Evaluasi kualitas air fisik-kimia mata air Uluna dalam sistem hidrogeologi CAT Manado

Abstract

Uluna Spring in Tuutu Village, South Tondano District, Minahasa Regency serves as a natural water source for local hygiene and sanitation needs. This study evaluates water quality based on physical and chemical parameters within the hydrogeological framework of the Manado Groundwater Basin (CAT Manado). Grab sampling was conducted at a single discharge point with three replicates in December 2025 (SNI 6989.57-2008), analyzed at the Manado Community Health Laboratory. All tested parameters TDS (83 mg/L), turbidity (0.7 NTU), Fe (<0.0394 mg/L), Mn (<0.0058 mg/L), nitrite (<0.001 mg/L), nitrate (3 mg/L), and pH (7.6) complied with PERMENKES RI No. 2 of 2023 standards. Dissolved chromium was detected at 0.11 mg/L without a specific regulatory benchmark, necessitating Cr³⁺/Cr⁶⁺ speciation analysis in future research. The favorable water quality is attributed to high-permeability alluvial deposits acting as natural filters and the spring's position within the CAT Manado discharge zone. However, increasing recreational use poses potential contamination risks, underscoring the need for periodic hydrogeology-based monitoring.