He gave the example of nitrate, an agricultural pollutant that's present in the water supply in Des Moines.

他举了硝酸盐的例子，硝酸盐是得梅因供水中存在的一种农业污染物。

The Great Lakes coastal habitats are being degraded and increasingly populated, exposing the once pristine waters to industrial, urban, and agricultural pollutants.

五大湖沿岸栖息地正在退化， 人口不断增加，使曾经纯净的水域暴露在工业、城市和农业污染物中。