The Thoughts of a Food Waste Disposer Expert

We just got off the phone with Professor Robert Ham, the co-author of the previously mentioned report on food waste disposers (FWDs). Ham, along with his one-time graduate student Professor Carol Diggelman, is the country’s leading expert on FWDs and their impacts on sewer infrastructure, the environment and a city’s economic costs. He was been involved in this type of research for over 40 years.

We’ve already talked about some of the professor’s conclusions vis-à-vis disposer use but, to reiterate, he believes the FWDs are very beneficial for a city as a part of an overall solid waste removal strategy. Ham mentioned to us that the waste water treatment process is biological which means that the waste is processed by digestive organisms and then turned into the sludge (biosolid) end-product. Corroborating the views of Philadelphia’s Water Department officials, the professor remarked that this process is made much more efficient when extra organic material is deposited through a disposer. Because those digestive organisms love the highly degradable food waste (as opposed, for example, to inorganic chemicals) the resultant biosolid is of a much better quality. Ham added that in a combined system like New York’s the added food waste is even more beneficial because all the rainwater captured in our system dilutes the waste stream, making it very inefficient due to the lack of organic matter.

The Wisconsin University professor also outlined other disposer benefits as compared to other waste removal processes such as landfills and composting. The FWD/Waste Water Treatment plant process is the best for trapping carbon dioxide and methane, not only preventing these gasses from harming our environment but utilizing them as recycled energy. Ham also mentioned that the disposer system, by removing rotting, organic waste from stores and homes, helps reduce the number of rats and other disease-carrying vectors such as mosquitoes. He said, contrary to the DEP’s claims, that the rat population will not be diverted underground because trying to burrow into a vat filled with liquid food waste is not a very attractive option for a rodent.

During our conversation, we learned that Ham’s disposer study is the seminal work in the field and has never been disputed. In fact, it has been used to convince municipalities as well as countries all around the world to reverse bans on food waste disposers. He said that many of these bans are based on misconceptions, and that places like Japan, Korea, Austria and the whole of Scandinavia now allow FWDs, in part, due to his work. Also interesting was that Ms. Diggelman, the professor’s graduate assistant, was chosen because she was adamantly opposed to disposer use. Halfway through their intensive study, Diggelman approached Ham saying that she had been quite wrong about FWDs and, due to their exhaustive evidence, now sees their benefit.

Again we see the vacuity of the DEP’s claims about grinders. The leading expert in the field believes in their various benefits but the agency charged with running NYC’s waste water treatment infrastructure dismisses these claims based solely on its own questionable data and assumptions. In 1995, Dr. Ham testified in front of the City Council and convinced the body that residential grinders merited a pilot program and eventual legalization. We believe that the same will happen with commercial disposers when we hopefully have our hearings later this month.