posted 2 years ago
In my experience ,PVC and Cpvc will both leach chemicals into the water they carry or hold,
Other plastics have better or worse leaching issues.
If there is concern about chemical contamination I think filtering might be in order.
Personally, I drink artificial sweeteners on purpose, so it would be silly to be concerned with the quality of the rainwater I put on my garden.
In terms of getting large cross section tubes for rain water collection 3 in. x 4 in. x 10 ft. Vinyl Downspouts are 14 bucks at HOme depot.
Aluminum down spouts are often available as scrap.
As long as you are simply directing the downward flow of water, down spouts should work fine.
4" x 10' Corrugated Single-Wall Solid Drain Pipe is $9.58 at Menards, it's floppy but even cheaper.
Aluminum and steel downspouts are available for more money , but what the lining is made of isn't clear.
These and the pvc d2729 you mentioned are all rated as "safe" to discharge into the environment.
I'm sure you know, that assurance of safety should be taken with grain of salt.
The safest plastic piping I know of is PEX followed by ABS.
Large diameter steel,copper aluminum, or " black iron are all prohibitively expensive.
You are drinking from a filter, so the only question is how concerned you are for the plants you will eat.
The rainwater I use comes from a 25 year old asphalt roof,with a pine tree that looms over it,
It is collected in a old 55 gallon drum that used to contain sausage casings and distributed through a network of garden hose held together with pvc and poly pipe fittings.
I gladly eat what comes from that garden, but I also eat food out of dumpster and even worse, poptarts, so YMMV.
The safest plastic piping I know of is PEX followed by ABS.