Point Source Pollution — Problem Areas 



Point source pollution is generated primarily by 

 industries and municipalities and is generally inci- 

 dental to forest and range lands. However, several 

 kinds of operations associated with forest and range 

 lands do generate point source pollution. Some of 

 these are relatively permanent and generate pollution 

 on a year-round basis, but others are only temporary 

 or seasonal. Common sources of potential point 

 source pollution on forest and range lands include: 

 rock crushing and gravel washing; log sorting and 

 storage; wood processing; mining; food processing; 

 developed recreation sites; feedlots; marine vessels; 

 remote work centers (logging and mining camps); 

 summer homes; and organization camps. These 

 sources of point pollution are found, collectively, in 

 nearly every hydrologic basin identified by the Envi- 

 ronmental Protection Agency,'^ though not all are 

 considered pollution problems in all basins. In fact, 

 pollution from these sources is generally not signifi- 

 cant on a national basis, but it can be significant 

 locally if not controlled. A summary of the major 

 point pollution sources and the related types of 

 pollution is shown in table 7. 13 by each major region 

 as defined by the Environmental Protection Agency. 



Nonpoint Source Pollution — Problem Areas 



Most pollution from activities on forest and range 

 land is nonpoint source. As mentioned earlier, non- 

 point sources of pollution are becoming, or have 

 already become, the primary source of pollution in 

 many streams. There are several recognized cate- 

 gories of nonpoint source pollution including mining; 

 urban runoff; construction of roads and buildings; 

 silviculture — man's activities in growing and harvest- 

 ing timber; agriculture; hydrologic modification of 

 surface or ground waters; subsurface excavations — 

 industrial injection wells, septic tanks and landfills; 

 and saltwater intrusion into fresh water supplies. Of 

 these, mining, silviculture, construction, and the 

 grazing aspects of agriculture are commonly recog- 

 nized as causing significant nonpoint source pollution 

 from forest and range lands. The other categories of 

 nonpoint source pollution do cause significant pollu- 

 tion from forest, range, and associated lands in local 

 areas, but on a nationwide basis they are not consid- 

 ered a major problem. 



One of the greatest problems associated with non- 

 point source polution is that it is often difficult to 

 identify, measure, or treat because it is diffuse and 

 diluted. However, while impacts of nonpoint source 



'5 U.S. Environmental Protection Agency. National water 

 quality inventory, 1977 report to Congress, op. cit. 



pollution are often less concentrated and conspicu- 

 ous, they are not necessarily less harmful than the 

 impacts of point source pollution. To the extent that 

 forests and range lands and their uses contribute to 

 nonpoint source pollution, this will generally occur in 

 those stream reaches and lakes where the water is of 

 relatively high quality. Any degradation of quality in 

 these areas is easily noticed and difficult to treat. 



Another serious problem of nonpoint source pollu- 

 tion is separating pollution induced by man from that 

 which occurs naturally. Most wildlands, even under 

 natural conditions, are sources of many pollutants 

 which contribute to the total load of nonpoint source 

 pollution. These natural pollutants are in the form of 

 sediment, but organic and chemical pollution also 

 occur from natural sources. 



A third major problem related to nonpoint source 

 pollution is the lack of data on the sources, extent, 

 and impacts of nonpoint pollution on water quality. 



Just as there are general nonpoint source pollution 

 problems, so are there specific problem areas. The 

 agricultural industry is probably the largest single 

 contributor to nonpoint source pollution. By volume, 

 the major pollutant is sediment, primarily from soil 

 erosion of croplands and stream channels. Cropland 

 contributes about 40 percent or more of the total 

 sediment deposited in streams and lakes. About 19 

 percent is from forest and range lands and 30 percent 

 is from roadsides, streambanks, and mining. Urban 

 and other sources contribute the remaining 1 1 

 percent.'" 



Water quality is affected by nonpoint source pollu- 

 tion from mining in two ways — acid-mine drainage 

 and sediment, both of which are more common from 

 abandoned mines. Acid drainage occurs when ex- 

 posed sulphur-bearing rock reacts with air and water 

 to form sulfuric acid. This acid then leaches through 

 the ground, including tailings, where it dissolves 

 other minerals and metals, and continues its journey 

 until it reaches a stream or lake. Acid drainage affects 

 pH (the measure of hydrogen-ion activity of solu- 

 tions), dissolved solids content, and toxic aspects of 

 water quality. Sediment is produced by runoff from 

 any unprotected soil, whether it be from roads, areas 

 cleared of vegetation for mining, or tailings. Pollu- 

 tion from mining can be a special problem to com- 

 munities, both human and natural biota, located near 

 the source of the drainage. 



Silviculture is the primary source of nonpoint pol- 

 lution most commonly associated with forest lands. 

 Many activities inherent in forest management are 

 included in the term "silviculture," including nursery 



''•U.S. Department of Agriculture, Soil Conservation Service. 

 Environmental impact statement, rural clean water program, 

 August 24, 1978. 



305 



