Changes

*fresh and partially decomposed residues (the active fraction), and  

*fresh and partially decomposed residues (the active fraction), and  

*the well decomposed and highly stable humus (USDA, 2015).

*the well decomposed and highly stable humus (USDA, 2015).

The structure, drainage and fertility characteristics of soil are all highly affected by organic matter content. In LID BMPs, if the soil does not contain enough organic matter it will lack porosity, water holding capacity and be difficult to maintain healthy vegetation cover without addition of chemical fertilizers. When organic matter content is too high, the soil may leach nutrients into the water that infiltrates through it, potentially contributing to [[nutrient loads]] to receiving waters rather than

The structure, drainage and fertility characteristics of soil are all highly affected by organic matter content. In LID BMPs, if the soil does not contain enough organic matter it will lack porosity, water holding capacity and be difficult to maintain healthy vegetation cover without addition of chemical fertilizers. When organic matter content is too high, the soil may leach [[nutrients]] into the water that infiltrates through it, potentially contributing pollutant loading to receiving waters rather than improving [[water quality]]. So an important part of construction, assumption and verification inspections involves sampling and testing the media component of BMPs to ensure it meets the design specification for organic matter, or determine if it is still within an acceptable range.

reducing them. So an important part of Construction, Assumption and Verification inspections involves sampling and testing the soil component of BMPs to ensure it meets the design specification for organic matter, or determine if it is still within an acceptable range.

==Testing==

==Testing==

To determine if the soil component of an LID BMP meets design specifications or is within an acceptable range for organic matter, representative samples must be collected and submitted to an accredited Ontario soil testing laboratory for soil organic matter analysis. The recommended test method depends on the organic matter content of the soil sample:

To determine if the soil component of an LID BMP meets design specifications or is within an acceptable range for organic matter, representative samples must be collected and submitted to an accredited Ontario soil testing laboratory for soil organic matter analysis. The recommended test method depends on the organic matter content of the soil sample: