The conventional advice around town is that you should not drink the tap water, with rumours abounding that it may contain anything from harmful bacteria to arsenic – but how much of this is urban myth, and how much is based on hard fact?

It seems the slogan "think before you drink"might provide sage counsel to many of Phnom Penh's inhabitants.

But while vigilant residents and tourists alike imbibe gallons of bottled water each day, demurring from what they perceive to be an ‘unclean' local supply, data from authorities suggests that this advice might be more aptly applied at the local bar than at the kitchen sink.

Your average glass of tap water from the capital may contain unhealthy doses of hyper-vigilance, ambiguity and misinformation - but what else is in there?

Where does this stuff come from, and who puts what in it?  And is it really safe to drink?    

          

Doctor's orders

"Don't even think about it," says ex-pat general practitioner and tropical diseases specialist, Dr Gavin Scott, of the Traveller's Medical Clinic.

"I certainly do not drink the water here and would advise others not to," he says.

"With bottled water so cheap, there's just no need to risk it."

According the Scott, who has lived in Phnom Penh for 17 years, around 30 percent of the patients who come to his clinic are suffering from travellers' diarrhoea - the proverbial "runs".

Diarrhoea can be triggered by ingesting ecoli bacteria or gastro-intestinal parasites such as worms, amoeba or giardia as a result of faecal contaminants in the food or water supply.  And while some residents may build up temporary resistance to the nefarious ecoli, there is no immunity against parasites and worms or other more serious water-borne diseases such as rotaviruses, Hepatitis A and B and typhoid, all of which occur through faecal contamination.

With the myriad dubious hygienic practices potentially occurring out the back of your favourite restaurant or below the surface of the hotel swimming pool, it may be difficult to avoid, or even identify, sources of contamination.

If you can smell the chlorine, I means that there is no bacteria and the water is absolutely safe to drink.

But like other medics, Scott insists that drinking, washing food and brushing your teeth with bottled water is one way of limiting your exposure.

"There's never any guarantee of complete protection - it's all about reducing risk," he says.

"I have no confidence in the plumbing system here, and if the water supply doesn't already have bacteria in it, it definitely could by the time it comes out of the faucet."

With small bottles of water costing up to $3 in some nightclubs, drinking tap water is an option for those wanting to rehydrate after a long night of dancing.

What our city folk think about whether to drink

Jolynna Sinanan, 26, Australia

8 months in Phnom Penh

“I definitely don’t drink the tap water in Phnom Penh. I don’t trust it – I mean, have you seen the river? I could get any number of things. But I do brush my teeth with it, because I figure I will consume far less of the stuff than by drinking litres of it directly from the tap.”

Warren Jameson, 40, United Kingdom

2 months in Phnom Penh

"No, I don’t drink it unless it’s boiled, like in tea, or filtered. We have a filter tank at home so it’s easy just to use that. I don’t think the water here is treated correctly and the source certainly does not seem particularly clean. I do brush my teeth with it though and I’ve never had any problems with that.”

Hin Dan, 25, Kampong Speu province

5 years in Phnom Penh

“I think the tap water is not so clean, but I use it for everyday things like drinking and cooking. It’s not good for our health because sometimes it smells bad and it’s murky and even if I boil it I can’t kill 100 percent of the bacteria. But it is better than water in rural areas. When it smells bad I use tea to reduce that smell. I’m afraid that using the tap water will have long-term effects on our health, but I have no other choice. I want to use pure drinking water, but can’t afford it.”

Duy Sreyroat, 24, Takeo province

5 years in Phnom Penh

"At home I used to use water from the well and rainwater, so it’s a bit strange for me to have to use tap water for the first time in Phnom Penh. It’s easier than before, but I don’t think the water is good to drink because it comes from the river and is just cleaned with a machine. It has a lot of diseases that we can’t see even though it looks clear. I use tap water for cooking and cleaning clothes but boil it before I drink it.”

Ahti Westphal, 29, United States

5 months in Phnom Penh

“I don’t knowingly drink tap water. I drink water that is served at most establishments with a certain amount of faith that it won’t kill me. I haven’t yet been so bold as to draw a nice tall glass from the kitchen faucet and drink it down. I’m pretty sure if I did, it would be OK though. I figure that if there is bacteria or toxins in it, you’re going to be exposed to them anyway – through ice, eating out, washing your hands, et cetera.”

Thong Yort, 25, Prey Veng province

4 years in Phnom Penh

"I think the tap water is cleaned up for us a bit, and is okay to use, but its smell is not so good. It seems like they've put chemicals in it. I don't think we can drink it directly from the tap, and before I drink it I store it in an ceramic filtration barrel for a day or two. I think it might have an impact on my health one day, but I don't know how much and how long it will take to appear."

The authority from the Authority

By contrast, Ek Sonn Chan, director of Phnom Penh Water Supply Authority (PPWSA), is brimming with confidence.

"All citizens in the capital can drink the water straight from the tap - without even boiling it," he says. Ek Sonn Chan is so confident in the capital's tap water that in 2007 he said he would pay compensation to anyone who got a stomach ache after drinking it.

But then some degree of faith would be warranted, given he's risked his life for it.

After joining the war-torn PPWSA in 1993, Ek Sonn Chan implemented a dramatic overhaul of the organisation, rectifying leaks, illegal pipe connections and contamination, and increasing the utility's distribution network from 40 to 80 percent of the city.

Ek Sonn Chan's 12-year innovation made him the object of assassination rumours, but it also saw him awarded the Asian Development Bank's 2004 Water Prize to become a ‘water champion'.

According the director, PPWSA now provides 90 percent of Phnom Penh's residents with safe, treated and disease-free water from the city's own Tonle Sap river.

Unlike groundwater supplies in rural areas, the Tonle Sap is not subject to arsenic contamination, nor does it have toxic pesticide residues, a fact confirmed by the most recent World Health Organisation (WHO) survey, which described the river as a good quality source requiring only basic disinfection treatment.

However, Ek Sonn Chann is aware that many residents, mainly the more affluent classes, remain unconvinced.

"Most poor people drink tap water, but the rich people don't trust our workings," he explains.

"I'm always promoting the safety of tap water, yet they think it is unclean, and insist on drinking purified water."

But convincing wealthy Cambodians of the quality of PPWSA's product is not Ek Sonn Chann's primary concern.

"I'm not going to force these people to drink our water," he says.  "The main problem we face today is supplying safe water to everybody, not just 90 percent of the city."

Leading by example

Jan Rosenboom, Country Team Leader of the World Bank's Water and Sanitation program since 2003, is quick to affirm the quality of PPWSA's supply.

"It's a fantastic authority," he says. "There's been an enormous amount of renovation of the pipe and distribution system, and now it's a world-class facility."

Rosenboom's team has collaborated with organisations including the Ministry of Health and WHO to develop the current interim Cambodian Drinking Water Quality Standards (CDWQS), to bring the water supply in line with international standards.

And unlike medical authorities, Rosenboom encourages residents to follow his lead and do away with the personal and environmental expense of bottled water.

"The water quality here is great and the supply to the whole centre of town is fine to drink," he says. "I would suggest that medical advice saying otherwise is very outdated."

While pipe systems connected directly to the street are guaranteed to receive PPWSA's treated supply, Rosenboom explains that the old, open brick storage tanks used in some residences may pollute the supply with algae or other toxins.

However, it is not the possibility of biological contamination from outdated storage units which deters most residents from drinking tap water, but the chemicals added by the PPWSA to combat bacterial contamination.

"The funny thing," Ronsenboom says, "is that both in and outside of Phnom Penh, many people aren't aware of chlorine and don't like the taste or smell, so they're suspicious and won't drink the water. But if you can smell the chlorine, it means that there is no bacteria and the water is absolutely safe to drink."

Meanwhile, back at the lab...

According to Laboratory Manager at NGO Resource Development International Cambodia (RDIC), Andrew Shantz, water chlorination is a matter of fine lines.

"Too little chlorine and it doesn't kill the bacteria, too much and you'll get chlorine by-products," Shantz says.

Shantz also explained the cloudiness that may appear in a glass of tap water left standing overnight. "This is usually the result of iron reacting with oxygen, and is not a health risk," he said.

While RDIC endorses PPWSA's regulation of bacteria and chlorination, they also suggest that it is not the water source but its distribution which can be cause for concern.

"The water comes from the Tonle Sap, which is good chemically," says Deputy Director, Marc Hall. "They pull drinking water from the north of town, whereas the effluent is flowing to the south. The problem tends to be in the distribution system, which is variable," he explains.

"It's not the government's fault," he says, "but it's just an old city, and they didn't have access to new materials like PVC, so can't guarantee clean delivery without digging up the whole place."

In light of the idiosyncracies of Phnom Penh's plumbing system, RDIC makes no broad recommendations to residents about the safety of drinking tap water.

Their laboratory can analyse individual water samples and provide scientific advice accordingly. RDIC also provides low-cost, ceramic water filters, and distributes these to villages in the provinces. More information on their silver-impregnated, antibacterial filters is available on their website at www.rdic.org.

The final analysis

A random sample of Phnom Penh tap water was taken by the Post from a private residence in the city's Boeung Keng Kang 1 (BKK1) district.

The water sample was sent to RDIC for testing for biological and chemical contaminants, along with two samples of filtered water from commercial bottled water suppliers.

Surprisingly, the results suggested that the biggest difference between the bottled water and the tap water was the price.

All samples were free of arsenic, E coli and other chemical contaminants tested for by the laboratory. And while the chlorine levels in each sample fell below the optimum CDWQS range, RDIC explained that this would only be of concern if bacteria were also present.

The verdict?

"The water from the BKK1 sample would be absolutely fine to drink," says Shantz. 

So what's the go with my H20?

So where do these conflicting messages leave your average, thirsty Phnom Penh inhabitant arriving home after a big night, ill-equipped to rehydrate with a few litres of Evian?

In the absence of home-testing kits, filters, or the patience for boiling, these ambiguities may well raise the perennial question: "to drink or not to drink"?

Let's put it in perspective. Between the beef lak lak you just ate for dinner and post-monsoon gutter you just waded through to get home, a few draughts of PPWSA's highly esteemed water supply may be the least of the murky of waters you have to contend with.

 The facts: Phnom Penh’s water supply is put to the test

While it is impractical and unnecessary to test for all possible contaminants in water, the most likely cause of problems in Phnom Penh is bacteria, although metals and pesticides may also be of concern.

However a recent WHO study found Phnom Penh's water source to be free from pesticides.

For the Phnom Penh Post's tests, a sample of tap water was taken from a house in BKK1 and tested alongside two samples of bottled water at an independent laboratory for  the following:

• Iron: an indicator of rusted pipes, iron increases the "hardness" of water and can stain plumbing fixtures and laundry.
• Arsenic: an odourless and tasteless semi-metal, arsenic has serious health effects. It is not usually present in surface water, but can find its way into groundwater.
• Turbidity: a measure of the cloudiness of water, turbidity may be caused by mud, silt, sand, pieces of dead plants, bacteria, aquatic organisms, algae and chemical precipitates. It is a measure the effectiveness of water filtration.
• Conductivity: a measure of the water's ability to conduct electrical current, conductivity indicates the amount of dissolved minerals, or electrolytes, in the water, but does not indicate which minerals or metals are present.
• pH: a measure of the alkalinity or acidity of water. A pH of 7 is neutral, while lower pH is acid and higher is alkaline.
• Total coliforms: Coliform bacteria are present in surface water, and may indicate harmful bacteria such as klebsiella, cryptosporidium, giardia, or salmonella.
• E Coli: Escherichia coli is a type of faecal coli that indicates septic contamination.
• Chlorine: a disinfectant. When added to water, some chlorine reacts with organic materials and metals and is not available for disinfection. The remaining chlorine is the total chlorine, which is divided in turn into combined chlorine, the amount that has reacted with nitrates, and the free chlorine which is available to kill disease-causing organisms. A free chlorine level of 0.5mg/L will maintain the quality of water through a distribution network, but is unlikely to maintain the quality of water stored in a bucket for 24 hours.

None of the parameters tested exceeded the limits recommended by the Cambodian Drinking Water Quality Standards.

The tap water was higher in iron than the bottled water, with three to five times higher turbidity. It also contained electolytes, whereas the bottled water contained none. ADDITIONAL REPORTING BY MARK ROY