Analysis of Nitrogen Concentration (Nitrate, Nitrite, Ammonia) in Groundwater in Ngaglik SubDistrict, Sleman Regency, Yogyakarta Province

Groundwater plays a critical role in supporting all forms of life on Earth. The Ngaglik sub-district has experienced continuous regional development, which has led to increased human activities. Such activities contribute to higher waste generation, which can ultimately degrade the quality of surface water and groundwater. The objective of this study is to assess the concentrations of nitrite, nitrate, and ammonia in groundwater from the Ngaglik sub-district, to analyze the spatial distribution of these pollutants, and to identify the factors influencing groundwater quality. The research was conducted in the Ngaglik sub-district, Sleman Regency, Yogyakarta Province, at 14 well locations. Nitrite, nitrate, and ammonia concentrations were determined using spectrophotometry, following the Indonesian national standard method. To evaluate the spatial distribution of water quality, a mapping analysis was conducted using Quantum Geographic Information System (QGIS) software. Laboratory analysis revealed nitrate concentrations ranging from 1.102 mg/L to 14.503 mg/L, nitrite concentrations from 0.045 mg/L to 2.175 mg/L, and ammonia concentrations from 0.208 mg/L to 4.65 mg/L. The study concludes that the concentrations of nitrite and nitrate in the groundwater met the environmental health standards set by the Ministry of Health (Regulation No. 2 of 2023), while ammonia concentrations exceeded the permissible limits.