The Gowanus Canal in Brooklyn became operational in the late 1860’s. Because of age, system failures and the increasing costs of constant maintenance, the New York City Department of Environmental Protection (NYCDEP), has taken steps to improve the infrastructure of the area by retaining D&B to design the needed improvements. NYCDEP is in the midst of a $140 million, 4 year construction project that will result in lower volumes of combined sewer overflows in the canal, less floatable debris and higher oxygen levels in the water.
One of the major construction areas involves closing the Gowanus Flushing Tunnel for 24 months to allow for renovations. The flushing tunnel brings higher quality water into the Gowanus Canal to avoid hypoxia. Before this closure could be accomplished, an alternate way of supplying oxygenated water to the canal needed to be developed. The use of standard aeration techniques were considered but rejected because of the potential for odor problems, disturbance of contaminated sediment and canal obstruction caused by the aeration system. The D&B staff designed an innovative oxygen transfer system (OTS), which uses pure oxygen to provide the necessary oxygen delivery to the canal.
Water is drawn from the head of the canal and sent into a chamber where it is supersaturated with pure oxygen by means of a proprietary oxygen dissolution process. The oxygenated water is then evenly distributed throughout the upper end of the canal through a 2,500 foot long submerged pipe which contains flow distribution nozzles. The pure oxygen is created on the site by the use of a pressure swing adsorption system, which separates nitrogen and oxygen from the air. The OTS has been operational for a month and measurements show the canal water having higher levels of oxygen than supplied by the flushing tunnel, during one of the warmest months in recent history. Visually, the canal’s appearance has noticeably improved.
Congratulations to the D&B team which includes Garrett Byrnes, Dennis Koehler, Roger Owens, Joe Baader and Michele Mastrangelo. If you want more information on this innovative aeration system or have a project where additional oxygenation is required, contact Bob Chlupsa at 516-364-9890, ext 3031.