Analisis Laju Infiltrasi Air Tanah Diarea Sekitar Pabrik PULP ( PT . Phoenix Resourses Internasional ) Teehadap Potensi Pencemaran Air Bawah Tanah
AABSTRACT Landfill activities have the potential to generate leachate that can impact environmental specifically groundwater should the leachate migrate through the soil layers. Soil water infiltration capacity is a key factor influencing the potential spread of leachate. This study aimed to analyze soil infiltration rates and physical soil characteristics, as well as to evaluate the potential for leachate migration and groundwater contamination at the PT Phoenix Resources International (PRI) landfill site. A quantitative approach utilizing a descriptive method was employed. Infiltration rates were measured directly in the field using a double-ring infiltrometer at quality five observation points selected via purposive sampling. The measurement data were analyzed using the Horton method to determine the characteristics of infiltration rate changes over time. Supplementary analysis involved testing physical soil properties, including texture, bulk density, porosity, and moisture content. The potential for leachate migration was evaluated based on the Soil Conservation Service (SCS) infiltration classification, while leachate quality was compared against the standards set by the Regulation of the Minister of Environment and Forestry of the Republic of Indonesia Number P.59 of 2016. The results indicated that infiltration rates at the five observation points ranged from 29.5 to 35.5 mm/hour, with an average of 32.8 mm/hour. Based on the SCS classification, these values fall within the moderate infiltration class (20–63 mm/hour). Horton method analysis showed that the infiltration rate decreased exponentially until reaching a constant infiltration state. Soil characteristics at the site were dominated by sandy clay loam to clay loam textures, with an average composition of 50.6% sand, 20.0% silt, and 29.4% clay. The average bulk density (1.44 g/cm³), porosity (45.81%), and soil moisture content (29.9%) indicate that the physical soil conditions support a moderate infiltration capacity. Based on the analysis, the potential for leachate migration into the soil layers is classified as moderate. Leachate quality test results indicate that most parameters comply with the standards set by the Regulation of the Minister of Environment and Forestry No. P.59 of 2016, meaning pollutant loads are relatively well controlled. The landfill management system comprising an HDPE geomembrane and a Leachate Treatment Plant (LTP), also plays a role in mitigating the risk of leachate seeping into the soil. Consequently, the potential for groundwater contamination in the study area is categorized as low to moderate.