220 OLYMPIC BLVD VA OUTPATIENT CLINIC 2023-02-09

O Oldcastle Infrastructure' INSPECTION AND MAINTENANCE GUIDE II A CRM COMPANY BioPodTM Biofilter with StormMixTM Biofiltration Media Description The BioPodTM Biofilter System (BioPod) is a stormwater biofiltration treatment system used to remove pollutants from stormwater runoff. Impervious surfaces and other urban and suburban landscapes generate a variety of contaminants that can enter stormwater and pollute downstream receiving waters unless treatment is provided. The BioPod system uses proprietary StormMixTM biofiltration media to capture and retain pollutants including total suspended solids(TSS),metals,nutrients,gross solids,trash and debris as well as petroleum hydrocarbons. Function The BioPod system uses engineered, high-flow rate filter media to remove stormwater pollutants, allowing for a smaller footprint than conventional bioretention systems.Contained within a compact precast concrete vault,the BioPod system consists of a biofiltration chamber and an optional integrated high-flow bypass with a contoured inlet rack to minimize scour. The biofiltration chamber is filled with horizontal layers of aggregate (which may or may not include an underdrain), biofiltration media and mulch. Stormwater passes vertically down through the mulch and biofiltration media for treatment. The mulch provides pretreatment by retaining most of the solids or sediment.The biofiltration media provides further treatment by retaining finer sediment and dissolved pollutants. The aggregate allows the media bed to drain evenly for discharge through an underdrain pipe or by infiltration. Configuration The BioPod system can be configured with either an internal or external bypass.The internal bypass allows both water quality and bypass flows to enter the treatment vault.The water quality flows are directed to the biofiltration chamber while the excess flows are diverted over the bypass weir without entering the biofiltration chamber. Both I the treatment and bypass flows are combined in the outlet area prior to discharge from the structure. BioPod units without an internal bypass are designed such that only treatment flows enter the treatment structure. When the system has exceeded its treatment capacity, ponding will force bypass flows to continue down the gutter to I the nearest standard catch basin or other external bypass structure. The BioPod system can be configured as a tree box filter with tree and grated inlet, as a planter box filter with shrubs, grasses and an open top, or as an underground filter with access risers, doors and a subsurface inlet I P 9 pipe. The optional internal bypass may be incorporated with any of these configurations. In addition, an open bottom configuration may be used to promote infiltration and groundwater recharge.The configuration and size of the BioPod system is designed to meet the requirements of a specific project. Inspection & Maintenance Overview State and local regulations require all stormwater management systems to be inspected on a regular basis and maintained as necessary to ensure performance and protect downstream receiving waters.Without maintenance, excessive pollutant buildup can limit system performance by reducing the operating capacity of the system and I increasing the potential for scouring of pollutants during periods of high flow. Some configurations of the BioPod may require periodic irrigation to establish and maintain vegetation.Vegetation will typically become established about two years after planting. Irrigation requirements are ultimately dependent on climate, rainfall and the type of vegetation selected. 2