national monument. noun. Definition of national monument for English Language Learners. : a place (such as an old building or an area of land) that is owned and protected by a national government because of its natural beauty or its importance to history or science. Britannica.com: Encyclopedia article about national monument.
Brown or discolored water is caused by minerals, sediment, or rust that may accumulate in the water mains over time. When the water from your tap is brown this indicates a disturbance in the water main that stirs up these deposits.
What Caused Toledo's Water Contamination? Massive algal blooms like the one that has turned the waters of Lake Erie florescent green and contaminated the drinking water of Toledo, Ohio, are caused when certain kinds of algae grow in response to changes in chemicals in the water, often from fertilizer components.