A few years ago, around 10,000 buildings in New York City were burning the cheapest, heaviest and dirtiest forms of heating oil, known as No. 6 and No. 4. That small percentage of real estate contributed more soot pollution than all the cars and trucks on the streets, the city found, and was a prime contributor to thousands of premature deaths, hospital admissions for lung and respiratory illness, and emergency room visits for asthma each year.

But three years into a four-year plan to phase out No. 6, barely more than half of the buildings that were burning it have switched to cleaner oil. And of those that have stopped using No. 6, hundreds have switched to No. 4, which though permitted for another 16 years, can be only slightly less noxious, depending on the supplier.

Under a 2011 city law, No. 6 will be banned as of July 1, 2015. By 2030, all buildings in the city must use cleaner fuels such as No. 2 oil or natural gas. The expense can be a major obstacle. Converting a boiler to a lighter oil can cost between $5,000 and $17,000, according to several property managers, and in some cases much more, depending on the condition of the burner, tank and oil lines. Switching to natural gas can cost hundreds of thousands of dollars.

Executive Vice President Tal Eyal is quoted on the challenges of complying with New York City's phase out of dirty heating oil in this New York Times article.
Article by The New York Times | Monday April 07, 2014