How Can We Clean Clay and Other Solid Sediments in Potable Water Lines

The only thing I can think of, is to use an in line pump, up above, connect the two ends using regular garden hose or similar, with pump in line. Back flush at high velocity until sediment is suspended in water, and then blow out lines until water runs clear. You may have to do this several times, but it should work.

Inject lots of air into the lines while maintaining a good flow of water. The air bubbles will work to agitate and scrub the sediment loose.

Given your size of lines you may need a rather large air compressor though but the injected air method works very well. I have been doing it for years now on our farm to remove the sediment from our water lines and it works!

If the "air" solution doesn't work, then you might want to investigate "scrubber" particles. I haven't seen direct links, but understand that they are inert pellets introduced at one end and ejected at the other during the flushing where they can be recovered for re-use.

I have seen "spherical" pigs for cleaning lines. For a 2" line they would have a .75 to 1" solid core with .75" flexible brushes on the outside surface. A series of these would be passed with at least 3m separation in the line so they don't tangle into each other.

Even multiple passes with one if you have sufficient water supply available.

The spherical pigs are able to pass around the corners that you nominate.

For DIY process, make a 2" sphere of open cell foam rubber and insert that in the line during flushing. This will be able to compress around your sediment, but each pass will abrade away some of it.

(We use 750mm diameter 1m long foam pigs in the city water supply.)

Be sure that all the valves and fittings are able to pass the foam. (For instance a butterfly valve would cause issues.)

Thank you for the replies.The introduction of air bubbles would seem to be a low cost solution and not have the risk of a scrubber or pig getting lodged somewhere in the system.So far, cannot find these inert pellets,only chlorine pellets.A few questions:Taking the air hose from the compressor,what sort of device is best to introduce the air into the system?When introducing the air is the system left at normal pressure and the air at slightly higher pressure? If an air line was dropped into the well would the introduction of air harm the submersible pump? Thank you again for your help.

Most options rely on the downstream end of the pipe being "open" to allow high flow velocity and to encourage turbulence in the line to disturb the sediment.

I would be reluctant to let air enter through the submersible pump for two reasons. not knowing the capability of the pump to cope with air, since some utilise the water flow to maintain balance and cooling and the other is that the air would not be trying to vigorously expand.

If your pressure near the pump is 7 bar, then injecting compressed air through a fitting at 8 bar (with the downstream end open) would create turbulent flow through the line with expanding gas, water from the pump line and the disturbed sediment.

If this doesn't work, then I'd try it on shorter portions of the total line, meaning you only have to expose the sections where you split the pipe to vent the flushing water.

If it's really bad and too expensive to replace then I'd build a "parachute dragged bottlebrush" to run through the line and break the line where each bend is located to remove and check this "pig".

How far apart in the line were the joints? You should be able to measure these with some accuracy and clean the pipe in sections. 2" and 3" polypipe didn't come in terribly long sections until quite recently.

The beads that I mentioned earlier from memory were "styrene" pellets. (Not the foam used for bean bags, but more like material used for injection moulding.) They have a density around 0.98 and rely on the turbulence for them to scour the pipe interior. Non-toxic, inexpensive, non-soluable and easily recovered.

your biggest issue is that you require a fire extinguisher, but do not wish to put out the fire, if you do not place a sediment filter within your system nothing will change. spend the 2000 and lay new lines leaving the old ones there, it is cheaper and faster.

I have used a tyre valve brazed into a fitting on poly pipe and sealed either end with ball valves.

Pumped up the pressure as high as the compressor would go about 100psi and then cracked the valve. KNOW YOUR PIPE PRESSURE RATING, this was small single cylinder comp. so I knew I was not exceeding the pipes wall strength

The pressure grows the pipe and the rush release of pressure moves the problem, in that case I had iron and calcium build up, do not stand behind the valve as material comes out at high velocity.

But experience I had in a vineyard , PVC pipes of different sizes where we had clay and other sediments building up I just increased water pressure and flow by bringing in water from another pump section and cut pipes in the gullies and added flush valves.

Worked so well I had people cleaning drippers for weeks as the sediment went from mains to submains to laterals. This vineyard had real problems with bad design and years of neglect by previous company.But build up of sediment happens because flow rates are allowing this to occur, so a cleaning may need to occur regularly.

Placing flush valves in low spots is a good way of moving the problem where lower pressure aids build up. We found in the gullies the 4inch pipes were nearly blocked when we cut the pipes to fit the flush valves, we added 3inch valves to make sure higher flow and higher pressure escaped at good velocity as this got things moving.

Some areas we added the use of a large aircompressor we had to help but in most cases added pressure and flows and adding flush valves worked.

But adding air in big amounts and high pressure( industrial compressor for Jack hammer and drilling rocks) has risks if valves are off so we always made sure the pipes were open to prevent pipe blow outs.

If water has high amounts of sediment if I remember right the use of Allum settled the clay particles out of suspension in the supply.

I am by far no engineer but why can you not use some sort of sonic wave or vibration to flex the pipe just a little as you are running water through it? We do a lot of irrigation here in Oregon and they make some pretty good filters to keep that from happening again.. Good Luck..

If it truly is potable water, how did the sediment get in in the first place, and what is in place to prevent a recurrence of this problem? Unless these items are addressed, the chances of a repeat problem at some time in the future tend towards 100%.

*You can seal the outlet line, fill in with hot water[ acidify with formic or acetic acid] or use Hydrogen peroxide in feeble quantity, allow the entire line to get soaked for 30 to 60 minutes. Start feeding water under pressure inside the line,Now the remove outlet cap, press , release for alternating pressure and release actions with palms or flat surface so that the agitaion and feed water pressure can take out all deposits. Phosphoric acid in dilution can also be tried. Additional cleaning with Air pressure line as mentioned above should also help.

Inject ice ice cubes into the line via a Y fitting . Use compressed nitrogen of you do not have sufficient air pressure. It will scrub the interior as it passes through.If it clogs, it will melt and you can start again.A ten pound bag at the time should be sufficient.You must get the ice in motion before it solidifies.Use the large cubes, not the crushed type of ice.Ball valves are no problem, but gate valves can be problematic.

If you can access the line you may be able to use a soft flexible "pig" and water pressure (do not use air pressure) to push the pig thru the line to clean this out. What type of valves are installed in this line ? They may prevent the pig from passing thru.

I think that you're going to need to flush out the pipelines by using a high velocity water flow, in excess of 15 Feet per Second (FPS), with the end discharge through a large enough fire hydrant nozzle, but flush at not less than 300 Gallons per Minute. That flow and velocity should be more than adequate to dislodge the sediment.

If that doesn't work, then you're going to have to obtain the services of a pipe jet-flush or "Sewer-jet" operator...akin to jet-flushing storm sewer lines and sanitary sewer lines. Works extremely well.

Until such time as you eliminate the source of this sediment you will experience this type of siltation problem occurring again and again. For a potable water system institute a water main flushing program that conducts main flushing no less that twice per year. Also, I highly recommend that you institute a valve exercising program where you exercise each valve on the mains and at each hydrant at least once a year so that the "leathers" and other seals do not dry out and remain flexible.....only prudent preventative maintenance will result in a well operating trouble free (or closely) water distribution system.

Good luck!