The influence of aquifer material to the groundwater potency in Ngawi Regency Ignasius Loyola Setyawan Purnama, Laelina Rahmawati, Vincentia Anindha Primacintya and Erick Febriarta E3S Web Conf., 325 (2021) 08011 Published online: 17 November 2021 DOI: 10.1051/e3sconf/202132508011