Arun Kumar Singh has left indelible footprints in all the sectors that he has worked including, urban development, agriculture and sanitation. He played an important role in decentralisation of Urban Local Bodies in Jharkhand and introduced several reforms related to urban development. Singh has made exemplary contributions in urban sanitation.

His innovative ideas like construction of skill development centers, community toilets, reverse vending machines and Google toilet locator, played an instrumental role in making cities of Jharkhand clean and citizen friendly. In the agriculture sector he introduced innovative measures to boost Cashew production. He has also introduced several innovative measures to bring more transparency and efficiency in the public distribution system in the state.