BMP Family |
BMP |
Classification |
Notes |
PollutionPrevention |
Housekeeping practices |
Yes |
Focus on rapid clean-up of paved surfaces after snowmelt |
Atmospheric control |
Marginal |
Control of auto emissions and industrial output usually not under local control, but exposed winter soils are controllable |
Chemical controls |
Yes |
Salt management and chemical spill control can be local programs |
Animal waste management |
Yes |
Strict waste control can be covered in local ordinance |
Streambank stabilization |
Yes |
Attention to local erosion sites can reduce ice damage and sediment load from high spring flows |
Runoff Volume Minimization |
Natural area conservation |
Yes |
Preserving pervious areas for meltwater to infiltrate is effective way to control volume |
Soil amendments |
Marginal |
Enhancing soil permeability will increase infiltration of meltwater |
Reduction of impervious surface |
Yes |
Preserving pervious areas for meltwater to infiltrate is effective way to control volume and to minimize mobilization of pollutants |
Grass drainage channel |
Yes |
Routing meltwater over a pervious surface will yield some reduction in flow and improved water quality |
Rain barrel/cistern |
Marginal |
Capturing meltwater from a building will reduce volume but ice build-up could be a problem unless collection occurs below frostline |
Permeable pavement/blocks |
Yes |
Recent research has shown this approach to be successful in cold climates when properly installed and maintained, and when sanding kept to a minimum |
Soakaway pit/drywell (designed so as not to qualify as a Class V injection well) |
Yes |
Effective as long as system is installed below the frostline to avoid ice build-up |
Stormwater planter |
Marginal |
These are designed more for the growing season, but they do provide a sump area for runoff to collect and will infiltrate some of the volume |
Rooftop garden |
Yes |
Recent research has shown that slow melting in the spring reduces the volume running off of roof surfaces |
Temporary Construction Sediment Control |
Preconstruction planning |
Yes |
Focus on sequencing to avoid open soils during winter and on limited grading prior to freeze-up |
Resource protection |
Yes |
Buffers reduce runoff by providing infiltration potential |
Runoff control |
Yes |
Stable drainageways and sediment basins assure erosion control and provide storage opportunities for spring meltwater |
Perimeter
control |
Yes |
These practices are especially effective during winter construction |
Slope stabilization |
Yes |
These must be installed prior to freeze-up to be effective; they must be checked often and maintained all winter |
Stabilized soil |
Marginal |
Seeding, blankets and sprayed stabilizers must all be in place and working before freeze-up; if necessary, blankets can be laid and held in place with sandbags or rock logs |
Inspection and maintenance |
Yes |
Essential for proper operation all winter |
Bioretention |
Rain garden |
Marginal |
By definition, these are growing season practices, but they do provide a sump area for storage and some infiltration during a melt |
Depressed parking islands |
Yes |
These can provide needed storage during the cold season and for spring runoff events; vegetation will not be a factor during winter |
Filtration |
Media filter |
Yes-to marginal |
Surface systems need to be fully dry before freezeup for these to work properly; sub-grade systems can be very effective for meltwater treatment |
Surface vegetative filter |
Marginal |
Vegetative filtering is reduced once vegetation dies back in the fall; some physical filtering will occur if vegetation density and depth are sufficient |
Combination filter |
Yes-to marginal |
See comments above |
Infiltration |
Trench |
Yes with caution |
Effective when designed, installed and maintained properly; caution applies to limitations on source area to avoid high concentrations of Cl and toxics |
Basin |
Yes with caution |
See above comment |
Stormwater Ponds |
Forebay |
Yes |
Effective if designed with enough available volume to accommodate meltwater in the spring |
Storage components |
Yes |
Adaptations must be made to allow meltwater runoff to receive appropriate amount of treatment (see discussion following in this section); treatment effectiveness usually lower than warm weather |
Outlet |
Yes |
Proper design of the outlet structure can be the key to ponding effectiv |
Constructed Wetlands |
Forebay |
Yes |
See comment for forebay above |
Storage components |
Yes-to marginal |
Volume will be less than typical pond, but provide location for storage, some infiltration, filtration and some microbial activity; biological activity at a minimum |
Supplemental Treatment |
Proprietary sediment removal |
Yes |
These devices are typically installed below ground and below the frostline, and can be effective in treating sediment-laden spring runoff |
Catch basin insert |
Marginal |
The location of these in a very cold location often leads to icing conditions; can be marginally effective for solids even if frozen |
Wet vault |
Yes |
See comment for proprietary devices |
Chemical treatment |
Yes |
These systems are designed to inject treatment chemicals for all flows |
Floatable skimmer |
Yes-to-marginal |
Proper installation of a floatable skimmer or baffle weir will allow water to pass even when thick ice is present; draws water from below ice layers |
Sorbents |
Yes |
These absorb chemicals usually in sub-grade systems |
Thermal protections |
No |
Do not apply to winter conditions |
Biological additives |
Yes |
See comment for chemical treatment |