Changes

===Preserve areas of undisturbed soil and vegetation cover===  

===Preserve areas of undisturbed soil and vegetation cover===  

Typical construction practices, such as topsoil stripping and stockpiling, and site grading and compaction by construction equipment, can considerably reduce the infiltration capacity (and treatment capacity) of soils. In some instances, the bulk density of construction compacted soils is similar to values for impermeable surfaces. Native undisturbed soils have a structure that takes many, if not hundreds of years, to develop. The structure is created by the growth and decay of plant roots, earthworm, and insect activity. In addition to destroying the structure during topsoil stripping and stockpiling, biological activity in the soil is greatly diminished. The shallow rooted turf of lawns and landscaped areas will not provide the same stormwater benefits as the agricultural and native vegetation that it replaces. During construction, natural heritage features and locations where infiltration-based SWMPs will be constructed should be delineated and not subject to construction equipment or other vehicular traffic, nor stockpiling of topsoil.

 

Stockpiling topsoil can damage the structure of the soil. This affects infiltration rate, microbiology and chemistry. The effects can be mitigated by [[Amended topsoil| amendment]] and care in its reuse. Soil compaction by heavy construction machinery is common on many development sites. This significantly reduces the infiltration capacity of the soils and must be minimized.<ref>http://trieca.com/wp-content/uploads/2016/07/Soil-Mgmt-Guideline-Mar-28-2012.pdf</ref>

In some instances, the bulk density of construction compacted soils is similar to values for impermeable surfaces.  

Native undisturbed soils have a structure that takes many, if not hundreds of years, to develop. The structure is created by the growth and decay of plant roots, earthworm, and insect activity. In addition to destroying the structure during topsoil stripping and stockpiling, biological activity in the soil is greatly diminished. The shallow rooted turf of lawns and landscaped areas will not provide the same stormwater benefits as the agricultural and native vegetation that it replaces.  

 

During construction, natural heritage features and locations where infiltration-based BMPs will be constructed must be delineated.

These areas must not be used for stockpiling, and must be protected from all vehicular traffic and any sediment accumulation.

===Avoid development on permeable soils===

===Avoid development on permeable soils===