The leading causes of sediment pollution are agriculture, municipal development, logging, and mining. The report offers a set of recommendations that include both regulatory and nonregulatory tools to address the problem. Agriculture generates sediment pollution in several ways. Plowing exposes the soil and increases its susceptibility to erosion, while drainage ditches facilitate the movement of dirt-laden runoff into streams and rivers. Clearing the natural vegetation along a streamside can lead to streambank destabilization and severe erosion.
Cattle can also destroy vegetation along streambanks, leading to erosion.
In the case of Christmas tree farming, soil erosion can occur during site preparation, when the ground is disturbed prior to planting the seedlings, or during harvest, when the trees are cut and removed, The construction of roads to access Christmas tree farms also contributes to soil erosion. Municipal development leads to sediment pollution by increasing the amount of paved or impervious surfaces, such as roads and parking lots, in a watershed. These impervious surfaces increase the amount of surface runoff and stormwater flowing into streams. Little progress has been made over the past quarter-century in reducing sediment pollution in North Carolina. There has been no decrease in the number of river miles in the state impaired by such pollution since 1984, despite the fact that North Carolina has made significant progress in cleaning up other types of water pollution.