Nowadays, groundwater in the world has been widely exploited along with the increasing population. One of the impacts of massive groundwater extraction is the decline in groundwater levels. This potential could occur at one of the airports in East Java which is one of the most crowded airports in Indonesia. The large number of passengers at the airport has increased groundwater extraction due to the increasing need for sanitation, airport facilities, and other operational needs. This study aims to determine the potential for groundwater level decline at one of the airports in East Java. The research method used is a quantitative method by projecting secondary data from the results of groundwater level sampling carried out every 6 months. The results of the study showed a decline in groundwater levels at one of the airports in East Java in the next 20 years due to the increase in passengers each year. The results of this study are expected to be one of the preventive steps for all of us to maintain the sustainability of groundwater resources.
 

The waste piles in the landfill pose a higher environmental hazard compared to the waste at its source due to the potential formation of leachate and air emissions. Consequently, waste management from the source is essential to minimize the amount of waste in the landfill. The waste management methods at each location typically vary based on the composition, characteristics, and quantity of waste present in that specific area. In this study, an analysis of waste piles at facility X was conducted through the process of sorting and weighing the waste during October 2023, with the objective of providing research findings that can be utilized to determine suitable waste management options for the location. The research revealed that the dominating composition of the waste consists of organic waste, with garden waste accounting for 55.95% and food residue comprising 10.75%. Composting was selected as the recommended alternative for waste treatment in the area. Garden waste, primarily composed of dry leaves, is suggested to be treated using the pile composting method, while food residue is suggested to be treated through a combination of Black Soldier Fly larvae biotechnology and Takakura composting.