The oil and gas industry generates a lot of solid, liquid, and gaseous waste, which harms the environment. Oil and gas companies adapted number of waste management techniques to reduce the environmental impacts of generated waste and reduce the associated management cost. Spent blasts (abrasive material) is one of the big volumes generated waste from oil and gas industry which need attention through proper handling, storage, and disposal. Grit blast is one of the abrasive types used in blasting activity. Grit blasting processes produce Grit Blasting Waste (GBW) that is contaminated with various impurities, including paint, rust, and heavy metals. If such pollutants are not properly managed, they pose a risk to the environment. Most of the explored options to improve GBW management are not looking into the root causes of high generation rates of GBW. It is mainly looking into recycling options after the generation of waste. There are many techniques to explore the root causes of this high generation rate, using process improvement and problem-solving tools. This research focuses on exploring the possible sustainable solutions for the poor management of grit blasting waste, utilizing six sigma process improvement and problem-solving methodology. The study investigated the five phases of six sigma process improvement methodology, i.e., define, measure, analyse, improve, and control for the oil and gas company. The research was conducted through following steps: (1) define and measure the current condition of Grit blasting waste management, (2) analyse the collected data, (3) identify the root causes of poor management, and (4) develop the possible sustainable solutions to improve Grit blasting waste management in oil and gas sector. At define phase, the GBW management defined goal statement and project timeline. The research measured the size, scope, and level of the problem through data collection of generated GBW afterward. It showed that the annual GBW generation rate is increasing and accumulating in GBW storage facilities without sustainable management. Different analysis tools (graphical and statistical) identified the root causes of poor GBW management. The causes are - (1) difficulty in blasting material selection: some of the wastes are not reusable, (2) different contractors following different standards for blasting activities resulted in different quantities of GBW, and (3) the number of reuse times of spent GB material in each location is different. The proposed sustainable solutions for better GBW management could be short and long-term. (1) Reusing the spent blast in blasting activities and exploring the feasibility of reselling the GBW to the supplier can be the short-term solution. (2) Exploring new technologies to generate less GBW and to find recycling options can be the long-term solution.