Stormwater Collection, Treatment, Recycling and Reuse in a Shipyard

摘要

Stormwater has historically been considered a problem of quantity to be addressed by channeling and diverting excess quantities of rainfall away from residential and industrial activities. The impact to receiving waters was thought to be insignificant because the rain water would eventually find its way to the rivers and streams in the watershed in which the rain fell regardless of alterations in the natural landscape caused by human activities. Increasingly it has become apparent that stormwater can become contaminated when it comes in contact with routine residential, municipal, commercial, and industrial activities. The evidence of this association has increased in recent years and relationships between land use/activities and alterations in the chemical characteristics of stormwater runoff have been frequently reported. Agricultural activities, land development, and general urbanization have all been shown to influence the chemical composition of stormwater runoff relative to natural conditions. Major problems with regard to stormwater quality occur when the natural or altered flow paths of stormwater runoff in a watershed cause the mobilization and transport of constituents to receiving water systems at concentrations which cause toxic or adverse health effects to aquatic organisms or humans exposed to these waters. It is known that both the stormwater flow path and the contact time with potential contaminants strongly regulates stormwater quality. Activities can occur in a watershed that generate or handle large quantities of a particular contaminant but pose no threat to receiving waters due to the lack of contact with precipitation or stormwater runoff (e.g. contaminants that are housed within enclosed buildings). Alternatively, activities where a small amount of a particular constituent is handled or generated can be more important if stormwater runoff contacts this material and it is easily mobilized to receiving water systems.