Project: Natural bathing water | Status: completed

Using rainwater to fill swimming ponds and natural swimming pools


Biotop Benelux

Project number:



Biotop specialises in the construction of swimming ponds and natural swimming pools. The company (together with other technology companies) commissioned a study into the feasibility of using rainwater as filling water (instead of piped/ground water). They are primarily interested in the legal challenges and technical solutions. The law stipulates the requirements for bathing water; these may vary from country to country. The focus for the customer is on the Netherlands and Germany. If it appears that the quality of the rainwater does not meet the legal standards, the technical possibilities to comply with the law must be explored. The technical solutions must be sustainable.


Describe the technical possibilities, limitations and challenges of using rainwater for swimming ponds and natural swimming pools. Focus mainly on the Dutch and German markets.

Research questions:

  1. What is the rainwater composition in the Netherlands and Germany?
  2. What are the legal requirements for bathing water in the Netherlands and Germany?
  3. What is the discrepancy between the above two research questions?
  4. What technical solutions are available to overcome the discrepancies in point 3?

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