Municipal Water - High pH

[bigredbarn]

Hello all,

I am recently hooked into a new municipal water source with peculiar attributes. The Ward sample looks pretty good, but the pH is high. I asked the water plant operator about it and he said they treat with Sodium Hydroxide. My understanding here is the downfall for brewing is the residual Sodium ions leftover in the water, but given the report I am more concerned about pH. Thoughts? Best way to treat, and/or neutralize?

Thanks!

Here's the report:

pH 10.1

Total Dissolved Solids (TDS) Est, ppm 74

Electrical Conductivity, mmho/cm 0.12

Cations / Anions, me/L 0.9 / 0.7

ppm

Sodium, Na 10

Potassium, K 5

Calcium, Ca 5

Magnesium, Mg < 1

Total Hardness, CaCO3 17

Nitrate, NO3-N 0.1 (SAFE)

Sulfate, SO4-S 4

Chloride, Cl 6

Carbonate, CO3 4.8

Bicarbonate, HCO3 6

Total Alkalinity, CaCO3 19

Total Phosphorus, P 0.36

Total Iron, Fe 0.15

 

[mabrungard]

Yes, with the low ionic content in that water, they need to boost the pH to help avoid corroding the pipes. The high pH has almost no effect on your brewing. Ignore it.

 

[bigredbarn]

Thank you for your thoughts, Martin. As is, the water has a bit of a drying sensation when consumed, with a slight bitter note that can't be explained by the report. Would you expect that to go away with acid treatment?

 

[mabrungard]

As is, the water has a bit of a drying sensation when consumed, with a slight bitter note that can't be explained by the report. Would you expect that to go away with acid treatment?

It may. With the minor amount of alkalinity in that water, it won't take much acid to bring the water's pH down.

 

[ajdelange]

I am recently hooked into a new municipal water source with peculiar attributes. The Ward sample looks pretty good, but the pH is high. I asked the water plant operator about it and he said they treat with Sodium Hydroxide. My understanding here is the downfall for brewing is the residual Sodium ions leftover in the water, but given the report I am more concerned about pH.

Your utility's water is very soft with only a tiny bit of carbonic acid (about 2-3 mg/L) and a tiny bit of bicarbonate (about 2 mg/L) dissolved in it. It's pH might have been in the low to mid 6's. Water with this amount of calcium in it will dissolve any calcium carbonate in piping through which it passes unless its pH is above 10. Your utility doesn't want the calcium carbonate in its pipes dissolved as that deposit protects the pipe from the corrosive effects of water. Thus the obvious thing to do is increase the pH to above 10 and the easiest way to do that is to add some NaOH to the water. Given that the carbonic and bicarbonate (both acids) content of the water is so low it only takes a tiny bit of NaOH, about 13 mg/L, to neutralize them and get the pH up to where a wee bit of CaCO3 does protect the pipes. Your utility has done this.

Thoughts? Best way to treat, and/or neutralize?

Ignore it! The tiny amount of sodium added (as part of the NaOH) is only sufficient to raise the total sodium content of the treated water to 10 mg/L which is inconsequential. Ward Labs pegged your alkalinity at 19 ppm. Again very small. That's 0.4 mEq/L so you would need but 0.4/11.8 = 0.03 mL of lactic acid for each liter of mash water to neutralize it.