North Atlantic 



Table 8. North Atlantic Pollution 



Sources Affecting Harvest- 

 Limited Acreage, 1990a.b 



Sources 



Maine New Massa- 



Hampshire chusetts 



Acres % Acres % Acres % 



Point Sources 



Sewage Treat Plants 115 57 9 100 120 85 



Combined Sewers 1 11 21/5 



Direct Discharge "\ 1 



Industry 11 5 4 44 9 6 



Nonpoint Sources 



Septic Systems 82 40 2 22 15 



Urban Runoff 24 12 6 67 50 36 



Agricultural Runoff 6 67 5 4 



Wildlife 6 67 19 14 



Boats 17 S 5 56 38 22 



Upstream Sources 



Sewage Treat Plants 2 ? 



Combined Sewer 



Urban Runoff 3 2 



Agricultural Runoff 



Wildlife 



a. Acres are times 1 ,000; % is percent of all harvest-limited 

 acreage in state, 



b. Since the same percentage of a shellfish area can be 

 affected by more than one source, the percentages 

 shown above cannot be added. They will not sum to 100. 



Narraguagas, Penobscot, Casco, 

 Saco. Boston, and Cape Cod bays. In 

 seven estuaries, additional acres were 

 classified. The majority of these were 

 prohibited acres in Penobscot, 

 Frenchman, Massachusetts, and 

 Cape Cod bays, because most of the 

 additional acres were classified as 

 prohibited. 



Most classification changes in Maine 

 and Massachusetts were a result of 



management decisions based on 

 increased sanitary survey and sam- 

 pling activities. Significant water 

 quality declines occurred in Hampton, 

 Little, and Rye harbors, and Cape 

 Cod Bay, and significant upgrades 

 occurred in the Winnicut, Oyster, and 

 Bellamy rivers, and Little Bay. 



Pollution Sources Affecting Shell- 

 fish-Growing Waters. The pollution 

 sources affecting North Atlantic 

 shellfish-growing waters reflect the 

 region's high population density in 

 areas such as Boston Bay, in contrast 

 to low population density in areas 

 such as Passamaquoddy Bay. Table 

 8 shows the major categories of 

 pollution sources affecting the har- 

 vest-limited waters in the North 

 Atlantic region. Data on pollution 

 sources by estuary are provided in 

 Appendix D. 



Sewage treatment plants affect 67 

 percent of harvest-limited areas. 

 However, the region has the smallest 

 number of point source dischargers, 

 about 400. Of these, 59 are found in 

 Great Bay and 69 in Boston Bay. The 

 metropolitan area of Boston, with a 

 population of over 2.5 million, impacts 

 shellfish-growing waters in both 

 Boston and Massachusetts bays. 

 Sewage treatment plants affect the 

 most shellfish-growing waters, fol- 

 lowed by septic systems, industry, and 

 urban runoff. In 1988, highly produc- 

 tive shellfish-growing waters (approxi- 

 mately $315,000 annual harvest) were 

 closed in Boston Bay because of 

 major malfunctions in the area's 

 overloaded sewage treatment plants. 

 Boston has since begun construction 



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