Water Pitcher Purchases made in Iowa - why keep buyer's address?

Factual Questions
1

Yesterday we bought a Pur brand water filtration pitcher - the kind where you fill the inner reservoir with tap water, and it runs through a filter into a pitcher that you keep in your fridge, or wherever. Anyway, the last page of the instructions was titled “Purchases made in Iowa” or something like that, and had a form for the buyer’s and seller’s address. The text said that the seller was supposed to keep this form on file for two years.

Does Iowa have stricter regulations on filtered water than other states do? What is the seller supposed to be doing with the buyers’ addresses, sending them notifications every couple months when it’s time to buy new filters or something?

I haven’t seen any other water pitcher instructions lately so I don’t know if it’s just Pur brand or if other brands like Brita also require the seller to keep track of the buyer’s address.

2

From Googling a bit, I think that you can’t sell water purfication systems to people in Iowa ulesss the State Dept. of Health has been show that they do what they claim, and the regulations are a bit stricter than most companies can comply with.

3

Hmm. I had one of those Brita pitchers when I lived in Huxley, Iowa. It worked OK. Then again, the local water supply in Huxley literally tasted like Alka-Seltzer. If you spilled it and let it evaporate, it left a chalky, limestoney residue.

The locals drank it, but I didn’t even give it to my dog.