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Water To Waste Section Four: Common sense information about how your wastewater system works
Where does it go when you do?
On average each of us ‘goes’ 6 times a day.
That translates into 12 - 36 gallons per day per person depending on whether you have a water efficient toilet in your home or business. Multiply that by a school (400), or a small town of 1000 ......... ?
Also, on average, we use about 20,805 sheets per year, according to data provided by Kimberly-Clark. At an average 4.5 inches per sheet, that's 1.5 miles of toilet paper per person.[USA Today]
On Pages 6 and 7 we will be taking a look at all the other ‘non-human’ products and substances that find their way down to the sewer or septic tank. What happens once the little bits and pieces of humanity arrive there is basic biology and chemistry with a bit of the basic laws of physics thrown in for good measure.
Basic plumbing! Bless your ‘U’ bend!
Have you ever wondered why the ‘U’ bend is there under the sink and under the toilet bowl?
Basic chemistry: think of the wastewater system as a lot like your internal bodily functions. You put things in at the top, they work their way down via gravity and pressure, they get chewed on and digested at the mid point, and then miraculously reappear the other end. When you get gas, and make those noises we are all too polite to talk about, this is pretty much what’s happening out in the septic system or sewer. What generally keeps all those internal gasses contained is a system of loops and bends in your internal plumbing. What keeps the same gasses contained in your household plumbing is the wonderfully simple ‘U’ bend.
Be very grateful to those 18th and 19th century plumbing inventors (this Sy-Clo illustration is c.1906) for, without the humble ‘U’ bend, all those noxious sewer gasses would be as offensive to you as they were back in the reign of Queen Elizabeth I when a ‘privvy’ created just for her proved too odorous for her majesty’s use!
After you flush, the ‘U’ bend keeps a barrier of water between you and what is down in the septic/sewer.
Gasses generated include methane,
hydrogen sulphide, carbon monoxide
all of which can be life threatening and explosive!
These gasses are released safely to the air via a roof vent.
If you start to smell that unpleasant odor, check to see if the roof vent is plugged. The culprit can include spider webs, bird nests, ice build up. Please, be careful!
This is just one of the many good reasons to always have a reputable, professional service provider do routine maintenance on your system.
Out Of Sight = Out Of Mind?
The humble, but oh so essential, basic septic tank comes in many shapes and sizes, made of concrete, fiberglass, plastic - the basic rule of thumb when setting the size is how many bedrooms, or how much expected commercial or domestic fluids will the system have to deal with at peak flow.
In northern Michigan, many commercial properties, as well as homes, are served by septic, or ‘onsite’ systems.
When properly designed, properly installed, properly used and maintained they provide as good, if not better, environmentally sound water recycling service as a municipal system.
(Photo credit: www.onsiteinstaller.com/editorial/863/2008/05)
THE POWER OF POO
Somewhere out in your back yard, buried and often forgotten, lies one of the least understood, under appreciated, essential conveniences of modern life!
The septic tank is the ‘stomach’ of your personal wastewater treatment plant. Its only function is to collect everything you throw at it, put it into a holding and settling stage, allow time and gravity to separate out the heavier solid ‘stuff’ and then send the liquid ‘stuff’ on to the treatment/drain field where the real work takes place.
The tank is where a set of good bugs, who can only work in a place with no oxygen, start to break down the organic waste. This generates heat and gasses and is why there is money to be made by harnessing ‘poo power’ at municipal plants!
As wastewater flows into the tank from the home, it first meets an inlet baffle - the purpose being to slow the force and prevent those settled solids from being stirred up. Fats and scum float up to the surface.
When the fluid level reaches the outlet pipe - it’s off to the drainfield!
The drainfield is where filter material acts in pretty much the same way as a coffee filter. Gravel, stone, sand, crushed glass or even chipped tires, can be used. All will have air spaces in between which feed the good bugs, slow down the rate of flow and allow a biological process to further attack harmful bacteria. In any given tablespoon of ordinary soil, millions of beneficial organisms are hard at work performing a minor miracle of nature.
The difference between what’s happening in the tank and the treatment area is oxygen - one has it and one doesn’t.
Oxygen is the fuel which allows good bacteria to cannibalize the bad. When the chemistry and biology are working, gravity filters wastewater back to rejoin the water cycle.
Although the ‘ick’ factor repels us, human digestion by-products are one of the oldest forms of fertilizer.
Our waste contains all those ingredients found in commercial fertilizers - phosphorus, nitrates and nitrogen.
When the filter medium is working properly, those bacteria processes form what’s known as a ‘biomat’, a film of hard working dead and dying bacteria which regulate how fast liquid flows through to the soils below and maintains a balance to keep too many of those fertilizing nutrients out of the water cycle.
At least in a perfect world that’s how it’s supposed to work.
However perfectly a system is designed and installed, if YOU,the property owner, don’t pay proper attention to what goes down the drain, or don’t have regular maintenance done,
it’s like pouring money down the
Also see Water To Waste Section Six and Seven: The many amazing things that end up in the waste stream and why we should be careful and concerned.
For good basic operation and maintenance information see: http://septic.umn.edu/homeowner/index.html
Water To Waste Section Two: Water / Energy Efficiency information and EPA WaterSense Program
Water To Waste Section Three: The inter-relationship between water use, wastewater, the water cycle and wastewater systems.
Water To Waste Section Five: Installation, siting, operation and maintenance.
Water To Waste Section Six and Seven: The many amazing things that end up in the waste stream and why we should be careful and concerned.
Water To Waste Section Eight and Nine: The state of our region - an attempt to survey wastewater systems.
Water To Waste Section Ten: The Case For Community Management
Water To Waste Section Eleven: Small community options, choices and solutions
Water To Waste Section Twelve: Understanding northwest Michigan geography and geology and how this relates to wastewater.
Water To Waste Section Thirteen: Information about different types of wastewater systems and case studies.
Water To Waste Section Fourteen: A terrible waste to waste - when there's money to be made and saved by innovation.
Water To Waste Section Fifteen: A word about who we are and our goals for the future - how you can help.
Water To Waste Section Sixteen: Gratitude to our sponsors and links to more information.
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