Input sewage

Grimalt JO, Fenandez P, Bayona JM, Albaiges J, Assessment of fecal sterols and ketones as indicators of urban sewage inputs to coastal waters, Environ Set Technol... 

Fortunately, we are beginning to actually detect measurable improvements in the water quality of some estuaries due to scientifically based nutrient reductions and extensive longterm monitoring studies. For example, the Patuxent River in Maryland (USA), a tributary of the Chesapeake Bay, experienced extensive eutrophication from sewage inputs and non-point sources over four decades (1960-2000 D Elia et al., 2003). 

Watershed types are based on the primary sources of N to each estuary. Watersheds dominated by urban N sources (e.g., point, septic, and non-point source runoff) were classified as urban, watersheds dominated by agricultural N sources (e.g., fertilization, fixation, and manure) were classified as agriculture, and watersheds dominated by atmospheric N deposition were classified as atmospheric. Effluent from sewage treatment plants in the Barnegat Bay watershed is discharged offshore sewage inputs to the Barnegat Bay estuary are from septic systems in the watershed. Modified from Castro et al. (2003). 

Nixon et al. (1996) have compiled N and P data for many of the watersheds and estuaries feeding the North Atlantic Ocean. In many of the watersheds of eastern North America, the input of N from anthropogenic atmospheric supply and sewage is a considerable fraction of the total input. This is not the case for the Amazon shelf, where atmospheric and sewage inputs are small relative to riverine input and upwelling. For the embayments and estuaries of the North Atlantic, Nixon et al. (1996) observed a significant correlation between %P exported and the mean freshwater replacement time. During the AmasSeds cruises the freshwater... 

Beside industrial emissions sewage input mainly characterizes anthropogenic contamination of riverine systems, attributed to different groups of fragrances, personal care products, plasticizers or technical additives (see Table 4). 

Additional compounds associated with fragrance and cosmetic products could serve as potential tracers of sewage inputs due to their source specificity, although data on their persistence are to be elucidated. All the following compounds presented were widespread detected and mainly quantified. 

River downstream of the sewage discharge has been estimated to be attributable to the treatment plant (19). More recent data (28) suggest that 20 to 40% of the trace metal content at Site 4 results from sewage inputs under normal flow conditions, with the remaining amount contributed from upstream transport or from the Minnesota River. 

Another study by Wade et al. (1988) determined that the source of PAHs to sediment and oysters from a wide area over the Gulf of Mexico was not sewage because of the lack of correlation with coprostanol, an indicator of sewage input. They also concluded that petroleum was not the source of PAHs to Gulf of Mexico sediments because the ratio of phenanthrene to anthracene ranged from 1 to 4.8 this ratio is closer to 50 in petroleum, which contains very little anthracene. They could not, however, rule out... 

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