Leachate water pollution is a very serious issue when it occurs. Imagine how serious it is when foul sewage overflows in a city district. The experience is not a pleasant one for us humans when we can simply use our feet and move away from the pollution source, but the flora and fauna that live in rivers and streams have nowhere to go when pollution flows in their habitat.
Now consider that landfill leachate is (depending upon the source) between 10 and 100 times stronger than sewage, and consider how damaging that can be to natural organisms in our rivers and streams.
During a leachate pollution incident the organic contamination in leachate which is represented by the concentration of BOD (Biochemical Oxygen Demand) feeds micro-organisms in the water which take oxygen out of the water in order to grow. This means that there is little or no oxygen left for higher organisms such as fish to breath, and the first effect of leachate water pollution is usually that passers-by notice dead fish lying on river banks and floating down with the flow.
However, when this occurs you can bet that a whole host of invisible creatures that would normally support the life of the fish are also suffering and dying. The result is that the entire ecological balance of the watercourse is impaired and may take many months, or years to recover to its original clean and thriving condition.
However, in addition to the effect of reduced oxygen levels which we have already described, leachate contains many other contaminants. The hardest to remove and most damaging to streams and river it might enter is ammoniacal-nitrogen. (People often refer to this as ammonia, but ammonia in water is a combination of dissolved ammonium and gaseous ammonia – so we will call it ammoniacal-nitrogen to make it clear that we refer to the total ammonia (gas) and ammonium (dissolved)).
Ammoniacal-nitrogen is normally present in sewage at between 10 mg/l and 50 mg/l (10 ppm to 50 ppm), but in landfill leachate from a normal sanitary landfill it will be found at between 500 mg/l and 3,000 mg/l.
Now consider what level of ammoniacal -nitrogen higher organisms can tolerate in normal largely pH neutral river and stream water and it is about in the 5 mg/l to 50 mg/l range that they become stressed and may die. From this it follows that even an average strength landfill leachate needs to be diluted at least 10 to 100 times before it becomes harmless from the point of view of ammoniacal-nitrogen.
So, leachate water pollution is a very seriously dangerous pollutant to our rivers and streams, and it is worthwhile expending a great deal of care and hard cash to prevent leachate water pollution occurring.
Leachate information pages you may find interesting on other websites:
Leachate Water Pollution
Related terms: Effects of Water Pollution, Sources of Water Pollution, How to Stop Water Pollution, Causes Water Pollution, Information On Water Pollution, Water Pollution Facts, Water Pollution Problems, Pollution in the Ocean