Wastewater treatment's primary purpose is to protect surface water quality, aquatic life, beneficial and recreational uses of waterways, and primarily comply with local water emission standards. Lately, additional requirements were added for these facilities, concerning minimization of a series of sidestream environmental impacts (i.e., odours, generated waste by-products, etc.), air emissions, including CO2, methane and nitrogen greenhouse gases (GHGs), and mitigation of various other likely impacts resulting from energy and chemical use in treatment processes. This paper describes a case study in Northern Europe, where critical analysis of an industrial wastewater treatment plant's present conditions, during an evaluation of upgrade possibilities to improve regulatory compliance, led to a sustainable intervention proposal. According to the formulated proposal, process improvement, energy recovery, and overall savings and GHG emissions reduction could be simultaneously achieved with a series of relatively simple interventions.