Low pressure when running multiple facets

Terry,


I have a shallow well with a 2" sandpoint set at about 25 feet which is located in my basement so actually it's at 33 feet from ground level with about 4 feet of water in the pipe. My house is a two story with bathrooms on both levels. When I turn on any facet I get about 30-35# of pressure but once I add another fixture (be it facet or toilet or outside house) my pressure drops to about 5#.
Within the last year and half I've replace my pump with a new 1-1/2hp pump and have placed the tablets in the well pipe twice. The pressure gets a little better after the tablets but doesn't take long and it's back to same situation. I do have alot of iron in my water. I have pulled my sand point once and replaced with a 2" stainless stell about 6 years ago and now I'm wondering if I'm just plugged up to the point of having to pull and clean it?

Any ideas??

Mike
Princeton MN

It sounds like your well production might be slowing down.Is there a foot valve in the well. What type of pump do you have?How long does it take to build to its shut off pressure. Is it 4' to water from the top of your well or is there only 4' of water in it? Do you notice spurts of air in your water first thing in the morning?

SAM

What is the pressure tank switch set at as far as on off pressure and how many gal. is it?.

Sammyhydro

Thanks for the reply. I have a check value at the top of the point right before the pump which seems to be working fine. When last checked I do have about 4' of water standing in the pipe before attempting to pump. I have not experienced any air in the system. My pressure switch is set to shut off at 55# and kick in at 30#.
I also wonder if my point was becoming plugged to the point it was having a hard time drawing and that is the reason when I put the pellets down it gets a little better. When I pulled my point the last time it was very plugged and because it was an inexpensive one to start with I upgraded to a stainless steel point.
At the time I pulled the first point I put in the very same hole and drove it back to the same depth, was that the correct procedure or should I have relocated it to a different spot?
Another question I have is in reference to the sizing of my pressure tank. Right now my tank is I believe 30 gallon and I wonder if a bigger tank would make any difference.

Thanks again for any help,


ME

ME,
it sounds like your point could be plugged again. As far as putting it down the same hole,i don't advise it,but sometimes its the only alternative. Alot of times the water bearing material outside of the screen gets plugged up with iron as well and by driving the point into a different location your starting fresh. The screen needs to be treated with an acid soulution. I imagine thats what you have been doing but for liability purposes i don't advise it.Hydrochloric acid needs to be handled by a professional.The well also needs to be developed. You need to remove the check valve and mount a pitcher pump right on top of the well,prime the pump,and start cranking. When primed,you should notice tthe water being extremely dirty. This is from the incrustation being broken up. Once the water gets some what clear,i would remove the pump to drop the prime and the column of water back down the well. The water flowing back down the well will blow water back through the screen and loosen up any material that has bridged around the screen and the slots. Repeat this process until that water is clear. The more times you drop that column of water the better.

Your tank storage should be equal to the pumps GPM. Once you get the well developed to produce more water then we can move on to your tank size.

SAM

Another problem with pressure is that your pulling the water at least 21' with your shallow well jet pump. Twenty five is outer limits, so you have already used up a lot of that 1.5hp just getting the water to the surface.

I also wonder if your went another 5 feet or so, if the water level might come up and you might get further into the vein. This would get the screen out of the plugged material Sammy was referring to.

bob...

Speedbump is right,the more water you have over that screen the better. With only 4' of water you can only have so much drawdown on the outside of that well before the pumping water level reaches that screen. Thats when you start sucking air and your the volume becomes limited. I like to see atleast 5 to 10 feet of water over the well screen and thats in nice porous material. The finer the material the deeper you have to be in the water bearing zone to stabalize your drawdown. So listen to speedbump and try to drive that screen deeper,maybe another 5' feet. But before you do that i would let that system sit and take another measurement for that water level. I'm surprised that the system pumped water for that long w/ only 4' of water in it. Last but not least you need to develop that well real good until you can't get any fine material (dirty water) out of it. A poorley developed well will only last so long.

SAM

Thanks to both responders it sure sounds good, I'll be giving it a try.


Thanks again,


Mike