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Environmental and Social Management Frameworkh. Contamination of SoilSoil contamination can arise from inappropriate construction practice, as well asfrom accidents during both construction and operation stage. Pollution risksoriginate from transportation of hazardous materials during road construction andsubsequent traffic operations. Metals such as chromium, lead, and zinc remainand continue to be an environmental hazard in the soil for hundreds of years.Pollutants settling in roadside soil can impair the growth of vegetation and thegrowth of soil organisms, thus increasing the likelihood of soil depletion anderosion. These impacts tend to be localized, affecting only a narrow zone oneither side of the road.In colder climatic zones in mountainous area, salting of roads can lead to soilcontamination, and subsequent decrease in soil fertility and losses of organismsvital for good soil quality.i. Quarrying of Construction MaterialsThe construction of road, particularly the structures such as retaining walls,culverts, bridges, road surface works etc. require large quantity of boulders,gravels, sand, and other types of construction materials. Good road buildingmaterials are hard to find. Poor quality of material will often lead to prematurefailures of the road pavement. As a result, it is normally necessary to extractmaterials from wherever a good enough source is available, mostly locally. Suchmaterials are normally mined in nearby locations on local streams and placesnear the road alignment with a view to save the transportation cost.Uncontrolled quarrying by contractors from non-approved sources is a damagingactivity which must be controlled. However, sometimes such activities are beyondthe control of the road constructing engineers (see Box 4).Box 4Case Examples demonstrating Local Impacts from External Quarry ActivitiesThe Jogimara, on Naubise-Pokhara road is a most significant negative example ofhow quarrying operations, that have no context to road works, result in massiveenvironmental hazards.. During the 1980s and early 1990s, an outcrop of limestonewas quarried just above the road to supply a number of cement factories. Thequarrying was not properly supervised and contributed to a catastrophic scale ofinstability.River beds are common source of materials for roads and other constructions. Ifextracted in relatively small quantities, this appears to have no damaging effect.However, in a number of places the extraction of stones from river beds has becomeexcessive. The worst example is the Naubise Khola and its tributaries, which supplya constant stream of stone, crushed aggregates, gravel and sand to the constructionactivities in the Kathmandu Valley. The result is that the river beds have beenstripped entirely of the larger debris which helps to regulate flood velocities. It maybe that the flood of July, 1993 which caused so much damage to the Naubise-Mugling road would have been slower and less damaging if it was carrying a heaviersediment load.Source: Briefing Paper on Environmental Issues and Environmental Assessment in Road Sector, RAP, 1999The extraction of materials from inappropriate places or in excessive amount canseriously damage the local environment. For example, quarrying from a highslope and fragile terrain can result slope instability; extraction of sand and gravelin excessive amount from river can cause river bank cutting and erosion andchanges in river regime. This will eventually affect the local environment in termsof erosion, flooding of cultivated land, damage to community infrastructures,affect road itself, and eventually affect the entire livelihood of local people.April 2007 Chapter 4-13