The vulnerability of large landslides takes place due to many anthropogenic and natural factors. Frequent collapse and triggering of landslide take place in active foothills of the Himalayan region. The main primary factors causing destabilization of the slope include rainwater infiltration in the topmost weathered layer, earthquake forces, and local inhabitant activities. A vulnerable landslide zone having a residential area is envisaged in ‘Mangan’, North Sikkim, India. An interesting factor affecting the slope stability in the area under study has been noticed that in addition to rainwater and earthquake forces; the other forces being sewer line carrying wastewater outfall of households across sections. The long-term disposal and subsequent accumulation of sewer water caused an increase in pore space and overall density of soil due to saturation, rainwater additionally reduces cohesion of overlying mass causing slip-off from the parent strata. Preliminary stability analysis has been carried out for critical sections using LEM slide software and the effect of intermediate micropiles (Zinc-Chromium coated stainless steel) has been evaluated using the FEM technique. It has been seen that the top 100 m of slant length of the slope is quite unstable. Accordingly, intermediate series of micro piles have been installed with profiled benches in the unstable slope. Superstructure loads from the residential zone lying on the slope profile and vehicular loads at the road level have been considered for severe conditions. Furthermore, the location and length of micropile have been optimized based on concentrated stresses and strength reduction factors. It has been observed that there is a 48.5% and 37.8% increase in safety factors under static conditions and seismic conditions respectively. Analysis shows that micropiles work effectively in controlling local displacements due to sliding and add global stability to the affected region.