land and water pollution

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LAND AND WATER POLLUTION BY JEAN FAULLIMMEL Background Water is one of the most essential commodities for all living species and upon which all life on Earth depends. For most nations, economic development is inextricably linked to the availability and quality of freshwater supplies. There are regions around the world with a natural abundance of freshwater, but for other regions the availability of water is a matter of life and death. The quantity and quality of freshwater, land degradation, pollution and health of the population, are today major economic and environmental concerns. Water pollution is the contamination of rivers, streams, lakes, groundwater, bays, or oceans by substances harmful to all living species. It is a local, regional and global issue all countries are facing today. For example, a study done by United States Environmental Working Group between 2004 and 2009 (graph below) detected that most American States face serious chemical contamination of freshwater. It concerns the number of regulated and non-regulated chemicals found in water bodies that can have an impact on the health of a nation: Overall agricultural pollutants amount to 97, sprawl and urban pollutants are 86, industrial chemicals are up to 205, and pollutants from wastewater treatment amount to 42. These are all synthetic chemicals that do not belong to nature. These data show the seriousness of water pollution, especially for a developed country. But what about developing countries, which for cultural reasons and/or lack of environmental awareness, have lower pollution standards? 1

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Written by Jean Faullimmel PhD

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LAND AND WATER POLLUTION

BY

JEAN FAULLIMMEL

Background

Water is one of the most essential commodities for all living species and upon which all life on Earth depends. For most nations, economic development is inextricably linked to the availability and quality of freshwater supplies. There are regions around the world with a natural abundance of freshwater, but for other regions the availability of water is a matter of life and death. The quantity and quality of freshwater, land degradation, pollution and health of the population, are today major economic and environmental concerns.

Water pollution is the contamination of rivers, streams, lakes, groundwater, bays, or oceans by substances harmful to all living species. It is a local, regional and global issue all countries are facing today. For example, a study done by United States Environmental Working Group between 2004 and 2009 (graph below) detected that most American States face serious chemical contamination of freshwater. It concerns the number of regulated and non-regulated chemicals found in water bodies that can have an impact on the health of a nation: Overall agricultural pollutants amount to 97, sprawl and urban pollutants are 86, industrial chemicals are up to 205, and pollutants from wastewater treatment amount to 42. These are all synthetic chemicals that do not belong to nature. These data show the seriousness of water pollution, especially for a developed country. But what about developing countries, which for cultural reasons and/or lack of environmental awareness, have lower pollution standards?

Sources of freshwater contamination

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In the context of China, since the beginning of the country’s economic development 30 years ago, environmental development has been neglected because of lack of understanding about the negative impact of pollution. It has resulted in severe water and land contamination. The impact of such pollution can only be seen over time, when the increasing pollution generates side effects such as algae and eutrophication in lakes, rivers and water streams, which destroys aquatic ecosystems.

On a recent environmental mission, in June 2012, to Kunming, the capital of Yunnan Province, in China, I discovered the impact of an increasing human population on the water quality of Dianchi Lake and its surroundings. In China the number of contaminants entering lakes and rivers has increased severely due to industrial expansion, and as more land was cleared for housing and agriculture development, for an overwhelming large population.

The economic development and population growth around Dianchi Lake since the 1980s has resulted in serious phosphorus and nitrogen pollution coming from point sources such as industrial and urban activities, and non-point sources such as crop and animal farming, and water runoffs during the monsoon season. This has resulted in the formation of blue-green algae during the warmest months of the year from March to September. During the winter period from October to February, the algae slowly disappear from the water surface via biodegradation to settle at the bottom of the lake in the form of sediments. Warmer water, sunlight and high nutrient concentrations, are the main factors, responsible for algae growth.

Lake Dianchi, Kunming, Yunnan

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Blue- green algae in Dianchi Lake

To reduce phosphorus and nitrogen pollution, the Kunming Municipality has implemented bio-remediation of the lake by developing wetlands and by periodically planting water hyacinth that will absorb phosphorus and nitrogen during the plant’s growth. In order to stop such pollutants coming from industrial activities, the industries were removed from the surrounding lake area and moved inland to cut them off from discharging wastewater. But the pollution still persists as water streams and rivers enter the lake from different locations, and urban wastewater treatment plants continue to discharge their treated effluents. Urban wastewater usually contains a high concentration of phosphorus and nitrogen, and if not treated properly, wastewater treatment plants will continue to feed the lake with algae nutrients.

Water pollution: sources of phosphorus (P) and nitrogen (N)

Algae require nitrogen and phosphorus for growth. However, although nitrogen is important, it is phosphorus that is the limiting factor for algae growth. A direct relationship exists between the amount of phosphorus in a lake and the amount of algae growing in the lake. Reducing phosphorus input removes therefore a key algal nutrient.

External sources of phosphorus such as storm water runoff, septic system effluents, fertilizer (NPK), farming runoffs and wastewater, are all linked to the development of blue-green algae. And if environmental legislation is not severe enough, it can also be a major source of phosphorus pollution. However, sometimes even removing external sources is not enough. Phosphorus-enriched sediments can also continuously release phosphorus into the water through a process known as internal loading. The picture below illustrates the nutrient cycle:

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The nutrient cycle

The concentrations of these substances in water and sediments control the total amount of organic matter that can grow. In most lakes, phosphorus is the least available nutrient, so its abundance depends on the source of it. In order to work at the source to reduce the concentration of nutrients, a strong analytical database of phosphorus and nitrogen is necessary: how much comes into the lake from external and internal sources, how much goes out, and where does come from. The analytical data should help to develop a pollution map.

From land pollution to water pollution

Land pollution is intrinsically linked to water pollution. Contamination of land is done with chemicals that do not belong to the land. Hazardous waste from industry, municipal waste, fertilizers, pesticides, excess heavy metal, are all materials that are not found in unspoiled ecosystems. Eventually pollutants go from land into water bodies as illustrated below:

The point and non-points sources of land and water pollution

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Contaminated river or lake water used for crop irrigation brings back land pollution. And before being washed away by rainfalls, land toxic chemicals can enter the food chain. Vegetables, fruits trees and other crops take up the pollutants. Subsequently contaminated food ends up in the plate of the consumer and the polluter.

Throughout the world extensive amount of fertilizers, herbicides and insecticides to kill insects, weeds, fungi and rodents are used to maximize crop production. Yet because these chemicals are not completely absorbed by crops, weeds and insects, their excess remains in the environment, eventually part of it, vaporizes into the air creating air pollution, and the other part is washed away by rain creating water pollution.

In addition, the lack of proper municipal and industrial solid waste disposal procedures, and proper legislation, is another source of contamination, especially groundwater. Groundwater is mainly used as drinking water. And today 80% of the solid waste found in oceans comes from land sources, that is, from the population living along coastal areas. Without proper solid waste management for recycling, reuse and ultimate disposal, contamination of seas will continue unabated as illustrated below: 

The fate of municipal solid waste around coastal areas

Oils spills are another form of water pollution. Ocean ships can be loaded with chemical waste, oil and other oil derivatives that are used as fuels, lubricants and chemicals. Oil tankers can spill oil into the sea by accidents such as the oil spill of the tanker Amoco in 1978 along the French coast, and the Exxon Valdez in 1989 in Alaska. Such accidents have a negative impact on marine ecosystems and the fishing industry.

Water and population

Without doubt, today’s world population will be facing fresh water scarcity in the future. Global warming, climate change resulting in changes in rainfall pattern and pollution are threatening surface water and groundwater. The replenishment of aquifers becomes uncertain in some regions, while other regions are facing excess rainfall and floods. The contamination of these water bodies reduces further the availability of the little freshwater available on Earth. That is why freshwater must be protected from

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contamination: today only 2.5% of the Earth’s water is freshwater. Of these 2.5%, only 1% represents surface water. Of this 1%, the vast majority is found in lakes and soil moisture, and 1% of it is river water. The ocean water represents 97.5% of the total.

Going back in history, before the industrial revolution, it was possible to withdraw and consume water to everyone’s satisfaction However, times have changed as demographic pressure on water supply has increased in the last three centuries: 1 billion inhabitants in 1800, 2 billion in 1900, 6.6 billion in 2007 and 7 billion in 2011. The graph below illustrates the projection of population growth in developed and least developed countries:

It is a known fact that water, in a geographic sense, is unequally distributed on earth and population growth varies on every continent. Projections show that the demographic pattern of developing countries is becoming more significant, in particular in sub-Saharan Africa. Here access to clean water is already a challenge for the current population, presenting a high risk of increasing and irreversible water scarcity.

Water and climate change

The more fresh water becomes contaminated, the less fresh water will be available. Adding to that is the impact of climate change that will cause major changes in the precipitation pattern, water cycle and its geographical distribution. Some regions will receive less precipitation, some more, and this will significantly affect local economic development. For drought stricken African countries, the Intergovernmental Panel on Climate Change (IPPC) predicts that by 2020, in Africa, between 75-250 million people will be exposed to increasing water stress, and that in some countries crops from rain-fed agriculture may be reduced by 50%. And in Asia, freshwater availability is also

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projected to decrease.

Heavy rainfalls create another way of water pollution as they flush pollutants and soil into surface water. Storm-water runoff is one of the most significant threats to ecosystems and freshwater supply. Leaked motor oil on streets and parking lots, detergents, other toxic chemicals coming from landfills or waste dumps, are other sources of pollution. Through heavy rainfalls and floods chemicals can dissolve and infiltrate groundwater and concentrate in lakes, rivers and sea. Non-point source pollution can be linked to the creation of large dead zone in the sea. For example, sea areas in the Gulf of Mexico with not enough dissolved oxygen is often referred to as a dead zone because most marine life cannot survive in it. Habitats that would normally be teeming with life become essentially biological marine deserts.

The amount of oxygen in water is one of the most important indicators for water quality. The lack of oxygen is an indicator of water pollution by organic matter. Oxygen is consumed by bacteria during biodegradation. Some marine species have very defined lower limits of dissolved oxygen that they can tolerate. Most fish cannot survive in water with a dissolved oxygen concentration of less than 8 ppm (parts per million). An increase in oxygen indicates improvement in water quality.

In summary, ongoing climate change will mean that the freshwater supply, whether in high or low rainfall regions, will lead to more freshwater scarcity and uncertainty for a growing population. In view of an increasing world population, water management requires stricter legislation to prevent water pollution, the need for better water supply, and cooperation between countries and communities, especially when rivers and lakes draw borderlines between countries.

Pollution Prevention

Mitigating climate change involves pollution prevention measures. That requires a pollution prevention hierarchy (shown below) by starting to reduce or eliminate waste at the source, then recycling, reusing, treating, and finally disposing the ultimate useless waste in sanitary landfills.

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Reducing waste at the source, involves improving manufacturing processes, using more energy efficient technologies to reduce greenhouse gas emissions, having better environmental legislation, and implementing conservation techniques. Switching from non-renewable energy to renewable energy is also of paramount importance to mitigate global warming. In any country, pollution prevention should be a major environmental policy, and be aligned with the concept of Sustainable Development.

The weakness in China is that the country practices mainly pollution control, rather than pollution prevention, and there is serious lack of a sound analytical database based on facts: what chemicals, their amount and sources. If we don’t know the type of contaminants, the exact amount that goes into the environment and where it comes from, it is impossible to solve pollution issues upstream. An analytical database is essential to set up objectives and targets to stop or mitigate pollution.

Untreated wastewater entering the lake

Conclusion

Lake management approaches fall into two categories, the “quick-fix” and long-term management. The quick-fix offers a short-term solution such as periodically removing manually algae from surface water or by a liquid-solid separation technique such as filtration or centrifugation at an algae-water separation plant. A successful lake restoration program should strive to manage to reduce both external and internal nutrient sources. It is a long-term management process.

At Dianchi Lake an attempt has been made to reduce phosphorus and nitrogen using bio-remediation with water hyacinth and developing wetlands and moving industrial activities inland. This is pollution control. Now a great effort has to be made via pollution prevention to reduce the continual phosphorus and nitrogen flow into the lake. Its rate must be less than the rate of nutrient uptake by algae and other plants, and consequently the growth of less blue-green algae. In the long run, pollution prevention is cheaper than pollution control.

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The Kunming Monitoring Station will also need to invest in better, more reliable and accurate analytical instrumentation in order to obtain a better database that can be defended scientifically. This is very critical in making progress and achieving pollution prevention. This is a must for better water quality management.

To make progress, it will also be important that all parties working on the restoration of Dianchi Lake, understand what each other is doing and what progress or setbacks has been made. It is important to know what works and what does not work, where improvement can be made, and whether a new objective must be set or the old one corrected. All parties must have an overall understanding of the situation. It is teamwork, a common effort where everybody speaks the same language, has the same information and objective. Not one party knows enough, it is all a continuous sharing, learning and improvement process for everybody to attain the objective, that is, to allow Dianchi Lake to recover to its natural beauty.

Is the present pace of economic development in China sustainable? It is not. Although improvement have been made, environmental indicators show that more solid waste is produced every year, greenhouse gases emissions go unabated, and more freshwater becomes contaminated. Sustainable Development has three objectives: economic, environmental and social developments. They all go together hand in hand, and should progress at the same pace. When the economic development rate is greater than the environmental development rate, we continue to pollute the ecosystems we live in. If

we destroy our ecosystems and biodiversity, we destroy ourselves.

References

1. J. Faullimmel, Environmental mission, ECTI Paris, June 2012.2. Kunming Urban Drainage Monitoring station, Kunming, Yunnan, China.3. Mrs Franks’ Pollution web page.4. IPPC Fourth Assessment report, Spain, 2007.5. National Oceanic and Atmospheric Administration.6. Department of Natural Resources and Environmental Control.7. Environmental Working Group.8. S. Brennan and J. Withgott, “Environment” Pearson, 2004.

JF/27/08/2012

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