MSW-Ash Field Study: Achieving Optimal Disposal Characteristics

The principles of proper site management, including adding the optimum water of solubilization and attaining optimal compaction, are applied to test patches subject to portland cement and quicklime (CaO) in-situ additive treatment. Processed and compacted municipal-solid-waste (MSW) ash achieved in-place compacted dry density of 113.31 lb cu ft (1,830kg/m3) and compacted wet density of 134.82 lb cu ft (2,180kg/m3). Field testing yielded permeabilities between 10-6cm/s and 10-9cm/s, after 14-28 days curing, determined by laboratory (room temperature and humidity) and field (New England-winter temperatures) measurements. The results of prior laboratory investigations confirmed portland cement and CaO treatment of MSW ash. Adding CaO achieved an order of magnitude reduction in permeability, suggesting a concrete-like behavior of MSW ashes. Assuming a worst-case 10% portland cement addition for in-situ additive treatment, applied by an outside specialty contractor, savings of $200,000-$450,000 per acre ($494,000-$1,110,000 per hectare) could be realized compared to the single, double, synthetic, and clay liners currently under review for MSW-ash monofill implementation. Pending legislation fails to consider such properties and concrete-like behavior and fails to recognize the application of engineering management principles.