SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Nothing like having a prestige zip code to raise the cost of living. It can be that you're expected to hire a service guy to change lightbulbs. Your particular situation is uncommon enough that manufacturers have largely ignored it. One low-pressure-capable sprinkler head has been discontinued. Even a few towns may not be paying enough attention to the negative-pressure phenomenon, if the pressure boosting systems in some new construction I've seen were an indication.

I have to say I am not too confident in the pro's that I have had come to my home. They priced out and designed a system without even reading the pressure at my home. From everything I have read on this forum and irrigation tutorials I have not seen anything warranting professional installation. The simple truth is that it is relatively easy to install PVC, Poly, rotors, etc. The hard part is having the knowledge to make it all work correctly. The only reason I checked the pressure myself is that I have been a lifelong resident in my town. I remember 25 years ago when my parents had an irrigation system professionaly installed and it never worked. To make matter worse I am in an area that is a contractors dream. If a project is $5000 in one town in Livingston/Short Hills NJ that same project is twice the amount. It is actually a joke in the contactor community.

Any problem can be solved by throwing enough money at it. A new water connection, with at least one-inch copper. A pro could go the extra yard to select a special-order booster pump that wouldn't create any negative pressure. But then again, the pro is going to get at least five thousand dollars for installing a sprinkler system on a lot your size.

I have not heard from the town and checked the static pressure again at 35 psi. At this point I will call the town again and most likely not install an irrigation system and sod. I'll go with seed, nature & a garden hose. I appreciate all your response. Thank you

No increase in pressure after the Water Department visit? You'd be boosting pressure for the entire house, if you bought one of those package deals, and even the smallest one is capable of creating the negative supply line pressure you want to avoid. Their drawings are missing the suction-side check valve(s) you need to isolate the higher house pressure from the street.

Any pump with a flow capability that subtantially exceeds your measured flow, as you gave in the first post, will be capable of creating that negative pressure you want to avoid. I've observed this phenomenon before, when a sprinklers-only booster pump created negative pressure in the house plumbing. Open a sink faucet, and you hear it sucking air instead of seeing it deliver water. If the pump is set up as a whole-house booster, the negative pressure can still exist in the supply line between the street and your home.

I have been looking at the Davey HS series pump and it looks like it may work for my situation. The following is a link that shows the pump as well as recomended connection to municipal water. http://www.daveyusa.com/hsinfo.html. Does anyone have any experience with this pump? What is your opinion on the connection diagram? Thank you for all the help

You do eliminate the need for isolation check valves upstream of a pump if you put the RPZ upstream of the pump. You also complicate matters, because the RPZ is intended to go outdoors. That places the pump outdoors as well. And since the house plumbing is upstream of the pump, there will be little if any pressure in the house when the sprinklers are on.

install the pump after the rp

Your town might demand something between their supply and your boosted pressure, apart from any backflow in the system itself. The reasoning is that your boosted pressure is capable of pushing back into the town water. Town Water ~ Check valve(s) ~ Booster ~ Sprinkler Backflow ~ Sprinkler System

All your packaged booster setups are capable of pumping more water than you measured. That's where the 'negative pressure' can happen.

The water department came by and verified my pressure reading 35 psi static. They are looking into the low pressure as they have on record my location as having 70PSI. In any case, my lot is not large (I do not have my plan on hand) and is less than 3/4 of an acre including my house, deck, driveway and stonework. Not much on the lawn and beds. I came across the Davey HS series pressure pumps and they do mention irrigation and boosting town (metered) psi. I am concerened about water contamination and have been looking into the back-siphonage issue that can surfacwith the use of a pressure booster. I have been compiling a list of parts for the system and when it came to backflow immediately went after the safest solution with the RPZ backflow preventer even with the increased pressure loss - of course this was before I took the reading. I remember reading that RPZ address both backflow & backpressure. For backsiphonage problems an air passage from the atmospheric vent is opened. If the RPZ then protects you from "irrigation" contaminents than what is the increased risk for household water. It's still the same water I currently use just with a greater psi. Is it correct to assume that a pressure booster, backflow & back-siphonage combinations through an RPZ a safe solution?

Thank you for all the assistance