Investigating viable residential uses of old urban wells in Middelburg

Abstract

This study assesses the feasibility of utilizing well water in historic Middelburg, Zeeland, the Netherlands, as a source of drinking or graywater for residential purposes. Wells are prevalent in century old Middelburg houses when these were dug to access otherwise scarce freshwater. These wells became obsolete as modern amenities made freshwater available in all houses. However, many of these wells remain and some still discharge water, to the extent that it has to be pumped out and wasted. Given the specific challenges faced in this delta, of increasingly dry summers and saltwater intrusion in aquifers, freshwater can become even more scarce and costly. It is essential to explore every potential freshwater source, including this neglected well water. Therefore, seven wells in Middelburg were tested for common water quality parameters over a period of 6 months, including pH, temperature, dissolved oxygen, conductivity, phosphate, lead, copper, and E. coli. The conductivity confirmed the water to be freshwater, pointing to rainwater as a source, which finds its way underground and flows on remnants of sandy tidal creek beds. Dissolved oxygen levels were low in all wells except one. E. coli was not found, but unidentified coliform bacteria were present. All other parameters tested were within a normal range for drinking water. Despite these yet unknown coliform bacteria, the water in some of the wells is still useable as graywater. As most of the water is now pumped out, the residents can use the results of this study to find useful applications for their water as water stress in the area is increasing. By investigating new freshwater sources, this study contributes to the ongoing search for solutions to mitigate the ever-growing pressures on global freshwater resources.