Confined Space Entry Procedure

Purpose. This procedure sets out the steps that must be followed before, during and after entry to any confined space, including sewer manholes, wet wells, pits, tanks, reservoirs and chambers.

1.Identifying a confined space

A confined space is an enclosed or partially enclosed space not designed for continuous occupancy where there is a risk from an unsafe atmosphere, engulfment or restricted entry. Every sewer manhole, sewage pump station wet well, water reservoir, chemical tank, valve pit deeper than 1.2 metres and dosing chamber is a confined space at this business. The confined space register lists each one with its known hazards.

2.Planning the entry

The crew leader must first consider whether the work can be done without entry, using camera inspection, remote cleaning or lifting equipment. Where entry is required, the crew leader must complete a Confined Space Entry Permit in the Permit to Work Register, identify the hazards, specify the controls and confirm that every entrant and the standby person hold current confined space competencies.

3.Atmospheric testing

The atmosphere must be tested with a calibrated four-gas detector before entry and continuously during the entry. Oxygen must be between 19.5 and 23.5 percent, flammable gas below 5 percent of the lower explosive limit, hydrogen sulfide below 10 parts per million and carbon monoxide below 30 parts per million. Test at the top, middle and bottom of the space. If any reading is outside limits, ventilate and retest; do not enter until every reading is within limits and stable.

• Bump test the detector at the start of the shift
• Record the readings on the permit before entry
• Continuous monitoring is worn by the entrant

4.Controls during entry

Forced ventilation must run for the time on the permit before entry and during the entry. Every entrant must wear a full body harness connected to a retrieval line and tripod. A trained standby person must remain at the entry point at all times, maintain communication with the entrant and never enter the space. Sewer flows must be isolated or plugged upstream where the work requires it and the plug must be secured. Traffic control must be in place if the entry point is on or near a road.

5.Emergency and rescue

The rescue plan on the permit must be practical for the space and the crew on site. The standby person must be able to raise the alarm and begin retrieval without entering. Emergency services must be called for any entrant who is unresponsive or cannot self-rescue. A rescue exercise must be carried out with each crew every six months.

6.Closing the permit

When work is complete, the crew leader must confirm that every person and every item of equipment is out of the space, replace the cover, remove the isolation and close the permit with the finish time. The permit is retained in the register for two years.