Catch basin program helps prevent pollution

To help prevent floatables from littering area waterways and beaches, New York City’s Department of Environmental Protection (DEP) initiated a city-wide catch basin inventory and hooding program. The program’s goals are to replace or repair missing and damaged hoods. Repair work began in 1996.

The hoods were created to help catch the lightweight litter, or floatables, that wash into the sewers during rainstorms and float through to the ocean. Floatables are mainly a problem during wet weather, when 80 percent of the flow from the city’s sewers bypass treatment facilities.

All of New York’s catch basins were designed for hoods, but some of the hoods were damaged over the years, and others were detached or disappeared. Meanwhile, new sewers were added to the system, and, by the mid-1980s, the city was unsure how many catch basins it had. Therefore, before the repairs could begin, the city had to conduct an inventory.

The inventory and hooding projects for New York City catch basins were incorporated into a Combined Sewer Overflow Abatement consent order between the state and city. HydroQual, Mahwah, N.J., which had performed a city-wide floatables study beginning in 1989, was hired for the inventory.

The company then subcontracted with Hansen Information Technologies, Sacramento, Calif., to create a database with catch basin information and connect it to a GIS. That would provide an interactive automated mapping/facilities management system for the city.

The basic inventory is complete, but the mapping will continue beyond winter 2000. The city originally estimated that it had 100,000 basins, but 130,000 have been located. The city is replacing and repairing hoods, and it is scheduled to complete that phase of the project next summer, DEP Commissioner Joel Miele says.

Catch basin hooding is one of several techniques the city is using to control floatables pollution. The city also has installed booms or floating barriers at 23 locations where combined sewers discharge. Smaller DEP skimmer vessels maintain the sites, and floating debris in open waters is removed by a 118-foot skimmer vessel.