Monday, February 14, 2011

Gowanus Canal Offers a View into America's Contamination History

by Duane Craig

Visitors to the Gowanus Canal
Perhaps few places are as symbolic of America’s free-wheeling days of massive contamination than the Gowanus Canal in Brooklyn, N.Y. It sits in an area that was pre-industrially low-lying and marshy. Today, lined by empty lots and a mix of empty and occupied industrial buildings, it is now an EPA Superfund site.

According to an account at about the Brouwer family, the area called Gowanus figured interestingly in the Revolutionary War when, in 1776, hundreds of soldiers drowned during Washington’s retreat from Long Island. Called Gowanus Kil in the early days by the Dutch colonists who inhabited the area, it was a bay when the tide was up and otherwise a swamp drained by the creek known as Gowanus. At current day 3rd Avenue and 27th Street in Brooklyn, Adam Brouwer and his two sons ran a gristmill. Adam had previously dug a canal through a sand bar at the mouth of the Gowanus so boats could row up to his mill, thus beginning the area’s industrial heritage.

Over the next 100 years, a canal began developing as successive landholders and city officials saw the economic opportunities inherent in a port. The canal was completed in the 1860s and it stretched from the mouth of the Gowanus northeast almost to Butler Street.

With the canal came a teeming industrial complex made up of tanneries, coal yards, soap makers, paint and ink manufacturers and mills, and eventually included refineries, cement makers, and chemical plants. The waterway allowed easy movement of materials into and out of the area and at one time was considered to be a major international port. Since the 1960s, it has been mainly occupied by concrete plants, warehouses and parking lots.

As early as 1911, the city recognized the problem with pollution in the canal and so it constructed a flushing tunnel that moved fresh water through the canal to replace the stagnant water. According to the EPA, that system worked until the 1960s. By one account, a worker dropped a metal utility cover into one of the fans and that put the flushing tunnel out of commission. The canal returned to being stagnant and the pollution in it continued to rise. It was apparently not uncommon over much of the last century to dig holes and bury drums of chemicals in the soggy earth along the length of the canal. Later the city repaired the tunnel and it still carries fresh water into the canal.

Besides an accumulation of toxic substances in the sediment of the canal over the years, there are other systemic contaminants entering it from the surrounding area. These include untreated industrial wastes, raw sewage, and surface water runoff with its typical load of petrochemicals from vehicles and asphalt. The canal hosts a variety of contaminants according to the EPA:
...polycyclic aromatic hydrocarbons (PAHs), volatile organic contaminants (VOCs), polychlorinated biphenyls (PCBs), pesticides, and metals. PAH concentrations were found to be as high as 45,000 milligrams per kilogram (4.5%) and the contamination was found to traverse the entire length of the canal. Many of the detected contaminants are known carcinogens. The contaminated sediments pose an immediate risk to the fishery located just downstream of the canal in Gowanus Bay. This fishery is well documented, and fish caught there are used as food.

To pay the estimated $400 million in remediation costs, the EPA is looking for potentially responsible parties (PRP) and has homed in on National Grid and New York City. The city, in turn, is looking for PRPs, no doubt to spread the cost out, and that effort also includes National Grid, which is taking the responsibility for contamination by three out-of-business manufactured-gas plants

Read more about this interesting contamination site here and here, and discover more about one of the more dangerous compounds in the canal, here.

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