Wastewater catchment area data are essential for wastewater treatment
capacity planning and have recently become critical for operationalising
wastewater-based epidemiology (WBE) for COVID-19. Owing to the
privatised nature of the water industry in the United Kingdom, the
required catchment area datasets are not readily available to
researchers. Here, we present a consolidated dataset of 7,537 catchment
areas from ten sewerage service providers in the Great Britain, covering
more than 96% of the population of England and Wales. We develop a
geospatial method for estimating the population resident within each
catchment from small area population estimates generated by the Office
for National Statistics. The method is more widely applicable to
matching electronic health records to wastewater infrastructure.
Population estimates are highly predictive of population equivalent
treatment loads reported under the European Urban Wastewater Treatment
Directive. We highlight challenges associated with using geospatial data
for wastewater-based epidemiology.