在荷兰，所有从地下水中制备的饮用水都在不使用化学消毒剂的情况下进行处理和分配。约三分之一的供水中使用的地表水必须通过多重屏障才能去除微生物和污染物。消毒阶段适用于大多数地表水，这些地表水不经过土壤通道，但饮用水在没有或消毒剂残留量较低的情况下分配。通过一系列措施防止饮用水再污染，包括防止反虹吸、控制消防栓的使用、清洁和维修协议以及监控。再生是通过维持生物稳定的饮用水、使用与水接触的生物稳定材料以及进行定期冲洗程序来控制的。许多技术用于评估饮用水的生物稳定性，包括评估易得可同化有机碳（AOC）的浓度，以及饮用水的生物膜形成特性（生物膜形成率和生物膜形成潜力）。 这些技术已应用于许多供水系统中，以获得确定饮用水生物稳定性的数据。本文描述了莱顿市供水调查的结果。

In the Netherlands, all drinking water prepared from groundwater is treated and distributed without the use of a chemical disinfectant. Surface water, which is used in about one third of the water supplies, must pass through multiple barriers for the removal of microorganisms and pollutants. A disinfection stage is included for most surface water that does not undergo soil passage but drinking water is distributed without or with a low disinfectant residual. Recontamination of drinking water is prevented by a series of measures including the prevention of backsiphonage, controlled use of fire hydrants, cleaning and repair protocols, and monitoring. Regrowth is controlled by maintaining biologically-stable drinking water, by the use of biologically-stable materials in contact with the water and by conducting a regular flushing program. A number of techniques are used to evaluate the biological stability of drinking water including the assessment of the concentration of easily available assimilable organic carbon (AOC), and biofilm formation characteristics of drinking water (biofilm formation rate and biofilm formation potential). These techniques have been applied in a number of water supply systems to obtain data for defining the biological stability of drinking water. This paper describes the results of such an investigation of the water supply of the City of Leiden.