Leonard J. Brown Plumbing Inc.
888.489.5840

Question: With all the talk of water conservation, why do we flush our toilets with water pure enough to drink?

Reply: Good point! It so happens that there is a lot of effort being made by people in the plumbing industry toward water reuse. There are two different techniques involved.

One is reclaiming treated water. The City of Los Angeles, which has undergone severe drought conditions in recent years, has one of the most ambitious water reclamation plans around. Water from toilets, sinks and showers get treated at an existing water treatment plant and reused for flushing and landscaping in public facilities. The program started with a couple of city golf courses and is expanding to public parks and municipal buildings. A long-range plan envisions the city recycling up to 40% of its wastewater by 2010. That would save tens of millions of gallons of water each day in a metropolitan area that often goes months without rain.

On a smaller scale there are a few hundred large commercial buildings and developments around the country that treat wastewater on-site and recycle it as flushwater for toilets and urinals, sometimes landscape irrigation as well. The equipment for doing this has been around since the 1970s.

The second technique involves simply recycling partially treated or untreated "graywater" for non-potable purposes. Graywater refers to the discharge from washing machines, showers and baths, sinks and dishwashers, but not the so-called "blackwater" from toilets, which is best flushed away down the sewer.

Many people in drought-stricken parts of the country have been reusing graywater on an informal basis. In some areas where sprinkling has been banned, public authorities have encouraged people to collect dirty bath and dishwater for flushing toilets and watering plants.

It has been estimated that an average of around 30 gallons of water per day, per person, can be categorized as graywater and potentially recycled. Capturing that would go a long way toward resolving water shortages where they crop up. However, this would require either on-site treatment or separate graywater piping systems. Studies are now underway to determine the cost and technical feasibility of implementing such systems on a widespread basis.

Early indications are that there is great potential for cost-effective water recycling throughout the country, mainly for commercial and industrial applications. The expense seems prohibitive for most single-family residences, however.

Even more than cost, the overriding concern is health. Studies have shown that graywater can harbor dangerous levels of microorganisms, as well as detergent chemicals and other contaminants. Certain plants can be harmed by graywater, which restricts irrigation and landscape usage.

Normal piping systems - one for water supply, the other waste and drainage - would have to be changed to accommodate separate graywater lines. Even with two sets of pipes, bad plumbing occasionally results in cross connections or the backflow of dirty water into the potable supply. Plumbing codes exist to prevent such occurrences. They would have to be revised to cover a third system of pipes and valves for graywater.

In fact, graywater reuse is technically illegal in many parts of the country. Code authorities will have to be persuaded of the safety and feasibility of water recycling before they permit complicated installations to take place.

Despite these obstacles, we definitely appear to be headed towards an era of widespread water reclamation. I'm confident we'll find a way to solve the problems. Why?

It all goes back to your original question. The fact of the matter is that with all the pressures on our water supplies from population growth and building development, it simply doesn't make sense to flush so much pure water down the toilet.