Do you need a Construction Stormwater General Permit from Ecology? If your project disturbs over an acre of land or is in a subdivision, you probably do. This permit states that all sites disturbing over an acre of land must have a Certified Erosion and Sediment Control Lead (CESCL). The CESCL is trained to inspect, install, and manage stormwater controls on your site. Ecology requires a CESCL to be on-call at all times, so most companies will need more than one employee trained as a CESCL. This certification is good for three years.