Believe it or not, there’s an environmental argument in favor of the lowly in-sink disposal. Seems that grinding up your food waste and sending it to the local water treatment plant acts like a municipal compost pile.
The organic materials that end up in your trash bucket eat up energy by adding to the load trucked to the landfill site. At the landfill, they decompose into methane, a much more potent greenhouse gas than carbon dioxide. Another decomposition by-product is an acidic leachate that can find its way into local groundwater. They decompose at a different rate and the organic gas they produce is difficult to capture for re-use.
Food waste is about 70% water, so it makes sense to grind it and send it to the wastewater treatment plant where the water can be extracted, and the remaining solids can be treated for soil conditioner and fertilizer.
For those homes with private waste disposal systems one manufacturer, InSinkErator, offers a treatment and specific septic model of disposer, the Evolution Septic Assist (left) that helps the solids to decompose easier. Disposals have evolved recently to provide a quieter motor and easier installation, as well.