Sand Point Well Low Yield

[Josh11L]

3 years ago I pulled my sand point which is in my basement and replaced with a new one to the same depth. The old one was drawing very little water so I assumed it was plugged. I assume it was original (installed around 1980). The new point worked great for about 2 years then I noticed it was starting to not draw as much water. Recently my pump has been losing prime due to it not being able to draw water (the static water level is at 15' below my basement and the well is 21' so there is water there). I tried pouring water down the well and it would take a long time to drain. I pulled the point this week and it didn't appear to be clogged but I has already bought a new one so installed it to the same depth 21'. Poured water down the well again and it still wouldn't drain. I jacked the point up to a depth of 19.5' and poured 5 gallons of water down and it disappeared right away so I hooked everything back up and was able to fill up a 5 gallon jug in about 1.5 minutes.

3 days later it started doing the same thing. Not drawing water again. If I crank the tap wide open the pressure drops to near zero and takes about 10 minutes to fill up a 5 gallon jug.

My well is 1 1/4", the point is 3' long, the pump is 1/2 hp. There is iron in my water.

Questions -
1. What has changed why I cannot draw as much water anymore? Water table is still the same level.
2. Could the iron and fine sand have plugged up the area around my well?
3. Do I need to move my well to a different location?

Thanks,
Josh

 

[ACWxRADR]

Josh,

There is lots of information to cover here... But to make it simple I can explain one aspect very quickly.

When you draw large amounts of water through the same well point over a long period of time, minerals will encrust the sand point and block the water flow. These minerals and the blockage is not limited to just the well screen at the depth that you had it installed initially, but they will build up in the substrate all around the well point (in the water bearing formation). So there is sand and gravel hopefully around the well point, but it is becoming occluded with all those mineral deposits, too.

Simply installing a new well point into the same hole to the same depth won't help your situation for very long. Your new well screen was clean, but the sand and gravel pack around the well has also been building up encrustations of minerals.

In best practice, you should relocate the well at least six feet laterally from the original well point. Being installed in your basement, you probably didn't have that option unless you drilled a new hole through your basement floor and installed the new sand screen there.

Going deeper or even shallower within the same hole might buy you some time here, but that depends upon other factors like was there water bearing substrate at those levels.

You also must consider weather the water level is still the same. Maybe another well near you has drawn it down to a lower level or a drought has allowed the level to fall lower.

There are methods to determine what the major problem is here, but you may have more than one issue.

RADAR

 

[Sponsor]

 

[ACWxRADR]

Josh,

Now, if you can figure it all out (the why) you may have an opportunity to attempt a fix for your well.

Nothing here is quite certain YET. But it sounds to me as though the substrate around your well is mineralized and clogged up. Deposits of calcium and rust and fine sands have built up in the water bearing formation around your well.

I can give you some advice, but my advice may NOT be the appropriate or best method to fix this situation and if my advice worked at all, it would only buy you some time and you would still have to move the well laterally, at least eventually.

RADAR

 

[ACWxRADR]

If the sand or gravel pack around your well screen is blocked with minerals, you can do all or any one of three things to "buy" you some time on this well. A 9mm bullet down the throat of the well may clean your screen temporarily. However, it sounds as tough the screen should be fairly clean since you put a new one in semi recently.

The other options are to "purge" and dissolve the mineral deposits from around the sand point or well screen .

If it is not badly occluded, try 2-3 gallons of white vinegar down the well and work it in using a secondary well supply.

This white vinegar trick will work to some extent if you pressurize the well with the vinegar and the well is not too bad off.

Another trick is to pressurize it with muriatic acid, but that is an extreme measure and you have to purge it out very well to avoid the acid eating at your screen and pipes. Simple ordinary White vinegar works really well and you can leave it in the well for a long time so that it works out into the water bearing formation and dissolves the minerals. Then you can pump it out and condition the well as it if were a new installation. Both options may delay you from having to install an entirely new well at another location, but it is probably inevitable.

I have removed all valves and plumbing from the top of the well string and poured the muriatic or the vinegar down the well. CAREFULLY of course, especially with the muriatic because it will "belch" acid and fumes back up right in your face! Wear a face shield and gloves and old clothes and protect the area around the well. It can be like a volcano.

Then I cap the top of the well string pipe very tight so that it seals off. All the pressure that builds will push the acid out into the formation and begin dissolving the minerals. I let it stand under pressure this way for several days to a couple of weeks and then CAREFULLY uncap the pipe and purge it with a cheap, junk pump until all clear of acid.

You might add a pipe fitting that would allow you to pressurize the well with air from a compressor if using the vinegar.

I refurbed a neighbors well this way once. It had been unused for a decade, uncapped and flood water had gotten into it with silt. It was stuck tight with sediment. Within a month and a couple of muriatic acid treatments, it was pumping great and it lasted for almost seven years!

RADAR

 

[ACWxRADR]

The 9 mm bullet trick is not a method that I recommend. And totally not what one should do if you use the well for potable water. The concept of the use of such a measure is to "shake" off the encrustation from the well screen with the percussion. Since you have already replaced the well point not too long ago, that is not likely a necessary measure. I mention it here simply because I know others have applied it in the past. It does work, but only temporarily and it is not the most sound practice because of the danger and the lead introduced into the water.

Muriatic acid and acetic acid (vinegar) methods are much more powerful tools. The results are much more effective and last longer. For a situation such as a cabin well, that is used only seasonally, the vinegar application is a great option. you can winterize the well system and pour the vinegar down the well pipe and let it work for the entire off-season. You can get decades of use out of a well screen even if it is in a poor substrate.

The white vinegar is only mildly corrosive, so your pipes and screen will not be harmed, especially once the vinegar becomes diluted and also if the well materials are SS or PVC. If you get this well open to your satisfaction, I would suggest using vinegar treatments periodically, just to maintain the well.

RADAR

 

[Josh11L]

Thanks for the information. I figured that my only option may be to relocate the well.

I did try vinegar before I pulled the point but only let it sit for a day. I heard you can buy these nuwell acid tablets but I would have to order them and since we are a family of 4 can't be without water for that long.

Supposed to be good weather this weekend. Perhaps I will try and drive a new point outside of the house.

Josh

 

[Valveman]

Nuwell tabs are probably your best bet. But you will need to chase them with water slowly for some time to dissolve them and wash them back into the formation. If you can't be out of water for that long you will have to drive a new point in a different location.

 

[ACWxRADR]

Sorry Valveman, but I am going to have to disagree with you on the NuWell tabs. That is a gimmick. All those tablets are is a salt pellet (not table salt of course) but a concentrated elemental compound that forms a weak acid when dissolved in water.

The manufacturers and retailers charge a high price for such snake oil remedies and a gallon or two of white vinegar from the grocery store is much more effective than these liver pills. These are money making gimmicks and that is all. Their concept is true and correct, but they are charging the consumer who is unaware of the chemistry for something that you can purchase for 1/100 the price in the grocery store and is equally 1/100 the strength. In other words, it is a suckers deal. Don't buy them.

RADAR

 

[Valveman]

Vinegar is a weak acid as well. I just like the concept of being able to slowly dissolve them and wash them back into the formation. But anytime the formation is clogging up, you are probably better off moving the well to a new area.

 

[ACWxRADR]

Vinegar is a weak acid as well. I just like the concept of being able to slowly dissolve them and wash them back into the formation. But anytime the formation is clogging up, you are probably better off moving the well to a new area.

This is so true Valveman, I won't argue this point at all. Fortunately for me, I can move my wells easily. I recommend at least six feet if not further from the original bore hole. but, the first thing I attempt is to drive a few feet deeper after treating the screen with mild acid like white vinegar. The screen is the first to clog up, then the sand within the formation will eventually follow. Depending upon how long the well has been in service and how much draw it has been subjected to, the condition of the well will vary.

We have had a sand screen at our cabin in use since 1963 and it is still good today. We have pulled it out twice and cleaned the encrustation of minerals off with muriatic acid and put her right back down the same hole.

This well produces probably the best water anyone has ever found. I do not mean just in our local community, I don't mean just in our state, I don't mean just in our region either. I mean the best water in the whole damned country! I do not jest. We used to send the water to a lab every year for testing. The tech always commented on how great our water quality was -without filtration and straight out of the ground.

We are lucky, I guess.

RADAR

 

[Reach4]

All those tablets are is a salt pellet

http://www.holeproducts.com/products/NuWell-Acids

Phosphoric acid is not a salt.

 

[ACWxRADR]

http://www.holeproducts.com/products/NuWell-Acids

Phosphoric acid is not a salt.

It must be - unless all chemistry teachings are incorrect in HS and college and universities.

https://en.wikipedia.org/wiki/Phosphorous_acid

 

[ACWxRADR]

https://en.wikipedia.org/wiki/Salt_(chemistry)

 

[Reach4]

I think these are the links:
https://en.wikipedia.org/wiki/Phosphoric_acidhttps://en.wikipedia.org/wiki/Phosphoric_acid
says "Phosphoric acid is a mineral (inorganic) acid having the chemical formula H3PO4."

https://en.wikipedia.org/wiki/Salt_(chemistry)
says "In chemistry, a salt is an ionic compound that results from the neutralization reaction of an acid and a base."

 

[ACWxRADR]

Sorry Reach, I did not intend to belittle you in any way. I did want to correct this thought, however. It is just a misnomer that many people are unaware of. Most acids are simply salts of metals which are dissolved in water. A salt of phosphorus, phosphorus being a metal, dissolves in water to form phosphoric acid. The tablets they sell to treat wells under the guise as a well treatment "pill" are nothing more than such salts that dissolve into water to form a mild acid.

That is all these things are, nothing more elaborate than that. White vinegar from the grocery store is much more powerful and more effective that these "salt pills". Like I stated in a previous post, these items are gimmicks.

RADAR

 

[ACWxRADR]

I think these are the links:
https://en.wikipedia.org/wiki/Phosphoric_acidhttps://en.wikipedia.org/wiki/Phosphoric_acid
says "Phosphoric acid is a mineral (inorganic) acid having the chemical formula H3PO4."

https://en.wikipedia.org/wiki/Salt_(chemistry)
says "In chemistry, a salt is an ionic compound that results from the neutralization reaction of an acid and a base."

Yep. Now you know what it is. It is the same concept as boiling your car battery dry and then adding water back to it. Once boiled dry, what remains is the salt of sulpuric acid. Reconstitute it with water and the salt dissolves back into the watr to form the acid.

RADAR

 

[Reach4]

Yep. Now you know what it is. It is the same concept as boiling your car battery dry and then adding water back to it. Once boiled dry, what remains is the salt of sulpuric acid. Reconstitute it with water and the salt dissolves back into the watr to form the acid.

RADAR

Don't presume that I buy into your salt, acid, or battery statements.