Treated water smells of sulfur and becomes dark gray

[Jrstevens]

Greetings,

I recently had a new well drilled. I hooked it up to existing equipment with the plan to get a water test and purchase new equipment. The treated water was acceptable for a couple of weeks, then sulfur smell started to creep in. It has only gotten worse. I'm hoping to get advice on narrowing down the exact cause and how to adequately address it when I install new equipment.

Water test results attached.

Current Setup
Well Depth = 117' including a 25' well screen at the bottom
Check valve at the top of the well casing.
Current Equipment & order from the well: Goulds shallow Well jet pump --> 65 gal pressure tank --> 10x4.5" sediment filter (1 micron at the moment) --> 1.5cf water softener with a fleck 5600 mechanical valve --> chlorine pellet feeder (I think it is an Automated Pure Water branded model 400 feeder) --> 1.5cf GAC with a fleck 5600 mechanical valve.

New Equipment En Route
2.0cf water softener with a fleck 2510SXT
2.0cf Jacobi catalytic carbon filter with a Fleck 2510SXT AIO oxygen chamber system
No chemical feeder currently

I was able to deal with the sulfur smell, unbearable as it was, until the water started to turn dark grey! This is the treated water, including hot and cold. It can come out of the tap already dark or it can come out clear-ish and darken over several minutes. I cranked up the hot water heater to 140F which helped the hot water smell. Cold water still smells though. I cleaned the pellet feeder and adjusted it to its max setting (60PPM chlorine injection). I'm still getting sulfur smell, though it might have helped a bit with the water color.

Here is a video I took of the treated water as I add a capful of liquid bleach. The water turns from dark grey to clear within seconds. Sulfur reducing bacteria?

 

[Reach4]

I presume your shallow well jet pump is for the old well.

New well would get what -- a 10 gpm 3/4 hp submersible?

I notice your test did not test sulfate. That is what feeds SRB.

My sanitizing procedure https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ is written with a pitless and well cap in mind, but a well seal with a removable plug or vent could let you inject and circulate. Sanitizing can knock down the well bacteria. I don't know how quickly it will rebuild, but I think the flooding volume is key to letting that last longer. Vinegar may be hard to come by now, but muriatic, which requires extra care and measuring, should be available.

When you sanitize, include your plumbing and water heater.

You might want to run your carbon tank drain out into the yard or shrubs.

 

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[Jrstevens]

Thanks for the feedback Reach4. I re-used the shallow well jet pump for the new well. The well depth is 117', but the water table is only 10' or 15'. The well is caped with a cemented PVC cap. I would have to cut and re-cement to access it.

I have a separate test from a different lab that simply lists sulfides as "positive". Can you recommend a test (at home or via lab) that can determine if SRB is present and at what level?

If it is SRB, would it be correct to say an AIO system cannot kill sulfur bacteria? If so, if I didn't want to continually sanitize the well itself, what would be the best course of action?

 

[Reach4]

I have a separate test from a different lab that simply lists sulfides as "positive". Can you recommend a test (at home or via lab) that can determine if SRB is present and at what level?

I can say that if you had a number, that would not mean much to me. I think you can infer it by your nose results. My sulfate is 134 mg/L. The smell was why I bought my backwashing filter, but the iron was a close second. The smell was not really strong, but I did not like it.

You referred to a chlorine pellet feeder. Where does that come into play?

Thanks for the feedback Reach4. I re-used the shallow well jet pump for the new well. The well depth is 117', but the water table is only 10' or 15'. The well is caped with a cemented PVC cap. I would have to cut and re-cement to access it.

How about a photo? What you describe sounds unusual. What diameter is your casing?

 

[Jrstevens]

The chlorine pellet feeder is in the current setup. It sits between the water softener and the carbon filter. Interestingly enough, I set it to its max setting of 60PPM of injection, put the carbon filter in bypass, and tried sanitizing the indoor plumbing with chlorine. Even at max setting, I couldn't get a reading of residual chlorine from two different branded chlorine test strips. The max setting does seem to help with the water color though. Here is what the feeder looks like - https://www.nelsencorp.com/itemdetail/FEEDER-400

Photo of the well head attached. 2" casing except for the 25' of well screen at the bottom. I think that is 1-1/4".

 

[Reach4]

Well Depth = 117' including a 25' well screen at the bottom

Is the "Well Depth = 117' including a 25' well screen at the bottom" a typo?

The chlorine pellets would be before the carbon, I would think. Is there some kind of contact tank or settling tank for the chlorine to act and to collect sediment?

If you did want to work out some kind of sanitizing for that, I think you would cut that cap off, and put a full-bore ball valve up top. Then have some kind of connection above the ball valve.

Your pvc should be protected from UV. Mock rock, or something.

Who designed this arrangement -- your well dealer?

 

[Jrstevens]

The chlorinator is indeed before the carbon. The carbon is the last treatment before water enters the house.

There is no contact tank currently.

All of the drilled wells I've seen in the area look like mine. The water treatment equipment varies quite a bit though.

I appreciate the idea you have of making the well more serviceable, but would sanitizing the well be a futile effort? Wouldn't bacteria recolonize very quickly?

To ask this a different way, is there any way to determine if the new equipment that I have on order (which does not include any chlorine injection) would be sufficient before I install it? If I have to re-introduce a chlorine system and a contact tank, I will, but I would like to avoid it if possible.

 

[LLigetfa]

Since you did not have this bacteria problem from day one, it suggests the bacteria was introduced into the aquifer when the well was drilled. The driller should have sanitized it but perhaps he didn't. If you can sanitize it using the overload method to push the chlorine down far enough into the aquifer, there is a chance of it working. If it doesn't, you will need to mitigate it constantly at the surface.

 

[Reach4]

he chlorinator is indeed before the carbon. The carbon is the last treatment before water enters the house.

Got it. Softener, then inline chlorine pellet chlorinator, then carbon.

All of the drilled wells I've seen in the area look like mine. The water treatment equipment varies quite a bit though.

If it works, good. New to me, that's all. So the static water level is high all over your area. But I guess there was supposed to be better water deeper.

 

[ditttohead]

Actually, chlorine, baffled contact tank (chlorine requires time to effectively kill), carbon tank then softener. You do not want to put bacteria filled water through the softener. What chlorine injection method do you have? If it is a pellet dropper, I would rarely recommend those. We have seen too many damaged wells possibly caused by this design. It is rare, but when it does occur it is very costly. Use the sanitizing methods recommended abovce

 

[Jrstevens]

Thanks for the feedback everyone. I also appreciate your patience while I try to understand everything.

If I'm reading the sanitation procedure correctly, it depends on a water supply being available after the well cap is open. My water supply will stop the moment I cut the cap off. I do have an irrigation pump available that feeds from a surface pond, but I'm not sure it is a good idea to use that dirty water.

Can I drop chlorine pellets (Calcium hypochlorite) down the well instead? They will sink to the bottom and dissolve. I think I would only need 5 pellets of 76% Calcium hypochlorite to reach 50PPM assuming the well casing has about 17 gallons of holding capacity.

 

[Reach4]

Actually, chlorine, baffled contact tank (chlorine requires time to effectively kill), carbon tank then softener. You do not want to put bacteria filled water through the softener. What chlorine injection method do you have? If it is a pellet dropper, I would rarely recommend those. We have seen too many damaged wells possibly caused by this design. It is rare, but when it does occur it is very costly. Use the sanitizing methods recommended abovce

He puts it inline after the pressure tank.

If I'm reading the sanitation procedure correctly, it depends on a water supply being available after the well cap is open. My water supply will stop the moment I cut the cap off.

If you put a valve up top, you could open and close that. The rest of this are ideas that may or may not be worthwhile. There are little hand pumps to help start a siphon.

Yes, you can drop pellets, but I don't know what you can drop to lower the pH. I have some ideas.

As far as a flooding volume, you could have a container held high on a picnic table or something. Fill it with water. Add chlorine plus your chosen acid. The water can be siphoned down the casing. Do a calculation as to how much water you should need, and maybe double it. Alternatively, how about dropping a 1/2 inch pex or other small poly line to the bottom, and feed your solution down that. https://www.menards.com/main/plumbi...r-polyethylene-pipe/13020/p-1444431568977.htm

But after you get your column full of pH4 to 5 water and 250 ppm of chlorine, you need to add treated water you saved up for the purpose.

 

[LLigetfa]

If it is a pellet dropper, I would rarely recommend those. We have seen too many damaged wells possibly caused by this design.

When I hear pellet dropper, I think of pellets being dropped down the well casing but the OP has a sealed well casing. I don't know what pellet system injects into a pressurized system.

 

[Jrstevens]

He puts it inline after the pressure tank.

If you put a valve up top, you could open and close that. The rest of this are ideas that may or may not be worthwhile. There are little hand pumps to help start a siphon.

Yes, you can drop pellets, but I don't know what you can drop to lower the pH. I have some ideas.

As far as a flooding volume, you could have a container held high on a picnic table or something. Fill it with water. Add chlorine plus your chosen acid. The water can be siphoned down the casing. Do a calculation as to how much water you should need, and maybe double it. Alternatively, how about dropping a 1/2 inch pex or other small poly line to the bottom, and feed your solution down that. https://www.menards.com/main/plumbi...r-polyethylene-pipe/13020/p-1444431568977.htm

But after you get your column full of pH4 to 5 water and 250 ppm of chlorine, you need to add treated water you saved up for the purpose.

Thanks for the ideas. Much appreciated!

When I hear pellet dropper, I think of pellets being dropped down the well casing but the OP has a sealed well casing. I don't know what pellet system injects into a pressurized system.

To clarify, it is a feeder, not a dropper. It is designed for pressurized lines. The instructions document the theory of operation - https://www.cleanwaterstore.com/technical/water-treatment-manuals/Model-400-Chemical-Feeder.pdf

 

[ditttohead]

Correct word, "theory" of operation. The design is unique but highly inaccurate. It assumes the air pocket that expands/contracts during the pump cycles does not go away very quickly. It does. These feeders are a very cheap way to dose chlorine. They are far from accurate but they are sometimes effective. I still stock and sell a few every now and then, but we have moved most people away from this design and over to amore controlled peristaltic pump injection method.

 

[WorthFlorida]

..........I was able to deal with the sulfur smell, unbearable as it was, until the water started to turn dark grey! ........

Can I ask what part of Florida? Why did the well driller only go down to the ~100' depth?

I lived in Palm Beach County for twenty six years and from my own irrigation well and having a friend that has lived his whole life in Florida this is what I have learned. To about 50 feet deep the water is heavy with iron. Any old home with a shallow well will have rust stains all over the place. My well was 72 feet and it was sulfur water. OK for irrigation with no staining and the stink was bearable depending on out temp and wind. For non sulfur drinking water you need to go down about 250' but will still need water treatment equipment.

I was present when the well was drilled. To about 50 feet it was soft earth before hitting the shell rock, then continued to around 70 feet when the noise changed to a hollow sound. That is where the water pocket was.

 

[Jrstevens]

Can I ask what part of Florida? Why did the well driller only go down to the ~100' depth?

I'm in western Palm Beach County. What follows below is the sum of talking to three well drillers. I can only trust their experience as I cannot verify any of it myself.


The preferred well depth varies significantly across Palm Beach County. Even within the same zip code the limestone depth may vary by several tens of feet.

Wells in my area are rotary drilled in just a few hours, but even just a few miles east might require a percussion drill that takes a few days to drill.

Most drinking wells are about 40' in my neighborhood. Irrigation wells are 80-100'. The reason the drinking wells aren't typically drilled deeper is because of salts. TDS levels can be 1800+ which would require RO to treat.

One driller mentioned that beyond 180' or so in my neighborhood you'll hit marl, which won't give water. This layer goes to about 1,200'.

The driller that I hired estimated a 50/50 chance of getting water under 1k TDS with a 100' well. Ultimately I wanted a well that had very low or no iron present in case I wanted to do whole house RO in the future with minimal pre-treatment. I think I came out okay with 641 TDS and 0.23PPM Iron.

 

[WorthFlorida]

Eastern part of the county is hard because of salt water intrusion is very possible. I lived at 441 & Lake Worth Rd and I know Wynne Parker of Parker Well Drilling. He maybe retired but the website still list the same address off the turnpike. Did you talk to him at all? If you did he is about th ebest in the county. He has been drilling his whole working life.