The State of Minnesota
Sustainable Building Guidelines (MSBG) Version 2.0

S.3 Soil Management

Intent
Maintain the permeable structure and biological health of the soil in order to optimize plant health and species richness and optimize water infiltration and filtration.

Required Performance Criteria
A. Create a Soil Management Plan for construction to protect soil profile of site.

B. For all sites: Limit site disturbance (defined as piling, tilling, scraping, storing, and removal of any and all soil) to 40 feet beyond the building perimeter, 5 feet beyond primary roadway curbs, walkways, and main utility branch trenches, 5 feet beyond tree driplines and the edges of site areas identified for protection and 25 feet beyond pervious paving areas and stormwater management features that require additional staging areas in order to limit compaction in the constructed areas

C. Maintain > 350' of undisturbed buffer for delineated wetland boundaries or to Board of Water and Soil Resources (BWSR) current buffer requirements, whichever is more stringent.

D. Protect trees as individuals or in groups (canopies < 10' apart) with tree protection fence prior to any and all site activities

E. Mitigate all compaction impacts to future planting areas during construction with deep vibration technology greater than or equal to 24". Maintain and install/re-spread topsoil to a minimum 12" depth.

F. Do not sell or export any top soil from project site

G. Maintain or mitigate mycorrhyzeae populations viable in all topsoil stockpiles per Mycorhizal standards per (MNDOT Standard Specification Section 3896.2 Soil and Root Additives) immediately prior to respread.

H. Innoculate all future planting areas with Mycorrhyzeae to Mycorryhizal standards per (Reforestation Technologies, Inc.)

I. Where trees are planted in hard surfaces (patios, driveways, car parks, plazas, parking islands) use a structural soil media mix of minimum soil volume of 500 cubic feet (cf) per tree (600-1,000 cf per tree recommended) if intending to meet S.7 Recommended Performance Criteria OR of minimum soil volume of 350 cubic feet (cf) per tree if intending to meet S.7 Required Performance Criteria (assumes trees are being watered when water content of soil drops below 15% of average water-holding capacity, or monthly). If soil volumes cannot be met it is recommended that trees be planted in minimum 8' wide by approximately 3' deep trenches so that small soil volumes per tree become "interconnected"

J. Mantain soil porosity through maintaining a soil column porosity greater than or equal to 36" as defined by the NRCS for that Soil Series type.

Note: Portions of this guideline are adapted from LEED Version 2.0.

Compliance Tools and Resources

• Cornell University Structural Soil (www.asla.org/latis/pdf/Structural_soils_updated081202.pdf)