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2.3E+ 05 kg/day

Sources: Data in table taken from Brosnan and O'Shea, 1996a is modified from HydroQual (1991), based on data from the late 1980s. Note: Values in a row may not equal 100% because of rounding.

"Other = combined loading from industrial discharges, landfill leachate, and direct atmospheric deposition.

Sources: Data in table taken from Brosnan and O'Shea, 1996a is modified from HydroQual (1991), based on data from the late 1980s. Note: Values in a row may not equal 100% because of rounding.

"Other = combined loading from industrial discharges, landfill leachate, and direct atmospheric deposition.

the pollutant considered. Combined sewer overflows, for example, account for only 1 percent of the total freshwater input to the harbor but contribute 89 percent of the total loading of fecal coliform bacteria (Brosnan and O'Shea, 1996a). Effluent from water pollution control plants contributes about one-half to three-quarters of the total load of BOD5 and nutrients, while watershed runoff via tributaries accounts for 80 percent of the total suspended solids (TSS) load. Table 6-3 presents a summary of the distribution of effluent flows from municipal water pollution control plants (WPCPs) and industrial point source discharges to New York Harbor waterways (HydroQual, 1991; O'Shea and Brosnan, 1997). As presented in Table 6-3, approximately 2,500 mgd of treated wastewater was discharged in 1995 from 81 water pollution control facilities located in New York City, six New Jersey coastal counties, two coastal Connecticut counties, and Westchester and Rockland counties in New York (O'Shea and Brosnan, 1997). Of the total 2,500 mgd, facilities operated by the City of New York accounted for 1,490 mgd in 1995.

Long-term water quality records for most locations within the estuary clearly illustrate degradation from population growth and inadequate sewage treatment through the mid-1960s and gradual improvement following construction of wastewater treatment plants and implementation of secondary treatment. Using historical data collected at 40 stations in the harbor from 1968 to 1993, an analysis of harborwide long-term trends clearly documents more than an order-of-magnitude improvement in total coliform and fecal coliform concentrations (Figure 6-17). The dramatic decline in bacterial levels is attributed to water pollution control infrastructure improvements that eliminated raw sewage discharges and upgraded all water pollution control plants to include disinfection by chlorination (O'Shea and Brosnan, 1997). Other improvements, reductions of approximately 50 percent in bacterial levels for most areas of the

TABLE 6-3 Distribution of Wastewater Flows into New York Harbor Waterways

WPCPs Direct Industrial Discharges

TABLE 6-3 Distribution of Wastewater Flows into New York Harbor Waterways

WPCPs Direct Industrial Discharges

Waterway

Flow (mgd)

% Total

Flow (mgd)

% Total

Hudson River

0 0

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