration.