Newtown Creek, a 3.5-mile (6-kilometer) a long estuary that forms part of the border between the boroughs of Brooklyn and Queens, has been designated a Superfund site for environmental clean-up and remediation of the waterway's recreational and economic resources for many communities. One of the most heavily used bodies of water in the Port of New York and New Jersey, it had been one of the most contaminated industrial sites in the country, containing years of discarded toxins, an estimated 30 million US gallons (110,000 m3) of spilled oil, including the Greenpoint oil spill, raw sewage from New York City's sewer system, and other accumulation.
Try to answer this question if possible (otherwise reply "unanswerable"): How long is Newtown Creek in kilometers?
6