For many of us, clean water is so plentiful and readily available that we rarely, if ever, pause to consider what life would be like without it. Marcus Samuelsson
As of today, there are two methods for monitoring water quality; direct and indirect. Both methods leave some uncertainty regarding the water quality. Indirect monitoring is continuous, and monitors physical parameters, but since it indirectly monitors water quality it cannot detect contaminants with 100% certainty. Direct monitoring is done by manually collecting and analyzing water samples. The results from direct monitoring are accurate and precise, but they only describe the quality of the water for the specific point in time when the test was taken. Meaning a contamination can occur and by the time the analysis detects it, the contamination might have caused an outbreak or moved further along the distribution network making it more difficult to stop. These methods might give an indication of the approximate overall water quality and contamination risk, but the precise water quality will always be uncertain.
It is possible to achieve a better approximation and reduce the water quality uncertainty by increasing the sampling frequency of direct monitoring. However, direct monitoring is costly, time-consuming, and it becomes a decision of cost vs gain. Since a significant number of all samples are negative, the expense of increasing the sampling frequency might outweigh the increase in security. There is an equilibrium point where the uncertainty is acceptably low and the expense acceptably high. Any potential gain from reducing the uncertainty will be insignificant in comparison to the cost of increasing the sampling frequency.
A direct and continuous monitoring device placed directly into the distribution network in critical locations will reduce the water quality uncertainty, without increasing the monitoring costs.
Consequences of contaminated water
Saying I took my clean water for granted is an overstatement. To tell you the truth, I didn’t even think about it. Ashlan Gorse Cousteau
People that become sick from drinking contaminated water, will in many cases never realize it was the water that made them sick. They might think it was something they ate, something their kids brought with them from kindergarten or something else. Many of those who fall ill from contaminated water will never see a doctor, and almost no case of waterborne diseases is recognized as an outbreak.
Several studies indicate that the water quality is unsatisfactory even in highly developed countries, and that the number of incidents related to drinking water is very high. It is estimated that:
- Contaminated water causes 2-5 million deaths worldwide every year.
- Infectious intestinal disease occurs in one in five people in England each year.
- In the United States of America there is an estimated 19.5 million cases of waterborne diseases each year.
- Up to 37% of the total drinking water-related cases of gastrointestinal illness might originate from contamination in the distribution system.
This clearly shows that water monitoring is an important task that is not handled effectively today. Considering that most manual tests are negative, and yet contaminated water still makes people sick. There is definitively a need for early warning systems and effective continuous monitoring. Not only of the water quality at the water treatment plant, but throughout the distribution system to ensure that the water quality is sustained before it reaches the consumer.
Threats to drinking water quality
More people die from unsafe water than from all forms of violence, including war. Ban Ki-Moon
We have listed four main threats to water quality; farming, wastewater, water terrorism and climate change, but this does not cover the whole picture. Air pollution, population growth and over-consumption does all impose a threat to water quality.
- Water scarcity issues are growing, and with climate change decreasing water availability and population growth driving over consumption, clean water is becoming a scarce and valuable resource.
- Chemicals and pesticides are becoming common in water used for consumption, and the list of targeted chemicals to monitor is limited and incomplete.
- Current measures for the improvement of water quality do not account for the effects of toxic chemicals, and ecological risks posed by toxic chemicals are considerably greater than what has generally been assumed.
- The water distribution network is old, vulnerable and at risk, both to intentional and unintentional contamination.
- Under-reporting of waterborne disease outbreaks is a large problem in Europe and America, leading to underestimation of the disease burden from waterborne diseases.
- In EU in 2050, 20 million people will remain potentially at health risk to drinking water quality problems, equivalent to 4% of the total population.
Social costs from uncertainty about water quality
The social cost from water quality uncertainty is the total expense of people falling sick, including the costs of their doctor or hospital visits, their loss in productivity, utility loss, and other expenses they face related to their sickness.
The social costs also include the financial burden on society from its inhabitants falling ill. For example: sick leave payments, the loss in productivity, the costs of treating the patient that is not covered by the patient, and other expenses that the society face related to the illness. If there is a large outbreak where many people falls ill, other expenses arise. For example: critical functions in society might not function as normal, hospitals might not have the capacity to cope with the number of sick people, and the health care workers might get sick and not be fit to work. All expenses must be covered by the society and by the people falling ill, and totals as the social costs from the water quality uncertainty.
Hospitalizations from water related diseases alone cost over a billion dollars in the US every year. The alternative is absolute certainty, where no one would fall sick from drinking contaminated water. The total cost of water contamination under full certainty equals the cost of providing the cheapest available alternative resource of clean water.
Environmental effects of uncertainty about water quality
Uncertainty of water quality creates a need for preventive use of water treatment to avoid contaminants in the water. This makes the use of chemicals and treatment in the water higher than it would have been without uncertainty. The environmental effects from treatment in the water are dependent on how much treatment there is in the water, and the higher the uncertainty about the water quality, the larger is the need for preventive use of water treatment, increasing the negative environmental effects from water treatment.
Uncertainty about the quality of the tap-water is the main reason why people buy bottled water, even when tap water is of better quality than bottled water in almost all cases. This means that the consumers uncertainty about water quality might have an impact on their consumption of bottled water, and in turn have a large impact on the plastic waste that follows from the bottled water production. Producing bottled water does also mean wasting approximately three times as much clean water as you produce. In times where water scarcity is a growing and serious issue, wasting three fourths of all water produced seems unacceptable.
Providing safe, clean and well tasting tap-water is the easiest, best and most environmental friendly way to solve this issues.
Societal and environmental benefits of continuous monitoring
Continuous monitoring of water quality will dramatically reduce the uncertainty about the quality of the water.
Early stage calculations about the societal gain from continuous monitoring of water quality show potentially large gains from continuous water quality monitoring, even if it imposes some cost of finding alternative water resources. The cost of finding alternative water resources, or the cost of bottled water, is in almost every case fairly small compared to the total social cost of people falling ill from contaminated water, even when the fraction of people that actually fall ill is very low.
With more certainty about water quality, the use of chlorine and other water treatments will be more targeted, and in almost all cases, unless the water is extremely contaminated, the use of treatment will decrease when there is continuous knowledge about water quality. The preventive use of water treatment will no longer be necessary. This might have a large impact on the environment, as water treatment and chemicals added to the water is taken up and must be decomposed by nature.
The quality of the water delivered to the consumers will also improve as they will receive safer, cleaner water with less use of treatment and chemicals in their tap. Those times that boiling the water or drinking bottled water is necessary due to contamination in the tap water, the consumers will be informed, and they can therefor always rely on the safety of the water unless they are told not to. This might have an impact on the consumers decision to buy bottled water, as their perception of water quality increases. Reduced consumption of bottled water reduces the plastic waste and the water-waste from the production of bottled water, and has a potentially large beneficial environmental impact.
BiWAS technology provides safe, environmentally friendly, cheap and robust solutions for continuous monitoring, and we hope to contribute to safer, cleaner and better water in the future, and to a more sustainable use of this valuable resource.