Admin Order 58-14-01-F - Laserfiche WebLink

Home Browse Search

technologies that are not on the approved list may be used in a "treatment train," to provide additional treatment when approved by the City. Manufactured treatment devices must be able to fully treat the peak runoff from the Water Quality Design Storm and fully bypass the peak flows from the Flood Control Design Storm. 2.2.5 Facility Underdrains and Surface Overflows It is important to note the distinction between an underdrain and a surface overflow. While both the underdrain and the overflow require a connection to an approved discharge point, the underdrain is typically set at an elevation below the growing medium to drain treated flows that pass through the growing medium and are trapped in a facility where the surrounding soils infiltrate 2" per hour or less. An overflow is typically set at an elevation above the growing medium and is included to drain flows exceeding the stormwater quality design capacity of the facility or in case the vegetated facility becomes clogged. 2.2.6 Source Control Devices Source control devices include Spill Control Manholes and oil /water separators. They are used to meet the source control requirements specified in Chapter 3. Stormwater Management Manual 2.4 Eugene 2014