India is one of the top producers of coal based fly ash. But, 40–50% of that produced is expelled to waste annually. The disposal of this un-utilized fly ash creates a bigger challenge for thermal power plants. Generally, wet disposal of ash is the most common practice adopted. Because of the continuous deposition process, sedimented ash deposits have been formed and they have a poor density, high compressibility, and low bearing capacity. A proper laboratory-scale design and experimentation have already been carried out in this context. Design and field-scale experimentation of several in-situ stabilization methods are necessary to enhance the engineering performances. The present investigation aims to provide an insight on in-situ stabilization techniques using chemical columns and make a comparison study of NaOH column and mixed chemical column [NaOH + Ca(OH)2] to improve geoengineering properties of sedimented ash bed and it is found from the result that NaOH is more effective in stabilizing the ash bed at a disposal site.