How are water quality standards determined?

Work Instructions
Chapter 20 discusses water and water pollution. For this week’s individual work, please write a 1-2 page paper (counting body text only, not title or reference pages) in double-spaced, one-inch margins on all sides. Please respond to the following:
How are water quality standards determined?
Distinguish between water quality criteria pollutants and maximum contaminant levels.
Please make sure all of your assignments:
Are written in paragraph form.
Use 12 point, Times New Roman font.
Include title & reference pages (per APA rules).
At least one full page of text to the body of your essay.
One-inch margins on all sides.
Include a reference list at the end of your essay. That includes all web sites, journals, articles, etc., you used.
Please make sure you have not copied and pasted any information directly from any source; that is considered plagiarism. There is no need to copy, or quote, anyone for this assignment. It is to be a written summary reflecting your own thoughts of your reading & research on this topic. However, you should include in your reference list the source of your reading & research.