Aluminium trihydrate delivery gets suspended in eastern states, flood disconnects WA railway link

Authorities have warned regional water utilities that the severance of the rail link between Western Australia and the eastern states poses a "escalating risk" of water treatment chemical shortages.

The New South Wales water directorate said on Wednesday that a major supplier of aluminium sulphate, or alum, had alerted eastern clients that flooding on the east-west railway had caused deliveries of a vital element, aluminium trihydrate, to be suspended.

“At the same time as this potential supply shortage, recent widespread heavy rainfall across regional NSW is likely to create water quality challenges. Water utilities must carefully operate and monitor their critical control points, especially when raw water conditions change,” said the directorate.

While the chemical can be substituted, Prof Stuart Khan of the University of NSW's department of civil and environmental engineering said, "it's not something you'd want to have to move over too quickly."

While there was nothing to be concerned about, the sudden shortage demonstrated that "it's a dominoes game." It just takes one weak link in the chain to fail, and you're left with a slew of unanticipated repercussions,” added Khan.

After severe rains, many interior rivers were already muddy, necessitating the use of extra alum for treatment.

“There would be a high demand for good coagulation and you need to get that coagulation right in order to have the right conditions for chlorine disinfection [to treat pathogens]. If you are struggling to remove colour and turbidity from water because you haven’t gotten your alum dosing right, then you potentially risk your disinfection performance. “If you are struggling to remove colour and turbidity from water because you haven’t gotten your alum dosing right, then you potentially risk your disinfection performance,” added Khan.

Ixom, a Melbourne-based alum supplier, and Alcoa WA, a producer of aluminium trihydrate, were contacted for comment.

“The NSW government takes the issue of safe and secure water very seriously,” said a spokesperson for the planning and environment department.