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Management Measures for Agricultur Sources - Facility Wastewater and Ruff- Large Confined Ani... Page 5 of 8 <br /> stream from this area will be improved. <br /> Dikes are used to prevent wetlands and to form wetlands. The formed areas may be fresh, <br /> brackish, or saltwater wetlands. In tidal areas dikes are used to stop saltwater intrusion, and to <br /> increase the hydraulic head of fresh water which will force intruded salt water out the aquifer. <br /> During construction there is a potential of heavy sediment loadings to the surface waters. When <br /> pesticides are used to control the brush on the dikes and fertilizers are used for the establishment <br /> and maintenance of vegetation there is the possibility for these materials to be washed into the <br /> i surface waters. <br /> • b. Diversions(362):A channel constructed across the slope with a supporting ridge on the <br /> lower side. <br /> This practice will assist in the stabilization of a watershed, resulting in the reduction of sheet and rill <br /> erosion by reducing the length of slope. Sediment may be reduced by the elimination of ephemeral <br /> and large gullies. This may reduce the amount of sediment and related pollutants delivered to the <br /> surface waters. <br /> • c. Grassed waterway(412):A natural or constructed channel that is shaped or graded to <br /> required dimensions and established in suitable vegetation for the stable conveyance of <br /> runoff. <br /> This practice may reduce the erosion in a concentrated flow area, such as in a gully or in <br /> ephemeral gullies. This may result in the reduction of sediment and substances delivered to <br /> receiving waters. Vegetation may act as a filter in removing some of the sediment delivered to the <br /> waterway, although this is not the primary function of a grassed waterway. <br /> Any chemicals applied to the waterway in the course of treatment of the adjacent cropland may <br /> wash directly into the surface waters in the case where there is a runoff event shortly after spraying. <br /> When used as a stable outlet for another practice, waterways may increase the likelihood of <br /> dissolved and suspended pollutants being transported to surface waters when these pollutants are <br /> delivered to the waterway. <br /> . d. Heavy use area protection (561):Protecting heavily used areas by establishing vegetative <br /> cover, by surfacing with suitable materials, or by installing needed structures. <br /> Protection may result in a general improvement of surface water quality through the reduction of <br /> erosion and the resulting sedimentation. Some increase in erosion may occur during and <br /> immediately after construction until the disturbed areas are fully stabilized. <br /> Some increase in chemicals in surface water may occur due to the introduction of fertilizers for <br /> vegetated areas and oils and chemicals associated with paved areas. Fertilizers and pesticides <br /> used during operation and maintenance may be a source of water pollution. <br /> Paved areas installed for livestock use will increase organic, bacteria, and nutrient loading to <br /> surface waters. Changes in ground water quality will be minor. Nitrate nitrogen applied as fertilizer <br /> in excess of vegetation needs may move with infiltrating waters. The extent of the problem, if any,. <br /> may depend on the actual amount of water percolating below the root zone. <br /> • e. Lined waterway or outlet(468):A waterway or outlet having an erosion-resistant lining of <br /> concrete, stone, or other permanent material. <br /> http://www.epa.gov/ow6w/nps/MMGI/Chapter2/ch2-2bl.html 2/6/2009 <br />