Laserfiche WebLink
SECTION 8 – LANDSCAPING <br />95 <br />8-2.7 STRUCTURAL SOIL <br />Structural Soil shall provide a layer suitable for supporting the growth of permanent vegetation. All <br />materials shall be obtained from the existing soils within the construction limits, an approved <br />commercial source, or project-specific borrow pits. The Structural Soil shall be a fertile, friable and <br />loamy soil of uniform quality free from any objectionable plant material or undesirable vegetative <br />debris which would be harmful to plant life. All landscape shrub beds and tree pits within paved areas <br />shall be backfilled with a Structural Soil mix as further described below. <br />All materials used to develop the Structural Soil shall consist of 40-45% sand, 7-20% clay, <br />and 35-40% silt and must be placed at the depth of the tree root ball at a minimum depth of <br />24 inches. <br />All components and amendments to the Structural Soil shall be added and mixed with <br />pulverized topsoil and prepared offsite at the supplier’s facility creating a uniform mix. <br />Structural Soil shall be installed uniformly in grassed parkway locations and urban <br />environments as may be necessary for the viability of trees and other landscape amenities. <br />Structural Fill shall be stored in stockpiles at the producer’s or supplier’s facility and be protected from <br />erosion, absorption of excess water, and contamination at all times. <br />8-2.8 TREE GRATES <br />The size and location of Tree Grates shall be in accordance with the tree species size classes listed in <br />the Street Tree Master Planting List and Section 9-2.3(c). All tree grates shall be installed with a metal <br />frame, such as angle iron, on which the grate will rest. At all tree grate locations, a water percolation <br />test shall be conducted to ensure not standing water is present within planting beds for greater than 12 <br />hours. If proper drainage cannot be achieved, underdrains are to be provided where standing water <br />will restrict healthy plant growth. <br />8-3 MAINTENANCE AND WARRANTY <br />All vegetative features, where applied, shall be warranted for a period not less than 2 growing seasons <br />from project completion. During the warranty inspection period, planting areas will be rated per the <br />following scale: <br />Good: 81-100% of foliage, no major structural defects, no insect or disease concern, <br />high vigor <br />Fair: 66-80% of foliage, minor structural defects, minor insect or disease concern, <br />medium vigor <br />Poor: 26-65% of foliage, major structural defects, mechanical damage, insect or <br />disease noticeable decline, poor vigor – remediation plan and action required <br />Dead: 0-25% of foliage – replacement required <br />Areas rated as “poor” will require a remediation plan and action. Areas rated as “dead” will require <br />replacement.