A Multimedia Hydrological Fate Modeling Framework To Assess Water Consumption Impacts in Life Cycle Assessment

Abstract

Many new methods have recently been developed to address environmental consequences of water consumption in life cycle assessment (LCA). However, such methods can only partially be compared and combined, because their modeling structure and metrics are inconsistent. Moreover, they focus on specific water sources (e.g., river) and miss description of transport flows between water compartments (e.g., from river to atmosphere via evaporation) and regions (e.g., atmospheric advection). Consequently, they provide a partial regard of the local and global hydrological cycle and derived impacts on the environment. This paper proposes consensus-based guidelines for a harmonized development of the next generation of water consumption LCA indicators, with a focus on consequences of water consumption on ecosystem quality. To include the consideration of the multimedia water fate between compartments of the water cycle, we provide spatial regionalization and temporal specification guidance. The principles and recommendations of the paper are applied to an illustrative case study. The guidelines set the basis of a more accurate, novel way of modeling water consumption impacts in LCA. The environmental relevance of this LCA impact category will improve, yet much research is needed to make the guidelines operational.

Integration of environment and nutrition in life cycle assessment of food Items: opportunities and challenges

“…Following the development of volumetric water use indicators and water scarcity indicators, Núñez et al (2018) advocate for a third generation of water use indicators. Many water scarcity indicators consider watersheds as a single water compartment or possibly distinguish water from surface water bodies and aquifers but without connections between the two.…”

“…Many water scarcity indicators consider watersheds as a single water compartment or possibly distinguish water from surface water bodies and aquifers but without connections between the two. Núñez et al (2018) recommend considering multiple water compartments, most importantly including also soils, and the flows between such compartments and regions. Additionally, they recommend assessing impacts at the endpoint (as is sometimes already done, as previously noted), but following a mechanistic characterization factor structure that accounts for multiple steps along the cause-effect chain through fate, exposure or sensitivity, effect, and damage factors.…”

Quantifying net water consumption of Norwegian hydropower reservoirs and related aquatic biodiversity impacts in Life Cycle Assessment

“…This enables a more regional specific Life Cycle Impact Assessment, which is needed to assess the biodiversity impact of water consumption on a global scale. 43,101 Hanafiah et al 44 reports an average CF of between 2.51*10 -15 PDF*y/m 3 and 1*10 -08 PDF*y/m 3 below 42° latitude north. Our CFs varying between 7.1*10 -12 PDF*y/m 3 and 8.0*10 -7 PDF*y/m 3 are therefore generally higher.…”

A Regionalised Life Cycle Assessment Model to Globally Assess the Environmental Implications of Soil Salinization in Irrigated Agriculture

“…33,34 However, in our model, the calculation of the addition of salts in soil at steady state resulting from irrigation is done at the inventory as a connecting step between LCI and LCIA because our approach lumps all fate processes together as a function of the leaching and drainage management. The dynamic nature of soil salinity in large-scale modeling was tackled by Payen, 35 who developed a daily time step model called E.T. and used it in LCA to calculate water and salt balances on a mandarin orchard irrigated with a drip system.…”