Before discussing the impacts, it is important to relate the genesis of Philly’s disposer decision. According to Mr. Healy, a native New Yorker who has been with his unit since the late 1960s, the Streets Department (which handles both water and sanitation services) became increasingly concerned with the public health threat of putrescible food waste being thrown into dumpsters. Not only did the juices from the rotting fruits and vegetables leak onto the street but rodents and other vermin were attracted to the refuse. As Healy mentioned to us in a phone interview:
There was an obvious public health benefit to the program so we [the Water Department] saw no reason to object.Therefore, in the mid 1990s, Philadelphia passed the aforementioned law to remedy a public health menace and, based to our conversations, the legislation has been successful to that effect. But the question of impacts still remains. Remember, the New York City Department of Environmental Protection (NYC DEP), along with a number of environmental groups, concede that there are some benefits but still largely oppose commercial grinders because, they say, the negative environmental impacts outweigh any benefits. Again, let’s look to Philadelphia for guidance.
When asked about the possible negative effects of grinders, Deputy Commissioner McCarty responded that her department has witnessed no such consequences. In fact, according to McCarty water use has not increased noticeably, increased nitrogen loads are not a problem, sewer pipes have not been adversely affected and the waste water treatment plants are still operating efficiently, removing 95% - 98% of suspended solids. As for the question of whether grinders will lead to increased sewer overflows (CSO), the Commissioner said that CSOs are a problem for a system like Philadelphia’s (and therefore New York’s) but that grinders have very little bearing on the issue.
Both McCarty and Healy also mentioned the benefits of the grinder mandate in terms of recycling. After the waste is shipped via the water stream and processed at a treatment plant it is turned into a recyclable biosolid. Philadelphia uses/sells this end product for composting, soil enrichment, mine reclamation and a variety of other uses. Healy specifically pointed out that that a higher percentage of organic material in the waste stream results in a better quality, more valuable biosolid.
Almost as interesting as the benefits (and lack of negative impacts) of disposers is the fact that no one from the NYC DEP has bothered to contact Philadelphia about its experiences. Despite the fact that Philly has a similar sewer system, the DEP has not reached out to either Healy or McCarty. It seems the agency is so steadfastly opposed to the use of commercial grinders that it isn’t going to let facts or real world data from other cities interfere with its predetermined conclusions.
It also appears that so-called environmentalists, such as the NRDC’s Eric Goldstein, are basing their strident resistance to a commercial disposer pilot program on less than sturdy grounds. The Philadelphia example demonstrates that many of the environmental concerns are unfounded (as the DEP also demonstrated in its report on residential disposers), and that, at the very least, the impacts of commercial grinders should be tested in NYC. If the NRDC and other such groups are so confident about their dire predictions then why are they opposing a pilot that would test them? Is it, perhaps, that these apocalyptic assertions are based on flimsy or non-existent evidence? Is it, perhaps, that in the end the pilot will show that commercial grinders will not only have a de minimis impact on the sewers but will also greatly benefit the city in terms of public health and cost efficiency?
Philadelphia’s Deputy Commissioner McCarty sums up it best. After mentioning to her the objections to grinders among certain NYC environmental groups she responded:
I consider myself an environmentalist and in my opinion – I have a PhD in environmental engineering and have been working in this field for over 20 years – it is environmentally more responsible to send our waste through the sewer than to a landfill.Hopefully, all relevant New York City elected officals and agencies will realize this as well and allow for the expeditious passage of the commercial grinder pilot program, Intro 742.