Best choice for under ground water line.

[griffy71]

Indeed.... I also said "Likely not". The international plumbing code permits it, but a lot of jurisdictions don't like it. I have seen jurisdictions that require backflow preventers at every takeoff in a building but not on the main. That has been the starngest so far. The authorities all have their preferences, and he may be fine...... But he may not. Best to check.

[toalpi]

Originally Posted by Larry S.

I have twenty+ year old black poly in my lawn sprinkler system and it is developing pin hole leaks, a few more each year. I've been told that 20 years is about the lifetime of underground black poly by the sprinkler installers here.

Thinking 3/4 but 1/2 probably would do. Tank outlet in 1 inch. I will price copper before committing to buying materials. .

Some black poly was made and sold just for sprinkler use. It is pretty thin walled and often rated for 80psi or less. Get a 200ft roll of one inch poly well pipe with a 160psi rating. It will out live you and everybody else that is reading this today. Pex would also work but it is more expensive and you would need the tools. Again, one inch minimum.