Improving risk assessment for recycled water: domestic laundries and recreational parks

澳大利亚最近的干旱意味着循环水对于确保我们水资源的可持续性变得越来越重要。根据微生物污染程度，循环水分为四类（A、B、C和D类）。人口接触再循环水的潜在水平决定了适合各种再利用目的的水的类别。由于需要解决澳大利亚的水循环问题，因此出现了越来越多的创新性循环计划，如双重网状系统，向家庭提供两种水质的水，一种是高质量的饮用水，另一种是管道系统，提供经处理的循环水供非饮用水使用。在本项目中，我们将通过使用具有不同已知微生物浓度的水来模拟不同等级的循环沃茨，来研究在不同情况下使用循环水的安全性。由于缺乏安全数据，澳大利亚大多数州的卫生当局不批准使用再生水进行机洗，但在洗衣店使用再生水可以大大减少对高质量饮用水的需求。我们将进行实验，以帮助确定在洗衣机循环过程中使用循环水漂洗衣服的安全性。再生水的另一个用途是用于娱乐公园的灌溉。出于安全考虑，当使用B或C类再生水时，一些州主张公众必须在浇水后等待至少4小时才能获得。这个时间段可能是不必要的。我们将进行实验，以评估公园使用者在使用不同等级的水灌溉后的不同时间段内可能接触到草地中的微生物。从该项目获得的信息将有助于卫生和水管理机构的决策。

Recent droughts in Australia have meant that recycled water is becoming increasingly important to ensure the sustainability of our water resources. There are four different classes of recycled water (Class A, B, C and D), depending on the level of microbiological contamination. The potential level of exposure of the population to recycled water determines the class of water suitable for various reuse purposes. The need to address water recycling issues in Australia has resulted in increasing numbers of innovative recycling schemes such as dual reticulation systems which supply two qualities of water to households, one of high quality for drinking and a second piped system delivering treated recycled water for non-potable (non-drinking) use. In this project, we will investigate the safety of using recycled water in different situations by using water with different known concentrations of micro-organisms to simulate recycled waters of different classes. Most state health authorities in Australia do not approve the use of recycled water for machine washing because of a lack of safety data, but its use in laundries could significantly reduce the need for high quality drinking water. We will perform experiments to help determine the safety of using recycled water for rinsing clothes during a washing machine cycle. Another use of recycled water is for irrigation of recreational parks. Because of safety concerns, when recycled water of Class B or C is used, some states advocate that the public must wait at least 4 hours after watering before they can gain access. This time period may be unnecessary. We will perform experiments to assess the potential exposure to micro-organisms in grass for park users at different time periods following irrigation with water of various classes. The information obtained from this project will help in the decision-making of health and water regulatory agencies.