According to Ben Urbonas, president of the Urban Watersheds Research Institute, these nutrient contaminants tend to be more of a problem in closed water systems,like lakes, where concentrations can build up.

VOA: standard.2010.08.04

That creates all sorts of social consequences that we'll talk about sustainability, with shipping water long distances, all the plastic involved, people's distrust of public water systems that's unfounded, and things like that are very interesting and have big public health consequences.

这就产生了很多社会问题,比如我们将要谈到的饮水污染问题,饮用水在长途运输的过程中,会受到各种塑料污染,还有人们对公用自来水系统,毫无理由地不信任,类似这些现象都很有趣,而且会导致重大的公共健康后果

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Another is that we learned a lot of things about engineering of public systems, like water supplies.

另一个原因是,我们懂得了有关公共系统知识,比如供水系统

耶鲁公开课 - 生物医学工程探索课程节选

The rain harvesting systems mean that a family member no longer has to walk long distances to get water.

VOA: special.2009.07.27

As part of the plan, the Army Corps of Engineers built roads, canals and water-control systems throughout South Florida.

VOA: special.2010.09.21

The systems are especially useful for those who are too sick to go a long way for water.

VOA: special.2009.07.27

These include transportation and communications systems, water and power lines, and public institutions including schools and hospitals.

VOA: special.2010.04.02

Eric Hartman,the director, described the water collection systems in blog postings from Tanzania earlier this month.

VOA: special.2009.07.27

And to do that, we need a lot of surveys and geological surveys on water preservation systems.

VOA: standard.2009.10.06

"If you have an imbalance, or literally too much nitrogen and too much phosphorous getting into those systems, you can essentially deplete the oxygen in that water.

VOA: standard.2010.08.04