Saturday, April 2, 2011

Cleansers in a Soil-based System

I've recently been discussing greywater reclamation with a few folks, and the topic of cleansers came up. There are a fantastic array of "natural", "green", "biodegradable", and "eco-friendly" cleansers on the market today... and almost every one of them are NOT appropriate for use in a greywater reclamation system where you use the water to irrigate food crops.

Why not? They're better than all those old harsh chemicals, right? Hey, look, they're EPA-approved!

Well, yes... and no. Most of the environmental concerns that are addressed by these cleaners are for AQUEOUS environments, not TERRESTRIAL environments. For the vocabularily-challenged, they're designed to be (or become) safe in water, not soil. Since the vast majority of our new-world sanitation is done through a combined grey/black water sewage treatment plant (everything gets flushed down the drain), and the liquid effluents from those plants are eventually returned to fresh waterways and the ocean (or back into our city water supply!), it is very important that any residues from cleansers be safe for introduction to waterways and other aquatic life (your dish soap can't be killing the fishes!) and/or breakdown rather rapidly in the presence of water or air.

To this end, phosphates were reduced because these cause horrible algae blooms; nitrates were reduced because these can also cause horrible algae blooms (as well as blue baby syndrome -- although that's normally associated with run-off from synthetically & over-fertilized fields, and some cancers); chlorine and sodium ingredients harmlessly decompose in water, and borates and other elements either don't react or are so diluted they aren't harmful. The alkalinity of most cleansers and their chemical elements aren't a major issue because seawater (the eventual end destination of most effluent waters) is alkaline and all the critters that live in it can handle the alkalinity, and there's plenty of fresh water in most rivers and lakes to dilute the alkalinity in those.

However, when you're putting water that contains cleansers directly on/in the soil it's a whole different story. Soil and it's ability to provide nutrients to healthy growing plants has an almost opposite set of rules. Chlorine is a powerful disinfectant... it also "disinfects" the good bacteria that help breakdown plant nutrients in the soil. Sodium, and all the other salts but sodium in particular, is extremely alkaline and can rapidly alter the pH of the soil either killing the plants or locking up the nutrients that the plants need to grow. Boron is a great water conditioner, pesticide and fungicide... unfortunately, these properties are extremely harmful to a happy, healthy garden. Phosphates and nitrates are generally just hunky-dory in soil (within reason of course!) since they are both plant food... which is what makes them so bad in aquatic environments. And buildup of elements is much more of a concern in soil since there certainly isn't enough water in it to dilute it, and some elements take a very long time to decompose in the absence of water and/or air (like salt). Most plants prefer neutral or slightly acidic soils, the nutrients they need are most active/available at neutral or slightly acidic pH, so high alkaline cleansers made for alkaline seawater are completely inappropriate unless you have seriously acidic soil that you're trying to neutralize.

And you never, ever, ever, want to use anything that is marketed as "antibacterial", "antimicrobial" or "disinfecting"... you're going to kill your good soil bacteria, not just that "bad" bacteria that might make you sick. I say "might" because routine exposure to low levels of "bad" bacteria is normally not harmful at all and can actually result in a stronger immune system. Hmm... maybe all these "sanitizers" are actually making us sicker?

Also try to avoid using anything that has enzymes or is labeled "biodegradable" unless you know exactly what they are, what they break down, and what they break down into... or you can totally mess up your soil's microorganisms, nutrient ability/composition, and the soil structure itself. They're not all bad, just be careful! Biodegradable and compostable aren't the same thing... most biodegradable products are designed to biodegrade anaerobically, in landfills or septic tanks, not aerobically in your compost bin or garden mulch.

OK - So what am I supposed to clean with then?

Surprisingly, a great many cleaning tasks can be accomplished with plain old soap (lye & fat) and water. For a little extra kick you can add a mild acid (lemon juice or vinegar) if you aren't cleaning marble/stone, rubbing alcohol, hydrogen peroxide, household ammonia (ammonium nitrate -- use with proper ventilation!), or a small amount of baking soda (sodium bicarbonate -- use sparingly, it is still a salt).

If you must disinfect something (like food processing tools), boil them. If you can't boil them, use steam... either an autoclave if you can afford it or a handheld unit. If steam won't work for you, citrus and many herbs and essential oils have natural antimicrobial properties (rosemary, peppermint, tea tree, etc). And sparingly, as a last resort, hydrogen peroxide or ammonia or alcohol.  Instead of using chlorine to disinfect/treat your water supply, swimming pool or hot tub... use concentrated hydrogen peroxide instead, your plants will thank you.

The best bleach in the world is sunlight. Hang your whites in the sun the dry and I guarantee those stains will disappear without any chemical assistance. You'll have sparkling white socks and panties without bluing or other optical brighteners. But if you absolutely must use bleach, try pretreating with lemon juice first, and then use hydrogen peroxide instead of chlorine bleach. Which brings up "Oxygen Bleach"... yes, these don't have chlorine BUT they are chock-full of sodium. Use real hydrogen peroxide instead, your plants will thank you.

Washing your laundry rarely requires detergent. Yes, you read that right... simply soaking your clothes overnight is enough to remove most dirt and debris from your clothes because water is the universal solvent and also lifts particles from clothing fibers all on it's own. However, if you want to make this work a little better, or you have some pretty tough stains, try using something slightly alkaline (like plain soap or ammonia) because most stains on clothing are acidic (perspiration, oil/fat, blood, etc). Rubbing a little plain soap (or Fels-Naptha soap) on a stain before washing will do the trick most times, no need to add soap to the water. Adding just a half-cup of ammonia does a wonderful job cutting any body oils and deodorizing through neutralization not fragrance... and no your laundry won't stink of ammonia, the smell dissipates as soon as it's dry. The only caution is to be careful using ammonia if you pre-treat spots with Fels-Naptha because this contains a small amount of chlorine and we all know to never mix chlorine and ammonia!

There are a gajillion tips for treating stains of different origins all over the internet, I won't repeat them here ;)  But remember that soap and ammonia are slightly alkaline, so do add a little vinegar or lemon juice to your laundry rinse water... it helps your clothes feel softer (gets out the last of the soap residue), reduces static cling, removes any soap scum from your laundry tubs, and helps neutralize your greywater.

A little bit of plain liquid soap in the wash water and white vinegar in the rinse water gives you squeaky clean dishes. A little vinegar, water and alcohol give you sparkling windows and counters (but not if they're stone!). A little vinegar in the mop water and your hard surface floors will shine (unless they're stone!), or a little ammonia if they're really greasy grimy.

Vitreous china, glazed ceramics, or enameled surfaces in the bathroom can be cleaned with lemon juice, vinegar, or ammonia since all three will cut through soap scum and hard water deposits. If you must scrub, make a paste with a small amount of baking soda and water, wipe up the majority of it and throw it away instead of rinsing it down the drain. If you have mildew stains, try applying straight lemon juice first, then hydrogen peroxide, and if that still doesn't work apply a paste of borax and water, apply it directly to the affected area, scrub a little and let it sit for a little while -- wipe it off and through it away rather than rinsing down the drain.

Rubbing alcohol in any formulation helps cut through oils, especially petroleum oils which are harder than biological oils to cut through, and just evaporates away into nothing so it rarely leaves any sort of residual gunk in your greywater... but I wouldn't go pouring straight rubbing alcohol on your garden because it has a high desiccant factor (it dries things out), which is also why it's not so great for cleaning wood surfaces.

Hydrogen peroxide is slightly acidic, not so much that it makes a difference unless it's super-concentrated though. Hydrogen-peroxide straight out of the bottle is a potent disinfectant, but the effect doesn't last very long. However, hydrogen peroxide rapidly decomposes into plain water and oxygen... so, by the time you drain the hot tub, or dump the laundry basin, you don't have to worry about what it's going to do to the garden (not that it would really hurt it anyway!).

Now, having said all that, if you need to or want to use chlorine bleach, borax, biological washing soda, or any other of the "no-no" cleansers as long as you capture that water separately and dispose of it somewhere that you don't want any plants to grow... like your paths and driveways.

Of course, periodically flushing your greywater system and irrigating your garden with rainwater or snow melt (which as close to pH neutral as we can naturally get) will help keep salts and other elements from building up in your garden soils and causing problems.

A Little Note on SOAP:

When I say soap, I mean soap... lye and fat. Any other cleaning product (with the exception of a saponin product like Laundry Nuts) that is not made of lye and fat is a detergent. Soap is basically just the fatty salts that are left over when the lye finishes reacting... the result of the process of saponification.

Real soap is mildly alkaline after it is properly aged... soap doesn't have to be pH neutral or pH-balanced to our skin (which means mildly acidic). In fact, in order to clean us properly, since our perspiration and body oils are mildly acidic, soap actually needs to be mildly alkaline. In a properly made and aged soap, there is no caustic lye left in the bar.

Lye in soapmaking is either sodium hydroxide (NaOH - red devil) or potassium hydroxide (KOH - potash), although sodium hydroxide is most commonly used and it's hard to find potassium hydroxide commercially (although you can make your own by leaching hardwood ashes). The biggest difference is that NaOH makes a hard bar, whereas KOH normally results in a soft gloopy "cream" texture (the original liquid soap). The type and amount of fat used in the recipe also affects the consistency, texture and lathering of the soap -- hard fat like beef tallow makes a harder bar (or very thick gloop) that barely lathers, and soft fats like olive oil makes a smooth liquid soap. Most NaOH soaps that use only oils are liquid soaps, and most soaps that use tallow or lard are bar soaps... although there are exceptions, I'm not going to get into soapmaking here either ;)  Keep in mind that all soaps lather poorly in hard water, but a soap doesn't have to lather to clean well (it's a psychological thing I think, needing to foam away the dirt!).

A Final Ecological Note:

If you aren't trying to reclaim your greywater for irrigation, and are just trying to disperse it so it can be soil treated, as long as your dispersal area is large enough, you probably don't have to worry as much about "salting the earth". But, if there is any possibility that you will produce so much greywater that it will cause excess runoff, or be washed by runoff before soil treatment is completed, and thereby contaminating nearby waterways... be mindful of the fishies! In that case, you may want to consider constructing an artificial wetland with appropriate aquatic plants and beasties to treat your greywater instead of just pouring it out or spraying it on the ground.


Urbancowgrrl said...

Very interesting! Do you think these cleaning tips would be beneficial to those of us still living on a sewer system as far as "going green" is concerned or do you think that would just be overkill and not worth the effort? (ie: just stick to EPA approved stuff?)

Also, what about glycerine soap - is that still considered a detergent and therefor not good for greywater disposal? I assume so since I'm guessing (no chemistry education here) that glycerine is not a compound of lye.

I was under the impression that antibacterial soap is bad stuff on all levels no matter how you dispose of your water because it kills all bacteria - not just harmful ones. Plus, it only kills bacteria on one's skin so antibacterial dish soap for example only works as an antibacterial on you skin - not the dishes. I've heard of people now putting bleach in their dishwashers out of fear of bacteria. Yikes. I think middle American needs a quick lesson on not fearing bacteria so badly and trusting things like plain ole soap and water.

Plickety Cat said...

Most of these cleaning tips probably wouldn't hurt a water-based system like conventional septic or sewer... but that system is much more forgiving of the new "green" cleaners so you don't actually have to go too much out of your way unless you have chemical sensitivities.

Glycerin is a byproduct of regular soap making with lye (for every 3 soap salts created, one glycerin unit is created), so glycerin soaps are pretty much the same as regular soap but with all the opaque salts removed. They're fine for greywater.

Antibacterial hand soaps aren't effective unless the soap remains on your hands longer than 20 seconds. For the most part, they just go into the environment killing innocent good germs and mutating resistant strains of bad germs. Antibacterial dish soap actually does kill the bacteria on your hands and your dishes... of course, if there are germs in your rinse water, dish drain, dish towel, kitchen counter, cupboards... well, you get the point... it's all for naught.

becky3086 said...

Humm, this was all great information. I was going to use my laundry water to water a small bed in the yard this year. Now I am wondering if I should I have held off because I am not sure which soap to use and I have tried regular soap in the wash and it did NOT clean.

Plickety Cat said...

You may want to try soaking your clothes overnight and try regular soap flakes again (just grate a bar). Or you could try the ammonia method, just 1/2 cup in the wash cycle. In any case vinegar in the rinse cycle is a great fabric softener and helps neutralize your wash water.

Or you could try Soap Nuts, they're the dried fruit of the Soap Tree. They contain natural saponin (the stuff we create with fat & lye during saponification). You can also brew a tea with soap nuts to make a liquid cleaner, which I hear works great for dishes and as shampoo. They don't suds much, but suds don't equal cleaning power.

Soap Nuts now are available a lot of places, I prefer Maggie's, and Amazon sells a 5-load sample pouch if you want to check them out

Urbancowgrrl said...

@becky - what kind of soap did you try in your wash? We are on a sewer system so not so much in need of using products other than our Planet or 7th Generation brand soap - but they don't always clean that well either (just as good as any other commercial laundry detergent ... which is not always that great). I'm tempted to try the amonia and/or vinegar treatment because I don't like using bleach on so many washes. Also, I rarely use hot water for my wash and switched to that today in lieu of using bleach and I noticed a positive difference. This discussion has been good for me to hopefully get off my woefully bleach-filled laundry ways.