Figure 23.7. Fecal coliform bacteria trends (as summer geometric means) in the Hudson River in the Albany Pool near Glenmont, NY and off of 42nd St., Manhattan, NY. Albany Pool data represent 6-8 samples per summer, except for 1975, 1976, and 1987-92 which represent 4 or less samples per summer. Data collected off of Manhattan represent 8-14 samples per summer. The NYS Primary Contact or "Swimming" Standard of 200 cells per 100 ml and Secondary Contact Standard (e.g., for wading, boating, fishing) of 2,000 cells per 100 ml are also depicted.
York City's WTPs by 1985 (personal communication, Diane Hammerman, NYCDEP). Disinfection reduces wastewater concentrations dramatically, for example, the average discharge from New York City WTPs in 1998 was less than 150 cells/100 mL (NYCDEP, 1999). In response, fecal coliform levels off of Manhattan have declined by two orders of magnitude from almost 10,000 cells/100 mL in the mid-1970s to less than 100 cells/100 mL in the 1990s (Fig. 23.7). The most significant decline occurred after the North River and Red Hook WTPs achieved primary treatment in 1986 and 1987, respectively. Further declines in coliform bacteria levels in the lower Hudson have been achieved by additional improvements in the operation of NYC's sewage collection system that has reduced bypassing by 96 percent, abated over 9,500 m3 d-1 of illegal discharges harborwide, and reduced the incidence and volume of combined sewer overflow (CSO) discharges (Brosnan and Heckler, 1996). The result is that by the mid-1990s, average summer fecal coliform levels off of Manhattan were estimated to meet the New York State swimming standard (Fig. 23.7).
Note, however, that data collected shortly after rain events show that coliform concentrations increase significantly due to CSOs (Brosnan and Heckler, 1996). Many older cities in the country, including many cities along the Hudson in New York and New Jersey, have combined sewer systems, that is, sewers that convey household and industrial waste to WTPs during dry weather, as well as surface water runoff during rain events. When runoff flows exceed the hydraulic capacity of the WTPs, a mixture of untreated sewage and urban runoff is discharged to the local waterways. CSO discharges have been estimated to contain 3.5 million fecal coliform cells/100 mL and are responsible for over 95 percent of the current coliform load to New York Harbor (NYCDEP, 1999). In the lower Hudson, CSOs can cause fecal coliform concentrations to increase from less than 100 cells/100 mL to over 2,000 cells/100 mL (NYCDEP, 1999). CSOs are also responsible for 85 percent of the floata-bles load, with an average of 1.5 million floatable items (primarily plastic street litter and less than 1 percent sanitary or medical waste) discharged each month into New York Harbor from surrounding communities in New York and New Jersey (Leo, St. John, and McMillan, 1992).
Improvements in the sanitary quality of the Hudson River have led to increased human use of the resource. In lower New York Harbor, over 67,800 acres of shellfish beds have been upgraded since 1985, including removal of restrictions on 30,000 acres off the Rockaways for direct harvest and in
Raritan Bay for a site relay program in the late 1980s (USEPA, 1996). Seagate Beach on Coney Island reopened in 1988 for the first time in forty years and South Beach and Midland Beach on Staten Island reopened in 1992 for the first time in twenty years (Brosnan and Heckler, 1996). Wet weather advisories were also lifted at seven of ten New York City public beaches and the wet advisory was reduced at the other three. Closures of beaches in New York City and New Jersey due to floatables have been virtually eliminated since the early 1990s.
Examples of recovered human uses in the middle Hudson include the town of Bethlehem tapping an aquifer fed by the Albany Pool for drinking water in 1996 and the reopening of Croton Point Beach in Westchester County for the first time in a decade (Stevens, 1996). The NYSDEC classifies the "Best Usage" of the river as swimmable from northern Columbia County to Manhattan and a series of public meetings were held to discuss the feasibility of developing additional public swimming sites in the Hudson River Estuary (NYSDEC, 2000).
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