Assessing presence of emerging contaminants of concern (ECCs) associated with wastewater treatment plant discharges

Globally, emerging contaminants of concern (ECCs) are recorded consistently across all water types (surface water, ground water, drinking water, recycled water and wastewater). Harmful impacts have been recorded for some chemicals, but a key issue is that harmful effects have not yet been investigated for a large number of chemicals. The continued synthesis of new anthropogenic chemicals further compounds the situation, especially when there is limited information on break-down products after release, longevity and impacts to the environment and human health. Even at trace concentrations, the diversity, toxicity, high mobility and long-lived nature of these ECCs, create challenges for regulators, particularly in relation to removing them from drinking water, wastewaters, and aquatic environments. Wastewater treatment plants (WWTPs) and sewage treatment plants (STPs) often act as a conduit for release of EECs from industrial and urban environments directly into aquatic ecosystems. EECs are frequently detected in raw wastewater influents and treated effluents both globally and within Australia. ECC types and concentrations in WWTPs will be highly dependent upon the treatment level (primary, secondary or tertiary) and influenced by the socio-economic composition of the surrounding population. Whilst many contaminants are being monitored in Queensland, particularly from large and medium sewage treatment plants in south east Queensland, regional areas receive far less attention. The range of ECCs investigated in this project in Northern and Central Queensland regions included a targeted list of microplastics, bisphenol A (BPA), personal care products, pharmaceuticals, hormones, food additives and flame retardants. The current project aimed to determine: temporal variations in multiple suites of ECCs from WWTP effluent discharge across wet and dry seasons in the catchment of three regional councils in Northern and Central Qld regions; and dissipation of ECCs from point of discharge to two diffuse points downstream.