[dee]

My local water treatment facility has just announced that they are starting to adding phosphate (via phosphoric acid) to gradually reduce the pH of our drinking water from 8.9 to 7.5.  The reason given is to reduce the amount of chlorine (chlorine dioxide) used and thus reduce chlorine byproducts.  The plan is to implement this over an 15-18 month period.  Since they are adding acid, instead of reducing the lime they add currently, what impact do you think this will have?  My most recent profile water profile is Ca 12 Mg 2 NA 7 Cl9 SO4 5 CaCO3 26. 

[kylekohlmorgen]

Thats a pretty clean water profile! Do you know if its consistent throughout the year?

How do pre-treat before brewing? Just carbon filtering and then some brewing salts? If so, you'll just be adding a bit less acid.

I would highly recommend checking the profile (at least) seasonally... some municipal water treatment facilities change water sources quite often (like Indianapolis).

[tommeier]

With water this soft, this won't make a bit of difference..  It might take one drop of dilute acid to shift 5 gallons of your water this much in pH.

[BrewArk]

My local water treatment facility has just announced that they are starting to adding phosphate ... 

Just love the hypocrisy of the government mandating that private enterprise remove phosphates from their products then adds it to the water they are trying to clean up.  It's like the air pollution people demanding that disinfecting sprays remove alcohol from their products to clean the air.  I'd rather see fewer diesels on the road & have my disinfectants disinfect!

[mabrungard]

That water profile is typical of a lime-softening treatment process.  Lime is added to bring the pH to about 11 and that causes the excess calcium and magnesium to precipitate out of the water.  Some Ca and Mg still remains due to its solubility, but most of it is settled out.  The clear water is then taken off the sediment.  The acid addition is necessary to bring the pH back down within drinking water standards after treatment. 

I am a little surprised to hear that the utility is using phosphoric acid for the neutralization since its typically more costly than hydrochloric or sulfuric acid.  Maybe they got a good deal or they have some other concern they need to address. 

You've got good water there.  Enjoy.

Martin Brungard, P.E., D.WRE
Indianapolis, IN