Water and Wastewater Management in the Home
In the Western world, governments require water providers to test the quality of water they supply several times a day so that all water going to its customers is of drinking quality. We customers then use this high-quality water to wash dishes, clothes, floors, and flush the toilet. We use it to water gardens and lawns and wash down driveways and sidewalks. In a land where water is abundant, that might be okay, but what about in a land where water is scarce?
Water Demand and Waste
Most of the water production in and around cities goes to private residences, who very often waste it. In areas where water is scarce, like Australia and the American Southwest, and it comes from utility companies rather than wells, as water companies have become overloaded with demand. They are running out of water to supply at the same time that populations are growing.
Building new supply sources costs billions of dollars that most governments don't have now. Rather than doing more building, it makes better sense to decrease the demand of users by encouraging them to use water more efficiently.
Save Water by Recycling
Residential customers can help by installing new technologies manufacturers have been developing. In addition to changing behaviors (bathing less often and for shorter periods, washing only full loads of dishes and clothes, etc.) homeowners can install these new "waste water" systems to reuse water that's still mostly clean, thereby reducing their own demand.
Wastewater (Recycling) Systems
Some of the terms below describe new technologies; others are nature's cleansing techniques that can be adapted for use in the home.
Greywater refers to tap water that has been used for cleaning or food preparation. This amounts to 50–80% of water used in the home. Plumbing is altered to send water from sinks, tubs, and the washing machine, through a filter of some sort, to a storage container or pump for a second, specified use.
This term refers to the use of toilet water or sewer water for a second (or third) use, after filtration and a minimal degree of purification, usually for plants outside.
In nature, water filtration occurs when gravity pulls water down through sand or silt into the water table. The sand or silt captures and holds any solids (which plants can use), while the water takes out any loose salts, chemicals, or minerals (many of which our bodies need). They clean each other. Natural filtration is often included as part of a greywater or blackwater system.
Conversion by Plants
This is also a natural occurrence in the wild, where what we call sewage is actually food to plants. In China and other agricultural cultures, human wastes were used on a regular basis to "fertilize" their crops. We in the western world regularly use chicken and fish feces as fertilizer (plants love it). If we in the West were healthier people, we could use human wastes this way too. This natural phenomenon is the basis for blackwater conversion systems.
As of 2009, there were more than 8,000,000 greywater systems set up in the United States. Of those, 1.7 million were in California, only 200 of which required permits. Nearly 100% of houses in the country older than 70 years are set up with greywater systems, according to California Greywater Policy Data.
The complexity of the greywater system you choose for your home will depend on your current plumbing setup. Installing one that is too complicated can waste your money, yet you'll want to get the best benefit possible and only about 15% of users currently do. Here are descriptions of several different types of systems available.
Different Water-Recycling Systems
One system lightly treats and moves used water from the shower/bath and bathroom sink to a storage tank to use for flushing the toilet. This system depends on the availability of space in a basement, under the bathroom sink, or next to the toilet for additional piping and water storage.
Another type of system reroutes used water from the washing machine to water the landscape outside. Excess water can be set up to replenish a small water feature or even a series of shallow birdbaths. The system is fairly easy to install and is common in drought-prone areas of the world.
A whole-house system collects water from all sink drains (except maybe the kitchen) and the washing machine, treats it as needed and sends it outside to use for landscaping. Kitchen water is sometimes not used, because food grease and garbage in used kitchen water can too easily clog pipes.
Some DIY systems install a plastic tank to store greywater until needed, but this is illegal in most localities. In those areas where it is legal, this water is required to be used within 24 hours to avoid buildup of harmful bacteria.
The Earthship whole-house system sends all sink/shower drain and washing machine water to indoor planters with special setups that filter, as they water decorative and edible plants. Excess water from the planters is captured to use for flushing toilets. Toilet drainage must have been built separately from sink drainage for this system to work. This is the most complete and practical system of all.
Note: Diaper water is considered blackwater and is most properly disposed of in the toilet.
Treatment of Effluent (Blackwater)
Efficient blackwater recycling systems focus on nurturing a healthy set of bacteria to process the waste—in other words, to make it non-toxic and healthy for garden plants. The piping is the same for all systems, in that sludge is piped from the house toilet(s) to a processing tank outside. The difference between systems is how the sludge is treated. There is no odor with a healthy system and the landscape thrives with the extra nutrition.
One system introduces bacteria in a two-step process, using water and air injection to encourage bacterial growth. The last step injects a small amount of chlorine to decontaminate, thereby meeting the requirements of most local health codes. The amount of chlorine is small enough that it doesn't hurt the landscape when watered.
A different system positions the tank on the south side of a house in a sunny location, using the heat of the sun to enhance aerobic digestion of the sludge and UV rays to disinfect.
Some use a tamped-down version of the same chemical process used by waste reclamation plants. They first screen out solids, compacting them to send to the landfill, while passing the liquid on. They use oxidation to start bacterial processing of the liquid, pass it through a finer filtration screen, then use an Ultra-Violet treatment for disinfection. Finally, they chlorinate it. This system, of course, costs more than any of the others. It's also unnecessarily complicated for most homes.
Note: Most systems have no smell. If there is a smell, check what you are putting into the waste stream. If you are flushing disinfectant, medications, or something that will harm bacterial growth, the result of their struggle to stay alive is likely causing the smell.
With the installation of systems such as these, the definition of wastewater changes. Water in all of its stages of cleanliness becomes valuable, as long as it can be used in some way. "Waste" water then becomes only that which, in the end, has no more use in the home that anyone can think of. That reduces the amount of wastewater to almost nothing, especially for those who live in the country, where regulations are looser. If there is any water left over after these reuse procedures, it can be disposed of using the regular house sewage system.
Water Reuse Cautions
As with any new technology, there are certain behaviors that need to be learned or changed. Here are a few things to watch out for:
Don't throw anything toxic down the sinks or toilet. Better yet, don't even have toxic materials in the house.
Check on and follow local codes related to installation of greywater and blackwater systems. If codes are not favorable to use of such systems, work with city or county officials to get them changed.
Instead of throwing unused medications down the toilet or sinks, return them to the pharmacy you got them from.
Keep pets away from toilets. This is not drinking water anymore.
Use biodegradable soaps, instead of the normal ones.
Eat healthy to create healthy human fertilizer for your plants.
Recycled Water and Health Regulations
In spite of the huge number of households with greywater systems already installed in the United States, there are as many who would like to install, but can't, due to restrictive health, sanitation, or plumbing codes. If you have already located an installer, that person will probably know what the restrictions are. They may already have found a way around them. However, if you want to install a system yourself, here is a way to check on whether your local codes allow or restrict the installation:
What regulations are on the books? Go to your city's website. Locate the phone number of the city clerk and call. Tell them your plans. Ask for a copy of whichever regulations stand in the way. If they are not the right person to talk to, ask who is, although they'll most likely give you the contact info right away.
Look through whatever the city sends you to see where the sticking points are. Call a local installer to see what problems they may have run into. This will arm you with ideas to meet the code, or ways to protest the code and perhaps help rewrite it.
If changing the code is in order and you are up to it, post somewhere in a public place that you are looking for other people interested in installing grey or blackwater systems. Get together with them to discuss potential procedures. It always helps when making waves to have support.
Find a lawyer or someone with legal skills to help you write new legislation. Add a builder or plumber to your group too. Take questions to a public city council meeting to test their receptiveness to this kind of change in code. It may be that one of the councillors would be interested in working with you to frame new legislation and/or get it passed.
Follow through until it works, staying pleasant but persistent. Homeowners, local utilities, and the city will more than likely all appreciate you for it. And you will end up with a more water efficient home.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2012 Susette Horspool