Small Water Bottles Pass Microbial Tests but Are More Acidic Than Allowed

Five brands of small bottled water passed contamination tests, but none meets the minimum pH required by Dominican standards.

Five samples of small bottled water analyzed by Diario Libre passed microbiological tests at the laboratory of the Santo Domingo Aqueduct and Sewer Corporation (Caasd). However, all of them showed acidity levels above what Dominican regulations allow for non-carbonated bottled water.

According to Diario Libre's analysis, the samples included three major brands widely sold in the capital, with broad presence in corner stores and shops, and two store brands sold in supermarkets. These small bottles can be bought for about nine pesos.

The analyses, carried out in October 2026, recorded pH values between 5.64 and 6.03. The Dominican Standard (Nordom) 64 sets a range of 6.5 to 8.5 for bottled drinking water, so none of the five samples met the minimum limit.

On contamination, the laboratory found no total or fecal coliforms and no Escherichia coli, and the pseudomonas tests were negative. The aerobic mesophile count was also far below the permitted limit in all samples.

The director of Water Quality at Caasd, engineer José Mateo Mota, told Diario Libre that the acidity is caused by the reverse osmosis process used by bottling plants. That system removes impurities but also much of the water's natural minerals, which lowers its pH.

Mateo Mota believes companies can correct the problem with remineralization processes applied after reverse osmosis, and called on the Dirección General de Medicamentos, Alimentos y Productos Sanitarios (Digemaps) to enforce compliance with the parameter.