The furnishings of a performance guaranty in favor of the Borough of Glen Gardner in an amount equal to 120% of the cost of installation of streets, grading, pavement, gutters, curbs, sidewalks, street lighting, shade trees, surveyor's monuments, water mains, culverts, storm drainage structures, erosion control and sedimentation control devices, public improvements of open space and public on-site improvements, as well as landscaping.