More than a third of Cambodians lack access to safe water, leading to poor levels of sanitation and hygiene and high rates of water-borne disease, according to a statement from Unicef.

Young children are especially vulnerable, the statement released today to mark World Water Day said, adding that about 3.9 million people who do not have access to safe drinking water are impoverished and living in rural areas.

“Attention to rural water supply, sanitation and hygiene will unquestionably deliver results – less child deaths, better learning at school, less disease, more productive workers, less health costs for the people and the system,” Rana Flowers, Unicef representative to Cambodia, said in the statement.

“The sector requires substantial investment . . . and strengthened commitment and inter-ministerial collaboration at both national and local levels,” she went on to say.

Unicef also made the case for increasing investment in clean water by claiming the health impacts, particularly treating diarrhea, the leading cause of infant mortality in the country, was costing the government $146 million per year.

Officials at the Ministry of Health could not be reached.

Sophary Phan, a technical officer at the World Health Organization Cambodia, said that the government should improve water supply facilities and existing infrastructure, use more up-to-date technology and work more closely with private companies.

Lin McLennan, program manager at local NGO Watershed, said that “Cambodia’s fortunate in some respects. The issue is the quality of the water”.

“We think there a lot of opportunities to engage with the private sector. People are trying to aim more at the poor and vulnerable, but people have got used to subsidised water.”

Touch Khon, a representative of the Phnom Bath community who were evicted from Borei Keila in 2012, said the government had promised them water at the relocation site, but they still relied on store-bought water and unclean sources.

“The authorities came to tell us three months ago, that they will make a clean water system to connect into our new village. But until now, we have no clean water,” he said.

“The water from the pump [is not clean]. We buy big bottles [of water] for cooking for 500 riel (12 cents). I want the government and company that brought us here to improve the water supply and electricity. Sometimes, when the people drink the water, they get diarrhea.”