Assessment of Quicklime and Aluminum Sulfate for pH Neutralization and Organic Matter Reduction in Dug Well Water in Jongaya, Indonesia

Dug well water in the working area of the Jongaya Community Health Center often fails to meet clean water quality standards due to low pH (6.1) and high organic matter content (14 mg/L), exceeding the limits set by Indonesian Ministry of Health Regulation No. 32 of 2017, which poses a risk of digestive disorders and skin diseases. Addressing this gap, this study evaluates the effectiveness of quicklime (CaO) and aluminum sulfate [Al₂(SO₄)₃] in improving dug well water quality through a quasi-experimental pretest–posttest control group design. Water samples were purposively collected from contaminated wells and treated using quicklime, aluminum sulfate, and their combination at doses of 1 g, 10 g, and 20 g, each replicated three times, with pH and organic matter content measured before and after treatment and analyzed using a paired t-test. Results showed that 1 g of CaO significantly increased pH from 6.1 to 7.88 (p < 0.05), meeting the clean water quality threshold (≥ 6.5), while 20 g of Al₂(SO₄)₃ reduced organic matter content from 170.91 mg/L to 126.11 mg/L, and the combined treatment achieved the best outcome, with a 46.75% reduction in organic matter and a pH increase to 8.63, both meeting standards. All treatments were statistically significant (p < 0.05), indicating that CaO and Al₂(SO₄)₃ are effective for improving dug well water quality in at-risk communities. The findings highlight the urgency of promoting proper application and optimal dosing, supported by long-term monitoring, and provide novel evidence on the combined use of these chemicals for addressing a local public health challenge.