Wastewater - Turning Problem to Solution

Separation and elimination of contaminants prior to discharge The separation of contaminants at source has been shown to improve treatment capacity. Appropriate and advanced pre-treatment or full treatment at source can remove critical pollutants, producing a high-quality effluent and reducing the pollutant load on the municipal sewage and wastewater treatment plants that they might otherwise not be able to manage. Reduced wastewater output can reduce levels of discharge fees, providing additional economic incentive for on-site treatment and recovery of wastewater (WBCSD 2020). • Promoting source-separating toilets that collect urine and faeces separately, making it possible to remove nitrogen and phosphorus from urine, which carries higher levels of resources and lower levels of contaminants (see case study from Malmö), lowers cost of wastewater treatment (Otto and Drechsel 2018) and reduces environmental impact, for example by preventing eutrophication (Mayer et al. 2016). • Identifying municipal services and industries that have sector specific contaminants, such as hospitals, factories, intensive animal production and develop on-site, decentralized treatment before the effluent can be released into the municipal sewer systems (State of Green and Danish Water Forum 2016). • Trading with other industries locally or within the value chain, e.g. where lower-quality standards are required, potentially reducing investment and operational costs. Separating contaminants at source from municipal and industrial sources Separating contaminants at source from domestic sources

Reducing the input of contaminants from domestic sources

• Lobbying industry to make safe biodegradable products. • Education and awareness to inform the choice of household cleaning products and personal care products. • Ensuring appropriate use and disposal of pharmaceutical products. • Selecting appliances that can reduce input into the wastewater flow, e.g. compost toilets, source-separating toilets that separate urine and faeces. • Using washing machine filters to reduce microplastics from textiles. • Avoiding excessive consumption of dietary protein, adhering to the recommended dietary requirements for good health would reduce pressure on wastewater treatment capacity.* • Regulating the production, use and/or disposal of particularly toxic contaminants or other non essential products that increase the cost or difficulty of wastewater treatment, e.g. certain ingredients used for sunscreen (oxybenzone and octinoxate) have been banned due to their impact on marine life. • Applying the polluter pays principle to incentivize avoidance of environmental damage and hold polluters responsible for costs resulting from pollution events. • Providing safe and accessible disposal options for substances of concern (e.g. take-back schemes for unused or out-of-date household and veterinary pharmaceutical products). • Running public education and awareness campaigns to reduce the input of contaminants into the sewage network, targeted at the different stakeholder groups. • Supporting innovation and uptake in changes of practice or technology to avoid or limit pollutant- and nutrient rich waste streams. Policies and regulations for reducing the input of contaminants

*Almaraz et al. (2022) concluded that if United States citizens reduced current excessive levels of protein consumption to meet the recommended dietary requirements, projected nitrogen excretion rates would decrease by 27 per cent by 2055, despite population growth.

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