QUESTION: Will adding lime with 1ppm lead in it, add too much lead to our rainwater tank drinking water? 13 Apr 2008 NSW, Australia

Hi,

A friend recommended that we add lime to our rainwater tank to increase the PH. The tank (100kl)is used for drinking water. I bought some lime from a garden supplier but notices that it contains 1ppm of lead.

Will adding this to our drinking water be dangerous?

Thanks Paul

ANSWER: 20 Mar 2009

Hi Paul,

You have not said how much lime you need to add to your tank in order to obtain the correct pH so it is not obvious to me that you will be adding a lot of lime.

I can tell you, that to comply with the Australian standard for lead in drinking water, the lead concentration needs to be below 0.01 mg/L so if you are concerned about lead in your tank water (and I would suggest that the lime is the least likely source of significant lead in your tank water) then you can always have it tested at a lab.

Ask your Council if they do this testing or otherwise you can purchase a kit from us which you can use to collect a sample of water from the tap and send it to the lab for lead analysis. Please see Do-It-Yourself-Lead-Safe-Test-Kits and you may also want to read "What to do if you have too much lead in your tank water"

Yours Sincerely

Elizabeth O'Brien