On Wed, Feb 21, 2018 at 1:46 PM Ray Hackett <3659745> wrote:

https://water.usgs.gov/edu/

wwvisit.html

A visit to a wastewater-treatment plant:
Primary treatment of wastewater

Here’s a step-by-step guide describing what happens at each stage of the treatment process and how pollutants are removed to help keep our waterways clean. This information is courtesy of the Greater Vancouver Regional District.