HD Taylor Water Treatment Plant

Settling lagoon

You can see the settling lagoons from the bike path. This water has puzzled me. It often looks dirtier than the river. I thought maybe they were using some sort of biologically treatment. They are not. 

This is water that has been used to clean the filters. They can't immediately return it to the river because it now contains Alum and Chlorine. The alum settles out into these ponds and the Chlorine evaporates. Then the water is returned to the Willamette.

We were not allowed to take pictures of the great big intake screens in the river or the pumps that bring the water up about 27ft to the level of the treatment plant. I'm sure one would see them if one happened to be rafting on the Willamette. I suspect that this level of "secrecy" simply makes the tours more exciting.

After the water is pumped up out of the Willamette, the giant pipe carrying the water meets with smaller pipe that pumps in Chlorine and Alum against the flow of the water. The two streams hitting each other causes a lot of turbulence, which results in nice thuroughly mixed chemicals. This is the first of two time Chlorine is added to the water.

After the chemicals are added the water goes through sensor which measure the quality of the incoming water including chlorine concentrations, turbidity. 

This station monitors the quality of the incoming water after the chemicals are added.

A closer view of the sensors

The plant was off for maintenance during the first half of the tour. So these values are not characteristic of the plan when it's up and running.

Settling basins.

 The water flows through these basins starting where I was standing when I took this pictures and moving away from me. Each basing does progressively slower mixing. The idea is to create phloc. That is particles that are big enough to settle out. The first basin is like speed dating. The idea is to get the chemicals in contact with as many other chemicals a possible. After the initial mixing, the subsequent basics do succesively slower mixing in order to continue to build the phloc without breaking until it finally settles out. 

Vertical Paddle Wheel in the Basin.

After the water has been through the basins, it's forced up though these screens.

The screens provide surface area that the phloc sticks to and then sloughs off. These screens are self cleaning.

A different kind of paddle wheel

Water leaves the basins though this big red pipe

After the settling basins the water goes through porous media consisting of activated carbon silica and sand. Next, it travels into the chlorine contact basin, which i covered to keep debris from falling in the clean water. The Chlorine contact basin is serpentine to allow the water to have the necessary contact time with this final dose of chlorine. After the Chlorine contact basin the water goes into an undergound storage known as the clear well.

This is one of the pumps that move water from the clearwell to the reservoir

Here's a little perspective on that pump

The pressure gauge on the pump. The pump isn't running so the pressure is neutral.

This measures the turbidity of the treated water.  

Turbidity is a measure of amount of light that is blocked by the particulate in the water. For example muddy water in a muddle has a high turbidity. Your tap water should have a low turbidity (at least if your pipes are in good shape.)

A view down into the clearwell.This looks like a big black hole because the limitations of the camera. However if you look closely, you can see that it's tube going down into a pool of very clear water. There is a lighted up logo for the city of Corvallis at the bottom to show you how clear this water is.

This drinking fountain pulls water directly out of the clearwell below us.

Uh Oh!

Matt died, but don't worry. We revived him for the presentation.