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Two line jet pump diagram (C) Carson Dunlop Associates Well Screen or Well Bore Debris Cleaning
How to clean sediment out of the bottom of a well bore; how to clear a clogged well screen or foot valve

  • WELL CLEANING PROCEDURES - CONTENTS: methods for clearing silt, sand, debris from the bottom of a bore hole or well casing or well bore; how to clear a well screen or a clogged foot vavle without having to pull the well piping: cleaning a well bore or well screen in place
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Well bore & well screen cleaning:

This article describes approaches for removing silt, sand, or other debris from the bottom of a well bore or well casing; these methods may also be used to clear a clogged foot valve or well screen.

Water flow rate or water pressure improvements can be obtained if we un-block a clogged well screen or foot valve.



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Methods Cleaning the Water Pump Intake Screen or Well Bore Sediment

Reader Question: how to clean the well bore sediment or screen clog without pulling well piping

(Aug 18, 2014) Bill K said:

Would it be conceivable to use a jet pump to clean out sediment at the bottom of a water well bore? We have six windmills on our ranch that are all around 140 feet deep that are 50 to 60 years old and sediment can get to be a problem over time. I was hoping to achieve a new "lease on life" for these wells if I could clean them out in some way and a jet pump is the only thing I could think of that would be able to lift mud and such off the bottom if it could fit down the bore hole.

Page top sketch courtesy of Tornto home inspection & education firm Carson Dunlop Associates.

Reply:

Bill

It's no surprise that articles on removing sand or silt from water wells mostly focus on filtering the water using various methods ranging from a cartridge filter to a centrifugal sand separator. But for removing sand or silt from the bottom of a well bore, well drillers have had to deal with this matter for generations and have several approaches.

The most common approach, provided we're not also going to exhaust the well's flow rate, is to pump silty sandy water from the well bottom for an extended period of time - possibly days. (Normally the water pick up in a well is set several feet above well bottom to avoid picking up settled debris).

You could use a 2-line jet pump whose pickup is at the end of the pair of pipes near well bottom COMBINED with some other jet to stir up muck to try to pump it out of a well bore, but you may destroy the pump in the process. Well drillers have a variety of approaches to removing debris from wells. Typically a pump particluarly designed to handle sludge is used. Some examples are the Waterra pump line (waterra dot com)

Or search for sludge-pumps made by a variety of manufacturers.

Assuming your well bores are lined, it's possible that your lining has leaked or corroded or cracked. So you want to inspect the well bore (well bore camera) and if necessary, insert appropriate repair sleeves to cut the dirt or sediment or sand entry rate into the bore.

In 2010 the state of New Hampshire in the U.S. published a helpful article "Sand and Sediment in Water Wells", WD-DWGB-3-14 online as a PDF. des.nh.gov

Farmshow dot com has an interesting article about a home-made well-cleaner (Richard Guthrie's design) that uses a combination of a steel cylinder lowered into the well and compressed air - which may not be practical for deep wells such as you describe.

(Aug 19, 2014) Anonymous said:
Thanks Dan.

That gives me a lot more directions to go than I had before. I've been searching for an affordable well camera or even a rental place for one for several days now but they seem to be few and far between in West Texas. With six wells, not all working but we have plans for renewal on two, I'm tempted to buy one but at $3 to $4 grand or more each I'd hate to have one just sit for years after using it several times. I'd assume their resell value, if intact, would hold, though.

One personal theory of mine is that old well bores like this may also decline in production due to lime deposits at the layers of water production and may need to either be scraped in some way or acidized to promote continued flow.

This would produce a lot of debris that would need to be removed from the bottom of the bore but the cost of drilling another well (hit-or-miss proposition at $$$/ft regardless) and either moving the windmill or putting in a solar pump like we've done on one last year makes you go "hmmmm....". The well that's given us the most problems over the years is a high sulfur content water well.

As of earlier this year the sulfur aquifer or layer has either played out or caked over and what little water is coming out is now sweet but production has gone down to almost nothing. Hence my longing for a well camera to reduce the guess work. Have any suggestions for any brands or opinions yea or nay on personal ownership?

Reply:

A bit costly to buy a well bore inspection camera. Here are a couple of ideas;

See if there are any chimney sweeps (probably not) in your area. Those guys may have a camera that can inspect the dry portion of the bore (which would be a partial exam)

OR

See if you can partner with a local well driller - one of the younger, more interested, technical fellows but who does not have an inspection camera. Offer to share the camera cost with him or her in exchange for examining your wells. S/he will then have a tool and expertise that expands her business.

(Aug 19, 2014) Bill K said:
Thanks again Dan,

I finally had time to more carefully read over your suggestions and the well cleaner of Mr. Guthrie's in Early, TX is intriguing. My uncle may actually be acquainted with him as he's from that area. I may contact him or his family to get a better understanding of that cleaner's design. We have an old well cleaner in the barn that might be convertible to this method. And, yes, we have our own "magic pile" of junk that we've been re-purposing for three generations now! You NEVER throw anything away on a ranch or farm. Junk is a ag man's gold.

Our wells were drilled at a time that casing was only partially inserted down the bore to a depth, I'm assuming, that the rock layers began. I guess they thought the rock wall would hold for at least a generation or two but that would put us just about at the end of that time line.

Reply:

(Aug 20, 2014) (mod) said:
Indeed the casing is usually stopped some short distance into the rock if rock is encountered - since we expect water to enter the well bore through fissures in that very stone.

Other Sources of Debris that Clog the Water Sysem & Reduce Water Pressure

Watch out: debris in the water supply system, including crud that clogs faucet strainers, shower heads, water filters, will also result in poor flow rate or "water pressure" at building plumbing fixtures. If the debris is not coming from the water supply itself it may be originating within the piping system or building equipment. See:

...


Continue reading at WATER PRESSURE PROBLEM DIAGNOSIS TABLE or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see WELL CASING LEAK REPAIRS - a cracked or rusted well casing can be a source of well contamination, mud, water loss.

Or see WELL CHLORINATION & DISINFECTION if the cleaning your well needs is to address bacterial contamination

Or see WELL WATER PRESSURE DIAGNOSIS for other reasons (besides clogged well screens or clogged filters) that can explain poor water pressure or flow.

Suggested citation for this web page

WELL CLEANING PROCEDURES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER TREATMENT SYSTEMS

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