Ignorant, can you guys help me get started on water softening ?

[Bannerman]

Dittohead says above that the carbon filter is inefficient and costly, is chlorine reduction common?

Dittohead was referring to to using cartridge filters for whole house chlorine reduction. He mentioned a back-washing carbon filter being the proper method when removing chlorine at point of entry. Gary mentioned cartridge filters only as a point of use method.

Chlorine can dramatically shorten the life of resin and valve seals and other soft components, depending on the exposure level. Most standard resin is 8% (or less) cross-link whereas 10% cross-link will better tolerate chlorine exposure. While chlorine has its uses in oxidizing contaminates and for killing bacteria, its presence can have negative effects for some particularly those with asthma and other breathing issues. As 10% c-l resin is more expensive, if you're considering a back-washing carbon filter, then buy standard resin.

Fine mesh resin can be more efficient when using a softener to reduce/remove small amounts of iron. That said, fine mesh is not often recommended even when iron is present as the finer resin packs too tightly and can restrict water flow through the softener.

A 10" X 54" tank is commonly used for a 1.5 cuft system while 12" X 52" is usually used for a 2 cuft system. While 1.5 cuft has a total rated softening capacity of 48,000 grains when the resin is first new and unused, programming is typically based on 45K grains (30K per cu/ft). To restore all 45K grains would require 22.5 lbs of salt (15 lbs/cuft) each regen cycle (=2,000 grains/lb).

Salt efficiency can be drastically improved by programming regeneration to occur when a lessor amount of capacity has been utilized. For example, only 9 lbs of salt (6 lbs/cuft) will restore 30K of capacity in a 1.5 cuft softener (=3,333 grains/lb) while 12 lbs (8 lbs/cuft) will restore 36K grains (=3,000 grains/lb).

With regards to your septic field, there should not be any issues particularly if the system is maintained and is programmed to use an efficient amount of salt each regeneration.

As you don't have any iron to speak of, a larger 2 cu/ft softener could also be utilized for your growing family. 12 lbs of salt (6 lbs/cuft) will regenerate 40K of capacity. With a metered softener, regeneration will normally occur only once the programmed amount of capacity has been utilized.

Edited to add: I just re-read your earlier post. Chlorine was not indicated in your test results and the presence of E-Coli and a small amount of iron, confirms that chlorine or at least an effective amount, is not present.

 

[MaplesonD]

I just called my water company to get more information on the chlorine, since it wasn't included on the test. They said I will hear back from them probably Monday. I was under the impression that the low iron probably meant there WAS chlorine present, is it the other way around?

So it sounds like a larger capacity system is no issue and that I should get a metered valve so that it only regenerates when we've used a certain amount, and that I should set it to regenerate slightly more often so that I get efficient salt use.

I called my septic guy and he said not to ever discharge brine to a septic tank, I called environmental health and they said the same thing. They recommended discharging to stormwater runoff area, so I guess I'm back to that plan. Who would be a reliable person to consult as to how far away to drain the brine or where to discharge it to? My concern is the salt killing trees or vegetation, so I want to make sure it goes to a place with adequate drainage/dilution or preexisting lack of vegetation. Septic , plumber, arborist?

 

[Sponsor]

 

[Reach4]

What size tanks correlate to 1.5 cubic feet? 12x52 is what the guy recommended.

10" x 54" 1.50 cu. ft. of resin.
12" x 52" 2.00 cu. ft.

Bigger on city water is not a problem.

 

[ditttohead]

Interesting read. http://www.uwsp.edu/cnr-ap/watershed/Pages/GWSofteners.aspx

From my personal experience of 25+ years, softener have not had a problem with the septic systems in the areas I have worked, primarily the Southern California area. I have installed too many systems to count onto septic systems. Brine discharge other than to a septic or sewer is not legal in California.

 

[Gary Slusser]

I called my septic guy and he said not to ever discharge brine to a septic tank, I called environmental health and they said the same thing. They recommended discharging to stormwater runoff area, so I guess I'm back to that plan. Who would be a reliable person to consult as to how far away to drain the brine or where to discharge it to? My concern is the salt killing trees or vegetation, so I want to make sure it goes to a place with adequate drainage/dilution or preexisting lack of vegetation. Septic , plumber, arborist?

The most frequent cause of failed septic tank systems is.... insufficient water flow through the system. If the septic was permitted before being installed, it was (normally is) sized based on the number of bedrooms (people) regardless of how few actually live there.

My suggestion is to get back with the naysayer folks and ask them why the (usually weekly) 'salt' dose from a softener is going to harm a properly sized septic system; assuming they believe it is the salt that does it... Ask them to prove their argument. Salt is a bad thing for the environment, unless it goes into the oceans...

 

[MaplesonD]

Hey Gary, they didn't have any specific evidence that was, say, backed up by a study or anything. The lady from the septic company had anecdotal evidence where she said they have seen where it killed trees around one person's septic field or that it changes the pH in the tank enough to have eaten through the concrete on someone else's septic tank. I called the environmental health office and they forwarded me an email from the Chief Plumbing and Fuel Gas Code Consultant of the NCDOI/OSFM Engineering Division where he said:

"Septic tanks are regulated by the environmental health onsite wastewater section of the NC department of public health. It is my opinion that chemical discharge from a water softener or water treatment system is not good for a septic tank but I will defer to those responsible for the septic system. Please contact your local sanitarian at the public health department or call Steven Berkowitz with EHHS at (919) 707-5876 for more information on what regulations may be in place for what can discharge into a septic tank."

As far as studies that support adding regenerant to septic systems, this study seems pretty well done. It basically says that if the softener is operated efficiently (>2000 gr/lb) with a DIR system it can actually improve septic tank effluent quality. But an inefficient system (<1000 gr/lb) will harm septic performance.

As usual with complex topics, the answer seems to be "it depends". It is probably safe to discharge the regenerant into the septic system (in terms of effluent quality) if I run my softener efficiently and it operates correctly (and this is probably why dittohead never saw any problems). The anecdotal evidence from the septic people could very well be from people that had a very inefficient system or by coincidence had a system failure while also having a water softener, but I havn't seen literature or a good source addressing those potential issues.
Edit: I just found this document that has some recommendations for discharge, so I'll look into a drywell for discharge too.

I'll probably call the Berkowitz guy and see what he has to say. I am wondering if my insurance company would have an opinion as well, would a septic system failure be covered by homeowner's insurance (just googled that, doesn't seem likely)?

I think that I have read people who said that the potassium salt is not harmful to vegetation when discharged to runoff. Is that true? How much more expensive is the potassium than the sodium? Edit: found this article that promotes use of K+

 

[Reach4]

Expect KCl to cost ~5 X per pound and I am guessing ~7 X after compensating for the additional pounds used. Plus potassium salt's saturation differs a lot with temperature, so you would be needing to compensate and at least using a brine-first softener.

Search for "Changes in Septic Tank Effluent Due to Water Softener Use." You probably have seen the report. A search will not only find the report of the study, but also you will find critiques of the report. I suspect that a fairly high percentage of softeners discharge into a septic. Do you see many reports of resulting problems? I think the base of tankless water heaters is much lower. Yet you see problem reports. But if you do not want expended brine to go into your septic, consider a dry well for just the brine.

Note that when you use 6 pounds of salt per cubic ft of resin, you will be discharging less salt than at at higher dosing levels.

 

[Gary Slusser]

MaplesonD, millions of softeners discharge into onsite septic systems for 3-5 decades with no problems. The discharge belongs in your septic tank. Dry wells contaminate the soil under the surface of your yard; and in most places contaminating soil is illegal but... you may end up contaminating your well..., if the dry well is in the recovery area of the well. And as you see, no one saying to not put the discharge into your septic can/will tell you (or even discuss) what they think is the basis for that "advice". BTW, sizing based on my sizing page gets you 3333 grain/lb salt efficiency.

 

[Bannerman]

It seems to me that your primary concern should be the safety of your water supply. You obtained a positive lab result for E. coli and coliform bacteria over a month ago but it appears nothing has since been done to correct the issue for the safety of your wife and child. Regardless of any claims made by the water suplier, an independent lab identified a health & safety issue that needs to be immediately addressed.

With regard to your septic system, it appears that much of the advice obtained elsewhere, amounts to personal opinions which is not necessarily based on proven scientific fact. It seems that the most scientific report you referenced, suggested that septic system performance is actually improved when a low amount of brine is included, specifically the amount discharged by a water softener when operated efficiently.

The advice provided on this forum, is often offered by industry professionals with many years of knowledge and experience. It appears that through their experience, they have not observed adverse effects in discharging sodium brine into a septic system.

 

[ditttohead]

Nicely put. The obvious disclaimer is that for the vast majority of septic systems, a properly designed and operated water softener is usually just fine. An improperly designed/operated softener or septic system could obviously cause problems.