Case studies of asbestos water pipe management practices
Prepared by Rawtec Pty Ltd in collaboration with Reincarnate and Prensa Pty Ltd for the Asbestos Safety and Eradication Agency, with six participating water authorities. Reviewed by Mark Rawson.
Summary published
There are 40,000 kilometres of asbestos cement water main in Australia — 26% of the national network — plus 5,000 kilometres of AC sewer main. Most of it went in between 1926 and the 1980s.
Less than 5% has been removed. As much as 90% will need replacing within fifteen years. The projected rehabilitation bill is $9.5 billion over fifty years at 2012 costs, against $400 million already being spent every year.
South East Water puts the shape of it plainly: it currently renews about 10 kilometres a year and projects a peak failure rate of about 160 kilometres a year by 2030. A sixteenfold increase in the work, with the same networks and the same crews.
Asbestos cement water main in Australia
Projected 50-year rehabilitation cost, 2012 dollars
Removed to date
South East Water’s projected increase in annual renewal
What six water authorities are actually doing
Technique choice is a multi-million dollar decision
South East Water’s five-year estimates: pipe cracking or bursting about $11 million, realign and leave about $14 million, lift and relay about $21 million. Lift and relay is the only method that leaves no asbestos in the ground, and it takes twice as long.
Regulation has already invalidated the cheapest method in one state
WorkSafe Victoria’s March 2015 guideline requires fragments generated by pipe bursting to be removed and disposed of as asbestos waste. Pipe bursting had cost 60 to 80% of new main construction. Goulburn Valley Water moved to realign and leave as a result.
Victoria carries the concentrated risk
“Some 70% of all AC pipes constructed in Australia between 1926 to 1947 — which are those currently at the highest risk of failure — were installed in the state.”
Long-term strategy is what separates the authorities
Authorities with a documented rehabilitation strategy “have clear indications of costs that can be then factored into financial planning and rates charges, and can adjust more nimbly to potential changes in regulations should they occur”.
In-house capability cuts the unit cost sharply
Central Highlands Water trains its own Class B staff. A six-metre removal at East Street, Daylesford cost about $500 in labour and equipment, two staff, roughly three hours. Barwon Water’s benchmark for its 20-kilometre-a-year program is about $200 per metre.
Liner technology is not yet bankable
“There are currently no commonly accepted standard or testing requirements that would allow a water authority to have confidence in the expected useful service life of liner.” Testing is constrained because “laboratories are reluctant to handle asbestos”.
Ingestion is not the exposure pathway
Both the Australian Drinking Water Guidelines and the World Health Organisation confirm asbestos fibres pose no risk via ingestion. The risk in this work is occupational and airborne, during the works themselves.
Public communication is the weakest link
“Whilst some water authorities have clear lines of communication with the public on AC pipe rehabilitation, there is an opportunity for a broader approach to communication on this issue.”
The four methods, compared
The most common approach. Disconnect and abandon the AC section in place, install a new pipeline alongside — often by horizontal directional drilling — transfer the service connections and cap the old one. Any pipe actually lifted goes out as asbestos waste.
Machinery pushed through the pipe expands, splits or breaks it, creating a void for the replacement. Fragments stay in the soil. Cheapest at 60 to 80% of new construction, and now constrained in Victoria.
The only method that leaves nothing behind. Pipe is removed in whole segments collar to collar to limit breakage. Requires full excavation and is the most expensive option.
A polyurethane spray or a resin-coated tube expanded inside the host pipe. Keeps the pipe intact, cuts leakage and corrosion, allows same-day return to service — but the service life is not yet certifiable.
Cost projections exclude the cost of removal and disposal of AC material. The report flags live regulatory uncertainty: “there is ongoing discussion within the industry and with state-based safety regulators on whether any rehabilitation options that leave asbestos material in situ fall within national asbestos management guidelines”, and Goulburn Valley Water notes “the interpretation of the legislation remains varied across Australia”. Two of the six authorities report no AC-specific network length or failure rate.
The other two ASEA reports
Same client, same team.
The full report profiles all six water authorities with their network figures, strategies, policies and cost data.
Working on an asbestos legacy problem?
These three reports came out of the same question: what does the evidence actually say about doing this well. If you are weighing up a removal program, a remediation business case or an asset renewal strategy, we would like to hear from you.