Asbestos-cement (AC) pipes
The removal, replacement or rehabilitation of AC pipe is regarded as asbestos removal work for the purposes of the Occupational Health and Safety Regulations 2017 (OHS Regulations). In particular, Part 4.4 Asbestos of the OHS Regulations provides specific requirements in relation to asbestos removal work. Duties under the Environmental Protection Act may apply.
Victoria's aging water infrastructure, has prompted removal, replacement or rehabilitation of AC pipe programs across all water authorities in Victoria.
Pipe removal or replacement techniques
Current pipe removal or replacement techniques can result in the creation of asbestos waste.
Any asbestos waste must be safely removed and disposed of in accordance with the requirements of the OHS Regulations.
Pipe bursting
Pipe bursting uses plant to expand and burst existing AC pipe while pulling through a replacement pipe, leaving the AC fragments in the earth surrounding the new pipe, resulting in asbestos waste.
Pipe reaming
Pipe reaming is similar to pipe bursting. Drilling fluid is pumped into the asbestos cement pipe and as the reaming tool that is attached to the replacement pipe comes forward, the pipe fragments are captured in the drilling fluid, along with some of the soil which is then flushed down stream to the receiving pit. The mixture of mud, soil, and pipe fragments can be collected for disposal.
By-passing
By-passing involves decommissioning a section of AC pipe. The AC pipe is left on site undisturbed. A new pipe is installed in parallel to form the new pipe connection. The connection process involves connecting the new pipe to the existing AC pipe infrastructure, which can cause the pipe to break or fragment, resulting in asbestos waste.
Sliplining and curing-in-place pipe lining (CIPP)
Sliplining involves using plant to pull through a smaller diameter pipe inside the existing AC pipe. CIPP involves lining an existing AC pipe by inserting a resin saturated fabric tube inside the AC pipe and then inflating the fabric tube with air or water until the resin saturated fabric hardens. Both Sliplining and CIPP require tapping in to the existing AC pipe infrastructure and may create asbestos waste (broken or fragmented AC pipe) as a result.
Pipe removal and replacement
Removing and replacing pipes involves excavating a trench to expose the existing AC pipe for the length of the section to be replaced. The AC pipe is sectioned into small sections to be removed.
Once the entire length of the existing AC pipe section is removed, a new pipe that does not contain asbestos is then installed in its place and the trench is then backfilled. All sections of AC pipe removed along with any fragments created during this technique are to be considered asbestos waste.
Leaving any asbestos waste underground, including sectioned, broken or fragmented AC pipe as a result of AC pipe replacement, removal or rehabilitation may be a contravention of environment protection law and Victorian occupational health and safety laws. For more information please contact Environment Protection Authority Victoria.
Removal of non-friable asbestos
Asbestos removal must be performed by an asbestos licence holder (Class A or B) if:
- the area of asbestos containing material to be removed exceeds 10 square metres in total
- the total time of all asbestos removal work, including collection, done in any period of 7 days exceeds 1 hour
Sites of previous asbestos-cement pipe removal, replacement or rehabilitation
Where a duty holder (for example, a water authority) has previously replaced, removed or rehabilitated an AC water pipe by using any technique that resulted in asbestos waste remaining enclosed by earth on site with the replacement water pipe, they must:
- ensure, so far as is reasonably practicable, that the known sites are safe in respect to risks to health and safety resulting from the enclosed asbestos waste
- provide a copy of the asbestos register in accordance with regulation 229 of the OHS Regulations
- provide a copy of the asbestos register in accordance with regulation 229 of the OHS Regulations