The Case for Drinking Water and Sanitation as Keys to Healthy Cities

Engineering the Healthy City Conference, November 1, 2004
By Hershel Guttman, P.Eng.

Except perhaps for clean air, there is no single issue more important to a healthy city than a safe and reliable water supply. To most North Americans, tap water is something you use to wash your dishes or your cars. Rarely does anyone think of it as life sustaining. But it is, in fact, it is a key component of public health.

Today, I want to make the case for drinking water and sanitation as keys to healthy cities. In May 2000, 7 people died, and over 2,000 got sick from drinking the water in Walkerton, Ontario. If anything good can come out of this tragedy, it is to focus the public's attention, on the safety of our water supplies.

There are 3 messages I would like to leave you with, and then some suggestions for action on your part. The 3 messages are:

• Drinking water is a key component of public health in our cities;
• Therefore, water must be made safe; it cannot be taken for granted, and
• Water is not free; it costs money to provide and deliver a safe, life sustaining product to your home.

1) So let's talk about drinking water as a key component of public health

The history of public water supply goes back well over 100 years. Initially, it had two purposes. The first was for fire protection, especially in an era of wooden buildings in close proximity. The ability to protect a town or city from being destroyed emerged as not only an economic issue, but a social one. Fires not only killed, but they destroyed homes. The connection therefore with the public health of the community was fairly direct.

An even more direct connection with a community's public health was the ability of water to reduce disease. This was because of its ready availability in the home for washing, cleaning, drinking and cooking. The ability to easily use water for these purposes promotes sanitation and thereby protects the public health.

Ironically, this also lead to poor sanitation conditions outside the home, as sewage was allowed to be washed away in the streets. It was not until Pasteur's work on the connection of bacteria with disease, that people began to understand that poor sanitation conditions and contaminated drinking water was a vector for disease. Cholera and typhoid fever epidemics became linked with unchecked pollution of drinking water sources, and the recycling of pathogenic bacteria via the drinking water supply. The reaction of public officials and in particular engineers, was twofold: first to collect and redirect the sewage by building sewers; secondly, to make the drinking water safe by disinfecting it. The method of choice for disinfection was chlorination and thus was born the public health engineer, which is what environmental engineers were called in the early part of the 20 th century.

In North America, chlorination was first tried in 1908 in Chicago, with the first large scale chlorination of a municipal water supply in Jersey City, N.J. It is interesting to note, however, that the town council filed a suit against the private water company for violating its contract to provide "a supply of pure and wholesome water". Nevertheless, public health engineers prevailed. In 1999, the Center for Disease Control in Atlanta, published their list of Ten Great Public Health Achievements in the 20 th Century . One of them was the "control of infectious diseases", and I quote:

"Control of infectious diseases has resulted from clean water and improved sanitation. Infections such as typhoid and cholera transmitted by contaminated water, a major cause of illness and death early in the 20 th century, have been reduced dramatically by improved sanitation."

And a major component of that has been the treatment of drinking water, not only with chlorine, but filtration and other means to protect the public health.

As the last century progressed, we went beyond treating for dysentery, cholera, and typhoid fever. We discovered other pathogens such as viruses which are smaller than bacteria, and protozoa, which are larger. Lately, drinking water professionals have been treating for such protozoans as giardia lamblia (beaver fever), and cryptosporidium which caused the deaths in Milwaukee in the early 1990's. And we continue to find and treat for new bacteria and strains, such as E.Coli O157:H7 and Campylobacter jejuni, which caused the recent illnesses in Walkerton.

The message here is clear: The public health of our cities depends on our drinking water and our sewerage systems to protect us. Which brings us to the second point:

2) Water must be made safe

It is easy for all of us to take this for granted, but I do not think we should. I think we need to be vigilant, both as providers and consumers, and here is why.

• people rely on it for its utility aspects
• industries rely on it for its utility aspects

But water is different from all other home deliveries: it has no substitute! Think about it:

• gas can be replaced by oil or electricity
• telephone and cable are interchangeable and can be supplemented via mail and couriers
• newspapers can be replaced by radio and T.V.
• cable T.V. can be replaced by books and videos
• power can be replaced by oil and gas

but only water has no substitute. It is essential for life, in fact, without it, there is no life, so we should never take it for granted. But if it represents life itself, it must be made safe to drink.

And that is where the public works engineers in our cities come in, who are responsible for your water supply. We can divide the delivery of a safe water supply into 3 areas, namely:

• the source
• treatment, and
• delivery system

In making water safe, there are issues and concerns to be dealt with in each of these areas.

1. For the Source

We not only need to secure sufficient quantities for our needs, but we need to protect its quality. Experience has shown that the better the raw water quality, the better and safer the finished water quality, so in trying to obtain the best raw water quality available, source water protection for well heads, for rivers, and for lakes, should be a priority. Now source water protection means:

• pollution prevention
• control of non-point sources such as:
• urban runoff (storm water)
• farm runoff with
• pesticides and
• fertilizers (nitrates)
• control of point sources such as:
• sewage, via sewers, and STPs properly engineered
• industrial effluents, and even
• farm effluents from feed lots (just another industry)

2. On Water Treatment

The issues are firstly proper disinfection, but we also need to remove solids and turbidity with filtration, as these can not only carry pathogens, but can interfere with effective disinfection.

Finally, we need to pay attention to the aesthetic qualities of water, such as taste, odour, colour, and even temperature. Although not essential for safety, they do impact our sense of trust in the safety of the water.

3. Now for the Delivery Systems

The water mains are probably the least understood by the public. Most know that the water comes to their houses via pipes in the streets, but most do not know that the size of the mains are governed by fire protection needs. This makes them much larger than they need to be, which can lead to the water becoming "stale" as it slowly moves through the system from treatment to your homes.

What this means is, that unless the water mains are clean and in good condition, the quality of the water coming from a pristine source can deteriorate in the mains; the delivery system.

There are miles and miles of mains in every city and town. Yet many of them were installed over 50 years ago. In fact in Toronto, some mains are over 100 years old. This aging infrastructure, if not maintained nor renewed, will deteriorate to the point of loss. We need to start thinking about these hidden pipes, as assets, to be managed in a sustainable fashion, or we will lose them, to the detriment of the health of our cities. Perhaps more importantly, a clean and maintained water system brings other benefits.

Unmaintained water mains, develop tubercles along their walls. This provides sites for bacterial slimes, which combined with the slow moving water, leads to the deterioration of the water quality in the mains. This is no way to treat the life sustaining product we need to keep us safe and healthy. You would no more consider putting 7-Up in a dirty bottle than you should be putting treated water in a dirty main. Which brings us to my third point:

3) Water is not free

There is a general belief in North America, that water is or should be free, after all, it falls from the sky, and is available to anyone who wants to capture it. No wonder people complain about their water bills, but silently pay more for their cable T.V. or their newspapers, but the drinking water that is delivered into our homes, as a safe and sufficient supply, is not free.

• It costs money to protect the sources from pollution: by buying up surrounding properties; by engineering and building effective pollution control plants; and even by lobbying for improved legislation and regulation.
• It costs money to treat the water to make it safe. Money is needed for properly engineered filtration plants, for trained staff to run them, for chemicals, for power to pump the water to you, and to keep them maintained.
• It costs money, both for maintaining and for investing in our water mains and sewers. After all, an aging infrastructure has to be maintained, and eventually needs to be replaced.

And this is money that the public living in cities should demand to pay, for the price of a safe water supply, and public health peace of mind. So, recognizing

• that drinking water is a key component of our cities public health,
• that it must be made safe, and
• that it is not free,

what can we do to protect our public water supplies?

1. Engage local politicians in what are they doing to

• protect the source
• provide the best treatment available
• protect its quality in the mains by maintaining and renewing the infrastructure

Ask them if they are charging enough for your own public health protection. Ask them if they are investing now in the future of these assets.

• Engage provincial politicians, especially on source water protection and pollution prevention issues.
• Engage your family / friends / neighbours / co-workers on these same issues.

If we want to live in cities, they must be made safe and healthy, and this starts with clean air and water. We should be prepared to pay for it for the sake of our public health, and we need to engage engineers to find effective solutions.