Geospatial analysis and method for integrating nature-based solutions while planning sewage treatment in cities

Area of Science:

• Environmental Engineering
• Geospatial Science
• Wastewater Treatment

Background:

• Nature-based Solutions (NBS), including Constructed Wetlands (CW) and waste stabilization ponds, are Natural Treatment Systems (NTS) for wastewater.
• NTS offer lower energy usage but require more land than mechanized systems, with land needs varying by climate and geospatial factors.
• Generalizing NTS land requirements globally is challenging due to diverse climatic conditions.

Purpose of the Study:

• To develop a novel geospatial decision support tool for determining the land requirement and 'treatment potential' of wastewater treatment technologies.
• To integrate location-specific geospatial data (temperature, solar radiation, elevation) into land requirement estimations.
• To provide a method for assessing the feasibility of NTS in urban planning.

Main Methods:

• Developed a decision support system utilizing open-source global datasets.
• Incorporated geospatial factors to define land requirement as a function of location.
• Generated visualizations including graphs, raster statistics, 3D surface plots, and land requirement maps.

Main Results:

• Demonstrated application to an Indian city, yielding a treatment potential of 128 KLD for a 0.9m deep CW with 75% efficiency.
• Calculated a land requirement of 88 m² for CW in a residential building context, validated by an existing 100 m² installation.
• The decision support tool effectively assesses preliminary NTS feasibility.

Conclusions:

• The developed geospatial decision support tool offers a novel approach for planning NTS in urban environments.
• It enables integration of site-specific land availability constraints with treatment technology potential.
• This methodology enhances the preliminary feasibility assessment of NTS by considering location-specific factors.