The EPA has published “Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category; Final Rule” which will dramatically change sediment control throughout the US over the next 4 years. We are still reviewing, but most significant is the require to sample discharges from construction sites and to meet numeric effluent limits that include turbidity. Use of flocculants is pretty much mandatory on sites that are over 10 acres.
It looks like the turbidity limit is 280 (corrected from an earlier post) nephelometric turbidity units (NTUs) – which is just about crystal clear. The following photo shows 5, 50, and 500 NTUs. Construction runoff will need to be between the two right samples. This will be a complete game changer for sediment control.
A good summary article is at: http://www.erosioncontrol.com/january-february-2010/epa-effluent-guidelines.aspx