The inspection of amended soils for potential problem areas is warranted from time to time to ensure that the intended characteristics are maintained.  If left undisturbed, amended soils should continue to provide stormwater management benefits such as a reduction in peak storm flows, increased infiltration and improved water quality.  In some jurisdictions across the country, soil amendments may be inspected as part of the sediment control plan for a site, usually done upon site completion. Information requested for a post-construction inspection may include:

• Infiltration test of amended soils.

• Site size, and volume and depth of soils that have been amended.

• Compost type, including its maturity rating and parent material.

• Composition of compost, including nutrients utilized and organic content rating.

The criteria for inspection of amended soils on a routine basis should include any aspect that may have the potential to affect the infiltration capacity, aeration and organic content of them.  Inspection points should include any areas where potential concerns appear obvious.  Typical post construction areas of possible concern include:

• Areas subject to compaction, such as soils in high traffic areas like foot paths and playing fields.

• Hydric or waterlogged soils, where the maximum infiltration capacity has already been achieved.

• Poor cover conditions, where cover conditions are far from optimal and vegetation is sparse, or rills and small gullies have started to form.

• Increased development, causing a disturbance of the already amended soils along with uneven water flow patterns due to restricted permeability.

• A decrease in organic content, usually visible by poor cover conditions and spotty growth.

In addition, a routine soil infiltration rate analysis of amended soils in potential problem areas is recommended. 

In some cases, once soil amendments have been established, added support to keep them and the grass growing on them in place will be required, especially along steep slopes.  A number of plastic polyethylene mesh products have been developed in order to help improve the capabilities of grassed areas to withstand heavy and/or intensive wear and to help slow down potential erosion. ¹ These products include anything from thin plastic mesh elements installed directly at the root zone to more heavy-duty (up to 50mm thick) interlocking extruded polyethylene mesh for higher traffic areas, including occasional vehicle traffic.  These support structures can be laid on existing grassed areas or seed can be sown over them.  They are easily installed on existing or recently amended soil and provide a stable surface capable of withstanding higher loads. As the planted grass develops the grass intertwines with the mesh to provide a completely natural appearance and near permanent protection against wear.

The benefits of utilizing plastic mesh products along with soil amendments include:

Netlon Turf Systems, © 2002

• Suitable for new and existing areas.
• Quick and easy installation with no excavation or pegging.
• Natural grass surface applied onto the top of existing grassed surfaces.
• Helps prevent surface erosion through reduced grass wear.
• Provides greater and more even surface drainage.
• Increases load bearing capacity of lawn.

Return to top

References

¹ Netlon Turf Systems, Inc., (www.gridtech.com)