An increasing number of people want to reduce their environmental footprint by using harvested rainwater as a source for drinking water. Moreover, implementing rainwater harvesting (RWH) enables protection against damage caused by increasing precipitation frequency and intensity, which is predicted for Western Europe. In this study, literature data on rainwater quality were reviewed, and based on Dutch climatological data the usable quantity of rainwater in the Netherlands was calculated. For two specific cases, (1) a densely populated city district and (2) a single house in a rural area, the total costs of ownership (TCO) for decentralized drinking water supply from harvested rainwater was calculated, and a life cycle assessment (LCA) was made. For the single house it was found that costs were very high (€60-€110/m ³ ), and the environmental impact would not decrease. For the city district, costs would be comparable to the present costs of centralized drinking water production and supply, but the environmental benefit is negligible (≤1‰). Furthermore, it was found that the amount of rainwater that can be harvested in the city district only covers about 50% of the demand. It was concluded that the application of rainwater harvesting for drinking water production in the Netherlands is not economically feasible. ... Read more

Veel consumenten hebben het idee dat ze hun milieu-impact kunnen verkleinen door zelf uit regenwater drinkwater te maken. We hebben een levenscyclusanalyse en een kostenberekening gemaakt voor decentrale zuivering van regenwater op het niveau van een stadswijk en een individuele woning in het buitengebied. Op wijkniveau zijn de kosten acceptabel, maar voor een individuele woning zijn ze erg hoog. De meerkosten staan niet in verhouding tot de te behalen milieuwinst. Belangrijke praktisch problemen zijn dat er in dichtbebouwde stadswijken te weinig regen valt voor alle inwoners en dat er te weinig ruimte is om een dergelijke zuivering te plaatsen. ... Read more

Often rainwater harvesting is considered as an important contribution to a more sustainable society. Rainwater is assumed to be clean water, requiring only limited treatment, and it is thought that there is sufficient rainwater available to provide people with drinking water. In order to check these assumptions, we carried out a desk study into the quality and quantity of rainwater. It was found that rainwater is cleaner than surface water, but still may contain contaminants. Especially the microbiological quality of rainwater is a point of concern, and therefore treatment, including disinfection, will be required. Furthermore, it was found that for densely populated areas, like a city district in Amsterdam, the quantity of rainwater that can be harvested from both built and paved surfaces equals only about half the amount that is required for the inhabitants. If rainwater is collected and treated at a neighborhood level, the costs are in the same order of magnitude as for centralized drinking water treatment. However, at the level of a single house costs are significantly higher. As rainwater requires less treatment than e.g. surface water, a small decrease in environmental impact may be realized. ... Read more

Innovatieve ideeën over het gebruik van regenwater als bron voor huishoudwater of drinkwater lijken de laatste jaren als paddenstoelen uit de grond te schieten. Maar
is het inderdaad een realistisch alternatief? En kunnen huishoudens hier zelf mee aan
de slag of moet het toch centraal worden geregeld? ... Read more