After living for years in a city and taking clean water for granted, we recently moved into our first rural home and have been struggling with problems involving iron and yellow coloured water ever since we got here. It's esthetically very unpleasant and it stains our clothes.
Finding the source of the problem and a reasonably priced solution has been a real puzzle. We still haven't solved it.
We had a very comprehensive test done of the water in the shallow well (18 feet deep and 4 feet in diameter) before we moved into the house, as well as several times after we moved in. Everything appeared to be within the drinking water guidelines except for high iron and manganese levels. The PH and tannin-lignins readings were within the guidelines, but are of potential concern as well.
iron 0.5, 1.4 and 1.6 mg/L measurements (at various times) - guideline is
0.3 mg/L ph 6.62 tannins & Lignins 0.2 mg/L - guideline is 0.4 mg/L or less manganese 0.67 mg/L - guideline is 0.4 mg/LThere was an old Manganese Greensand filter in the basement when we arrived. We were told that this would get rid of the iron (which we presumed at the time was the cause of the yellow water). It was in bad condition, so we had a complete replacement installed for $1600 including installation (We kept and reused the empty tank from the old installation. Everything else was new) .
This didn't work. A new test showed there was as much iron as before and the water stayed just as yellow.
We ran the filter for several months in this situation until we were finally told that the cause of the problem was that manganese greensand filters need a ph of greater than 6.8. While some internet sites indicated that the filter would work at a lower ph than 6.6, the minimum figure of 6.8 was specified in the instruction manual for the filter.
After a couple of months we found a reliable soda ash (sodium carbonate) system which raised the ph to between 7.3 and 7.6 and had that installed for another $1000. including installation.
Unfortunately, the water stayed yellow and the iron level stayed high.
We had the manganese greensand filter tested several times to make sure there wasn't a malfunction. While we couldn't see inside the unit to make certain nothing had been improperly installed, everything seemed to be working according to the user's manual.
Hair pulling time.
After some research on the internet, I found some sites which referred to "Brown Algae" which can grow in the dark in nutrient-rich wells. Our well, for some reason, has a high coliform content (not fecal coliform though - which is below the measurable limit, and we have a UV filter to sterilize the water). Recently, I saw a small fibrous plant of some kind floating just below the surface of the well. Does that mean the yellow is caused by Brown Algae? Even if that's true, why won't the Manganese Greensand filter remove the iron? Does the algae (if it's there) somehow prevent the filter from working properly?
We then put high concentrations of household chlorine bleach in the well on three separate occasions to kill any algae or other growth.
That seemed to work each time when the water went clear for a day or so. Then the water returned to its normal disgusting yellow colour. The iron level remained high when we next measured it.
The supplier of our Manganese Greensand filter has now begun to suggest that our problem might be caused by Tannin Lignins. After some research on the internet, I found several websites which referred to "Heme Iron", which apparently is iron bound up in a complex with molecules from decayed vegetation. Apparently, this can cause a yellow colour, somewhat like the colour of weak tea.
The measured level of the tannin lignins in our water is below the drinking water guideline level. Does that mean that tannin lignins could not be the cause of the yellow water? Could even a small concentration of tannin lignins somehow prevent the Manganese Greensand filter from working to remove the iron?
Some other sites on the internet suggested that, over time, acidic water would eat away the Manganese Dioxide coating on the Manganese Greensand Filter media (i.e. on the Manganese Greensand "sand" filter media), thereby rendering it useless. Since we ran the filter for several months in water with a ph of 6.62 (slightly acidic), could that conceivably be the cause?
In summary, the yellow colour and high iron content in the water could potentially be due to a poorly installed Manganese Greensand filter, or the adverse affects of tannin lignins on the Manganese Greensand filter, or the adverse affects of brown algae on the filter, or the presence of Heme Iron, or the effects of slightly acidic water eating away the coating on the Greensand media.
More hair pulling time.
I'm tired of spending money on solutions that don't work.
Anyone have any ideas?
Peter