ALBERT

Description: This dataset provides a consistent and comprehensive outlook of global wastewater production, collection, treatment and re-use at both the country-level and 5 arc-min resolution (gridded) for the year 2015. Country-level estimates of wastewater reported from various sources are used as basis, supplemented with predictions based on multiple linear regression using social, economic, hydrological and geographical predictor variables. Country-level wastewater data are provided in both volume flow rate (million m3 yr-1) and percentage terms. Wastewater data is downscaled to gridded (5 arc-min; m3 yr-1) estimates based on simulations of domestic and industrial return flows from the Water Futures and Solutions (WFaS; Wada et al., 2016) using the approach developed for PCRaster GlOBal Water Balance model (PCR-GLOBWB2; Sutanudjaja et al (2018)). Estimates of downscaled wastewater treatment and re-use are validated based on wastewater treatment plant capacities reported in various databases.

Description: Continually improving and affordable wastewater management provides opportunities for both pollution reduction and clean water supply augmentation, while simultaneously promoting sustainable development and supporting the transition to a circular economy. This study aims to provide the first comprehensive and consistent global outlook on the state of domestic and manufacturing wastewater production, collection, treatment and reuse. We use a data-driven approach, collating, cross-examining and standardising country-level wastewater data from online data resources. Where unavailable, data are estimated using multiple linear regression. Country-level wastewater data are subsequently downscaled and validated at 5 arcmin (∼10 km) resolution. This study estimates global wastewater production at 359.4×109 m3 yr−1, of which 63 % (225.6×109 m3 yr−1) is collected and 52 % (188.1×109 m3 yr−1) is treated. By extension, we estimate that 48 % of global wastewater production is released to the environment untreated, which is substantially lower than previous estimates of ∼80 %. An estimated 40.7×109 m3 yr−1 of treated wastewater is intentionally reused. Substantial differences in per capita wastewater production, collection and treatment are observed across different geographic regions and by level of economic development. For example, just over 16 % of the global population in high-income countries produces 41 % of global wastewater. Treated-wastewater reuse is particularly substantial in the Middle East and North Africa (15 %) and western Europe (16 %), while comprising just 5.8 % and 5.7 % of the global population, respectively. Our database serves as a reference for understanding the global wastewater status and for identifying hotspots where untreated wastewater is released to the environment, which are found particularly in South and Southeast Asia. Importantly, our results also serve as a baseline for evaluating progress towards many policy goals that are both directly and indirectly connected to wastewater management. Our spatially explicit results available at 5 arcmin resolution are well suited for supporting more detailed hydrological analyses such as water quality modelling and large-scale water resource assessments and can be accessed at https://doi.org/10.1594/PANGAEA.918731 (Jones et al., 2020).