Water Well Casing Steel or PVC?

[PSDStu]

Getting ready to put a well in and was wondering what the pro's and con's are between the steel and PVC casings.

I understand that with steel and a submersible pump that a lightning strike could cause a problem.

I am also being told that PVC can't be used in sandy soils because it could crush the casing.

Will probably be in the range of 100-150 feet deep, and most likely be limestone.

Just looking for some input from anyone who has put a well in recently and whether you used a pvc or steel casing.

Thanks

 

[slowrev]

I have never seen PVC used for a well casing. but one advantage I could see is no rust in the water.

Ben

 

[Jimbrown]

I have two wells in the 300ft range both have PVC in them and have been no trouble. I prefer it because of the lack of rust. I have not seen steel used in a long time except for the big irrigation wells. By law in this part of the world the first 20 ft has to be steel to seal the well it is usually in the 8 to 10 in size then they put 6 in pvc down the well hole.

 

[ByronBob]

I have never seen a PVC casing either. I believe the steel can handle the pressure better. Never heard of lightning hitting one. Go with steel

 

[Highbeam]

We still use steel in all the wells here in WA. At least all I have ever seen. I suppose if you used a thick PVC that it could hold up just fine, I'm thinking like sewer pipe thick. The wells here are driven so the casing material needs to be substantial and resistant to buckling. The welding of one piece to another prevents leaks from upper layers. I would worry that the gasketed PVC joints could pull apart and allow contamination. If the joints are glued then maybe you could get away with it.

The rust is likely iron in the ground, the PVC pipes we use here for shallow dewatering wells 20 feet deep or so seem to always come up stained rusty from all the iron in the ground.

No lightning trouble that I've heard of.

 

[GaryQWA]

All well casing will use threaded couplers for ease/speed in installation and so the casing can be pulled in the future if needed. Usually 21' lengths are used for ease of transport/storage. PVC is a good choice and it is pressure rated the same as the steel which has serious rust problems because it is mild unprotected steel pipe. IIRC both are sch 40 but I may be wrong on the schedule. Usually the steel is only 3/16" thick.

Sch 80 PVC in 21' lengths is also a good choice for the drop pipe and one manufacturer has a patented bell end with a no tread coupling feature. That's if you aren't going with the IMO better choice of coiled PE (polyethylene) tubing with only a fitting on each end. It is used in a continuous roll down to 500+' with either 160 or 200 psi rated. Galvanized is the worst choice due to corrosion and added iron to the water and then clogging due to rusting internally, which causes pressure loss and eventual replacement. That can happen in a short time depending on the water quality.

Lightening causes many pump failures each year although that doesn't mean the casing is struck.

Gary Slusser

 

[EastTexFrank]

When I had my well drilled 7 years ago they installed PVC casing and I never thought anything of it and I've never had a problem with it. I've seen PVC casing used in oil wells too so there can't be a problem with it structurally provided the correct weight and grade is used. On the other hand, I have cut and pulled steel casing that was so rusty, flaky thin that you could spit peas through it.

I don't know where the sand and PVC pipe thing comes from. Casing can collapse for many reasons and the well produce sand but there is usually some other reason for the casing collapse and not the fact that that it was PVC pipe set in sand.

 

[Egon]

Strange; one can buy insurance for wells and lightning strikes inculded on the home owner policy.

Mayhaps some areas are imunune to the forces of nature.

Egon /forums/images/graemlins/confused.gif

 

[penokee]

I always thought steel was the only way to go, but then I'm from a different era. Have a steel casing at my camp. high chloride content in the water and have had one quarter inch pump rod (hand pump) rust off at the static water level. Last two years have had a problem with iron bacteria (water smells like sulfur) - never though that it might be from the casing rusting.
Does the DEQ, Health Dept. and/or DNR approve PVC casings? Never heard of it in this area, but sounds like something to take a hard look at if it's an approved material.
penokee /forums/images/graemlins/smile.gif

 

[Alan L.]

My 500' well has PVC casing. Its 4" schedule 80 and is very common around here. There is a steel sleave on top, but the rest is PVC. The pipe bringing up the water is 1.5 inch galvanized, with a submersable at 399 feet.