Tt post jul 28 2015

"Here's the secret: They have alum this year, the mixy stick is not broken, and they know we are watching."

On Aug 19, 2014, justread wrote :

We know (Thanks to the required EPA disclosure that just came in our most recent water bills) that your staff at the Collins Park plant RAN OUT of Alum and had to come up with a protocol to make sure that it wouldn't happen again.

After the alleged crisis ended last year, we learned that one flocculator was broken, during the crisis.

A brief description about the water treatment process:

Water treatment begins 6 to 12 hours before water reaches the plant.
Toledo's intake crib is located about three miles off the shoreline in Jerusalem Township east of Oregon.
Raw Lake Erie water is drawn into the intake crib.
Potassium permanganate is added to raw water, which combats algae a little, but it's mostly used for taste and odor.
Potassium permanganate is also used to keep quagga mussels from clogging the intake. Quagga mussels are the exotic successor to zebra mussels.
The water arrives at the low-service pump station a half-mile south of the shoreline.
Powdered activated carbon is then added.
When the water arrives at the treatment plant in East Toledo, operators add alum.
The alum forces algae particles to bind together, making them easier to separate from the water.
That separation process begins in the flocculation basin, where the water is gently stirred.
The stirring has to be gentle so the algal clumps don’t break apart and become dispersed back into the water column.
Lime is added to soften the water.
Soda ash is used to counteract alum when there’s excessive algae and a need for more alum.
As the water completes three passes in the flocculation basin, with particles settling out, carbon dioxide is added to complete the softening process.
Then the water passes through a series of filters.
Chlorine is added throughout the treatment process to kill bacteria and any residual algae toxins.
Sodium chloride and fluoride are added near the end of the treatment process.
Fluoride helps prevent tooth decay.
Polyphosphate is added to help protect copper pipes.
The finished water is distributed to the public from the enormous force of high-service pumps that are wider and taller than many two-car garages.

It does appear that alum and flocculation are important to treating our water.