This is an example method statement for the excavation and placement of underground tanks. It can be applied to the installation of Sewerage package Plants.
General steps to reduce risks
- Banksman Present during works
- Area scanned for existing services, along with utility company records. This includes above ground services.
- No un-authorized persons allowed on site during excavations and installation.
- Area Inspected before works commence daily, and at suitable intervals during the day.
- Excavations fenced off and end of the day if works are incomplete.
- Excavated material to be kept a minimum of 1.5m away from excavation.
- Warning signs
- PPE to be worn at all times.
- Only Competent and trained persons to connect pipe work and electrical supply.
- Risk Assessments for Excavation and overhead/ buried services.
Safe Work Method
- The installation area will be inspected along with any design drawings.
- The existing or new pipework leading to the unit will be checked for line and level.
- The works area will be scanned for underground services, and local utility company records checked for location of services that are unable to be scanned, IE plastic pipes.
- Overhead lines will be checked and suitable measures taken should overhead lines be within the excavation/installation area, for example goalposts and warning signs.
- The normal company procedure is to complete the excavation/backfilling works in a single shift, Therefore the sequence for a dry fill site is as follows:-
- The excavation position will be set out, and the ground scanned prior to the excavation being started, the excavator will commence excavation works under the supervision of a trained and competent person.
- Levels will be taken at regular intervals until the correct excavation depth is attained.
- Should the particular specification require it, a base of pea gravel for example will be poured to the correct height. These methods require No access by staff into the excavations at any time.
- The designated unit will then be hoisted into the excavation using proprietary straps the average weight of the tanks is 200kg (large tanks will be hoisted using a crane)
- The unit will be aligned and leveled to the required tolerances.
- Backfilling will commence to the correct levels.
- The procedure for wet ground concrete backfill is to pour a base for the unit, and to fill the unit with water at the same rate as the concrete fill to the exterior. Care and attention will required to ensure the unit does not float.
- Once the backfilling is complete the connections will be made and tested. Any electrical connections will be made by competent licensed electrician. The commissioning phase will commence, and all required testing to full operation according to client and manufactures requirements will be carried out.
The full method statement is available in Microsoft Word ™ Format as an instant download HERE