Construction 



Construction activities are not a major nonpoint source 

 of pollution but can cause severe localized problems in some 

 instances. Sediment is the major pollutant, and erosion 

 rates from construction sites are generally 10 to 2 times 

 higher than those on agricultural lands (EPA 1985b) . Other 

 potential pollutants from construction activities are 

 nutrients from fertilizers, pesticides, petroleum products 

 and other construction chemicals, and solid wastes. 



Urban Runoff 



Runoff from urban areas can cause significant water 

 quality impacts to local surface and ground water resources. 

 Sediments and debris are the primary pollutants, but metals, 

 nutrients, and pathogens from animal wastes are also 

 sometimes present. Septic tanks can contribute nutrients 

 and pathogens to ground water (EPA 1985b) . 



Resource Extraction. Exploration, and Development 



Nonpoint source pollution from mining activities can 

 cause severe water quality impacts to receiving streams. The 

 most serious NPS pollutants associated with mining are 

 metals, acid-producing materials, sediments, and radioactive 

 materials. Many of the pollutants generated at active mines 

 are considered to be point sources that are regulated under 

 the Montana Pollutant Discharge Elimination System (MPDES) 

 and National Pollutant Discharge Elimination System (NPDES) 

 permit programs. Runoff of sediment from haul roads and 

 drainage and leachates from waste piles can be NPS problems 

 at active mine sites. However, the mining industry in 

 Montana is subject to water quality regulations, and nonpoint 

 problems are dealt with through monitoring and compliance. 

 At inactive mine sites and mine waste disposal areas, 

 drainage and leachates containing acid, metals, sediment, and 

 salts can seriously affect surface and ground water systems 

 (EPA 1985b) . 



Land Disposal 



Land disposal systems such as landfills, septic tanks, 

 storage tanks, wastewater treatment areas, and hazardous 

 waste sites can result in the release of toxins, pathogens, 

 and nutrients to local surface and ground water systems. 



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