Agriculture 



RESOURCE CONTAMINATION: ISSUES OF CONCERN IN THE BAY 

 WATERSHED 



Agriculture and forest lands cover 2/3 of the 1,061,000 acre Narragansett Bay Basin, 

 which includes portions of nine counties in the States of Massachusetts and Rhode Island. 

 Agricultural enterprises in the basin, though varied, primarily consist of small farming units 

 interspersed among population centers, industry, and other non-agricultural land uses. 

 Much of the $65 million annual agricultural market value of the basin originates in intensive 

 agricultural areas in Newport and Providence Counties, Rhode Island; and in Bristol, 

 Plymouth, and Worcester Counties, Massachusetts. 



Highly productive loamy soils in the basin's several significant farming areas produce 

 important crops, including, com, small grains, vegetables and fruit. Dairy, beef, hogs and 

 poultry operations make up a viable livestock industry. Erosion, sedimentation, 

 nutrient/pesticide runoff, and soil loss inventories were prepared during development of the 

 Rhode Island 208 Areawide Water Quality Management Plan, and subsequentiy by the US 

 DepL of Agriculture Soil Conservation Service (SCS) and Agricultural Stabilization and 

 Conservation Service (ASCS). These data indicate that at least in certain watersheds, 

 erosion and sedimentation management and improved farm waste management are 

 necessary in order to meet applicable water quality standards. 



Although construction and urbanization are major sources of erosion and sediment 

 problems, SCS calculated in 1984 that 400,000 tons of soil per year are lost per year to 

 agricultural sheet and rill erosion in the Narragansett Bay basin. Of this, roughly 20 

 percent enters rivers and streams. Of total cropland in the Bay basin, over 30 percent is 

 eroding at rates exceeding tolerable soil loss limits. (Tolerable soil loss is defined as the 

 maximum loss of soil due to erosion (in tons/acre/year) which can occur without reducing 

 the long term productivity of the soil.) Ephemeral erosion was estimated to contribute an 

 additional 80,000 tons per year, with 25 percent entering rivers and streams. 



Sediment loads are deposited in stream channels, and in ponds and reservoirs along 

 water courses. Water supply storage capacity has been diminished in affected reservoirs on 

 Aquidneck Island, and flood storage capacity has been lost throughout the Bay basin. 

 Contaminated sediments trapped in impoundments, furthermore, may be flushed during 

 major storm events, creating significant pulse loadings to the Bay. A major storm in April, 

 1987, for example, flushed impoundments in the Blackstone and Ten Mile Rivers. 



Sales of fertilizer for agricultural use have steadily declined in Rhode Island, due to 

 increases in fertilizer prices, higher analysis materials, lower application rates, and a 

 decrease in the number of full-time farming operations. Nevertheless, fertilizers increase 

 the pollutant potential of soils eroded into receiving waters, and are a source of concern in 

 some areas. 



Animal wastes, introducing nutrients, bacteria, and organic material into receiving 

 waters, have also adversely affected basin water quality. Significant runoff originates fi"om 

 feedlots, holding areas, and strcambanks where animals are allowed direct access to water 

 courses. In addition, manure applied to fields may become a source of runoff 

 contamination when incorporation in the soil does not occur, or where manure is spread on 

 frozen ground. Of the estimated 337,0(X) ton annual production of animal waste in the 

 basin, approximately 20 percent is produced ftx)m livestock operations which are so close 

 to water courses that very limited natural filtration occurs before the waste residuals reach 



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