Therefore, the concentration of PCB in the water column and fish tissue should decline over time through natural attenuation. Contaminated sediments will gradually be covered by newer, uncontaminated material, and chemical breakdown will eventually occur, though at a very slow pace. Natural attenuation may be the best implementation method because it involves less habitat disturbance and destruction. Unlike impoundments, Levittown Lake cannot be drained, so it would be necessary to employ expensive and disruptive mechanical or vacuum dredging to remove sediments. In addition to catastrophic habitat disturbance, dredging would cause resuspension of contaminated material, making PCBs more available for uptake.
Natural attenuation is also the least costly option.