Construction & Post-Construction Site Runoff

Construction Disturbances

Construction site operations generally disturb large amounts of land, and generate large amounts of waste that wash into surrounding watersheds, estuarine systems, and stormwater systems. These wastes include petroleum products, construction chemicals and solid waste, fertilizers and pesticides, and larger amounts of sediment than can naturally be deposited over decades. As such, construction sites that disturb an acre or more of land are required to control sediment, erosion, and waste, and consider potential water quality impacts of their projects.

Post-Construction Consideration

After construction is complete, redevelopment / new development projects that disturb an acre or more, and projects that are smaller than an acre but which are part of a larger planned development, must consider the permanent effects of their development on the greater stormwater system. New development can increase the amount of water flowing into nearby watersheds by establishing new water-impervious surfaces such as pavement, rooftops, or patio wood. Simultaneously, these new developments damage water quality by introducing pesticides, fertilizers, and excess sediment for stormwater to carry to the nearest watershed or storm drain. These effects can be mitigated by forward-thinking design and early consideration in the design process. Review more information on low-impact development.

Regulation Authorities

Nassau County does not issue building permits, and therefore is not the regulatory authority on construction and post-construction runoff. Instead, that authority rests with the towns, villages, and cities that comprise Nassau County. These municipal building authorities design and enforce stormwater regulations, and it is critical that construction site operators contact their local building authority in order to avoid penalties, fines, and permit denials.

View or download the Inspection Form for Contractors (PDF).