Well Stink

[Cass]

While I work on wells I am no expert. I have a friend that has, I would guess hydrogen sulphide in the well causing the rotton egg smell. I want to chlorine the well for him but I am not sure of how mich to use and if it will/can harm the pump. It is a submergable, the well is 90' and he is getting back to me as to the water depth in it. My question is, is there a formula as to the amount of chlorine to use based on the amount of water in the well? I know how to do it just not how much to use or how long to leave it in the well B4 flushing it out.
Thanks

[speedbump]

It sounds like you are going to chlorinate the well once, correct?

This will only temporarilly get rid of the sulphur smell. When the chlorine is gone, the smell is back.

I have a great system for eliminating sulphur permanently if he is interested. You can see it here:

bob...

[rshackleford]

How about a chlorinator? This is a device that bolts on the well casing and drops a chlorine pellet in every time the pump starts. The good thing about this is that it will control rust bacteria too.

[Gary Slusser]

Shocking a well (or the use of a pellet dropper) can cause expensive to fix water quality, pump, power cable, drop pipe and casing problems. And shocking is not the standard treatment for H2S unless it is being caused by IRB, MRB or SRB in the well/groundwater. And then shocking usually will make the problem worse over time to the point that the well will have to be chemically/mechanically cleaned or replaced IF the well is a well point of fully cased and screened well, as opposed to a rock bore well.

If no reducing types of bacteria (IRB etc.) the best way to treat H2S is an air pump system. The air pump system I use is a bit different than Bob's. it uses a medical grade air compressor, stone bubbler and vent to be able to use air/oxygen (no chemicals) to oxidize H2S, iron and manganese. That causes those things to convert into a particulate which must be filtered out of the water. For the filter, I use a Centaur carbon because Centaur was invented to remove H2S and if the air doesn't get all of the H2S, the filter will; it is not regular carbon, it is a catalytic carbon. If there is a bacteria problem then I use an inline erosion pellet chlorinator followed by a special mixing tank and a Centaur filter.

All filters must be sized for the peak demand flow rate (in gpm) of the family and house. Exceeding the SFR (service flow rating) of the filter prevents the filter from being able to remove all of whatever you are attempting to remove.

Gary
Quality Water Associates

[Bob NH]

Dropping chlorine into a well seems like an uncertain way of getting it to the pump inlet because the water comes from below the pump. If you could get a 1/4" tube past the pump you could introduce liquid chlorine solution (diluted bleach) by letting it run down by gravity through a solenoid valve that would open when the pump is on. The low concentration (1 to 2 parts per million) should not affect a stainless pump. You would then want a particulate filter of some sort to remove the sulphur and iron precipitates that result.

I am an advocate of lots of filter surface area. I can get a "Big Blue" size housing (4.5" x 20" cartridge) for less than $50 and one pleated cartridge will serve a normal household for a year if there is not a lot of nasty stuff in the water. If I had a shallow well I would use one of the Harmsco "one-micron absolute" cartridges, especially in areas with livestock. Chlorine doesn't effectively kill cryptosporidium and if you want to know what that does, Google "cryptosporidium milwaukee" and take a look at the first few returns. And there was an outbreak at Seneca Lake State Park in New York that made more than 2000 people sick in the summer of 2005.

If you can't get the chlorine below the pump you will need a chemical feed pump (about $250). If you are working with a shallow well jet pump you should have no problem getting the chlorine down near the foot valve.

If you want to remove the chlorine you can use a carbon filter, but if you adjust the chlorine to be less than 1 part per million (1 mg/liter) after filtration you should not taste it, and it will take care of bacteria and viruses that may exist in the well.

If you are adding chlorine regularly, you should have a test kit. I like the Hach CN-66F (USA Bluebook Stock 32467, $40.40) which will let you measure free chlorine (the kind that is most effective in killing bacteria and viruses) to within 0.1 mg/L.

[speedbump]

I'm not sure what Gary's inline erosion pellet chlorinator is, but I would recommend any chlorinator above ground for in line chlorination as opposed to putting the chlorine in the well. I have seen only a few systems that used the pellet droppers (I believe by Autotrol) and the casing, controls, wire everything were destroyed by the chlorine. They hurt a lot more than help in my opinion. I recently pulled a pump from a 4" well that used to have the dropper on it. The casing was encased in 6" of concrete from ground to about the 2' of casing height above ground. As we were beating the pump out of the well because of what the chlorine had done to the inside of the casing, we knocked the concrete loose to reveal where the pellets had been hitting the casing through the well seal, there was no casing from 2' to ground level on the south side. Not to mention what it had done to the droppipe, wire etc.

Bob NH's idea of dropping it through a ¼ tube is the best idea if you must put it in the well, but I would still rather see it used above ground.

[rshackleford]

What is the best way to know if the sulfur odor is caused by bacteria or not? In the case that this is not caused by bacteria, chlorinators would not be a good installation.

It sounds like the chlorinators you guys have worked with have been calibrated too high. The way they come from the factory definitely puts too much chlorine in the water. A person needs to plug the holes that regulate chlorination so that a pellet is only dropped in ever forth or fifth pump startup. Occasionally we will have customer whose pump will be completely clogged with rust bacteria within several months of installation. This is the most common use of chlorinators in our area.

I also cannot stress enough the need for frequent chlorination of any well to reduce rust bacteria growth on the well screen, casing, drop pipe, pump, and anywhere else in the system.

[speedbump]

That just goes to show how different areas use different types of equipment to handle water problems. There is no one fix does it all when you move around the country. Water is different from place to place and different types of systems are used. That is not to say, there may be a better or worse way to do so however.

bob...

[rshackleford]

You are right about different parts of the country and different treatments. My first thought is to look at the well. We are well contractors and don’t handle any water treatment equipment. If it can’t be handled at the well, we aren’t the people for you.

It would be good for me to know how to work with customers (or to direct them somewhere else). I think that we could successfully treat the water if the sulfur smell is a result of bacteria, but how is that determination made?

[speedbump]

Hydrogen sulfide is a gas, the smell does not come from bacteria. That's not to say that there isn't a sulphur bacteria. There is.

If you have bacteria running rampant in your well or plumbing, you can get an odor. I don't know what those little guys do in the water to cause this odor nor do I want to know.

But if you have sulphur, this is a gas and does not smell until the water meets the air. Then the gas comes out of suspension and enters the nose.

The way to get rid of the gas is aeration. Chlorine and carbon also work well to rid the water of the odor. I prefer the aeration method and do it differently than most. Sulphur removal system

bob...

[rshackleford]

So none of this gas is a result of bacteria action? The gas is naturally occuring in the water?

Thanks.

[speedbump]

I can tell you for sure that it is in Michigan and Florida. Some parts worse than others and some areas none.

bob...

[Cass]

The well water that I have been talking about does not smell on the hot side, just cold. Can anyone tell me why.

Thanks

[Gary Slusser]

I have to disagree with Bob, all H2S and other gases is/are caused by bacteria. They create gas in their digestion system as we all do. For H2S, it is sulfate reducing bacteria (SRB, mostly) BUT.. they live in the ground and groundwater, so the H2S can migrate to a well with the recovery water or be formed in the well by SRB, IRB (iron) and/or manganese (MRB) reducing bacteria. Each type is a group of bacteria. The groups can be made up of both aerobic and anaerobic types; needing oxygen or not.

As to the pellet droppers, there are a number of different brands and I sell them in certain cases like IRB shutting down a pump, or causing such rust that it blocks the drop pipe etc.. They can all cause serious damage if not set up correctly based on the water quality and how they are installed. All of them should insure that the pellets get down in the water that is usually done by including a piece of tubing down past any pitless or other obstructions. Always follow the manufacturers' instructions.

I wouldn't suggest BobNH's way due to too much owner involvement. Homeowners tend to skimp on doing what needs to be done when it needs to be done. Plus, in our rock wells, the water comes down from the static water level rather than up from the bottom of the well. In a cased/screened well, you'd need to put the chlorine at the screening with the largest flow if you held to the theory but, you have to chlorinate the whole column of water, not just what is going in to the pump inlet and there is a minimum contact time required for the chlorine to do it's job on iron, manganese bacteria gasses etc.. When you chlorinate in the well, we use the well as a retention tank. Usually the water will be very discolored if iron or IRB is present. And you don't want that stuff clogging up the drop pipe just moving through it up to the turbidity filter at the house that removes the 'dirt'. And the oxidation process has to be completed before the filter in most cases.

There is a knock off of the inline chlorinator I suggest. The one I sell is patented with a totally different inside workings than the knock off that is used for swimming pools.

A cold water odor of 'sulfur' says there is H2S in the water. Usually the hot water will smell too but the temp masks it. Yes Cass, there is a formula for chlorine demand; each ppm of iron, like 4 ppm of chlorine, H2S maybe 2-8 ppm etc.. I can never remamber it so I always follow the instructions wit hthe pellet dropper I sell. I don't shock wells anymore but used to use a 1/2 lb of pellets per 100' of water. You should find the info with a search for shocking + chart or some such. This will get you started:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wwg408?OpenDocument

Gary
Quality Water Associates

[speedbump]

Gary, if what you say about all sulphur gas being caused by bacteria is true, why is it in Florida that the deeper you drill into the lime rock the worse the sulphur gets?

bob...