In many countries, the ever-growing demand for housing and tourism in coastal regions has forced the development of low-lying estuarine floodplains and wetlands for major infrastructure including highways, railways, hotels and high rise apartments, and commercial buildings. The estuarine clays, often with high organic content, are usually characterised by very high settlement upon loading affecting the stability of all forms of infrastructure. In addition, pyrites and other sulphidic compounds that exist at shallow depths in these soils can oxidise to form sulphuric acid presenting a challenging environmental issue, which if not controlled can cause catastrophic damage to coastal aquaculture and agriculture industries. In this Keynote presentation, the authors will present an overview of the Australian coastal experience, highlighting the geoenvironmental remediation methods tailored for acid soil conditions in estuarine soils, and demonstrating the geotechnical improvement of soft clays using prefabricated vertical drains (wick drains) with special reference to embankments. The manipulation of the groundwater table for submerging pyrites thereby preventing oxidation and methods of treatment of acidic groundwater will be presented. The improvement of the geotechnical behaviour of compressible clays by inducing preconstruction consolidation via wick drains with vacuum pressure will be elucidated, through the latest research developments employing both experimental and numerical techniques.