New Well Advice

[jpaschich]

Just hoping to get some advice. I'll post details as easy as possible.
Old 100 yr old sandpoint screen is plugged. I'm drilling a new one 12 feet away to the same depth of 70ft. Old one was 1.5 inch casing. I'm drilling 2" pvc down to 70' and was planning on using that as my casing. I have a new 1.25" x 3" wellpoint I was going to attach to 1.25" pvc and drop it down my 2" pvc (1.5" pvc couplers wont fit inside 2" pvc). Or I could attach the wellpoint to 1.5" galvanized and drop it down but I dont think that will give me better flow than 1.25" pvc will it (1.25" wellpoint is the bottleneck???)?

My old well I ran a Flotec 1.5 hp jet pump with 1.5" inlet and outlet. My yard has about 3/4 miles of inground pvc for irrigation. I have a mix of 2", 1.5", 3/4" pvc but all 25 sprinklers are on 3/4 (maybe a couple are 1/2"). I really only need to run 6 plain impact sprinklers at a time and I'd be happy.

Should I change anything? Anything glaringly obvious that I'm doing wrong? I bought a new 1.5 hp jet pump. It has a 2" inlet and 1.5" outlet (I bought it when I thought maybe I'd be able to run 2" pipe up from my wellpoint but quickly realized that is a bit more difficult than I care to go for). Should I get a pump with a smaller inlet (1.5") or does that matter? I plan on drilling my 2" pvc down and leaving it because drilling down seems easy - pulling it up is damn near impossible.

 

[Valveman]

Driving a sandpoint works differently than casing. With casing you will need a foot valve on the bottom of the suction line. You can get turned down couplings and foot valves to fit in 2" casing. But you might be better off just driving a new sandpoint. 2X1.5 pump sounds like a sprinkler pump that won't build as much pressure as a jet pump.

 

[Sponsor]

 

[jpaschich]

Driving a sandpoint works differently than casing. With casing you will need a foot valve on the bottom of the suction line. You can get turned down couplings and foot valves to fit in 2" casing. But you might be better off just driving a new sandpoint. 2X1.5 pump sounds like a sprinkler pump that won't build as much pressure as a jet pump.

Maybe I'm using the term casing incorrectly. I'm using water volume to "drill" my 2" pvc down 70 ft (the depth of my old well). Then I was going to leave that there and attach my 1.25 wellpoint to 1.25 pvc and drop it down, and probably drive my 3' wellpoint 3' past my 2" pvc. If that makes sense to you? I dont know what a foot valve is but I guess I better Google it and find out if I need to use one.

I'm just trying to avoid pulling the 2" pvc up. cant it just stay there as a sleeve for my 1.25 wellpoint and pvc?

 

[Reach4]

A foot valve is a combination check valve + screen. A check valve is better at the intake if you have the choice.

A 1 inch foot valve would probably fit thru 2 inch PVC. You could consider using an SIDR polyethylene drop pipe, but you would have to allow for the clamp increasing the diameter.

 

[Valveman]

Casing works at atmospheric pressure, so you need a foot valve at the bottom of the suction pipe. Probably need 1" as advised to fit in 2" casing, and still need turned down foot/check valve and couplings.

Sand points work under vacuum and the check valve goes at the top. Driving a sand point screen below 2" casing will keep the sand point from sealing to the earth above the screen and it will not work under vacuum. Would be the same as having a well screen in the bottom of the casing, which would still require a suction pipe with a check/foot valve at the bottom.