Dust Control – Soil Stabilization – Erosion Control

Posts Tagged ‘effluent limitation’

An introduction to the EPA’s effluent limitations guidelines and source performance standards.

Check dams at a construction site are configured for use of chemical flocculant treatment.
Jesse Pritts, EPA

Although streams and rivers naturally carry sediment loads, discharges associated with construction activity can elevate these loads to levels above those in undisturbed watersheds. Discharges from land disturbance can increase the proportion of silt, clay, and colloidal particles in receiving streams because these fine-grained particles may not be managed effectively by conventional erosion and sediment controls that rely on simple settling.

In response to these issues, the U.S. Environmental Protection Agency (EPA) promulgated effluent limitations guidelines (ELGs) and new source performance standards for discharges from construction and development (C&D) sites on Dec. 1, 2009. ELGs are technology-based standards for control of wastewater and stormwater discharges from various categories of industry and are not risk-based, so different standards are not set for different receiving waterbodies. ELGs can be numeric standards (i.e., discharge limitations) and/or best management practices (BMPs) and process changes. Many of the C&D ELG requirements are already included in EPA and state construction general permits (CGP) and new requirements will be phased in over the next few years for sites to sample stormwater discharges and comply with a numeric effluent limitation of 280 nephelometric turbidity units (NTU). A sampling requirement will be triggered beginning Aug. 1, 2011, for sites disturbing 20 or more acres at once and beginning Feb. 2, 2014, for sites disturbing 10 acres or more at once.

Read the rest of this entry »