It is estimated that the amount of water needed by Universitas Diponegoro will increase in the years to come. Several efforts are required to ensure the fulfillment of water needed while also considering its sustainability. There have been studies on water conservation at the industrial level. Still, limited studies have discussed this problem in Indonesia specifically at university level. Therefore, this study discusses the water conservation program at Universitas Diponegoro that might be used as a reference for other universities to address water supply problems. This study aims to discuss in depth water conservation efforts at Universitas Diponegoro. This study incorporates a descriptive-qualitative approach along with direct observation. Some programs on water supply have been implemented in Universitas Diponegoro such as conservation, treated water consumed, water recycling and water-efficiency. The existence of rainwater harvesting tanks (RWH), reservoirs, biopores, wastewater treatment plans (WWTPs) and ponds are among the efforts that have been applied at Universitas Diponegoro in order to conserve the water. To date, Universitas Diponegoro has successfully conserved more than 75% of the water, recycling about >50% of wastewater, installing about >50% of water-saving equipment, and has treated clean water into drinking water using reverse osmosis.Keyword: water, conservation, sustainability, campus

The mining of waste in landfills has become the center of discussion. Refuse-derived fuel (RDF) is a waste processing technology that converts waste into more valuable materials, namely fuel. According to Cheremisinoff, what is meant by RDF is the result of separating solid waste between combustible and noncombustible fractions, such as metal and glass [1]. RDF is produced from dividing fractions with a high calorific value from the separation of municipal solid

Semarang, the capital of Central Java, had a population of 1,814,100 in 2019. City's Jatibarang landfill waste dump was expected to close in 2021. This dump can be rehabilitated by mining the backfill and utilizing mining materials. Herein, a mining feasibility study was conducted to examine the environmental, technical, and financial aspects to determine the condition of the waste dump zone. The environmental feasibility was evaluated using the integrated risk basic approach (IRBA); the technical feasibility was analyzed by conducting laboratory tests and determining the appropriate technology for processing fine materials; and the net present values (NPV), payback period (PP), and internal rate of return (IRR) were calculated for financial feasibility analysis. The total waste heap in zones 1 and 2 was 2,444,700 m 3 , with a fine material composition of 56% and density of 738.05 kg/m 3 . IRBA analysis results indicated a moderately hazardous dump. Thus, this dump can be rehabilitated via landfill mining. The fine material can be converted to granular organic fertilizer for use in the petrochemical industry. Overall, landfill mining is financially feasible, with a NPV value of IDR 11,126,547,566>0, IRR 33%>9.86%, and PP of seven years

Leachate is the product of the biodegradation process in the landfill. On-site treatment of leachate using leachate recirculation is one of the alternative methods to reduce the hazard. The operation of leachate recirculation provides benefits such as speeding up biodegradation, lowering pollutant concentrations, and increasing gas production. This study aims to evaluate the application of leachate recirculation on the concentration of CO2 and CH4 produced. Experiments were performed in a laboratory using 20 lysimeters, with 1 L in volume for 365 days. The lysimeter was divided into two groups, with 10 reactors, each group arranged in series. Leachate recirculation will be given to the second reactor until the tenth reactor, using a high leachate concentration for the first group and a low concentration of leachate for the second. The addition of leachate in the two reactor treatment groups significantly increased the organic content in the leachate. Leachate recirculation does not cause a significant escalation in CO2 and CH4 concentration compared to reactors without leachate recirculation. In the reactor group with high leachate concentrations, reactors with leachate recirculation produced a more stable gas concentration than those without leachate recirculation which produced more volatile CH4 concentration.