Water problems. Requirements and possibilities
According to the data of the UN Environment Program (UNEP) approximately one third of the world population lives in regions that suffer the lack of fresh water.
In less than 25 years more than two thirds of humankind will experience the same problem. Different countries have varying sweet water resources. However, the traditional belief that the sources of fresh water in Russia are unlimited can be a dangerous delusion.
Ubiquitous man-caused changes in the environment turn the situation to the worse even in our country that was always rich in water resources. Valid examples are the Lake Baikal that have been once the greatest sources of purest sweet water, and the vast Volga-Caspian basin that is now one of the most polluted river systems in Russia.
The issue of water quality is not in the least less urgent than the problem of water availability. However, but little attention is paid to this issue. This is especially true of the densely populated regions and the territories of large industrial and agricultural complexes.
Every seventh or even every fifth sample of drinking water studied in Russia in 2003 did not meet the hygienic requirements.
Approximately 30 infective episodes due to the water supply problems are recorded yearly in Russia.
Water sources. All included
Water from the natural surface sources is increasingly less suitable for direct application, either for industrial, agricultural use or for use as drinking water.
The cause of all this is contamination of water sources with untreated or poorly treated industrial and agricultural sewage, chemicals washed off the plough-land, radioactive waste, leaky canalisation systems, thermal pollution, etc.
Further implication for the quality of the natural water sources is the state of the atmosphere, because of the atmospheric precipitates that bring solutions of a number of undesirable compounds.
Oil products, phenols, easily oxidisable organic compounds, copper and zinc compounds, nitrogen in ammonium and nitrate compounds are the principal contaminants.
Some of the hazardous compounds like heavy metal salts accumulate in the bottom sediments of stagnant or slow-flowing basins. These sediments become especially dangerous in case of strong water level sinking.
The second part of the twentieth century was marked with emergence of yet another major water consumption problem. Organic substances, nitrogen and phosphor compounds are washed off the plough-land into the natural water sources, and are also carried by municipal wastewater and cattle-breeding sewage.
These substances cause eutrophication of natural water basins.
The implications are so grave that in some cases the polluted water without pre-treatment cannot be used even in industrial production. It is unsuitable for irrigation to tell nothing about drinking.
The example of Salekhard city is very remarkable. This city stands on the confluence of a great Siberian river Ob and its major tributary Poluy.
Despite that, the drinking water is an acute problem in this city. The Ob river basin is so contaminated with oil products that the tap water is absolutely unsuitable for drinking, and pure water is delivered in automobile cisterns.
According to the UN data, approximately one third of the world population uses water from subterranean sources for drinking. However, even this source is unable to provide pure and safe water.
First of all, the subterranean sources are very multifarious, and not all of them are artesian wells. Analysis of a selection of water wells in Russia has shown that the water in most of these wells is unsuitable for drinking. According to the UNEP estimates performed in 1999, more than 2 700 subterranean water sources in Russia were heavily polluted.
In densely populated, industrial, and agricultural regions the soils are too contaminated to have either filtering or buffer properties. Besides that, the state of underground pipelines is far from ideal. The uncontrolled and therefore unrepaired leakage of canalisation makes the problem the more difficult. All this results in unwanted substances contaminating the subterranean water sources.
A drink of water. Is it much or little?
Total water pollution impacts human health.
According to the international experts’ estimates, in 2000 the consumption of contaminated water endangered the health of 2 billion people worldwide due to malaria risk.
For comparison, the permanent number of people sick with malaria is about 100 million, and annual death rate caused by this disease is 1-2 million people.
Four billion diarrhoea cases are registered yearly with 2.2 million lethal outcomes. This is equivalent to 20 major aeroplane catastrophes daily.
More than 10% of the developing countries population is sick with helminth diseases.
About 6 million people have lost their eyesight due to trachoma. Two hundred million men suffer from schistosomiasis. Even in the relatively safe Europe enteric infection episodes occur due to the poor quality of drinking water. The statistic data show that children comprise two thirds of the people suffering from the unfavourable environment conditions.
Unfortunately, the quality of drinking water in Russia is intolerably low. This is often called the reason for the relatively low average lifetime expectancy compared to that in other developed countries.
The cost of risk and health loss caused by unsafe drinking water consumption is estimated approximately as 33.7 billion Russian roubles per year (about 1 billion Euro).
Statistical data show that one seventh to one fifth of the samples taken in drinking water supply systems in 2003 failed to comply with the hygienic requirements.
Ninety percent of the samples had bad organoleptic characteristics, 9 % of the samples contained chemicals in excess of the maximum permissible concentration according to the sanitary-toxicological criterion. Every ninth probe had too high microbial concentration, while 60% of the bad probes indicated a real risk of epidemic, because the bacterial contamination exceeded the norm by a factor of 20 or more.
No wonder therefore that about 30 infection episodes caused by the impurities in drinking water supply are recorded yearly.
Such dangerous diseases as dysentery, typhoid fever, hepatitis, meningitis are spread due to consumption of low-quality drinking water.
Drinking water can be also the cause of parasitic diseases. Pathogenic protozoa (lamblia) and helminth (ascarid) eggs are sometimes detected in the samples.
The implications of chemical and radiological contamination are not always possible to trace directly. The consequences of systematic consumption of low-quality drinking water might appear only after a long time.
Studies performed by many experts show that chlorides and sulphates have a detrimental effects on the gastrointestinal and cardiovascular systems. Excess of nitrogen compounds causes complications for kidney and liver. Aluminium acts destructively on the central nervous system and immune system. Iron promotes allergic diseases.
“SWIMMING IS STRICTLY PROHIBITED!”
Deterioration of water basins has yet another dangerous implication. Water becomes unsuitable for swimming. According to the estimates performed in recent studies, swimming in contaminated seas causes approximately 250 million cases of gastro-enteritis and respiratory diseases.
This amounts to economic losses of 1.6 billion US dollars every year. Note that this statistics does not account for the smaller rivers and stagnant water basins.
Contamination of food through contact with polluted water is yet another dangerous implication. Agricultural produce with excessive concentrations of nitrates is a well-known example. Heavy metal salts and radionuclides can be also detected in contaminated food. Consumption of clams and Crustacean that inhabit waters polluted with sewage causes 2.5 million cases of infectious hepatitis yearly.
Approximately 25 thousand cases have lethal complications, and as many cases result in severe liver injuries and long-time loss of working capacity. Calculations show that the annual effect of consuming such “dainties” on the human health is equivalent to the loss of 3.2 million working person-years and costs 10 billion US dollars.
Purification of water remains one of the most urgent problems. Moreover, this problem becomes daily the more difficult. The existing engineering structures are ageing, and fail to meet the modern technological requirements.
Water treatment systems developed and built decades ago are unable to cope with the increasing water usage and the decreasing quality of the input substance. Insufficient maintenance efforts (or even the complete lack of them) make many elements of the water supply equipment threateningly unsafe for the population.
Approximately 50% of the water supply systems in Russia are in emergency situation or close to it. The main reasons for it are pipeline corrosion, and also chemical and organic deposits that saturate the water with unwanted and often hazardous components.
Sometimes corrosion causes breaks in the pipelines. This leads to mud getting into the water, which runs in underground pipelines. So even an optimal treatment fails to ensure the drinking standard quality of the tap water.
Nikolay Tarasov, First Deputy minister of natural resources reviewed the state of the water supply systems in Russia at the parliamentary hearings “On the long-term perspectives of the national nature management in Russian Federation” on 18 March 2003.
He stressed unsatisfactory state of the drinking water supply systems due to the low quality of the tap water. He named contamination of surface and subterranean water, inadequate state of the supply pipelines, and, last but not least, insufficient application of modern techniques of drinking water treatment among the main reasons for this state of affairs.
All debts should be repaid
Any ecosystem has a potential for natural purification. However, this potential is no unlimited. If the contamination is too severe, nature can fail to recover the balance. This is often the case when the contaminants are man-made materials.
Therefore only effective fighting against pollution of natural water resources can save us from grave problems in the future.
The experience of the West-European countries shows that wastewater purification can be made very effective. So, e.g. the content of phosphor in the sewage at the output of the municipal wastewater treatment facilities decreased by 50-80 % since 1980s.
This resulted in an essential decrease of phosphor concentration in many lakes that were previously heavily contaminated with it.
Unfortunately, no decisive measures have been taken in Russia to develop an effective system of sewage collection and treatment. Moreover, river pollution with sewage even increased in the end of 20th century.
This is the more dangerous because the industry in Russia became more “dirty”, according to many studies. Ageing equipment and low-quality raw materials with high content of hazardous substances are among the reasons for this. It is clear that such outdated factories have inadequate or no sewage treatment facilities.
Sometimes such intolerable practices are applied as the industrial sewage disposal either directly into natural water basins or into the municipal sewerage system. This damages the municipal sewage treatment facilities that are unsuited for industrial wastewater processing, and increases the environment pollution.
Negative tendencies of water crisis aggravation inherited from the recent century make the solution of this crisis one of the most urgent problems of the world community. The search for new economically effective techniques of water treatment both for technical applications and drinking is one of the major contributions to the stabilisation of the environment.
The ecological condition of the water basins in the most populated and industrially developed regions of Russia were reviewed at the session of the State Council of Russia in summer 2003 and found unsatisfactory.
The principal rivers: Volga, Don, Kuban, Dnepr, Northern Dvina, Pechora, Ural, Ob, Yenisei, Lena, Kolyma, Amur were classified as “polluted”, in several locations – as “heavily polluted”. The major tributaries: Oka, Kama, Tom, Irtysh, Tobol, Miass, Iset, Tura were classified as “heavily polluted”, and in several locations – as “extremely polluted”.
The environmental state of a number of smaller rivers was found catastrophic. Subterranean water resources are less polluted than the surface ones. However, recently the purity the former has been found to decrease. The sanitary state of the water basins attributed to the 1st and 2nd categories of water use in Russia is still unsatisfactory.
Almost half of the water basins used for central water supply systems do not meet the sanitary requirements. The sewage volume discharged into the surface water basins exceeds 55 cubic km, while only 11% percent of the wastewater are treated according to the standards.
Among the water samples taken in water basins serving as sources for water supply systems in 2001, 22% did not meet the hygienic requirements according to the microbiological criteria, and 28% - according to the chemical criteria.
The ratio of samples containing pathogenic flora increased and reached 1.5% in 2002. Only 1% of water in the open water sources complies with the requirements that ensure the proper quality of drinking water. Among the water supply systems fed by open water sources, 34% have incomplete set of purification facilities, 20% lack decontamination equipment.
Installation of modern water treatment technologies goes very slowly. The water supply pipeline ageing reaches 60%. Among the tap water samples taken in 2001, 19.5% did not meet the hygienic requirements according to the sanitary-chemical criteria.
The highest microbial contamination in the 1st category water sources was found in St.Petersburg: 80.3% of the samples contained microbial flora, 12.3% of the samples contained pathogenic organisms, while the average ratio of pathogen-containing samples in Russia is 2.27%.
Consumption of poor quality, contaminated drinking water causes 15 to 30 episodes of acute intestinal infections, typhoid, and virus hepatitis A with the number of patients up to 2.5-3 thousand men.
Russian information agency Regnum