People who do fermentations of lactic-acid bacteria sometimes place pieces of calcium carbonate in the medium to maintain a constant pH. As the bacteria grow, they produce lactic acid, which is neutralized by the calcium carbonate, converting it to calcium lactate and carbon dioxide. The effect is the same as simply adding lactic or a similar carboxylic acid. This might work for you, but you would have to add other nutrients in order for the lactic acid bacteria to grow.

A decrease in pH can reduce the carbonate levels in water and thus alter the ability of M.O. to form hard calcified structures. The scientists found that when the bacteria, which has been extracted from a number of places including brick kilns in the Indian city of Satna, is used as an enzyme it converts CO2 into CaCO3. The enzyme can be put to work in any situation, like in a chamber fitted inside a factory chimney through which CO2 would pass before being emitted into the atmosphere, and it would convert the greenhouse gas into calcium carbonate. The economic viability, cloning, expression and single-step purification for the bacteria is being studied by a team of researchers in india..

Research leading to microbial  Calcium Carbonate precipitation and its ability to

heal cracks of construction materials has led to  many applications like crack remediation of  concrete, sand consolidation, restoration of  historical monuments and other.. when a concrete structure is damaged and water starts to seep through the cracks that appear in the concrete, the spores of the bacteria  germinate on contact with the water and  nutrients. Having been activated, the bacteria  start to feed on the calcium lactate. As the  bacteria feeds oxygen is consumed and the soluble calcium lactate is converted to insoluble limestone. The limestone solidifies on the cracked surface, thereby sealing it up. It mimics the process by which bone fractures in the human body are naturally healed by osteoblast  cells that mineralise to re-form the bone.The consumption of oxygen during the bacterial

conversion of calcium lactate to limestone has an additional advantage. Oxygen is an essential element in the process of corrosion of steel and when the bacterial activity has consumed it all it increases the durability of steel reinforced concrete constructions

Thanks Greg and Kenneth, probably Bactria  need feeding and nutrients, but recently, I read an article, indicated  increasing the flow-rate of CaCO3-Clogged irrigation emitters by using B. subtilis OSU-142 and Lactococcus garvieae. It had great effect on flow-rate. here is the link of research:

http://www.sciencedirect.com/science/article/pii/S0301479711004452

I wanted to know that these bacteria can have same results in CaCO3-clogged drainage pipes, which is perforated and covered by porous media such as geo-textiles. The problem is drainage pipes are saline and have high electric conductivity (EC) around 10 ds/m. 

Dear blessy,

Thanks for your answer, but I'm looking for something vice versa. The bacteria that convert CaCO3 to other substances. 

You need to find a process and substrate so that a bacteria can derive energy from utilizing the substrate together with CaCO3. I don't think there is a substrate that do this and is acceptable to have in a drinking water supply system.

If you aim for a continuous solution to the scaling you should look into reducing the alkalinity (decreased pH) or hardness (decreased Ca2+ concentration) at the waterworks.

If your water is in equilibrium with atmospheric CO2 it might help to add a small concentration to make it slightly supersaturated.

Thanks Henrik,

Actually I intended to use this method which is much harder and more complicated than reducing alkalinity by acid, but the goal was preparing no side effects of acid for crops and preservation of soil chemical equilibrium. 

The permeable filter of subsurface drainage pipes in soil which contains high Calcium Carbonate, after usually two or three years lose their usage due to absorbtion of CaCO3 in porous media and it cause water clogging problem.

The case of precipitation of calcium carbonate in drainage pipes are quite different from a water distribution system.

The reason you experience precipitation in the pipes is that the water dissolves calcium carbonate in the soil which precipitates close to or inside the drainage pipe. The process is driven by that CO2 or organic acids formed by degradation of plant material in the soil decreases the pH in the water in the soil. As these disappear from the water then the water loses pressure and possibly becomes aerobic in the drainage pipe the pH goes up and the precipitate reforms.

To solve this I can think of modifications such as keeping the drainage pipes flooded. Perhaps a U-bend type modification of the pipe on the downstream end can do it.

Substrates that creates acid by oxidation such as sulphide and Fe(II) are not practical to apply into the soil.

Thanks Dr. Andersen,

Another reason that makes drainage pipe clogging is higher rate of soil surface evaporation in arid zones. Low depth water table near soil surface (about 1 meter) cause substance (CaCO3 and dissolved salts) rising and during this phenomenon, Calcium Carbonate is fixated and precipitated around drainage pipe envelopes. 

I think there is a misunderstanding in where CaCO3 precipitate, inner part of pipes has not this issue but the envelope and cover of permeable pipes have this problem. 

Leaching and flooding the land by huge amount of water is not very environmentally friendly in two aspects, First, using two much amount of water is not appropriate in regions that scrimmage with water scarcity and on the other hand more drainage cause more saline and degraded water fluxes which is endanger lowlands and lakes or seas environmental.

I am enthusiastic to find another way to solve this problem without use too much water and acid.