Historical Water Quality Issues

In reports sent back to Europe, Captain Thomas Young, one of the early European explorers of the Delaware estuary, noted that "the river aboundeth with beavers, otters and other meaner furrs ... I think few rivers of America have more ... the quantity of fowle is so great as hardly can be believed. Of fish heere is plentie, but especially sturgeon." Early colonial advertising copy like this, circulated widely in Europe, presumably inspired Old World colonists to emigrate to the Delaware Valley (Sage and Pilling, 1988). The estuary was abundant with striped bass, sturgeon, shad, oysters, and waterfowl.

Beginning with the Industrial Revolution and the development of the Delaware Valley as a major industrial and manufacturing center in the nineteenth century, waste disposal from increasing population and industrial activities resulted in progressive degradation of water quality and loss of the once-abundant natural resources of the estuary. By the turn of the twentieth century, the American shad population had collapsed. By 1912-1914, low DO conditions were all too common in the Philadelphia and Camden area of the river (Albert, 1997). Sanitary surveys conducted in 1929 and 1937 documented poor water quality conditions in the nontidal reaches of the Delaware from Port Jervis, New York, to Easton, Pennsylvania. During high-flow conditions, black water from the Lehigh River-Easton area would result in closing of the water supply intakes at Trenton, New Jersey (Albert, 1982).

In the tidal river between Trenton and Philadelphia, the discharge of raw sewage from Philadelphia, Trenton, Camden, Wilmington, and other communities, along with untreated industrial wastewater discharges, resulted in gross water pollution of the estu ary. Peak bacterial densities of ~6,000 to 8,000 most probable number (MPN)/100 mL were recorded during the late 1960s and early 1970s in the vicinity of the Philadelphia Navy Yard (RM 90) (Patrick et al., 1992; Marino et al., 1991). Fecal coliform bacteria levels were high as a result of raw or inadequately treated wastewater discharges from the large municipalities. Acidic conditions from industrial waste discharges were observed in the river near the Pennsylvania-Delaware border; pH levels ranged from approximately 6.5 to 7.0 during 1968-1970 in the section of the river from Paulsboro (RM 89) to the Delaware Memorial Bridge (RM 68) (Marino et al., 1991).

During the summer months in the 1940s, 1950s, and 1960s, DO levels were typically approximately 1 mg/L or less over a 20-mile section of the river from the Ben Franklin Bridge in Philadelphia (RM 100) to Marcus Hook (RM 79). Under these anoxic and hypoxic conditions, the urban-industrial river ran black, and the foul stench of hydrogen sulfide gas was a common characteristic (Patrick, 1988). Dock workers and sailors were often overcome by the stench of the river near Philadelphia, and ships suffered corrosion damage to their hulls from the polluted waters. Aircraft pilots landing in Philadelphia reported smelling the Delaware estuary at an altitude of 5,000 feet. Water quality conditions were so bad that President Roosevelt ordered a study in 1941 to determine whether water pollution in the Delaware River was affecting the U.S. defense buildup (Albert, 1982; CEQ, 1982).

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