How long should you boil water to make it safe to drink?

This report published in Communicable Diseases Intelligence Volume 22, No 9, 3 September 1998 contains information on boiling water for safe consumption.

The recent incidents of contamination of the Sydney water supply with Cryptosporidium and Giardia have generated considerable interest in the issue of how long water should be boiled to make it safe to drink. CDI inadvertently muddied the waters (so to speak) in last month's edition when our 'Advice for travellers' recommended that water be boiled for at least 10 minutes.¹ This information was sourced from the fourth edition of the Commonwealth Department of Human Services and Health's publication Health information for international travel.² This reiterates the unreferenced recommendation of earlier editions of the same publication. Our attention has since been drawn to the Centers for Disease Control (CDC) recommendations for boiling water, which were made in September 1994 on the basis of a contemporary literature review.^3,4 These recommendations have been followed by the New South Wales health authorities in responding to the contamination incidents.

CDC recommends making water microbiologically safe to drink by bringing it to a rolling boil for one (1) minute. This will inactivate all major waterborne bacterial pathogens (for example, Vibrio cholerae, enterotoxigenic Esherischia coli, Salmonella, Shigella sonnei, Campylobacter jejuni, Yersinia enterocolitica and Legionella pneumophila) and waterborne protozoa (for example, Cryptosporidium parvum, Giardia lamblia, and Entamoeba histolytica). It will also be effective for waterborne viral pathogens such as hepatitis A virus, which is considered one of the more heat-resistant viruses. An increase in boiling time to three (3) minutes is recommended if viral pathogens are suspected in drinking water in communities at elevations above 2 km.

References

1. Anonymous. Advice for travellers. Commun Dis Intell 1998;22:154.
2. Department of Human Services and Health. Health information for international travel. Fourth edition. Australian Government Publishing Service, 1994.
3. Anonymous. Assessment of inadequately filtered public drinking water - Washington, D.C., December 1993. MMWR 1994;43;661-668.
4. Anonymous. Assessment of inadequately filtered public drinking water - Washington, DC, December 1993. JAMA 1994;272;1401-1402.

Water crisis hampers growth

SUE NEALES   Chief Reporter     January 04, 2007 12:00am

TASMANIA'S ageing and inferior water and sewerage infrastructure is so bad it is hampering economic growth, says State Treasurer Michael Aird.

Mr Aird said that while Tasmania was lucky it had copious supplies of water, the key issue facing the Government was whether it was being delivered properly to the right places.

The Treasurer has already initiated a major review of the water and sewerage sector in Tasmania, with the issue expected to feature in state politics in 2007.

Many parts of Tasmania have just experienced their driest year on record, while drinking-water bacterial contamination remains a major problem.

"Everyone knows what the problems are -- we have 90 water supply areas, three bulk water authorities, up to 30 places on permanent boiled-water alert and inadequate infrastructure on the East Coast," Mr Aird said yesterday.

"It's not a good look (for Tasmania) and we need to fix it up."

He said the requirement for so many towns to boil their water before it was safe to drink meant the state's pristine green image and valued "brand" was suffering.

"The aim is to have communities that are sustainable in the long term," Mr Aird said.

"But right now we haven't been able to develop the (water and sewerage) infrastructure to match economic growth, and in some places that is actually becoming an impediment to further growth."

He pointed to the Sorell and southern beaches region to Hobart's east, where overloaded septic tanks are contaminating groundwater and have forced the Sorell Council to stop issuing new home-building permits until a proper sewerage treatment system is installed.

"It is wrong to say the State Government is ignoring the issue or doing nothing," he said. "What I say is that Tasmania has a wonderful opportunity now to update its infrastructure and become the best manager of water in Australia."

Mr Aird says he has always had a keen interest in water issues, going back to his days as environment and planning minister in the minority Field Labor government, when he felt frustrated because water was not part of his portfolio.

Now, as Treasurer, he is excited to be able to play a major role in how Tasmania treats its water.

So far he has overseen the launch of the State Government's discussion paper on the reform of Tasmania's water and sewerage sector, released in December and available for public comment until the end of next month.

Mr Aird and Water Minister David Llewellyn recently met Malcolm Turnbull, the powerful federal parliamentary secretary to the Prime Minister with responsibility for national water issues.

More than $2 billion of federal funds are available to help states such as Tasmania fix infrastructure.

In 2005 the national engineering professional organisation Engineers Australia rated Tasmania's water and sewerage infrastructure the worst in Australia.