DC used to have one of the worst records in America when it came to water treatment...tons of really bad stuff used to flow DIRECTLY into the Potomac and Anacostia rivers. But today, what a difference. I had a chance to go on a tour of The Blue Plains Advanced Waste Water Facility, the largest of its kind in the world!!! Over 150 acres of processing turning really ugly, polluted water into pure (although not drinkable) water that flows back into the Potomac. I've put a brief description  just below the image to give you a better idea of how the plant functions.

Primary Treatment PondPrimary Treatment Pond

The image above is one edge of a VERY large circular pond in the Primary Treatment section. There are 36 of these ponds. This is where the water comes in with much of its "junk" and the junk either floats to the top or sinks to the bottom. Skimmers on the top and the bottom skim the junk into the next stage.

Secondary Treatment Section.Secondary Treatment Section. The image above is one of the secondary treatment ponds. It's a timed exposure to show that the sludge is constantly moving. The sludge normally looks like brown...well, er, sludge. But it's alway on the move. 

Secondary Treatment SectionSecondary Treatment Section The image above is another view of the Secondary Treatment section. Although this is also a timed (slow shutter speed) photo, the time is much shorter so you get a better idea of what the sludge looks like.

The image above shows some of the nitrification/denitrification ponds. This is close to the end of the cycle. Gradually, the plant removes and converts the water from "pure sludge" to pure water and reusable solids (fertilizer). Water is sent to Blue Plains from all of D.C., parts of Fairfax and Loudon counties in Virginia, and, Montgomery and Prince George's counties in Maryland.

Out of service purification/filtrate machineOut of service purification/filtrate machine The image above is an out of service machine. Normally, the v-shaped things are laying flat on the surface below and moving the sludge around.  At the end of the process, we looked at the water and could not tell the difference between the fully processed Blue Plains water and tap water...it was that clear.

This is an awesome place.