{"id":67097,"date":"2026-09-19T08:00:31","date_gmt":"2026-09-18T23:00:31","guid":{"rendered":"https:\/\/norimen.net\/?p=67097"},"modified":"2026-09-18T21:57:48","modified_gmt":"2026-09-18T12:57:48","slug":"well-cleaning-method-air-and-water-flushing","status":"publish","type":"post","link":"https:\/\/norimen.net\/en\/well-cleaning-method-air-water-flushing\/","title":{"rendered":"How to Clean a Well | Causes of Clogs and Steps for Internal Cleaning Using Air and Water"},"content":{"rendered":"

Hello, everyone.<\/p>\n

This is Enta.<\/p>\n

When I'm working on drilling jobs, I occasionally get requests like, \"Take a look inside the well.\"
\nI usually work on excavating slopes and anchor holes, but when it comes to dealing with pipes in the \u03c650 to \u03c6100 range, well drilling is actually quite similar.<\/p>\n

But that's beside the point.<\/p>\n

In this post, I\u2019ll walk you through the actual steps involved in cleaning a well\u2014something anyone who\u2019s ever cleaned a well has probably wondered: \u201cHow do you actually clean a well?\u201d<\/p>\n

\n

Why Do Wells Get Clogged in the First Place?<\/h2>\n

Wells tend to deteriorate inside over time, and there\u2019s always a chance that bacteria could grow in them. (It depends on the well\u2019s location, so I can\u2019t make a blanket statement, lol.)<\/p>\n

Generally speaking, the term \u201cwell cleaning\u201d refers to the process of removing sand and sediment that has accumulated inside the well.
\nThe conditions vary depending on the type of well, but in this case, it\u2019s a commonPipes with diameters ranging from approximately \u03c650 to \u03c6100<\/strong>I'll proceed on that assumption.<\/p>\n

When sand and sediment build up inside the pipes, the water flow slows down.
\nAs long as the groundwater continues to flow, even slowly, fine sand will gradually be carried into the pipe, and with each pumping cycle, soil particles from the surrounding area will be more easily drawn in.
\nThe longer you leave it, the more sediment will build up, and if bacteria start to multiply inside, it will affect the water quality.<\/p>\n

Clogs can also occur depending on the quality of the pipes you\u2019re using, right? Things like rust, for example.<\/p>\n

My impression is that most inquiries about well problems follow the pattern of \u201cI noticed the flow had gradually slowed down\u201d rather than \u201cThe water suddenly stopped flowing.\u201d
\nI find that it\u2019s harder to notice changes in a well that\u2019s used every day, whereas, conversely, a well that\u2019s used only occasionally is more likely to develop a clog when you need it most.<\/p>\n

That is precisely why, rather than panicking and trying to fix the problem after a clog occurs, we need to adopt a maintenance approach that includes regular internal cleaning.
\nIf you get into the habit of checking the depth and water level\u2014even if it\u2019s just once every few years\u2014it\u2019ll make it easier to make decisions when the time comes.<\/p>\n

\"Infographic:<\/p>\n

\n

Things to Do Before Cleaning | First, Measure the Depth<\/h2>\n

Before you jump right into cleaning, there\u2019s something you absolutely must do first.<\/p>\n

How deep is the well?<\/strong>...It's important to understand this first.<\/p>\n

The method is simple: tie a weight to a string and lower it to the very bottom of the well.
\nWhen the string reaches the bottom, measure its length\u2014that\u2019s the depth of the well.<\/p>\n

For example, if a well that was originally 15 meters deep turned out to be only 10 meters deep when measured, a simple calculation would show thatIt's packed with 5 meters' worth<\/strong>That\u2019s how it works.
\nIf you make sure to keep track of this, you'll be able to see in numbers just how much improvement there was after cleaning, so it's definitely something you should do.<\/p>\n

There are even measuring tapes that beep when the water level reaches a certain point, so that's what most pros use, lol. When you step into the water, it goes \"beeeeeeeep.\"<\/p>\n

It\u2019s a good idea to make sure you clearly communicate this depth measurement to the client or document it with photos. For us public works contractors, photos are really important! lol<\/p>\n

If you keep a record of how much the drain cleared up after the first cleaning and how quickly the clog progresses the next time it happens, you'll have a better idea of what to expect.
\nSimply keeping a record of the numbers will make it easier to estimate when the next cleaning is due and will help the conversation go more smoothly when you consult a professional.<\/p>\n

Once you've checked the depth, the next step is to get a 3-minute polyethylene hose.
\nIf the well is 15 meters deep, it\u2019s best to plan for about 20 meters.
\nWhile you generally won\u2019t need more than 15 meters, it\u2019s definitely a good idea to have a slightly longer one on hand to allow for maneuverability and give yourself some leeway on site.<\/p>\n

As for the hose diameter, if it\u2019s too thin, the water and air flow won\u2019t be enough, and if it\u2019s too thick, it might get stuck depending on the well\u2019s diameter, so go for something just right lol
\nFor wells with diameters ranging from \u03c650 to \u03c6100, I think a 3-mm polyethylene hose offers a good balance between ease of handling and cost.<\/p>\n

Since hoses that are too short are a common mistake on site, it\u2019s best to allow for a little extra length when preparing.<\/p>\n

We\u2019ll be lowering this hose into the well, but if we just lower it as is, it will cause problems later on, so we need to make one more adjustment before doing that.<\/p>\n

\"Well<\/p>\n

\n

It uses a dual-pipe system to clean thoroughly in one go using air and water.<\/h2>\n

To remove sand from inside a well, we use a strong stream of water and air.<\/p>\n

However, if you insert a thin pipe into an empty hole with a diameter of 50 to 100 and blow air in from the bottom, the force of the air will cause the sediment inside to be expelled all at once.
\nThis is actually quite dangerous, so to prevent it,Double Pipe<\/strong>I'll go with that.<\/p>\n

The design involves threading a 3-minute polyethylene hose through a pipe with a diameter of \u03c650 to \u03c6100, which serves as protection.
\nYou can use a trumpet-shaped pipe, or you can simply drill a hole in a PVC pipe to connect it\u2014either method is fine.
\nIf you blow air into an empty space, it comes out with more force than you\u2019d expect, so it\u2019s best not to skip this double-tube setup. (Protecting the surrounding area is also a lot of work.)<\/p>\n

\"Well<\/p>\n

The 3-minute hose reaches all the way to the bottom, and sand is being blown up from the VP50 PVC pipe.<\/p>\n

The sand that is blown up is forcefully expelled outside through the PV50 hose.<\/p>\n

Lower the 3-minute hose all the way to the bottom while moving it up and down.
\nWhile it is possible to do the work using just compressed air, the deeper you go, the less effective compressed air alone becomes.<\/p>\n

If you can set it up so that water is also pumped through the system, the cleaning power will increase significantly.
\nSince water pressure is stronger than air pressure, it cleans thoroughly.<\/p>\n

For this application, we recommend using the largest compressor possible to ensure maximum air pressure.
\nAt our site, at the very least,50-horsepower compressor<\/strong>We'll use this (it's the smallest class we have).<\/p>\n

For a well with a diameter of 100 and a depth exceeding 30 meters, a minimum of about 100 horsepower (2.5 metric tons) is required.
\nIf the air volume itself is insufficient, cleaning power will be inadequate, and as the well diameter increases, the equipment itself will need to be larger.<\/p>\n

When actually performing the work, rather than lowering the hose all the way to the bottom at once, we adjust the depth gradually while blowing in air and water.
\nRather than blowing at a constant depth, moving the nozzle up and down and washing in stages will ensure that the clogged layer is cleaned evenly.
\nIt\u2019s also important that the water gushing out becomes clear.<\/p>\n

It can also serve as a rough guideline for when to wrap things up.<\/p>\n

Here's what the machine looks like.<\/p>\n\n\n\n\n\n\n
Conditions<\/th>\nCompressor Guidelines<\/th>\n<\/tr>\n<\/thead>\n
\u03c650\u2013\u03c6100, shallow (up to about 30 m)<\/td>\n50-horsepower class (0.5 metric tons)<\/td>\n<\/tr>\n
\u03c6100 and up, over 30 m<\/td>\n100 horsepower (2.5 metric tons) class and above<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

*Please note that this is based solely on my on-site experience and serves as a rough guideline; the number of units required will vary depending on the well\u2019s diameter, depth, and geological conditions.<\/p>\n

\"Well<\/p>\n

\n

Sterilization, Finishing, and the Limits of Liquefied Well Water<\/h2>\n

Once you've removed all the sediment from the bottom, you'll need to decide whether to sterilize it.<\/p>\n

Generally, the process involves adding hypochlorous acid, circulating the water inside to disinfect it, and then running the pump for a while to finish the process.
\nIf you drain the water and run it through once after disinfecting before using it, you can prevent using it while disinfectant residue is still present.<\/p>\n

That concludes the standard procedure for cleaning a well.
\nIf you treat the entire process\u2014from cleaning and sterilization to running the pump for the final rinse\u2014as a single set of steps, you\u2019ll be less likely to miss any steps.<\/p>\n

However, the problem is thatWhat should I do if I clean a well that stopped producing water after the earthquake?<\/strong>Is that so?<\/strong>That's the story.<\/p>\n

To be honest, this is a very difficult call to make.<\/p>\n

Cleaning can only address, at most,Only inside the tube<\/strong>That's it.
\nSince the area outside the pipe is still natural ground, we can\u2019t reach that far.<\/p>\n

It is not actually possible to verify the condition of the surrounding soil near the well, which was shaken by the earthquake and became liquefied.
\nHowever, I have the impression that if there are many areas where fine soil particles have accumulated after being dislodged, sand will continue to come out of the surrounding wells for a while, no matter how much you flush them.<\/p>\n

To be honest, I can't say how long this will last.
\nSometimes it gets better all of a sudden, sometimes it gets better right after washing, and sometimes it doesn't get better at all.
\nThis is something that depends on the specific circumstances, so we can't say for certain.<\/p>\n

We consider ourselves drilling pros, but none of us has actually seen the inside of a well clearly, lol.
\nTo see inside, you could connect transparent PVC pipes one after another and insert a borehole camera; that might allow you to see inside the ground to some extent.
\nIt sounds interesting, but since renting the camera alone costs a fair bit, it\u2019s not something you can just try out on a whim.<\/p>\n

I believe that if we can collect data both before and after liquefaction occurs, that in itself would be valuable information.
\nIf we can see in numerical terms just how far the cleaning process can restore the rock and at what point it can\u2019t, the accuracy of our judgments should improve significantly. (For those who love geology... lol)<\/p>\n

In my opinion, if the water volume and quality do not improve even after several attempts at cleaning, it\u2019s necessary to consider that a phase is complete and move on.
\nIn some cases, rather than endlessly repeating the same task, might it be better to consider this an opportunity to reassess the condition of the well itself?
\nI think it\u2019s realistic to view the cleaning results simply as a factor in deciding whether to dig a new well or continue using the existing one\u2014but of course, that also involves costs...<\/p>\n

As a general rule, it is recommended to clean wells regularly before they become clogged.
\nAs long as the material has not liquefied, there are certainly cases where it can be restored using the cleaning method described here.
\nTo put it another way, for wells that stopped producing water immediately after an earthquake, it might actually save you money in the long run if you don\u2019t panic right away, but instead wait and see how things develop\u2014and consult a professional if necessary!<\/p>\n

We can\u2019t see everything inside the well either, and while we can operate the machinery based on intuition to some extent, there are limits to what we can do.
\nStill, while there are some situations where we can make judgments based on the procedures we\u2019ve developed through experience on the job, we\u2019ve also been told that these aren\u2019t set in stone...<\/p>\n

\"Borehole<\/p>\n

\n

Cleaning a well may seem like a mundane task, but once you try it, you realize there\u2019s more to it than meets the eye.
\nYou can clean the inside of the pipe as much as you want, but there\u2019s nothing you can do about the surrounding soil.
\nEven though I understand this sense of frustration, I guess I just have to do the best I can within my means.<\/p>\n

Whether it's drilling holes or digging wells, the work ultimately involves dealing with an invisible opponent\u2014what lies beneath the ground.
\nSince you can't see it, I think relying on numbers\u2014like depth and water volume\u2014is actually a pretty reliable way to judge things. After all, numbers don't lie, right? lol<\/p>\n

See you later.<\/p>\n

I'm spending half of the Obon holiday working nonstop on drilling a well for disaster preparedness.<\/a><\/p><\/blockquote>\n