Black Material in Geothermal Filter

[CommanderDave]

I have a water-water geothermal system that is fed directly off a deep well. There is one water filter prior to entering the unit that is self cleaning. About a year ago I shocked the well, and I think I used too high of a concentration of clorox. Afterward I noticed some black material in the water, but it seemed have cleared up after running a hose for several hours a couple days. Today I had a small leak in the geothermal piping and when I turned the water off to fix it I also removed that self cleaning filter, which was completed full of a black kind of gooey material, that had blocked the filter. (see attached photo). So I am now concerned about the condition of the well. I note that the well water feed branches off to service the house, which has a whole house filter and a water softener, and I've not noticed any issues with that water. I don't know where the black material is coming from...is it from the pump? or from the casing? a water line? The most recent water test was 2 years ago and the results were fine. This is obviously important because replacing the pump is relatively easy as opposed to an issue with the casing or lines. Appreciate any thoughts.

 

[Fitter30]

Well Water Black Sediment

This past summer I shocked my well with chlorine. About a month later I changed the whole house water filter and it was really full of black sediment, which hadn't happened before. I then thought back and realized I had mistakenly used too much chlorine in the treatment. I used to change the...

terrylove.com

www.springwellwater.com/black-slime-on-plumbing-fixtures/
Be glad u have a filter would of stopped up the geo condenser.

Well Water Black Sediment

This past summer I shocked my well with chlorine. About a month later I changed the whole house water filter and it was really full of black sediment, which hadn't happened before. I then thought back and realized I had mistakenly used too much chlorine in the treatment. I used to change the...

terrylove.com

 

[Sponsor]

 

[Bannerman]

The most recent water test was 2 years ago and the results were fine.

Don't know what 'fine' means as every well contains a various amount of minerals, metals and bacteria. Suggest posting the full lab report so as to assist to determine possible substances that are accumulating on the filter element.

Due to the color and 'gooey' nature, I suspect manganese.

 

[CommanderDave]

Don't know what 'fine' means as every well contains a various amount of minerals, metals and bacteria. Suggest posting the full lab report so as to assist to determine possible substances that are accumulating on the filter element.

Due to the color and 'gooey' nature, I suspect manganese.

 

[Valveman]

Shocking a well is a temporary fix. Stuff grows in the pores of PVC pipe and other things. Shock only kills what is on the surface. It takes repeated shocks to kill what is in the pores. Maybe even needs a small dose on a regular basis.

 

[Reach4]

Your iron level is nicely low, but your manganese number is high -- about 6 times the SMCL (secondary maximum contaminate level). Manganese is black. Not dangerous but makes an undesirable taste. https://wqa.org/resources/manganese/

Is there a taste or smell to the water?

There are also black sulfides. I don't see a sulfate number in your test, and sulfates are what help feed H2S generating bacterial (SRB).

I note that the well water feed branches off to service the house, which has a whole house filter and a water softener, and I've not noticed any issues with that water.

Water softeners remove manganese.

 

[Bannerman]

Water softeners remove manganese.

While a softener is capable of removing ferrous manganese, the softener's hardness setting will need to be increased to compensate for the additional capacity consumed by the manganese.

As the appropriate compensation factor is an additional 5 grains per gallon hardness for each 1ppm of manganese, with 0.3 ppm manganese, increase your softener's hardness setting by an additional 1.5 gpg.

One issue with shocking a well is, chlorine is an oxidant.

Manganese within a deep well is typically in a ferrous state whereby the manganese will be fully dissolved in the water and will not be removed by a simple sediment filter. In shocking the well, the chlorine will have oxidized the ferrous manganese, converting it to a ferric state, thereby causing the manganese to be no longer dissolved, but instead converted to solids which precipitated out from the water and settled within the well.

You mentioned attempting to clear the black debris from the well by flowing through a hose (garden hose?) for several hours for a couple of days.

To more effectively eliminate a greater amount of ferric manganese solids from the well, will be to temporarily disconnect the house and geothermal supply piping from the pump's outlet, and allow the pump to discharge at the maximum delivery rate the pump is capable of supplying, with the least restriction possible. To direct the discharge directly to a field or suitable drain, temporarily install a short section of pipe of the same diameter as the pump's discharge fitting.

To most effectively eliminate the debris, the pump may need to be run continuously for several hours or even days, until the discharge eventually becomes consistently clear.