HELEN Gillard watched in dismay as the Ghanaian woman began digging down into the parched riverbed. Scooping out a dusty hole with a simple bowl-like calabash, made from dried fruit skins, she desperately tried to locate the water source that instinct told her had to be there. Behind her, another 50 women fought to ensure their turn came next. "The women were in a frenzy, fighting over who was going to go down next to get the water. But the real shock came when I saw what some of them had walked up to 12 miles to collect . . . it was muddy grey silt."

As a trade effluent advisor with Scottish Water, Helen thought there was little she didn’t know about water contamination. Her job brings her into daily contact with businesses pumping every kind of trade waste imaginable into Lothian’s sewers. However, even with her extensive experience, she wasn’t prepared for what she discovered in Ghana.

Just 48 hours before she was taken to the riverbed, Helen had flown into the Ghanaian capital, Accra, as part of a two-week fact-finding mission. There, the party from Wateraid - a charity dedicated to fighting drought by providing safe drinking water - met the country’s vice president, Aliu Mahame. He explained that while the government had allocated funds to set up projects to provide clean water in an attempt to tackle the problems of water-borne disease - in the north of Ghana, one child dies every 15 seconds in this way - they couldn’t afford to eradicate the problem completely.

Now back at work in Scottish Water’s headquarters in Buckstone, Helen says: "It doesn’t matter what you see on the television, or read in the papers, there is no comparison between that and actually seeing it for yourself. We were briefed before we left the UK that we would see people living in the very worst conditions imaginable and that then, at the end of the trip, we would visit a village that had been helped by Wateraid 15 years before to allow us to see what can be achieved, so I expected to see a lot of poverty."

Arriving in Accra, Helen soon witnessed that poverty . . . even though, by Ghanaian standards, the capital is considered affluent. "We flew in at night, and when I stepped from the plane into the 35-degree heat, I just thought: ‘How am I going to survive in this for two weeks?’"

With the dawn came the discovery that Accra was a dusty and arid place. But worse was to come when, after meeting Mahame, they flew to the town of Tamale in the north of the country.

"The interesting thing about going to the north was that we travelled with the local Wateraid staff. They work on the ground in Ghana, but even they were shocked by what we found," said Helen.

"As the plane descended through the clouds, the first view I got of Tamale was a scattering of little mud huts in the middle of nowhere. There were no roads - just dusty tracks. I had no idea how little the people there would have."

She spent that night in one of the citizens’ huts and discovered that the water supply came from a government-funded reservoir. But even though they had running water, that did not prevent the spread of disease, borne by water.

She explains: "The problem of water-borne diseases comes from still water that has become stagnant. In Tamale, they get their water from a big dam. It’s full of organic matter and is actually green in colour."

The biggest health problem caused by drinking such water comes from a parasite known as a Guinea worm, says Helen. "We saw a number of cases of Guinea worm in Tamale. The worms live in the mud on the bottom of the reservoir, and if you drink water that contains the eggs of the Guinea worm, they hatch in your stomach."

Over a period of six to nine months, the Guinea worm grows to five feet long and it can live inside its host for up to three years before eventually leaving the body.

"When it wants to get out, it starts to eat its way through your flesh to escape," says Helen. "It usually comes out through the leg or, in a woman, the breast.

"While we were there, we saw a three-year-old boy having one removed from his scrotum. It was excruciatingly painful, but once the worm has poked its head out through the skin they have to remove the whole thing, because if the head got broken off, what was left of the worm would begin to rot inside."

The next day at dawn, Helen travelled to an outlying village. "I spent the day with a local family, which was kind of unnerving because we were in the middle of nowhere. They lived in a series of small mud huts with a yard in the middle that was their main living area. Behind it was where they kept their animals - one young cow and a few guinea fowl - so you can imagine the smell."

Despite arriving first thing in the morning, when Helen met the father of the family she discovered the women were already on their way to collect the water for the day. Heading out to catch them up, she found them scrambling by the dusty riverbed.

But while these families don’t have Guinea worm to contend with, their major problem is Bilharzia, a parasitic infection caused by "blood flukes" (worms), which can be picked up via fresh water. The flukes, which are carried by infected snails, penetrate wet skin and, during a four to six-week incubation period, migrate to the liver.

Helen says: "The family I visited had problems with that, but a lot of the children in these villages also die of basic diarrhoea."

Preventing these deaths is easy, she insists, and doesn’t have to cost a fortune. "The amount of money spent in the UK on ice-cream in one year would provide everyone in the north of Ghana with water for life - that’s not a lot of money really."

In the second village that Helen visited, they are halfway to achieving that. After eight years of Wateraid support, the villagers now have a supply of clean water, although some of them still have to walk up to two miles to get to the water source: a hand-pump.

She says: "In the north, it’s so dry they sometimes have to drill down 650ft just to hit the water table, and in one village they’d had water for eight years but still didn’t have any toilets. So although they had the advantage of a clean water source, the problem remains that they are still using the bushes around the village as toilets, which creates a huge hygiene problem.

"That’s partly due to the fact that the elders of the village don’t want toilets, and Wateraid is now having to embark upon an education programme to explain the advantages of using latrines rather than going in the undergrowth."

That’s something the villagers on the Afram Plains - Helen’s third port of call - have learned in the 15 years since Wateraid first helped them.

"Those villagers had found that by simply having clean water close by, their entire lives had changed. Because they didn’t have to spend hours walking for water, they had more time to work and develop their community and, as their health improved, so the children of the village started going to school," she says.

"They had even set up their first money market - in the other villages of the north they still relied on the barter system."

Back home in Inverleith, where all it takes to ensure a flow of fresh clear drinking water is the twist of a tap, Helen is now acutely aware of how easy it is to forget how important a role something as simple as water plays in our everyday lives.

She says: "It was difficult to believe the situation I was in. I found it very disturbing that in the north they talked openly of ‘the dying season’, the dry season when they expected the weak to die, and it was only after I returned home that it hit me what I had actually witnessed.

"What upset me most was the fact that it was normal for them, and how as little as ?15 could make such a difference."