Cleaning a water well

[Cord]

I've been battling a well for a couple of years now and really thought I had the upper hand. Apparently not. When we first purchased the property it had been vacant for a while and the stagnant water was coal black and had a stringy slime in it. I'm told that this is iron bacteria and although unsightly it's harmless. We've installed a iron filter and with use the water has cleaned up. We recently replaced the well pump and went with a larger unit and this seems to have upset the apple cart. While the pump was hanging from the rig we flushed the well and got the same black water. This doesn't surprise me because the unrestricted pump was sucking pretty hard. The water really wasn't cleaning up so I asked the pump guy to leave the pipe hanging off the well casing and I'd run it later. Later in the day I ran the water for several hours and saw the color shift from black to gray to clear. Thought I was done so we dropped it back into the pitless. The next day we filled some 330 gallon totes and got more gray water. I also was battling a clogging issue with my screen filter because it was clogging. Desperate for a large volume of water, I removed the filter and installed a valve so I could isolate the domestic water system. Several times I saw clear water alternated with the gray water. Later in the day the color started to shift to brown. Now that we've pumped several thousand gallons of water there is a thick layer of fine mud in the bottom of the totes. Done for the day, I watered some plants and then checked the water quality off the sampling faucet. It was clear but did have a dark tint to the water. Thinking I was OK I reinstalled the screen filter and took a shower. Before I could finish my shower I saw brown water. Another slug of mud must have been sucked up and made it past the filter, iron filter and softener. Checked the water again this morning and it was clear so I set the iron filter to regen before I left for work. If it's still clear, I'll regenerate and then flush the softener system out tonight.

We just planted a new lawn and it appears we are headed toward a dry summer. This means I'll be sucking on this well pretty hard to run the sprinklers. I can't be coming home to find the domestic system was contaminated once again by this fine silt. I talked to the well guy this morning and he was less enthused with helping me. Guess that's what I get for supplying my own pump for him to install. I was wondering if any members have experience with a problem like this? I'm thinking I need to somehow clean out the well and remove the silt. I was thinking of pulling the pump up and resting the pitless on the casing and then using compressed air to help break the material up so it could be pumped out. Thoughts?????

365' well drilled in the 60's. The well is fully cased into a gravel bed so it only draws from the bottom of the casing. The well report (attached) doesn't mention the use of a screen. The pump is down 200' from the pitless and it's a 22 gpm pump. The well guy estimated the free flow at over 30 gpm and we ran it like this for several hours. This is obviously a very good well and I think it's worth the effort to try and save it.

 

[groundcover]

I would start with a chlorine shock. Dump a couple of gallons of bleach down the well, run a hose till you smell it, run the hose into the well to mix it up , then run the hose to waste till things clear up.

 

[CobyRupert]

Did you run it for several hours/ 1000's gallons continuously?
Seems like your keeping the silt stirred up, having it flow in and directly pumping it out vs taking water that has had a chance to precipitate the silt to the bottom. Instead the silt falls out to the bottom of your totes.

2 cents.

 

[RedNeckRacin]

This may be a dumb question, Are there any centralizers and an anti-torque collar on the tubing string?

 

[Cord]

The old pump had a iron drop pipe without a anti torque collar. One was added for the new pump because we went with a pvc drop pipe. Don't know what a centralizer it, but we don't have it anyways.

No, it was not continuous. We would pump 700 gallons and then stop because we'd have two totes full. I think the water may have cleared up when we were pumping continuously because it wasn't getting stirred up.

From what I've read, the problem is "percipates from iron". In other words, the iron is dissolved in the water and when it enters the oxygenated well shaft it solidifies and falls to the bottom of the hole. I believe that I'm now disturbing this material and it's making it up to the pump. To that effect I was thinking I need to stir things up more so I can reach them with the pump.

 

[bspeedy]

First of all, congratulations on having an abundant water supply. Many folks on this board are not so lucky.
From the well log, it looks like it was drilled in 1958. 10 inch casing set to a depth of 20 feet - likely that was the minimum requirement at that time. Also 6 inch casing set down inside to full depth. The inside (6")casing would have been perforated near the bottom - perhaps the last 2 or 3 joints - to allow water in and keep out sand and gravel. I suspect that your source of contamination is water that was cased off originally. Typically, water flows into a well from various depths. Upper water may have iron or other bad attributes, thus it would be cased off during drilling. With the setup of your well and the age of the casing, it is very likely that the upper (bad) water is finding it's way in through holes in the casing that have rusted through over time. It's very difficult to determine this for sure because, due to the high rate of water production, your well cannot be pumped dry with your current pump.
I would consult with a local drilling contractor. He may be able to advise you on saving this well. I would try to find someone who would clean out the well to it's original depth and set plastic casing down inside the 6" steel casing. This new casing could then be grouted to allow the upper water to be sealed off.
The reason you see water go from good to bad to good is very typical of a well with the issues I've described.
If possible, try to find the son - or grandson - of the original driller. He will have two things going for him - he will have years of experience in your area and he will be interested and excited to work on a well that his ancestor installed. FYI - my brother is running the family drilling business which was started by my grandfather. No one in the area has a better understanding of the local geology and what to expect underground.

 

[bspeedy]

By the way, one more thought...
I don't recommend spending more money on filtration equipment until you get to the root of the problem. The filters I've seen, which can cost into the thousands of dollars, don't do a lot except waste money and electricity.

 

[Ed of all trades]

I would dump 2 gallons of bleach in as was said above wait until you can't smell the bleach in the water and do it again. I have done that with well that had flood water in them and they tested good. It might not help but it can't hurt and ti is a cheep fix if it does work.

 

[Cord]

By the way, one more thought...
I don't recommend spending more money on filtration equipment until you get to the root of the problem. The filters I've seen, which can cost into the thousands of dollars, don't do a lot except waste money and electricity.

I agree with you on the second point. It would seem to me that buying additional filters is just a band-aid for the problem.

The installer estimated the new pump was free flowing over the casing at 30gpm plus. This would be feasible because it wasn't building much pressure. I know that at 70 psi the pump will still flow 17 gpm which I knew the well would deliver per the report. Even at 30 gpm over several hours I was not able to draw the water level down to the pump. Now, I'm wishing I had gone with a bigger pump!

 

[Cord]

I would dump 2 gallons of bleach in as was said above wait until you can't smell the bleach in the water and do it again. I have done that with well that had flood water in them and they tested good. It might not help but it can't hurt and ti is a cheep fix if it does work.

As a requirement; when the pump was replaced the well was chlorinated. This is the reason why I waited several hours before pumping over the casing.

 

[RedNeckRacin]

Centralizers do what they sound like. They keep the pipe from kicking back and forth inside the well bore and knocking stuff down. IT sounds like you have a pretty stout pump and I figured with it moving around that the inside walls were getting a cleaning.

 

[kc5dlo]

I feel uncomfortable with this suggestion as I Have not worked that much on wells. I do have some experience with pumps however. If the symptoms appeared after installing a bigger pump, throttling the flow down to that of the original pump should bring the performance back to like it was with the old pump.

 

[KevT]

We had to replace our well last year. The original well was done in steel pipe, and after 11 years a hole rusted through the casing. We were sucking a lot of lime rock, sand, shell, and rust in our system. So we are lucky enough that we only have to drill 40 feet set the pump at 30. It was more expensive to sleeve the old one than to drill a new one, so I use the old one for irrigation.

 

[Cord]

I think we are going to pull the pump tonight and pump over the top of the casing. To stir up the debris I'm going to try to drop a hose down the casing and get it past the pump. The hose would be lowered all the way down to the bottom of the well and then I'll pump water down the hose. The hose will have a nozzle to increase the water velocity and this should serve to stir things up nicely. With the pitless hanging off the casing I won't have water so I'll have to store some in a tote. Because the water could be contaminated I'll chlorinate it so the well stays clean. The biggest problem that I can see is trying to get the hose back out of the well because it could get hung up on the pump. It's also a lot of weight hanging off the hose so maybe I should take a rope to it as well?

 

[Cord]

Got the pump up and over the casing last night. Couldn't get the hose down the well; couldn't get it past the torque arrestor. Let the pump run all night and this morning we had clear water with just a trace of sand. I let it run until noon and my wife reported a smaller amount of sand and the water was still clear. I'll start the pump back tonight. If it stays clear and there is only a trace of sand I'll drop it back into the pitless and start flushing the domestic. The pic is what I started with last night.

Oh, btw: I looked at the pump chart and with the friction loss of the pipe I'd be pumping 35gpm and that pump ran all night long. Wishing I had put an even bigger pump in!

 

[Cord]

I've started to shut the pump off to let things settle and then turning it back on a few hours later in the hope of stirring up something and being able to pump it out. There is a little turbidity when I do this, but it's not too bad. Enough that I'd feel comfortable putting the water through the softener. After a while the water does become clear but I'm still getting sand. Not a huge amount, but in a 5 second water sample I have a quarter sized spot of sand on the bottom. I put the bucket under the discharge stream and captured a half bucket of sand over a two hour run time. Realize this was very turbid water so I probably lost the majority of the sand that was pumped. At what point is this just material that has settled in the well vs a screen that has gone bad?

 

[Cord]

Ok, this is total FAIL of a project. Apparently by flowing the well we have now pulled in the bottom. Many well guys are saying the well is shot. In the mean time, I continue to wait for somebody to come out. I'm done waiting. I want to pull this pump tonight and measure the depth of the well to see just how much it has filled in. I remember a past well guy having a derrick that somehow clamped onto the side of the casing and then provided him with a tower he could lift with. I can't remember the specifics of the design though. Please post your past pump hoist contraptions so I can see if I can copy it.

 

[RedNeckRacin]

WE used a tri-cycle set up that worked very well. Two fixed wheels pointed towards the pipe and the third one slid into the table to clamp the pipe with the pressure being adjustable. One of the fixed wheels was driven by a motor and it plugged into 110V ac plug and would walk the pipe right out of a well.

 

[Sprinklerman]

There is a process called redeveloping a well . Using a diesel compressor and fittings , to blow the well Ask a well company about it .

 

[Cord]

The concern has been that to blow this well will too aggressive and we end up damaging the formation and lose the well. On Monday they are going to try to sand bail it. We pulled the pump last night and it looks like we are 20' short on casing depth. If bailing is successful, I'll have them put a gravel pack in and hopefully the well will be good for another 50 years. Hopefully...