Pool fill line downstream irrigation - totally confused

[tomormatt]

I have spent an hour searching the forums on this topic and I am more confused than when I started. I realize local code differs and that may be why the various threads are difficult to understand.

As context, I live in southern California. Our main water line splits into irrigation line and house line in front of our house. The irrigation line has both a reduced pressure valve and a RPZ backflow preventer immediately after it splits (see picture). The main irrigation line has one tee that goes to the sprinkler manifold / valves.

Our previous setup for the pool line had the water main going to a valve that is 12" above ground (see picture). I am relocating this to a different part of the backyard and want to make sure I install properly.

Main questions are 1) is if tying into the main irrigation line downstream from the tee that goes to the sprinkler valves / manifold is okay and 2) if yes do I need to have an additional RPZ backflow preventer, check valve, vacuum breaker, etc on the pool supply line even though we have one upstream preventing any backflow to the water main?

Link the pictures

Pool supply line - Google Drive

 

[mknauss]

In most jurisdictions once you pass the backflow preventer on the irrigation side that line is now ONLY for irrigation. Pool water must not be taken from that line.

But, you need to check your local code.

 

[tomormatt]

Would adding another RPZ immediately before the sprinkler valves solve the issue? Although the current setup prevents any backflow to the water line to the house and city water main, the issue at hand seems to be potential for backflow from sprinklers into pool supply line. If I put an RPZ upstream from the sprinkler valves it would seem to keep the water supply line pure?

 

[mknauss]

For that you need to check your local codes. It sounds reasonable, but that does not always meet building codes.

 

[santacruzpool]

We have ours connected to our landscape line as it comes uphill to our pool. The above ground RPZ backflow prevention is at the bottom of our lot close to the street meter for this water line. This was a requirement of our city - and we had lots of inspections - now that doesn't mean it is done to code. Especially since it is not higher than most of our spinklers...hmmm

The pool fill line is at the highest spot of our property and the only other device at that height is a hose bib. There is a anti-siphon valve at that location as well.

On occasion if we haven't used the fill line for a while I will turn on the hose bib first to flush the line, since I tend to get some dirty water at the very beginning of the water flow when it hasn't been used in a long period of time...