The sub-contractor shall familiarise with the project site and ground profile. He shall be responsible for any protection and preventive measures to control any soil erosion and situation problems at all planting areas. He shall restore or replace any portion of the site, which erodes, silts up or is otherwise damaged by outwash and compaction. As such, soil erosion control mat may be required to be installed and especially on sloped areas. The sub-contractor shall be responsible for the costs of these operations and to make provision for them in the rates for soil mix.