Up for a challenge? Low pH, high iron, + Mn, discharge to septic...

[challenged]

And probably iron bacteria. Long story, I'll try to keep it as brief as possible. Bought a house...

Previous owners had an old Myers ? Slantback softener, set to regenerate every 3 days. Before closing, post treatment water test showed iron .161 ppm (161 ug/L), pH 7.0, alkalinity as CaCO3 7.2 (very low), soft soft water. Everything else normal. The owners had the water flushing when the agent arrived, who knows how long, and it flushed for another 10-15 min after she arrived. They had mild iron staining in sinks and showers, clear water, clearly some green deposits/pinhole leaks at junctions and history of frequent replacement of tanks and pumps every 6-7 years it seemed (not all disclosed by them). Corrosive for sure but iron and pH seemed controlled. Mixture of copper and PEX in the house. Iron staining in toilet tanks but no sheen or slime, and no sign of rust staining in toilet bowls at all. Seemed manageable.

I did attempt to do a pre-treatment sample but the agent got confused by an old decommissioned well line (with I now know has reversed flow direction), came back with high iron and lead but we realized it wasn't the right supply and wrote it off to water in infrequently used faucet. Sellers were very attached to their closing date so I didn't insist on delaying to have it done again since softener seemed to be taking care of whatever was there.

Before closing, owners suddenly announced they were replacing the pressure tank. Said it made a funny noise that morning, bladder leaking, had it replaced. I asked to be there but plumber didn't call me until after old tank was removed. They didn't disinfect the plumbing system in the house after the work. Brine tank had lots of salt at pre-closing walk through. (Plumber later told me a different story about the pressure tank, but I digress).

Couldn't move in right away. Three weeks after closing returned to run some water and check on things. All the toilet bowls now iron stained. Ran faucets - all discharged intermittent plugs of red thicker water, some gas, some particulate rust, water back to clear in between plugs of red water. Some filamentous fronds in bowl when toilet flushed. Very brief sulfur smell from shower but hasn't come back since that one time. No gas in lines since that one time either.

Check softener, salt is empty, water has a bit of black dirt (typical salt dirt I thought), no sheen or slime initially but some sheen/oily film at water surface after the few days it took me to figure out what salt to buy.

At that time I knew little about softeners, never had one before so had local independent water guy down to check it and advise what kind of salt to use, settings since house wasn't being lived in yet etc.

He did on site water tests and disposed of the samples into the brine tank (no sink down there). Wasn't a fan of that.

His tests: pre-treatment hardness 3 grains, ferrous iron 21 ppm (yes, 21,000 ug/L) - essentially first draw I think since nowhere to discharge water down there, and house hadn't been lived in for about 3 weeks, so relatively stagnant water in pipes. Ferric 2 ppm, manganese 0, pH 7. Post-treatment hardness 0, ferrous 4 ppm, ferric 1, manganese 0, pH 6.5. No salt in the brine tank at this point so softener hadn't regenerated properly in not sure how many days. Probably not more than one or two weeks at most, and no water use in the house . Mechanical control head pretty seized and very hard to turn, said he could service it but probably time to replace.

Told him the previous lab tests had shown very low alkalinity, so with the softness and low pH corrosive water. Also the well, 8 years old had a production rate of only 2 GPM when drilled, no idea if that was in wet or dry season. Previous owners said they'd had no problems with water supply but they were careful to not run washer and dishwasher at same time etc. Plumber indicated they'd actually had intermittent water supply issues for up to a year, not sure if the problem was the pressure tank or well but they decided to replace pressure tank just before closin.

So local water guy recommended a venturi-type aerator and 1252 Nextsand unit (claimed this would handle up to 30 ppm iron), said no need for a softener. That's it. Would keep what little hardness there was so could help a bit with the corrosion in the house pipes, and could throw some calcite in with the Nextsand if you wanted to. Would expect to rebed the Nextsand every 5 years, maybe longer at a cost of $400 which would be offset by not having to buy 40 lbs of salt a week. Sounded good to me, no salt lugging, just annual maintenance of the head and rebed every 5 years or so. Sweet. Asked about the low well production rate (2 GPM), not sure what pump rate I get. 3/4 HP pump. He said no problem for backwashing the Nextsand, would program pauses to allow well recovery.

Tried to do a bit of research on Nextsand - seems impossible to find anything for iron applications (??)

Had Culligan guy down for a second opinion a few days later. I was now going to house daily to run some water and try to keep toilet stains at bay. Salt had been refilled with plain premium plus and some Iron Out thrown in. His results pre-treatment now 'only' 8 ppm iron (800 ug/L), now 10 grains hardness (of many tests, this is the only one that has shown any significant natural hardness in the water, I wonder if it was a false read), TDS 142, pH between 6 and 7 on field test, 6.8 on office pH test 3 days later (drawn Friday, checked Monday so may have risen in the meanwhile). Post treatment now 3 ppm total iron, 2G hardness.

He recommended a new high efficiency softener and guaranteed the new softener would take iron to 0. He was aware of the higher iron numbers from a few days before. He did not seem to be able to answer intelligent questions with intelligent answers and I think just has stock answer rather than anything tailored.

Meant to go ahead and try Nextsand and get moved in but life threw me a few curveballs and got delayed another few months. Was going to the house every day or few days at most to run some water, try to keep toilets from staining and keep an eye on salt use. Had put iron out pucks in toilet tanks to try to help. Then things started to get ugly.

Water got colored to varying degrees, clingy reddish film in toilet bowls, sheen and slime started in toilet tanks, filamentous fronds floating in bowl after flushes. Seemed to clear a bit after a couple of defouling doses of iron out, but would return. Tried system care salt, wasn't sure if it still needed iron out added or not (found out yes!), tried iron remover salt which actually seemed to make things much worse in terms of water color at the tap. Salt use did slow significantly with the iron remover salt, didn't know if it just dissolved more slowly or if the unit wasn't running it's cycles. Wanted proper raw water test to figure out WTH I had to deal with.

Agent came back 4 months after closing to repeat the raw sample for lab testing she messed up in the first place. Flushed the well supply line 10 mins before taking the sample. Stay tuned...

 

[challenged]

The saga continues...

Lab results now (raw)
Iron 11.6 ppm (11,660 ug/L), lead 6 ug/L (acceptable limit 10 ug/L), Manganese now 215 ug/L (.215 ppm), hardness as CaCO3 57.7 mg/L (3.4 grains), pH 5.9 (!), alkalinity as CaCO3 1.0 mg/L (not a typo - next to 0 buffering). Everything else normal. TDS 212.5 mg/L, TOC <0.5 mg/L. Conductivity 380 uS/cm, tubidity 5.77 NTU. Acidity getting worse, going to leach more metals obviously which I can hope will get a bit better once I move in but neighbour says iron really fluctuates there.

So: very acidic water with negligible buffering, very high iron, now manganese (had had some black staining in toilets and now in PEX), well production rate 2 GPM at time of drilling 8 years ago, still don't know pump rate. Well is drilled 165' (slate/basalt), now snotty rust-tinged slime in toilet tanks with filamentous bits when flushed, so I think iron bacteria although I don't know if they're in the well or just the house plumbing from contamination when the new pressure tank was installed, or water guy threw samples in brine tank. Water visibly colored anywhere from yellow to reddish brown, seems to vary daily and even per flush. Particulate rust in tub when hot run. Bathroom cold tap has obvious flow restriction.

Tired yet? I am! Thinking now I want something to kill bacteria but have no choice but to discharge backwash to septic so chlorine's out. Decide to have the iron blaster (ozone) dealer down and tell him all the gory details.

His field tests: pre-treatment (with three buckets tossed first, so not too stagnant although water hasn't been run in the house since the day before, except for the kitchen tap sample run first) pH between 5 and 6, TDS 196, iron approx. 13-14 ppm - said his test got hard to read above 7 so had to dilute with bottled spring water - could be higher if still near his max even with dilution? He ran a sample through a mini softener with only 0.3 ppm left after that which he claimed would all be ferric because the softener would remove ALL ferrous. hmm. Refused to test hardness on the raw water, said it didn't matter.

Post-treatment with the poorly functioning, probably fouled old softener still in service - pH was still between 5 and 6, TDS 219, hardness 1 grain, iron 2.5 ppm (2500 ug/L), so the old softener was still getting a fair bit but not nearly enough. I did hear it start a cycle a few nights before.

Final stretch if you're still with me.

He said too much iron for iron blaster alone, all the oxidized iron would be 'too messy'. He won't put one in alone over 5 ppm iron. His first choice would have been a chlorinator with contact tank, backwashing calcite filter, air encapsulation iron filter then carbon filter, with no softener. Since I have no alternative for backwash discharge other than the septic field, not really an option. He says he has no experience with peroxide systems and no good field test to figure out dosing for peroxide.

His plan B given the septic is a new high efficiency softener with iron out maintenance, then backwashing calcite unit, followed by air encapsulation iron filter to catch anything getting through the softener, which could be switched out for ozone iron blaster if I find the slime comes back. I had cleaned out the toilet tanks with peroxide cleaner to see if the slime would recur or if it's just in the toilet tanks, and so far after only a week it's not bad, but it hasn't been long yet. I asked about the backwash volume for all that given low well production and dry spells in summer (~75L for softener, 35L for calcite, 75L for iron filter) and he said no problem, he'd stagger them through the night. Hmmm...? Usage metered but override every 5 days max - I'll be living alone for the foreseeable future so not high water use.

He says he'd put the softener before iron filter because low incoming pH will help softener get ferrous iron before raising pH to help the air ox iron filter. Downside to me is any iron bacteria or ferric, which seems to come in waves may still foul the softener. Most was ferrous the day he tested but the ferric does seem to spike at times based on colour of water at the tap over time, and he knows this. He doesn't like iron filters in line first with high iron because it's 'too messy' - which may just mean he'll actually have to clean something at annual service visits instead of doing easy cleans and getting to sell you a new softener resin bed?

So...

I LOVE the thought of just aeration and Nextsand with no salt to hassle with if it would work. Am I dreaming? Last guy (who obviously wants to sell me something else) said this much iron would gum up an aerator in front in short order and Nextsand might last 6 months before not working any more. He also thought you couldn't put calcite in with the Nextsand. Even if I had to replace nextsand every few years, at the price quoted it would probably cost no more than salt with less hassle. I would spring for the iron bacteria test to make sure it's not coming from the well first, probably. Maybe.

Should I keep searching for someone who knows hydrogen peroxide systems? Nextsand? Full meal deal with the last guy? Softener or iron filter first to lower salt use? I originally planned to live there long term but those curveballs I mentioned may lead me to put it back on the market next year. I just want to be able do laundry without ruining clothes and keep the place from springing more pinhole leaks or destroying any more plumbing components. Already have a new pinhole leak in the upstairs toilet valve and increasing green crust at joints from the drop in pH since it's been sitting empty.

Thoughts? Help! And thanks for hanging in there!

 

[Sponsor]

 

[ditttohead]

So local water guy recommended a venturi-type aerator and 1252 Nextsand unit (claimed this would handle up to 30 ppm iron), said no need for a softener. That's it. Would keep what little hardness there was so could help a bit with the corrosion in the house pipes, and could throw some calcite in with the Nextsand if you wanted to. Would expect to rebed the Nextsand every 5 years, maybe longer at a cost of $400 which would be offset by not having to buy 40 lbs of salt a week. Sounded good to me, no salt lugging, just annual maintenance of the head and rebed every 5 years or so. Sweet. Asked about the low well production rate (2 GPM), not sure what pump rate I get. 3/4 HP pump. He said no problem for backwashing the Nextsand, would program pauses to allow well recovery. It is an old way to treat iron and is sometimes very effective. it is the lowest cost solution but in your application it would not be my first choice. If you wanted to try it I would substitute the Nextsand with Katalox Light. KL is basically nextsand (clinoptilolite) coated/impregnated with Manganese Dioxide ore (pyrolox or filox). Do not add calcite to the tank, that is kind of silly. It should be kept in a separate tank. Programming pauses... again, not a good idea. It takes a sustained backwash to effectively clean the media. I would recommend a larger or an extra pressure tank to allow for the proper backwash method. Pulsed can work but it is usually done with compressed air, very effective...

For your application I would go back to the basics, keep it simple. While I am not a huge fan of this design, it is tried and proven.

Chlorine injection, baffled contact tank, GAC backwashing tank, simple polyphosphate injection to protect your plumbing.

I sent you a PM, their are some other issues you need to consider, too much info to do in a DIY forum.

 

[LLigetfa]

Asked about the low well production rate (2 GPM), not sure what pump rate I get. 3/4 HP pump. He said no problem for backwashing the Nextsand, would program pauses to allow well recovery.

There are a few missing data points. Depth of pump in well, casing diameter, static water level, pump GPM and curve, dole valve. Chances are the pump will put out many gallons at rated GPM so long as there is no dole valve. I would not count on a larger pressure tank making up any shortfall. Murphy's law states that the pressure tank will have 1 gallon of drawdown left in it at the start of the backwash cycle.

A question for ditttohead, how many gallons of water do you estimate would be needed? Armed with that, calculate the needed tank size without Murphy's law.
http://www.wellmate.com/en-US/support/calculator/

I am not against using a large tank. A larger tank provides more contact time and mixing if the micronizer cannot provide enough air through the pump cycle depending on usage patterns.

My iron filter uses a micronizer air injection system and so the micronizer effectively acts like a dole valve limiting the GPM available. About 4 times a year (with normal water consumption), I do a manual backwash and introduce pulses of air into the water stream with a compressor.

If your well casing provides good reserve, I would not use a micronizer, opting for an air compressor injection system instead. Just make sure you have a pump monitor to protect from run-dry.

 

[ditttohead]

As to the pressure tank question, they can be used very effectively for additional storage especially if you know the main trick... use an RO storage tank, not a well tank. These use much larger bladders and are designed for a much larger drawdown/capacity instead of just being used as a pump cushion. This is why they are also a lot more expensive. The metal shell is cheap, the internal bladder system is where a lot of the manufacturing cost is.

FYI, the micronizer does not really act as a flow restrictor... technically you will simply increase velocity across the micronizer, even though it has what appears to be a tiny hole, the micronizer is still capable of flowing in excess of 15 gpm. A venture injector requires a differential pressure to operate and the micronizer does this by allowing you to restrict the bypass forcing more or less water though the injector. Fully open the micronizer works great at about 10-15 GPM. Fully closed it works at about 3-4 GPM.

 

[LLigetfa]

Fully closed it works at about 3-4 GPM.

which is close to how mine is hence for me it does work like a dole valve. If I let my pump go the rated GPM it draws up sediment.

 

[ditttohead]

That sucks, while this is not what they were designed to do, they work fairly well for that.. Throttling it back that far.... you get some amazing air draw I assume.

 

[challenged]

There are a few missing data points. Depth of pump in well, casing diameter, static water level, pump GPM and curve, dole valve. Chances are the pump will put out many gallons at rated GPM so long as there is no dole valve. I would not count on a larger pressure tank making up any shortfall. Murphy's law states that the pressure tank will have 1 gallon of drawdown left in it at the start of the backwash cycle.

A question for ditttohead, how many gallons of water do you estimate would be needed? Armed with that, calculate the needed tank size without Murphy's law.
http://www.wellmate.com/en-US/support/calculator/

I am not against using a large tank. A larger tank provides more contact time and mixing if the micronizer cannot provide enough air through the pump cycle depending on usage patterns.

My iron filter uses a micronizer air injection system and so the micronizer effectively acts like a dole valve limiting the GPM available. About 4 times a year (with normal water consumption), I do a manual backwash and introduce pulses of air into the water stream with a compressor.

If your well casing provides good reserve, I would not use a micronizer, opting for an air compressor injection system instead. Just make sure you have a pump monitor to protect from run-dry.

I unfortunately don't know the answers to the well questions, and was hoping to not have to get a well guy in if I could avoid it. I do have a brand new Flexcon 33.4 Gallon pressure tank. Use will be very low with only one living there. I've been told I should backwash every 5 days minimum regardless of use with that much iron to flush out, so that will probably override use-metered regeneration.

 

[ditttohead]

https://view.publitas.com/impact-water-products/2018-catalog-final/page/238-239

Since we do water quality improvement and not well systems we only sell the storage tanks and not the well tanks. Unfortunately I took the 120 gallon tank out of the catalog which had only slightly improved capacities compared to the 80 gallon tank. The 120 gallon tank is the same as the well pump tank design. They have not made a larger diaphragm for it yet.Check out the numbers and you will notice that the actual water capacity if very high compared to well tanks. If you used a well tank for storage it stretched the diaphragm and reduces its service significantly. You also pay a lot more for the larger internal diaphragm.

 

[SuperGreg]

I was under the impression that small amounts of residual chlorine were OK to flush to septic tank.

 

[ditttohead]

Small intermittent amounts should not affect a properly operating septic system but higher doses should be avoided.