Wednesday, September 21, 2011

Iron Bacteria killing the irrigation system !

A group of microorganisms commonly called iron and sulphate reducing bacteria cause a chemical change in the water they infect. Iron bacteria are found in all parts of the world, with the exception of the southern polar region. In KZN they occur naturally in dams, swamps, watercourses, lakes and groundwater. Reports of iron bacteria in bores have increased rapidly throughout these regions in recent years. Iron bacteria are micro-organisms which obtain energy by oxidizing soluble ferrous iron into insoluble ferric iron which then precipitates out of solution. This energy is used to promote the growth of thread-like slimes which together with the ferric iron, form a voluminous mass. Many species of iron bacteria have been identified. There are also some bacteria which live on manganese in water. However, as most groundwater's contain lower concentrations of manganese than iron, it is iron bacteria which have caused the majority of problems in bores. The resultant growth of iron bacteria in bores, cause water pumps, pipes, and bore holes to block up with a brown, slimy, clay like material. Sometimes there is a bad odour from the water, like rotten eggs. Iron bacteria are not harmful to humans, as are other forms of bacteria, but are harmful to bores and pumps. If left untreated they will cause the eventual blockage of the bore and failure of the pump.

Well point suction that is the main supply of water to the course.

The picture above is a 110mm pipe reduced to 40mm cause of the growth !
The irrigation system and main line at DCC is very old and due to that we have seen that pipe bursts are occurring more frequently and the pressure is decreasing due the the Bacteria growth in the pipes.

A leaking hose pipe connected to a bore hole spraying onto a log and this took 3 days.

Bore hole pump...

The bore hole pumps needs to be lifted and cleaned every so often as the sieve on the pumps gets blocked and even stops the pump from pumping. 

What are we doing : We are cleaning pumps and filters on a regular basis and have done test on chemicals testing to see if it help. We have applied a chemical to the well points and flushed the system for 12 hours to see if it will get rid of the build up. It worked but it was very expensive and only helps temporarily...
We are now looking for a more cost effective way of dealing with our problem...

1 comment:

  1. Hi Willie. Aquamarine is a water treatment company specialising in all forms of source water cleaning. Iron is a large problem for borehole water and we have several solutions for removing it. Please feel free to contact me, Grant MacGregor at