Getting Out the Sludge at the DEP

Who would have ever thought it possible? The NYC DEP is beginning to get the sludge out of its policy making process to suggest some innovative responses to waste disposal. The NY Times has the startling story: "New York City’s sewage presents a daunting and costly challenge: it creates foul odors and often contaminates waterways. But the city is now casting its sewage treatment plants and the vast amounts of sludge, methane gas and other byproducts of the wastewater produced by New Yorkers, as an asset — specifically, as potential sources of renewable energy."

About time-as we have been arguing for years, the disposal of food waste could become a valuable resource, either from composting, or from its use in a waste to energy process. And the University of Florida agrees in its discussion of biogas: "Through diverting food waste from landfills to anaerobic digestion, two beneficial products are produced. Biogas can be used on-site to remediate energy costs or sold to the grid. Biofertilizer can be sold to farmers and gardens or used on-site for gardens and landscaping. Food waste will no longer be thought of as a waste, but a resource to generate additional revenue."

And our land fills will  become less toxic: "A major source of this organic material in landfills is food waste, and by diverting food waste, methane emissions can be significantly reduced. In addition to methane, food waste in landfills can cause nutrient problems in leachate and odor and vermin problems, along with taking up unnecessary space in the landfill."

As we have also argued, the reduction of food waste at its source-in the city's restaurants, green grocers, and supermarkets, is a major cost savings and will promote the greater economic viability of these businesses. U of  F agrees with us: "Hauling and landfilling food waste represents a direct cost to businesses and many external costs to society with no economic benefits."

Which is why we have been advocating the use of commercial food waste disposers for the better part of a decade-and hitherto fore without any cooperation from the DEP, which has held fast against the disposer concept. Things appear to be evolving, however-as the Times points out: "For the city’s Department of Environmental Protection, which is to issue its strategy on Wednesday, it is a shift. Until now, the agency has mainly played the role of water utility and environmental steward rather than energy producer. But like other cities around the country looking to reduce both the costs of sewage treatment and disposal and the heat-trapping greenhouse gases emitted in the process, New York is beginning to look at its waste as an untapped resource."

The DEP is moving in the direction suggested by the university: "City officials, who hope to have a contract by 2013, said the solid could be harvested for gases that produce clean energy and could be used in more traditional ways, too, as fertilizer or as paving and building materials. The biggest potential source of energy, officials said, is the methane gas from sewage treatment plants’ digesters. About half of the methane produced by the city’s plants is already used to meet about 20 percent of the energy demands of the city’s 14 sewage plants, whose electric bills run to a total of about $50 million a year. Now the city wants to market the other half, which is burned off and wasted."

If this is pursued correctly, it could become a major breakthrough in the city's solid waste management strategy-currently stalled because of an inability to economically raise the current paltry recycling rates. But in order to truly maximize this energy producing resource, the city will need to enhance its accumulation of food waste-and here's where food waste disposers come in on both a commercial as well as residential level.

Even the NRDC is on board with the change: "If what you’ve got is lemons, of course you try to make lemonade,” said Eric. A. Goldstein, a lawyer with the Natural Resources Defense Council in New York who monitors the environmental agency. “It’s taking existing infrastructure and outfitting it to help solve other city problems.”

The potential here is enormous-and not only for energy production. If we can divert food waste on all levels we can further reduce the contamination of the rest of the garbage-making source separation and recycling that much more efficient and economical. In the process-and of crucial importance in these cost cutting times-we can reduce the number of  costly waste transfer stations needed to process the city's solid waste.

The elimination and diversion of food waste at the source also has other environmental and public health benefits-rodent and insect reduction through the elimination of their food supply. As we pointed out last year: "It is time for the city to admit its mistakes on the issue of commercial food waste disposers. The current rat and bed bug epidemic underscores just how imperative it is for NYC to become more innovative and less hidebound in this crucial area of organic garbage. If it does, we will see a dramatic improvement of city recycling and neighborhood public health-and an equally dramatic reduction of garbage exporting. It's past time for the city to start thinking outside of the garbage can."

It looks as if that is exactly what is happening. What the DEP is proposing is a seismic shift that should lead to a full re-evaluation of the city's SWMP-a shift that will, if properly implemented, reduce costs while increasing the levels of recycling way beyond current possibilities. The potential tapping of waste for additional energy sources makes all of this a win, win, win scenario-and we need to start to implement these changes right away.

We'll give the University of Florida the last word: "Food waste will no longer be thought of as a waste, but a resource to generate additional revenue. Food is one of the most essential elements for life, and therefore we should have an ethical and moral obligation not to waste it. With all the issues of unsustainable agriculture and global hunger, we should not be needlessly throwing good food into the landfill. Therefore we must simultaneously reduce the food waste that is produced while putting to good use that food that is not consumed."