Assessment of Groundwater Quality and Proposed Treatment using Aeration-Filtration Methods for Iron-Rich Groundwater at UPN “Veteran” Yogyakarta

Abstract

Groundwater quality often does not meet the standards as a result of geological factors and human activities. This study was conducted at the University of Pembangunan Nasional “Veteran” Yogyakarta (UPNVY), Condongcatur Campus, to evaluate groundwater quality and provide appropriate treatment recommendations. Groundwater samples were taken from three bore wells: Rectorate Building (SR), Nyi Ageng Serang Lecture Hall (SNAS), and Prof. Bambang Soeroto Lecture Hall (SAL). Sampling followed SNI 6989.57:2008, while laboratory tests were performed on physical parameters (turbidity and TDS) and chemical parameters (pH and Fe). The results showed that turbidity, pH, and iron concentration at most sampling did not meet the quality standards. Water turbidity reached 39.89 NTU at the SAL, far above the threshold of <3 NTU. Iron content was recorded at 5.85 mg/L in the SNAS, exceeding the 0.2 mg/L standard. The pH values at all three sites were also below the standard, ranging from 6.1 to 6.4, indicating acidic conditions. Geological analysis indicated that the high Fe content is associated with the weathering of volcanic minerals such as augite, hornblende, and biotite, which are abundant in Merapi Muda deposits. As a follow-up, a proposed water treatment system was designed using a multitray aeration and filtration combination with shell sand media. This method is expected to be effective in reducing iron concentration by up to 99.9%, decrease turbidity by more than 90%, and raise pH to a more neutral level. In the treatment scenario for SAL, Fe concentration decreased from 2.74 mg/L to 0.002 mg/L.