Figure 6-18 Long-term trends of DO saturation (summer average) at 42nd Street in the Hudson River. Triangle markers identify years of upgrades for Yonkers WPCP (1932, 1934, 1960, 1979) and North River WPCP (1986, 1993). Source: Brosnan and O'Shea, 1996a.

Figure 6-18 Long-term trends of DO saturation (summer average) at 42nd Street in the Hudson River. Triangle markers identify years of upgrades for Yonkers WPCP (1932, 1934, 1960, 1979) and North River WPCP (1986, 1993). Source: Brosnan and O'Shea, 1996a.

Figure 6-19 Long-term trends of DO saturation (summer average) at Baretto Point (Station E5) in the Upper East River and at 23rd Street (Station E2) in the Lower East River. Source: O'Shea and Brosnan, 1997.

Figure 6-20 Long-term trends in summer mean inorganic nitrogen. Data represent harbor-wide composite of 40 stations monitored since at least 1970. Source: NYCDEP, 1999.

Figure 6-20 Long-term trends in summer mean inorganic nitrogen. Data represent harbor-wide composite of 40 stations monitored since at least 1970. Source: NYCDEP, 1999.


Figure 6-21 Long-term trends in summer mean BOD5. Data represent harbor-wide composite of 40 stations monitored since at least 1970. Source: O'Shea and Brosnan, 1997.

Although not generally appreciated, the poor water quality conditions, particularly low DO levels, that characterized New York Harbor for most of the twentieth century actually had a beneficial effect for shipping activities, since wooden pilings and other submerged wooden structures were not destroyed by pollution-intolerant marine borers. During the nineteenth century, before water quality had deteriorated in the harbor, abundant populations of shipworms (teredos) and gribbles (limnoria) quickly devoured driftwood (naturally occurring) and wooden pilings (man-made). This natural ecological activity probably kept the harbor clear of driftwood, but created severe problems for commercial shipping interests, since untreated wooden pilings needed to be replaced after only about 7 to 10 years (Port Authority of New York, 1988). As water pollution problems increased in the harbor, populations of marine borers declined to such a level that, ironically, wooden pilings and other submerged wooden structures were preserved for many years while submerged in the noxious, oxygen-depleted waters laden with oil, bilge waste, and toxic chemicals. The dramatic improvements in water quality conditions in New York Harbor, as well as other East and West Coast harbors, have resulted in a resurgence of thriving populations of marine borers since the mid-1980s (Gruson, 1993) (Figure 6-22). The population boom of marine borers has resulted in severe infestation and rapid deterioration and collapse of wooden pilings and other submerged wooden structures in New York Harbor from JFK International Airport to New Jersey, including Brooklyn, Staten Island, and the east and west sides of Manhattan (Randolph, 1998; Abood et al., 1995; Metzger and Abood, 1998; Schwartz and Porter, 1994).

Figure 6-22 Trends in marine borer activity in Upper New York Harbor. Source: Port Authority of New York, 1988.

Over the past several years, advanced hydrodynamic and water quality models have been developed for water quality management studies of the harbor, including New York City's Harbor-Wide Eutrophication Model and, most recently, the System-Wide Eutrophication Model (SWEM) (HydroQual, 1995a, 1996, 1999). Earlier models, developed for USEPA's 208 Study of the harbor (Hazen and Sawyer, 1978; Higgins et al., 1978; Leo et al., 1978; O'Connor and Mueller, 1984), have been used to assess the impact of secondary treatment requirements on DO in the harbor.

The more recent New York City models, employing improved loading estimates and modern hydrodynamics (Blumberg et al., 1997), are being used to determine the feasibility and effectiveness of management alternatives for New York City point sources of nitrogen. For example, SWEM will enable New York City to evaluate options, as part of the facility planning for the Newton Creek water pollution control plant, the last remaining plant operated by the City of New York to be upgraded to secondary treatment (HydroQual, 1999). This model is further assisting the New York-New Jersey Harbor Estuary Program in understanding the complex relationships between physical transport processes, nitrogen loading, algal biomass, and DO in New York Harbor, the New York Bight, and Long Island Sound (HEP, 1996).

Recreational and Living Resources Trends

Since 1968, the New York City Council has required the New York City Department of Public Health to notify the Department of Parks of beaches that pose a potential health risk to the public. Such beaches were traditionally posted with wet weather advisories, following occurrences of heavy or prolonged rainstorms. These postings have long been replaced with seasonal wet weather advisory postings. The advisories are based upon the occurrence of high coliform concentrations, which may indicate the presence of raw or partially treated sewage and the likely presence of waterborne pathogens. Diseases associated with recreational swimming waters include typhoid fever, gastroenteritis, swimmer's itch, swimmer's ear, and some viral infections such as infectious hepatitis (NJDEP, 1990).

The most important source of pollution, contributing about 89 percent of the total fecal coliform bacteria load to the harbor, is wet weather CSOs (Brosnan and O'Shea, 1996a). Large volumes of water generated during rainstorm events, when combined with the regular volume of sewage, overwhelm the capacity of the collection system and discharge the mixture of storm runoff and raw wastewater directly into the harbor. During wet weather events, water quality may be seriously degraded.

Before 1900, untreated wastewater caused severe outbreaks of disease associated with exposure pathways by shellfish consumption and recreational swimming. Conditions improved somewhat as sewage treatment plants adopted primary treatment as a practice to settle out the solids in wastewater before discharge to the harbor. Pathogen reduction was further enhanced by upgrading water pollution control facilities to secondary treatment with chlorination of the effluent for disinfection. Improvements in municipal wastewater treatment practices have significantly reduced the incidence of waterborne disease outbreaks. Typhoid fever, once a serious swimming-related disease, for example, has not been reported in the last 30 to 40 years (NJDEP, 1990).

During the 1970s and 1980s, significant efforts were made to construct and upgrade water pollution control plants in the Hudson-Raritan Estuary to attain secondary levels of wastewater treatment as mandated by the 1972 Clean Water Act. With upgrades and chlorination of effluent, the discharge of raw wastewater to the entire Hudson-Raritan estuary has been reduced from 450 mgd in 1970 to less than 5 mgd by 1988 and essentially zero by 1993. The most dramatic improvement in bacterial conditions in the harbor occurred in 1986 with the completion of the North River water pollution control plant in Manhattan. Before construction of the primary facility, 170 mgd of raw sewage was discharged into the Hudson River from 50 outfalls on the west side of Manhattan (Brosnan and O'Shea, 1996a). Treatment of the raw sewage and year-round disinfection resulted in a dramatic decline in fecal coliform concentrations. The 1986 data revealed a 78 percent decrease in the fecal coliform concentrations in the Hudson River compared to values measured in 1985 before the primary plant came on-line. When the 45-mgd Red Hook water pollution control plant went on-line in 1987 in Brooklyn, abating the raw sewage discharge from 33 outfalls, fecal coliform concentrations in the East and Lower Hudson Rivers declined by 69 percent within 2 years. Continued improvements in water quality and decreases in fecal coliform bacterial concentrations on the order of 50 percent from 1989 to 1995 are attributed to improved maintenance and surveillance of the sewage treatment system. Management actions that have contributed to these improvements in water quality include abatement of illegal connections, reduced raw sewage bypasses from dry-weather malfunctions of pumping stations and sewage regulators, and increased capture of combined sewage during rain events (Brosnan and O'Shea, 1996b).

"Snapshots" of the distribution of total coliform bacteria from 1972 to 1995 in surface waters of the harbor (Figure 6-23) clearly document the significant reductions in bacterial concentrations that resulted from implementation of controls to reduce water pollution in the harbor. Following completion of the North River and Red Hook water pollution controls plants in 1986 and 1987, respectively, total coliform distributions in 1988 demonstrated significant improvements compared to 1985 before these two plants came on-line. The improvements attributed to CSO controls and reduction of the volume of raw sewage bypasses are also quite apparent with total coliform levels in the harbor declining by more than 50 percent at 45 of 52 stations in 1995 and compliance with water quality standards improving from 87 percent in 1989 to 98 percent in 1995 (Brosnan and Heckler, 1996).

Historically, many public bathing beaches in Lower New York Harbor have been closed to swimming to protect public health because of high bacterial levels that consistently violated water quality standards of 2,400 MPN/100 mL (total coliforms) and 200 MPN/100 mL (fecal coliforms) for primary contact. As a result of the construction and upgrade of water pollution control plants in the harbor, the capture of combined sewage and the reduction of raw sewage bypasses, the significant harborwide reductions in coliform bacteria levels (see Figure 6-17) allowed the reopening of public beaches that had been closed for decades. In 1988, Seagate Beach on Coney Island was opened to swimming for the first time in 40 years. South Beach and Midland Beach on Staten Island, closed since the early 1970s, were opened for swimming in 1992.

In July 1997, the New York City Department of Environmental Protection initiated

□ <70 13 71 -2400 ■ 2401 -10000 ■ > 10000 □ NOT MEASURED

MYS Standard»: < TO MPN/100ml = SA(ShelKtsMng); 70 - 2,400 MPN/100ml = SB(Bathlng); 2,400.10,000 MPN/100ml = ((FIshina)

(NOTE: This analysis does not necessarily imply compliance.)

□ <70 13 71 -2400 ■ 2401 -10000 ■ > 10000 □ NOT MEASURED

MYS Standard»: < TO MPN/100ml = SA(ShelKtsMng); 70 - 2,400 MPN/100ml = SB(Bathlng); 2,400.10,000 MPN/100ml = ((FIshina)

(NOTE: This analysis does not necessarily imply compliance.)

Figure 6-23 Total coliform trends in surface waters of New York Harbor. Summer geometric means for 1972, 1985, 1988, and 1995. Source: Brosnan and Heckler, 1996. Copyright © Water Environment Federation, Alexandria, VA. Reprinted with permission.

the Enhanced Beach Protection Program as a response to beach closings caused by a major failure of a pump station and the discharge of raw sewage into western Long Island Sound. Since 1997, the Enhanced Beach Protection Program has succeeded in significantly reducing the occurrence and duration of raw sewage bypasses resulting from operational failures of the conveyance system of 90 pump stations and 490 sewage overflow regulators (Oliveri et al., 2001); no beaches have been closed because of collection facilities bypasses (Loncar, 2002). As a result of management actions, other than the Enhanced Beach Protection Program, implemented by the City of New York to improve the surveillance, maintenance and operation of pump stations and sewage overflow regulators, the volume of raw sewage bypasses from operational failures has been reduced by over 96% from 1,845 million gallons per year as of 1989 to 61 million gallons per year as of 1998 (NYCDEP, 1999).

In addition to beach closings because of high bacterial levels, recreational beaches are also closed because of strandings of floatable debris on the beaches. Floatable debris includes ordinary trash washed off from city streets and illegally disposed medical waste such as hypodermic syringes and blood bags. As a result of increased abatement and control of discharges of floatable debris, beach closings in New York and New Jersey were greatly reduced during the 1990s. Except for 1998 when Rock-away Beach was closed for a day because of medical waste, no beaches in New York City have been closed because of floatables since 1989 (Brosnan and Heckler, 1996).

In addition to closing bathing beaches, the presence of pathogens and pathogenic indicator organisms directly impacts shellfish resources. Because pathogen levels were significantly reduced by improved wastewater treatment and year-round chlori-nation, 67,864 acres of shellfish beds in the estuary have been upgraded since 1985, including removal of seasonal restrictions for 16,000 acres in the New York Bight in 1988, and 13,000 acres in Raritan Bay in 1989 (Gottholm et al., 1993; NJDEP, 1990). Additionally, 1,000 acres of shellfish waters in the Navesink River are being considered for upgrading to a "seasonally approved" classification (HEP, 1996). Shellfish resources to a greater extent than finfish populations are directly related to improvements in wastewater treatment (Sullivan, 1991).

Although the long-term trends in the abundance of fish such as American shad and striped bass in coastal waters may be the result of degraded water quality (Summers and Rose, 1987), the National Marine Fisheries Service has indicated that overfishing, rather than changes in water quality, is probably the most significant cause of present changes in resource abundance for many species (Sullivan, 1991; Summers and Rose, 1987). The principal commercial fishery of the lower Hudson River estuary is for American shad. Shad landings from 1979 to 1989 were maintained, whereas landings of whiting, red hake, scup, and weakfish decreased during the last decade (Wood-head, 1991). Improved water quality has expanded the spawning area available for American shad (Sullivan, 1991). The prevalence of fin rot in winter flounder declined tenfold in the New York Bight region between 1973 and 1978 for reasons that are not clear (Swanson et al., 1990). Although the causes of fin rot are not well understood, it tends to be more prevalent in shallow inshore waters receiving municipal effluents, and therefore the decline in the incidence of fin rot lesions might reflect improvements at wastewater treatment plants (Sullivan, 1991).

Populations of some birds in the Hudson-Raritan estuary have historically been influenced by many aspects of this complex urban ecosystem other than water quality. Notable among these factors is the decimation of local bird populations in the latter half of the nineteenth century by the hunting and milliner's trade (Sullivan, 1991). Before the passage of federal protective legislation, such as the 1913 Migratory Bird Treaty, annual catches for food and feathers totaled more than a million birds per year. Even small songbirds, such as robins, were sought for sale in commercial markets. By 1884, the once abundant populations of common terns, least terns, and piping plovers, formerly present between Coney Island and Fire Island, had been reduced to but a few individuals. Populations of common and roseate terns, herons, snowy egrets, and many other species were similarly affected by hunting.

Populations gradually recovered over the next several decades until development and associated draining and spraying of wetlands for mosquito control encroached on, and degraded, waterfowl habitat. Between the late 1940s and its ban in 1972, DDT was heavily applied to the salt marshes of Long Island and New Jersey, with New Jersey marshes receiving the heaviest applications for the longest period of time. The DDT was transferred up the food chain to fish and shellfish, which are an important food source for many coastal birds in the harbor. DDT accumulated in bird tissues and contributed to the decline in reproductive success by affecting eggshell thickness (e.g., Hickey and Anderson, 1968). The osprey was probably the species most affected in the Hudson-Raritan Estuary area, although bald eagles and herons were also affected.

Recent concerns for shorebirds include the high concentrations of industrial chemicals, such as PCBs, measured in mallards, black ducks, scaup, and osprey. Due to the many factors contributing to the abundance of shore birds and the fact that they can be exposed to more than one geographic area through migration, there is only a tenuous linkage between improved water pollution control efforts and bird populations. Overwintering populations of waterfowl, however, have generally remained stable since the 1980s (Sullivan, 1991). For example, Canada goose populations of New Jersey increased from about 6,000 in 1975 to 23,200 in 1981 to 124,000 in 1990, a record high for the state. This increase is most likely the result of displacement of geese from other states, particularly Maryland.

Most remarkable among bird population recoveries is the return of herons to the heavily industrialized northwestern portion of Staten Island along the Arthur Kill and Kill Van Kull waterways. In these urban wetlands, undaunted by nearby oil refineries and chemical manufacturing plants, herons and other wading birds are making a comeback. The Harbor Herons Complex, first documented in the industrial Arthur Kill waterway in the 1970s, has become a regionally significant heron and egret nesting rookery (HEP, 1996). In 1974, snowy egrets, cattle egrets, and black-crowned night-herons began nesting on Shooters Island; in 1978, nesting snowy egrets and cattle egrets were found on Prall's Island, a 88-acre high marsh that in the past has served as a disposal site for dredged spoils. By 1981, these birds were joined by glossy ibises, great egrets, and black-crowned night-herons. In 1989, snowy egrets, glossy ibises, cattle egrets, black-crowned night-herons, yellow-crowned night-herons, little blue herons, and great egrets were found on the nearby Isle of Meadows. Ospreys,

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