What is Biofiltration?
Water biofiltration is the process of improving stormwater quality through the processes of filtration through biologically influenced media. This pollution control technique uses living material to capture and biologically degrade pollutants. Examples of biofiltration include bioswales, slow sand filters, and treatment ponds.
Bioretention removes contaminants as fluid passes through media or a biological system. In water treatment, and stormwater management, bioretention by microbes growing within soil or filter media enhance retention and degradation of contaminants from the water. The capacity to detain contaminants can buffer sudden concentration spikes from occurring in the outflow. Bioretention / bioinfiltration facilities are low impact design, green measures that reduce the creation of and then employ nature to address the detrimental impacts of urban stormwater.Stormwater biofiltration systems include: bioretention systems, rainwater gards, constructed surface flow wetlands, and constructed sub-surface flow wetlands.
In the past two decades, state and federal regulation has moved from detention strategies of simply storing the water during a major storm event, to natural control measures encompassing both small and larger storms. As noted in Congressional testimony, stormwater management techniques now necessarily include reducing the amount of pavement used, or disconnecting drainpipes so that stormwater runs over the grass, water reuse, and structures that integrate with nature, such as bioretention / bioinfiltration facilities, green roofs and pervious pavements.
The state of Maryland has been a leader in stormwater management designs, and BMP's from the state and from Maryland counties like Montgomery have set the norms for many states. Soil mix in bioretention construction is of paramount importance, with many states publishing guidelines of the ideal mixture composition for effective, long-term local biofiltration. Delaware requires all suppliers of biosoil media to register with the state, and publishes this list for professionals involved in panning bioretention construction projects.
Moon Nurseries is a registered supplier with the state of Delaware for bioretention soil mixture. Moon Nurseries also carries a full line of local vegitation for bioretention plantings, including moisture and flood-resistant grasses, shrubs and canopy trees.
For more information, or to order biosoil or bioretention plantings, contact Moon Nurseries at the number below.
Useful links:


