Water-Related News

Innovative mulch product a win-win for Hillsborough County

Residents benefit from sale of soil supplement comprised of discards

Hillsborough County is combining tons of mulched yard cuttings and biosolids (treated wastewater residue) to create an in-demand soil amendment.

Mixing, curing, and selling the product preserves disposal space at the Southeast Hillsborough County Landfill and will save taxpayers about $1.5 million in hauling, disposal, and other costs over five years. Selling the resulting soil supplement, meanwhile, adds new revenue.

After a successful pilot project, the County is moving forward with the process that makes something valuable out of the former discards. The resulting product protects against plant diseases; helps soil retain nutrients, air, and water; maintains a neutral pH, and builds good soil structure.

It takes about three months for the mixture to cure. County staffers monitor the piles' temperature and moisture content throughout the process.

To protect against rain that could interfere with the curing procedure, Solid Waste recently installed a fixed canopy at the landfill near Balm to cover piles of the combined material.

Yard waste - grass clippings, leaves, tree and bush trimmings, and small stumps - traditionally has been burned to produce electricity, or used for landscaping or cover at the landfill. Treated wastewater by-products, known as biosolids, have been trucked to the landfill for disposal.

The plan to produce and sell compost is the result of a partnership between two County operations - Solid Waste and Water Resources - committed to finding an efficient way to reuse the two types of waste. The product meets stringent federal guidelines and regulations, providing a nutrient-rich material that safeguards consumers, crop production, and the environment.