HIDROGEOKIMIA AIRTANAH TIDAK TERTEKAN DI PESISIR BARAT KABUPATEN SERANG DAN PANDEGLANG, PROVINSI BANTEN

Abstract

Proses hidrogeokimia terjadi karena interaksi antara airtanah dengan air laut. Proses tersebut akan mempengaruhi komposisi kimia di lingkungan pesisir. Untuk mengetahui seberapa jauh interaksi tersebut telah terjadi, dilakukan analisis tipe air berdasarkan jumlah anion dan kation yang paling dominan, dan analisis nisbah ion-ion utama. Pengambilan conto dilakukan di 38 lokasi conto air di pesisir barat Kabupaten Serang dan Pandeglang. Hasil penelitian menunjukkan tipe air didominasi oleh Ca(HCO3)2 55,26%, NaHCO3 39,47%, Ca(SO4)2 2,63% and NaMix 2,63%. Sementara hasil analisis nisbah ion utama Na+/Cl-, Ca2+/Mg2+, dan Ca2+/SO42- mengindikasikan bahwa telah terjadi pencemaran air laut di beberapa dataran alluvial pesisir Pandeglang. Pada sebagian besar pesisir barat Serang dan Pandeglang sedang terjadi proses pencemaran atau intrusi air laut.

Occurrence of hydrogeochemical process is due to the interaction between groundwater and sea water. The process will affect the chemical composition in the coastal environment. To find out how far the interaction has taken place, the water type was analysed based on the amount of most dominant anion and cation, and also the major ions ratios. The samplings were conducted in 38 locations on the west coast of Serang and Pandeglang Regencies. Results showed that the water type was dominated by Ca(HCO3)2 55,26%, NaHCO3 39,47%, Ca(SO4)2 2,63% and NaMix 2,63%. While the results of major ion analysis of Na+/Cl-, Ca2+/Mg2+, and Ca2+/SO42- indicated that there has been the sea water pollution in some coastal alluvial plains of Pandeglang. In addition, the process of pollution or sea water intrusion has been occurring on most of the west coast of Serang and Pandeglang.