City investigators have tracked down the source of a maple syrup smell that has puzzled New Yorkers several times in recent years. No offense, New Jersey, but it was you.
The harmless but long-confounding smell, which has drifted through swaths of the city at least nine times since 2005, was traced to a facility across the Hudson River that processes seeds for use as artificial flavorings.
Mayor Michael Bloomberg said that a team of odor investigators — environmental protection, health department and emergency management workers — "put our noses to the ground" to identify the culprit after another whiff in early January.
The investigation involved mapping the time and place of all the odor complaints to the city's 311 hot line, data that were then compared with wind and atmospheric conditions. Those were checked against air sampling tests during the periods that New Yorkers reported smelling the odor.
Bloomberg said the odor has been detected by New Yorkers only a small number of times because the conditions apparently had to be quite specific.
Conditions had to be right
"You have to have a day with winds at the right speed, going in the right direction, and high humidity, but no rain," he said.
Officials found that the highest concentration of calls often came from the Upper West Side of Manhattan, and that the odor reports tended to come on days when wind speed was moderate — fast enough to carry odors but slow enough that they were not immediately dispersed.
Investigators also found that the wind on the days in question generally moved from west to east, and narrowed the search to facilities in New Jersey that process food additives and fragrances.
The probe found that one facility in Hudson County was processing fenugreek seeds on the evening of Jan. 29, when multiple odor complaints came in. Fenugreek is a common ingredient in curry powders, and its extract is also used in artificial vanilla, caramel, butterscotch and maple flavorings.
New Jersey and city officials say the facility, operated by a company called Frutarom, does not appear to be violating any rules or regulations. The mayor said it was possible that other such facilities in the area were also responsible.
"We are officially closing the case," Bloomberg said.