PDA

View Full Version : Iron Or What???



Spyder
12-08-2009, 12:07 PM
Thought I'd post this issue we've had since we bought this property close to 5 years ago. The water source is a 402 ft deep well, 6.25" in diameter with the galvanized casing going down 42 feet. We have a few issues... was tested having low PH, 5.8. At the time of testing showed to have iron, 3ppm I think. Problem is it fluctuates. Everything else is OK including hardness which was 3 grains. Since we had a decent Rainsoft softener at the house we sold we bought it here. Thought it'd help with the iron and the little bit of hardness. Did nothing for the iron. We called out the local Rainsoft dealer and they told us about 2 systems we could go with. First was the usual iron filter, PH neutralizing filter, etc.... cheaper of the 2 but would require maintenance here and there along with rebedding. 2nd option was a chemical injection system. Said it has no limits like the filter setup, but of course it cost more and involves getting/refilling the chemicals often. We went with the chemical feed system... Basically the water goes to a 120 gallon retention tank, along the way it is injected with alum for the iron removal, caustic for the PH and bleach to help with disinfecting/iron oxidation. Our water didn't test for any bacteria, but in this state it (bleach) is required with systems like this. After the water is saturated with the chemicals in the 120 gallon tank it goes through a large wholehouse carbon filter (9"x48") then through the softener. Overall the system works great but the iron levels fluctuate, making it hard to keep dialed in. When we gets lots of rain after a dry spell or when we use alot of water daily, which I think draws it down faster than it can recover, etc..... it turns rather cloudy, like diluted orange juice at times. I have done alot of research and found that the typical veins feeding wells don't discharge alot of iron like this at once. We are thinking the main problem is the galvanized casing being corroded is causing this as the static water level rises and falls in the well, stirring it up each time. We contacted a few local well drillers about possibly video inspecting/lining it with PVC. Seems like a great option, but not cheap. Both guys pretty much told me it sounds like the problem and is an easy fix... Any of you have the same issues? It'd be nice to use less chemicals or be able to stop using them altogether. Thanks in advance.

Gary Slusser
12-08-2009, 12:45 PM
If I understand you correctly, you are thinking of spending big bucks to install a liner in your well because you don't want to set the chlorine dose high enough for the max iron content in your water and leave it there so the equipment will work, you'd rather adjust it up'n down to save a few bucks worth of bleach.

And you're justifying do that by now wanting to get rid of chemicals.

Question, say you do that and you cut your iron content in half. What are you going to do about the acidic water and is your softener capable of removing the iron with good salt and water efficiency?

BTW, a 5" liner seriously reduces the clearance for and volume of cooling water around your 4 inch diameter submersible pump. And if the pump overheats it can weld itself to the PVC. You also lose a lot of water storage in the well.

I use chlorine for your type water but I don't use a solution feeder for bleach or soda ash to raise the pH. I use an erosion chlorine pellet chlorinator and a backwashed acid neutralizer filter. And I would not use alum. I don't use large retention tanks, I use a bottom drain 12" x 65" tank with a patented mixing feature that is equivalent to a 120 gal retention tank; that usually does not have a bottom drain to get rid of 'sediment' build up in the tank.

shadow745
12-08-2009, 01:03 PM
Has nothing to do with the bleach cost... the food grade alum is rather expensive. This is what I use for each fillup. The first chem tank is 15 gallons of water and I dilute roughly 20-24 oz. of alum in this, more if the iron is higher. Alum works and does so well, but like I said it's expensive. The second 15 gallon tank is for the 50% caustic and bleach. I use 16 oz. of caustic and 64 oz. MAX of ordinary household bleach in this. Both tanks run down in about 7 days give or take a day.

I have thought about the volume reducing effects of the liner, but it would only go down slightly below the existing galvanized pipe (42 ft), so there is another 350+ ft. of water column below that. But I do see what you're trying to say. Even if we had that done I'd still run the system as is, just hoping to reduce or eliminate the alum. The caustic is expensive as well, but we don't use alot. Of course I'd still use bleach for disinfecting.

Based on what I've told you so far how much bleach would you use for 15 gallons of water? Like I said the carbon filter is approximately 9"x48" and I just replaced the media about 2 months ago. Would I be better off by possibly just use the 1 tank for caustic for the PH neutralizing and the other chemical tank strictly for bleach and no more alum? Anymore info would be appreciated... It's not that we want to spend more $$$, just trying to use what we have as effectively as possibly. Thanks!

Gary Slusser
12-08-2009, 08:32 PM
The amount of bleach depends on how much demand there is for chlorine based on how much iron, manganese and bacteria. You should have .2-1.5 ppm of Free chlorine residual.

I won't sell solution feeders because of the baby sitting they require. I've heard of using alum a few times but it is not common, and I wouldn't use it but why was it part of your system? I'm thinking it's to protect the carbon but regular carbon is not good to remove rust that the chlorination causes. I sue a special carbon that does a much better job and for much longer.

And a 9 x 48 1 cuft carbon filter is quite small for more than a family of 2 with more than like 1 bathroom.

Before I'd line my well, I'd get new water treatment equipment.

Spyder
12-09-2009, 06:27 AM
The alum is a coagulant and pulls the iron and other patriculates out of the water better and faster than most other chemicals. I do have a 10 year background in waste water treatment and learned alot about polymers, alum, caustic, etc. Some of this carries over into drinking water treatment as well.

I do agree the chem feed systems require babysitting, but at the time it was the best solution for the problem we have. I have since found a local chemical dealer that we buy the caustic and alum from for much cheaper rates than from the Rainsoft dealer that installed the system.

Well we can't buy new equipment, just have to work with what we have. Thanks!

Gary Slusser
12-09-2009, 02:50 PM
I know what alum does but it is used very rarely in residential applications and mostly because a coagulant is not needed.

The ferric iron particulate caused by oxidation because of the chlorination etc., is usually dealt with by a properly sized retention tank and then a backwashed turbidity filter, which could be a special carbon that will clarify the water and remove the chlorine at the same time. Some dealers use regular carbon and then replace it every year or two.

liveinfixer
12-15-2009, 10:22 AM
What is the major difference between regular carbon and special carbon? What is the name of this special carbon? I've been in water treatment for over 30 years and have never heard of a special carbon. Please inform us.

Not to put words in Gary's mouth, but I suspect he'd mean using a Centaur filter which is made with anthracite coal. Much harder, much longer lasting.

Bob999
12-15-2009, 11:33 AM
Not to put words in Gary's mouth, but I suspect he'd mean using a Centaur filter which is made with anthracite coal. Much harder, much longer lasting.

Centaur carbon is made from bituminous coal--not anthracite coal.

"CENTAUR® 12x40 is a liquid phase virgin activated carbon that
has been manufactured to develop catalytic functionality.† The
product is unique in that it concentrates reactants via adsorption
and then promotes their reaction on the surface of the pores.
CENTAUR 12x40 is produced from bituminous coal using a
patented process. Although it is not impregnated with metals or
alkali, it displays the catalytic functionality of these materials. In
most cases, it can be reactivated and does not present the
disposal concerns associated with impregnated carbons."