How To Clean A Shallow Well Point
Driven Point Well & Jetted Wells Water Flow Restoration
How to restore lost water flow from a driven point well, small diameter jetted / wash well
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Driven point well or jetted well yield restoration or improvement: how to restore the water flow from a driven point or small diameter jetted water well.
This article series explains installing, diagnosing, and repairing small diameter water wells including driven point wells, wash wells, and jetted wells, three types of water sources that may be used where water is close to the ground surface and a well pipe or point can be driven into the soil mechanically or by using hydrojetting.
We include an excellent UN FAO small diameter well document reference that will be helpful to those needing to construct a water well in areas where water is close to the ground surface and money or other resources are limited.
We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
Restoring the Yield of a Driven Point Well - how can I get my water back?
Diagnose the Cause of Driven Point Well Clogging Before Repair
Driven Point well restoration experts describe the importance of diagnosing the cause of the well clogging before trying to fix the problem.
That's where an experienced well driller or plumber can be helpful, as you will have better success un-clogging a well point when you match the solution to the nature of the problem.
For example, driven point well clogs may be due to bacteria or to silt and clay infiltration, to mineral deposits such as calcium where the order is hard or high mineral content, or from other debris clogging sources.
You may find that using a well disinfectant may be more-effective if the cause of well clogging is iron-loving bacteria.
The sketch shows two types of driven point well tips or screens - from a small well article provided by the United Nations, FAO, cited below. [Click to enlarge any image]
Common Causes of & Cures for Clogged Driven Point Well Screens
- Biological fouling at the well point: slimy organic deposits of bacterial growth clog the well screen. You may be able to clear the clogged well point using a combination of brushing, compressed-air, and disinfectant or well shocking treatment.
See WELL CHLORINATION SHOCKING PROCEDURE
Also see WELL DISINFECTANT pH ADJUSTMENT
- Debris fouling: soil and debris may enter the well pipe and screen from the surrounding aquifer or from corrosion or mechanical damage that cause holes and leaks in the well pipe.
Compressed air, brushing, and perhaps back-washing may give short term relief from debris clogging at the well point.
- Scale clogging at the well point or screen: scale or mineral deposits settle out of water that is high in mineral content, forming a clogging material ranging from rock-hard scale to gooey whitish paste.
An acid wash may be used to clear scale or acid wash combined with heat for greater effectiveness - described
by WELL REHABILITATION, [PDF] cited below.
- Iron fouling, usually caused by a combination of bacteria and high iron content in the water. Iron-loving bacteria clog the well screen with a reddish deposit of iron and bacterial debris.
The same remedies as for biological fouling of the well point can help with iron fouling of the well point.
See WATER STAINING CONTAMINANTS
See SAND POINT DRIVEN POINT WELL CLEANERS below in this article for sources, products, and research on clearing your well point.
Illustration of a driven point well from Wisconsin DNR cited in detail at the end of this article.
- Freezing: a less-common "clogging" problem in sand point or driven point wells is frost; a driven point well installed in a climate exposed to freezing needs frost protection for water pipes, pump, tank, controls that could be exposed to freezing temperatures. .
Above, adapted from the Wisconsin DNR's well guide cited in this article, we illustrate a driven point or sand point well installed in an insulated pump house to protect the well and water supply from freezing. ©InspectApedia.com
Notice the frost line location and water table location in the illustration. An additional small heat source may be required inside the pump house itself.
[Click to enlarge any image]
Reader Question: My Driven Well Point is Clogged - Do I Have to Drive a New Well?
The well digger tells me that I have a clogged point on my driven point well and it is not letting enough water in the well pipe to the pump. My water is good and the water pressure is awesome for about 2 minutes then it goes down to nothing. I wait about 30 seconds and it comes back.
Bad thing is the well digger hand drove this well for me about 4 years ago. Now he tells me the point is clogged not letting enough water in fast enough. He borrowed my 22 caliber rifle and shot about 7 rounds down into the well, but nothing happened.
I am being told by him that we need to drill another well right next to the old one. Needless to say I am not a happy camper. This well is on an extra lot I have that I use to grow a garden and store my boat in the winter. The only thing I use the water for is watering the garden.
Is there another fix for this thing? A friend says we could attach an air compressor to the pipe and shoot about 100lbs down there, or we could Get some pipe and drive it thru the point on the bottom to open it up. The well digger says when he drilled the first one that he drove that point in there so hard that would never come back up out of there.
Reply: Dynamite or Shooting a Rifle Down the Well are Bad Ideas
What you describe is loss of well yield, or loss of water flow into the driven point or lower section of the well pipe. This could be caused by the well itself going dry or going to a very reduced water flow, but the most common cause of this problem is just what your well driller says, a clogged well point.
While we know folks who used to drop dynamite down drilled or hand dug wells to try to correct the yield, neither dynamite nor shooting a rifle down into a water well are a recommended procedure.
If the well point is indeed clogged you would need to pull up the well piping and replace the point, then re-drive the well, or simply drive a new point down in the same area.
But first You could try sending high pressure water or even high pressure air backwards through the pipe to see if you can de-clog the point, but we're not optimistic. Also, some driven point wells also use a well screen that is at the top of the well pipe. Take a look at your well piping to see if there are any screens or fittings above ground that can be disassembled, inspected for evidence of clogging, and then cleaned or replaced.
Don't try driving an inner pipe through the well piping - you'll just break the point or jam things up worse.
Follow-up: Success in Restoring Driven Point Well Water Flow
We used an air compressor with about 120 lbs of constant pressure to blow air back down the well pipe. We attached a tire valve to a coupler which we attached to the well pipe to make it easy to hook up the air compressor to the piping, then we blew high pressure air into the well for about 10 minutes.
We then took off the well pipe check valve, which seems to be all plastic, and ran water thru it along with some WD40 to be sure that there was no problem with a clogged check valve itself.
Then we put everything back together and turned on the well pump. We had some pretty rusty water in the beginning but it cleared up, and I had beautiful pressure!!! My original problem was that the water pressure would not last, trickle down to nothing then build again.
I sprayed the garden hose for a good 20 minutes without missing a beat.
This process had restored water flow by clearing a clogged driven point on the well pipe bottom.
The fact that flow is now good and continuous argues that indeed the problem was the clogged driven point, not a loss of water flow in the ground around the point.
What we don't know is how successfully we've de-clogged the point, how many of its clogged openings we unblocked, and how long this repair will last, but it's a great attempt that might be totally successful.
Common Methods for De-Clogging a Driven Point Well Screen
Question: pellets or chemicals to un-clog a driven point well
2018/06/11 Wesley said:
Can you buy pellets to put down the point so you can clean that screen for a stopped up screen
Reply: Acids, pellets, compressed air, wire brushing, driven point well restoration methods
Products sold to "de-clog" the screen on a driven point well range from tablets to granular powders to more-dangerous liquid acids.
OPINION: Even if de-clogging of a plugged driven pont well screen is permitted where you live, before trying aggressive chemicals I might try wire brushing or mechanical cleaning, or simple compressed air to de-clog the point of a driven -point well. Several readers have had success with those methods. Well experts (cited below) point out that even if the wire brush method is not fully successful, it can increase the chances of success if you later use a well point cleaning acid.
Acids, including hydrochloric acid or HCL, also referred to as muriatic acid, and also Glycolic acid (hydroxyacetic acid), (or vinegar) have been used to de-clog well screens for generations but as we warn below, using acids in a well may be illegal in some jurisdictions.
Watch out: Do not simply pour acid nor anything else into your well without checking with local officials as well as the company producing the product you're considering using to de-clog your well screen.
Watch out: Check with your local plumbing and building officials before even trying to restore a clogged well screen on a driven point well at al. Here is an example guideline for plugged well screens from the U.S. Wisconsin DNR:
The well code defines screen replacement as well reconstruction. When the screen for an existing driven-point well in a basement or a pit becomes plugged, the screen may not be legally replaced.
The well must be properly abandoned and filled and a new well must be constructed outside in a complying location. - Wisconsin DNR, retrieved 2018/06/12, original source DRIVEN POINT (Sand-Point) WELLS cited in detail below.
OPINION: the reason that de-clogging or un-plugging a clogged driven point well screen may be prohibited in some areas is the concern that when you pour a potentially toxic chemical into such a well you risk contaminating the aquifer and the local environment with a chemical that may be difficult or impossible to completely remove. Therefore if the chemical is not properly applied, it's particularly harmful.
Question: drive the driven well point deeper for more water?
(Jan 31, 2015) norm f said:
I have a driven well, 40 feet deep 120 years old 6-inch diameter casing, has no driven point just casing with a few holes in it, had it cleaned with air and acid, now I want to deepen it can I drive down a three foot driven well point to get more water?
The sand point well illustration shown here is adapted from DRIVEN POINT (Sand-Point) WELLS, [PDF] Wisconsin Department of Natural Resources, PUB DG 022 2010 retrieved 2018/06/12, original source: https://dnr.wi.gov/files/PDF/pubs/DG/DG0022.pdf
Reply:
Norm, possibly yes. However I would be very skeptical about trying to drive a 120-year-old steel pipe or casing deeper into the soil.
We don't know the condition of the well pipe, the amount of corrosion, nor do we know the depth of the top and bottom of the water table where your well is located.
You risk damaging or even collapsing the old well pipe. I suppose that since the alternative is to drive a new sand point well, and as that's what you'll have to do in any event if trying to drive the old point well deeper crushes it, you might risk it.
Question: lose prime when the well sits for a time
(Mar 31, 2014) Anonymous said:
replaced pump and pressure tank, Have good water, but if it sits for a time I loose the prime on the well side of the foot valve. On the pump side of the foot valve keeps its pressure. Am at a lose.
There are some old fittings on the well side of the foot valve where it hooks to the sand point.
Reply: driven point well that loses prime means dropping water table or piping leak
Anon, on a driven point well that is normally very shallow and uses an above-ground single line jet pump, you should not be losing prime unless a check valve at the pump has failed, or if the point of the well is now out of the water level in the ground.
Check and replace any questionable check valves at the pump, then check that there are no visible leaks in the well piping;
You may have to replace leaky well piping or, less likely, drive a new sand point, and deeper.
Driven Point / Sand Point Well Restoration References & Products
- WELL CHLORINATION DRIVEN SAND POINT
- Carmichael, Robert E. "Well cleaner." U.S. Patent 1,484,601, issued February 19, 1924.
Methods or apparatus for cleaning boreholes or wells cleaning in situ of down-hole filters, screens, e.g. casing perforations, or gravel packs. - Charette, Matthew A., and Matt C. Allen. "Precision ground water sampling in coastal aquifers using a direct‐push, Shielded‐Screen Well‐Point System." Groundwater Monitoring & Remediation 26, no. 2 (2006): 87-93.
- DRIVEN POINT (Sand-Point) WELLS, [PDF] Wisconsin Department of Natural Resources, PUB DG 022 2010 retrieved 2018/06/12, original source: https://dnr.wi.gov/files/PDF/pubs/DG/DG0022.pdf
- Erickson, Paul E. "Sand-point." U.S. Patent 1,080,684, issued December 9, 1913.
- Gerhardt, Carl W. "Well point." U.S. Patent 2,744,579, issued May 8, 1956.
- Gillespie, George A., David Bruxelle, Christophe Malbrel, Phong Vu, and Michael William Neal. "Well screen." U.S. Patent 6,715,544, issued April 6, 2004.
- NU-WELL PELLETIZED ACID [PDF] sold by Johnson Screens, a division of Aqseptence Group, Johnson Screens Aqseptence Group, Inc. 1950 Old Hwy. 8 N.W. New Brighton, MN 55112 USA Tel: 1 651 636 3900 1 800 833 9473 Website: www.aqseptence.com
Nu-Well tablets (also sold in other forms) are a dry, pelletized acid that sink in water, intended for cleaning wells. These tablets are intended to remove mineral scale (calcium and magnesium carbonate) found in areas of hard water, iron deposits, and some biological debris. - retrieved 2018/06/12, original source: http://johnsonwellproducts.com/assets/pdfs/NuWELL.pdf
The NuWell brochure states:
A number of Nu-Well products are NSF approved for use in potable water wells and other water filtering facilities.
Excerpt from the company's product description:
Nu-Well 100 pelletized acid is formulated for pouring directly into the well. While it may be dissolved and pumped into the well as a liquid, the pellet form rapidly falls through the water column, providing concentrated acid cleaning power at the bottom of the well.The sinking pellets are ideal for wells with short to moderate lengths of screen at the bottom. Agitation of the acid into the blocked area will greatly enhance cleaning. The acid solution should remain in contact for a period of 12 to 24 hours, depending on the nature of the blockage. The table provides recommended dosages for general well cleaning.
The amount of acid consumed will depend on the degree of mineral scaling in the well.
- source: op.cit. - Pavelic, Paul, Peter Dillon, Karen Barry, Don Armstrong, Allin Hodson, Jim Callaghan, & Nabil Gerges. LESSONS DRAWN FROM ATTEMPTS TO UNCLOG AN ASR WELL IN AN UNCONSOLIDATED SAND AQUIFER, [PDF] (2008).
- SMALL DIAMETER WELLS [PDF] Natural Resources Management & Environment Department, Food and Agriculture Organization of the United Nations, FAO Corporate Document Repository - Self-Help Wells - see http://www.fao.org/docrep/X5567E/x5567e05.htm
This article has a nice section on well pipe or dropped tool fishing tools (WELL RETRIEVAL TOOLS) at its end. If a tool is dropped into a well or if a section of well piping becomes disconnected and drops into a well, special devices can be lowered into the well to attempt to grasp or hook the lost object (or pipe) to pull it back out of the well. See http://www.fao.org/docrep/X5567E/x5567e05.htm#4.11%20problem%20solving
This document describes the following types of small-diameter (hand-built) water wells
- Lloyd McVey at AKR - thanks for discussing using compressed air to restore water flow in a driven point well, July 2010
- Timmer, Harrie, Jan-Dik Verdel, and Antoine G. Jongmans. "Well clogging by particles in Dutch well fields." Journal (American Water Works Association) 95, no. 8 (2003): 112-118.
Well clogging is a serious problem for the water supply company - Hydron South Holland - in the Netherlands.
- van Beek, Kees, Rob Breedveld, and Pieter Stuyfzand. "Preventing two types of well clogging." American Water Works Association. Journal 101, no. 4 (2009): 125.
Identinfying screen slot and well bore clogging.
- Vandevivere, Philippe, and Philippe Baveye. "Relationship between transport of bacteria and their clogging efficiency in sand columns." Applied and environmental microbiology 58, no. 8 (1992): 2523-2530.
- Vandevivere, Philippe, and Philippe Baveye. "Saturated hydraulic conductivity reduction caused by aerobic bacteria in sand columns." Soil Science Society of America Journal 56, no. 1 (1992): 1-13.
- WATER FACT SHEET #3, USING LOW YIELDING WELLS - , Penn State College of Agricultural Sciences, Cooperative Extension, School of Forest Resources, web search 07/24/2010, original source: http://pubs.cas.psu.edu/FreePubs/pdfs/XH0002.pdf
- WELL REHABILITATION, [PDF] International School of Well Drilling, 5039 Creekview Lane Lakeland, FL 33811 USA, Tel:: 863 648 1565 Email: director@welldrillingschool.com Website: welldrillingschool.com retrieved 2018/06/12, original source: http://welldrillingschool.com/courses/pdf/WellRehabilitation2.pdf
Excellent detail about restoring or rehabilitating wells.
Reader Comments & Q&A
Scott
If you haven't changed the foot valve and the well previously was working, then I suspect something else; do you think the well point is clogged or is the problem that there's a leak somewhere in the well piping; The two mean very different repair paths.
i'm working on a 11 foot deep well point that lost siphon. how can i get the siphon going again? there's plenty of drop to the tank below and i've tried pumping water up the line to the well point, the released the water to flow down, but it doesn't draw the water up the well pipe (1-1/2 " galv iron).
so i put a 3/4" poly pipe with a foot valve at the bottom down into the well pipe and tried again. when i pull the poly pipe up and down, the foot valve opens and water comes out. but when i try to siphon, it stops.
i think that the spring on the foot valve is too strong and the siphon cannot keep it open. thoughts? renewable_energy@comcast.net
You could try some of the restoration stuff's on this page. We also can't tell from the comment whether the problem is clogging of the driven point or whether the flow rate to the point has simply deteriorated.
my point has 6' of water at 23' . my pipe filled with water . I tried flushing an turning the pipe . the pipe would not turn . I hooked up my pump and my point is only giving me 2gal/minute approximately . what do I need to do ?
Wesley
Yes. Please see your question and a detailed answer in the article above.
You may need to wait a few hours or clear your browser cache to see the updated article.
Can you buy pellets to put down the point so you can clean that screen for a stopped up screen
I think if that or at least you would have been water tested to make sure that it is potable or a safe to drink.
Do i have to do anything special to a new point drivin to 28' or just use it. I have 3gl a minute off the pump
See WATER PUMP WONT STOP RUNNING
Punk will only go up to 32 pounds
What to use to clean older well point
First I'd confirm that the pump works and was properly primed: an air leak anywhere could be the trouble;
Drove a 1 1/4 well point 22ft down.went easy but pipe holding water but will not pump.I live in Maine on a flood plane.also we live off grid.what could be problem?
...
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How To Clean A Shallow Well Point
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