Context. Acústica Austral took on this project after an initial SEIA submission —with another consultant— that was not admitted to processing due to observations on the noise and vibration studies: the firm reworked both studies and the project secured admission to processing and subsequent approval. It concerns the Environmental Impact Statement (DIA) of the «Rail Transport in the Antofagasta Region» project (owner Empresa de Transporte Ferroviario S.A., operator Ferronor), in the communes of Antofagasta and Mejillones, enabling rail transport of sulphuric acid and copper cathodes between the Minera Escondida site and the ports of Antofagasta and Mejillones, and incorporating two new support facilities: the Mejillones Workshop and the Antofagasta Yard.
Methodology — noise. The baseline condition was established with continuous and discrete measurements at 21 population receptors, complemented by field characterisation of the actual emission of the project’s locomotives and rail cars. Levels were modelled in CadnaA (ISO 9613), assessing fixed sources (marshalling yards) under Decree D.S. No. 38/2011 and rail traffic (mobile source) under the Federal Transit Administration (FTA) Transit Noise and Vibration Impact Assessment Manual, together with the synergistic effect on human health.
Methodology — vibration. The vibration baseline was measured at 13 receptors and the railway emission was characterised from the passage of 51 trains of varying composition. The assessment followed the three stages of the FTA guide (screening, general assessment and detailed assessment) and the Caltrans guide for structural damage, with a detailed 1/3-octave band analysis. As part of the study, Force Density Level (FDL) measurements of the locomotive were commissioned at the manufacturer’s test track abroad, validated on Ferronor’s tracks in Chile, incorporating track-type adjustments to represent the most unfavourable scenario.
Results. The noise study concluded that the project does not exceed the maximum permissible levels of D.S. No. 38/2011 (fixed sources) or the FTA limits (rail traffic), ruling out synergistic effects and impacts on native fauna and ways of life. The vibration study ruled out impact across all phases —construction, yard operation and rail traffic— as no sensitive receptors were identified within the regulatory compliance areas.
