1. Purpose Sewerage Transfer Assets This procedure defines specific requirements in addition to CORP H&S 053 Confined Spac e Entry and is designed to be read in conjunction with that document for work on Sewerage Transfer Assets. 2. Scope This procedure applies to all work done under a Sewerage Transfer Access Approval (ST AA) including confined space work in Melbourne Water s sewerage assets. Any entry into a Melbourne Water sewer is a confined space entry and must fully comply wit h CORP H&S 053 Confined Space Entry. Any work done on a Melbourne Water sewerage transfer asset (e.g. manhole or pump station) which involves exposure to sewage and/or sewer headspace gas and/or requires a Sewerage Transfer Access Approval (STAA) must comply with this procedure, even if there is no confined space entry involved. Following this procedure does not remove the requirement to comply with all other Melbourne Water procedures. This document is designed to be additional only. If a particular H&S provision is omitted from this document the relevant Melbourne Water procedure must be followed. These include but are not limited to: CORP H&S 008 Task Risk Assessment CORP H&S 022 Medical Assessments CORP H&S 038 Safety Equipment CORP H&S 053 Confined Space Entry CORP H&S 062 Fall Prevention CORP H&S 064 Permit to Work CORP H&S 068 Biological Hazards 3. Procedure 3.1 Entering Sewers Entry into sewerage assets is to be avoided wherever possible. 3.1.1 Access to Surcharged Sewers entry to a surcharged sewer is permitted. 3.2 Access Permits (additional to CORP 053 section 7.3.2) 3.2.1 Permit Approval Process To work on any Sewerage Transfer Asset which involves exposure of personnel t o sewage or sewer headspace gas it is required that the work party obtain a Sewer Access Approval in addition, and prior to, a High Risk Work Permit. A copy of the approved STAA and the associated High Risk Work Permit must be available on site whilst entry to a sewerage asset is in progress. The process to gain all permits to enter a Sewerage Asset is shown in Figure 1. Version: 4.0 Page 1 of 9
Figure 1 Procedure for Sewer Entries Permit/Approval Procedure for Sewer Entries Additional to CORP H&S Phase Permit Application Step 1 Access Sewerage Transfer Access Documents Access the SAA document and assess hazards Obtain the STAR template Step 2 Completed STAR form submitted to ICC along with SWMS/TRA&WMS When scheduling works please allow up to: - 5 days for works without isolations - 30 days for works with isolations. Be aware that hazardous conditions can impact any sewerage asset at anytime. Work may need to be cancelled or rescheduled at short notice Are Isolations Required? Approvals Step 3 Control Room process STAR in SAPs system and provides: - The approved STAA - A time to issue HRWP - A confirmed date and time of works Step 4 High Risk Work Permit Issued Applicant is contacted, isolations discussed, and a date for work is set Step 5 Risk Assessment/TRA/Take 4 Undertaken Step 6 Field crew ring ICC, quoting STAA number, prior to opening manhole Step 7 CSE Permit filled out (if conducting a CSE) On Site/Field Activity Acronyms: Step 8 ICC will advise if entry is still permitted based on sewage quality Step 9 After work is completed and site is made safe, field crew to ring and inform ICC CSE: Confined Space Entry SAA: Sewer Access Alerts STAR: Sewerage Transfer Access Request STAA: Sewerage Transfer Access Approval ICC: Integrated Control Centre SWMS: Safe Work Method Statement TRA: Task Risk Assessment SAP: Sewer Access Permit HRWP: High Risk work Permit Step 10 Work completed? Permit is cancelled Version: 4.0 Page 2 of 9
3.2.2 Sewerage Transfer Access Documents All documents required to apply for access to a sewerage transfer asset can be found at the Sewerage Transfer Access Documents site. Here you will find the: Sewerage Transfer Access Alerts Sewerage Transfer Access Request form Current ICC contact details Relevant Policy and Procedure for accessing Melbourne Water s sewers Any other relevant safety or access information 3.2.3 Sewerage Transfer Access Approval (additional to CORP 064 Permit to Work section 7.3) To obtain a STAA a Sewer Transfer Access Request (STAR see Figure 3) form must be filled out and forwarded to the Integrated Control Centre (ICC). This form is in addit ion t o a Safe Work Method Statement (SWMS) or Work Method Statement (WMS) with separate T ask Risk Assessment (TRA). This submission should meet all the initiation activities requirement s as per CORP 064 Permit to Work section 7.3. tification of the approval of a STAR will be in the form of a STAA which will be forwarded t o the applicant with any known information, at that time, concerning extra hazards associated with relevant sites. Safety requirements for all work done under a STAA All work conducted under a STAA permit must take the following safety precautions in addition to all precautions required by other Melbourne Water H&S Procedures: The ICC must be called immediately prior to the asset being accessed i.e. before t here is any potential exposure of personnel to sewer gas or sewage (call-in), quoting ST AA and High Risk Work Permit number The ICC must be called after the work party has made the sit e safe and before t hey leave (call-out) A 6-gas detector must be used for pre-work checks and atmospheric monitoring during work 3.2.4 Scheduling works On receiving a STAR and High Risk Work Permit (HRWP) application the ICC will determine any necessary isolations or precautions required for the works. Works where there are no additional isolations or precautions If there are no additional precautions or isolations required to conduct the work, the STAA will be issued and the date requested in the application will be confirmed. Confirmation will be given along with the STAA. The HRWP can then be collected from the ICC ahead of works commencing. When applying for work that does not require precautions or isolat ions allow a lead time of five days from the date that the ICC receives a complete STAR and HRWP application. Works where there are additional isolations and precautions required If a STAR and HRWP application requires isolations or additional precautions then the work party will be contacted by the ICC before the STAA is issued and a date for the works discussed. This date will be sometime within 30 days of the ICC receiving a c omplet ed ST AR and HRWP application. The HRWP will be issued to the work party once all isolations are in place. This will usually occur onsite and on the day of the works. A list of sewer locations that will typically require isolations will be available on the Melbourne Water Sewerage Transfer Access Documents site. Version: 4.0 Page 3 of 9
3.2.5 CSE Permits If the work involves a regulated confined space entry e.g. entry into a sewer manhole, a CSE permit must also be filled out onsite. The person in charge of the entry must complete the CSE Permit (see CORP H&S 053.1 for a copy of the Entry Permit) before any person is permitted t o enter the confined space. CSE permits should be completed as per CORP 053 section 7.3.2. 3.3 Atmospheric Testing (additional to CORP 053 section 7.3.5) 3.3.1 When is Atmospheric Testing Required? Atmospheric testing is required for all work that is done on Sewerage T ransfer Assets t hat involves any level of exposure to sewage or sewer headspace gas or requires a ST AA. Even if works do not involve an entry into the confined space, atmospheric t esting is st ill required. This includes both pre-entry (where pre-entry would be more correctly called pre-work in t his case) and continuous monitoring. This is required to: Detect if a sewer contains an explosive atmosphere where surface works may introduce a source of ignition and Detect any gasses that are lighter than air which may be educted out of t he manhole and impact personnel on the surface 3.3.2 What Atmospheric Testing is Required? As shown in CORP 053 section 7.3.5 all atmospheric testing for Sewerage Transfer Works must be done with a device capable of detecting the following 6 gasses and be set up to alarm at the levels specified in table 1 below: Table 1 Acceptable pre-entry and continuous alarm atmospheric levels Gas Acceptable Pre-entry level Alarm level (must exit space) Oxygen t less than 19.5% (by volume) t greater than 23.5% (by volume) Less than 19.5% Greater than 23.5% Carbon monoxide Less than 30ppm Greater than 30ppm Hydrogen sulphide Less than 10ppm Greater than 10ppm Explosive level Less than 5% LEL Greater than 10% LEL Volatile Organic Compounds Less than 10 ppm Greater than 10 ppm Ammonia Less than 25 ppm Greater than 25 ppm Detection of VOCs must be via a Photo Ionisation Detector (PID) with a 10.6 ev lamp. 3.3.1 Why is Sewerage Transfers Atmospheric Headspace testing different Headspace conditions within sewerage assets may be affected by trade waste discharges bot h authorised and/or unauthorised. These contaminants are potentially toxic or explosive. Sewerage Transfer requires monitoring for two extra gasses: Ammonia (NH 3) and Volatile Organic Compounds (VOCs). These compounds can present a risk to sewer worker healt h if inhaled. It is permitted to mechanically ventilate for both high Ammonia and High VOC detections. It is also permitted for an appropriately trained person to enter if they are wearing breathing apparatus (BA) which completely protects the worker from inhaling any sewer atmosphere. A chemical gas suit to protect the skin may be required for high ammonia entries or certain high VOC entries. Any entry under BA and chemical gas suit must be individually risk assessed by an appropriately trained person/occupational hygienist. Version: 4.0 Page 4 of 9
3.3.4 Atmospheric Testing related work processes Sewerage Transfer operators/control room personnel check known sewer conditions on every call-in for entry. One of three different classifications may apply: Go in place; where lifting of manhole covers and sewer entry is prohibited unless formalised arrangements have been made with the ICC/Sewage Transfer Team; or Special Headspace Testing is required; where Melbourne Water s preferred supplier of occupational hygiene services will be engaged to conduct headspace testing; or General warning ; where abnormal conditions are known to exist but t he risk has been assessed and it has been determined that normal confined space and/ or STAA procedures are sufficient precautions. General Warnings should be taken into account when risk assessing works on assets where they apply. Sewerage Transfer Access Alerts Document The Sewerage Transfer Access Alerts Document has all the most up to date sewer classifications (no-go s etc.) This document is prepared by Sewerage T ransfer personnel in consultation with the Retail Water Company (RWC) trade waste teams. It has informat ion on any known toxic or explosive conditions in the sewer. These classifications are constantly updated and the classifications could change at any time. A copy of the Sewerage Transfer Access Alerts Document is kept on t he Sewerage T ransfer Access Documents site. This document should be consulted when preparing t he ST AR/HRWP application risk assessment. From time to time there are unauthorised discharges (e.g. illegal dumping) into the sewer system that could impact the health of workers. Neither the Sewerage Transfer team nor RWC trade waste teams will be able to give warning about these unauthorised discharges. To protect people from this type of hazard it is important that all work crews use a 6-gas detector and exit immediately if it alarms. 3.3.5 Response procedure after detection of abnormal headspace conditions If the gas detector alarms during your pre-entry/pre-work test the following process should be followed: Version: 4.0 Page 5 of 9
Figure 2 High pre-entry atmospheric test alarm response process Gas detector alarms during pre-entry testing Is the alarm for high LEL? Exit the space immediately and isolate space (e.g. close manhole cover) taking care not to introduce a source of ignition Can extra ventilation resolve the issue? Once gas readings are normal proceed with entry Report the high LEL reading and location to ICC Isolate the space & report the nature/ level and location of alarm to ICC Sewerage Transfer Support team will initiate investigation Is this the second instance of this issue? ICC will inform Sewerage Transfer Support Team to log issue If the gas detector alarms during the continuous monitoring of t he spac e or you suspec t a dangerous gas, feel eye irritation, headache, dizziness, shortness of breath, or nausea: Put on the self-rescue respirator Signal to the surface Move immediately to exit the confined space If unable to exit by yourself signal distress to the surface attendant who will initiate the emergency rescue procedure. An emergency rescue procedure must be developed for all confined space entries as per CORP 053 Confined Space Entry. Once safely out of the confined space the process in Figure 2 should be followed. All high gas readings should be recorded on the CSE Permit. 3.4 Restricted Spaces and Surface Works All work that involves exposure of personnel to sewage gas or sewage requires a STAA even if the space is not a regulated confined space. These works include (but are not limited to): Entry into restricted spaces (even if only for inspections); and Works that take place from the surface of an open sewer manhole. 3.4.1 Restricted Spaces or Spaces Requiring Authorised Access There are a number of spaces in Melbourne Water s sewerage transfer net work t hat are not regulated confined spaces but require precautions due to the risks associated with hazardous Version: 4.0 Page 6 of 9
gases potentially entering the space. In order to enter a restricted access or authorised access only space the work party must: Hold a Sewerage Transfer Access Approval Confirm immediately before entry that any fixed mechanical ventilation for that space is in normal operation tify the ICC (9325 2555) immediately prior to, and immediately on conclusion of t he entry (call-in and call-out) Be contactable at all times A 6 gas detector is to be with the entry party throughout the entry and if the gas detector alarms the restricted space is to be immediately evacuated Self-rescue breathing apparatus must be available for each person entering and should be within immediate reach At least one member of the work party should also be confined space entry trained 3.5 Work Party Sizes (additional to CORP 053 section 7.3.8) For all entries into Sewerage assets the following requirements apply: Where there is one person working in the confined space there must be a minimum of two standby persons; or Where there is more than one person working in the confined space, there must be an equal number of standby persons. One member of the surface party must remain at the surface entry-point of the confined space, and the others must remain within hailing or hearing distance of any dist ress signal. Other members of the surface party may undertake other tasks on t he sit e, but all must be immediately available for assistance if requested. If the person in the sewer does not remain within constant visual contact of the surface part y, other persons will be required inside the sewer to enable constant observation. 3.6 Harnesses (additional to CORP 053 section 7.3.10) Harnesses and lifelines/retrieval lines are required to be worn for all confined space entries into sewer assets. Due to the credible risk of failure of the manhole ladders due to early life corrosion, all harness used must be suitable for both rescue and fall protection. Harnesses and lines should be used to prevent falls in compliance with CORP H&S 062 Fall Prevention in sewer works that present a fall risk. The fall prevention line can be detached once at the bottom of the ladder but the retrieval line should remain connected at all times. During entry and exit the control of the lifeline shall be via an approved winch. 3.7 Excavations into Sewers When a shaft or trench is excavated to enable break-in to a sewer (i.e. t here is a possibilit y that the work party will be exposed to sewer headspace gas and/or sewage) they will need t o apply for a STAA and take all precautions outlined in this document for the period the sewer is being broken into until it is resealed. It is likely that while the break-in is underway t hat t he shaft or trench will become a confined space (see definition in CORP 053) and t he work will have to comply with CORP 053. Air testing is to be conducted from just prior to the break-in until sufficient filling is replaced to ensure no gases are released from ground contaminated by sewage spills or surcharge. Version: 4.0 Page 7 of 9
Figure 3 - Sewerage Transfer Access Application Version: 4.0 Page 8 of 9
4. Definitions and Acronyms All definitions as per CORP H&S 053 Confined Space Entry Reference Sewerage Transfer Assets CSE HRWP ICC LEL PID STAA STAR SWMS TRA VOC WMS CORP 053 Definition Defined as all assets located between the interface with Retail Water Companies sewers, Western Trunk Sewer manhole 1 (WTS001) and South Eastern Trunk Sewer manhole 2 (SETS002). Confined Space Entry High Risk Work Permit Sewerage Transfer s Integrated Control Centre Lower Explosive Level Photo Ionisation Detector Sewerage Transfer Access Approval Sewerage Transfer Access Request Safe Work Method Statement Task Risk Assessment Volatile Organic Compound Work Method Statement Refers to CORP H&S 053 Confined Space Entry Version: 4.0 Page 9 of 9