2600 FEDERAL AVE 2021 PORT OF EVERETT 2025-09-29

Maintenance Guidelines In addition to these two activities, it is important to check The primary purpose of the Stormwater Management the condition of the StormFilter unit after major storms for StormFilter®is to filter and prevent pollutants from entering our potential damage caused by high flows and for high sediment waterways. Like any effective filtration system, periodically these accumulation that may be caused by localized erosion in the pollutants must be removed to restore the StormFilter to its full drainage area. It may be necessary to adjust the inspection/ efficiency and effectiveness. maintenance schedule depending on the actual operating conditions encountered by the system. In general, inspection Maintenance requirements and frequency are dependent on the activities can be conducted at any time, and maintenance should pollutant load characteristics of each site. Maintenance activities occur, if warranted, during dryer months in late summer to early may be required in the event of a chemical spill or due to fall. excessive sediment loading from site erosion or extreme storms. It is a good practice to inspect the system after major storm events. Maintenance Frequency The primary factor for determining frequency of maintenance for Maintenance Procedures the StormFilter is sediment loading. Although there are many effective maintenance options, we believe the following procedure to be efficient, using common A properly functioning system will remove solids from water by trapping particulates in the porous structure of the filter media equipment and existing maintenance protocols.The following inside the cartridges.The flow through the system will naturally two-step procedure is recommended:: decrease as more and more particulates are trapped. Eventually 1. Inspection the flow through the cartridges will be low enough to require • Inspection of the vault interior to determine the need for replacement. It may be possible to extend the usable span of the maintenance. cartridges by removing sediment from upstream trapping devices on a routine as-needed basis, in order to prevent material from 2. Maintenance being re-suspended and discharged to the StormFilter treatment • Cartridge replacement system. • Sediment removal The average maintenance lifecycle is approximately 1-5 years. Inspection and Maintenance Timing Site conditions greatly influence maintenance requirements. At least one scheduled inspection should take place per year with StormFilter units located in areas with erosion or active maintenance following as warranted. construction may need to be inspected and maintained more often than those with fully stabilized surface conditions. First, an inspection should be done before the winter season. During the inspection the need for maintenance should be Regulatory requirements or a chemical spill can shift maintenance determined and, if disposal during maintenance will be required, timing as well.The maintenance frequency may be adjusted as samples of the accumulated sediments and media should be additional monitoring information becomes available during the obtained. inspection program.Areas that develop known problems should be inspected more frequently than areas that demonstrate no Second, if warranted, a maintenance(replacement of the filter problems, particularly after major storms. Ultimately, inspection cartridges and removal of accumulated sediments)should be and maintenance activities should be scheduled based on the performed during periods of dry weather. historic records and characteristics of an individual StormFilter system or site. It is recommended that the site owner develop a database to properly manage StormFilter inspection and maintenance programs.. 5 Z