Recycling water is very common these days. At all levels, businesses, organizations, and residences are trying to reuse water. New activities require new terminology. However, these evolving “water words” can get confusing. The Gentlemen Plumbers, like any responsible professionals, believe that an important part of a good business relationship is an educated customer. So, here's a short guide to the most common terms, adapted from a very recent article in “PM Magazine” (Plumbing & Mechanical).
Drinkable or not?
potable water – This is a more formal name for “drinking water”.
non-potable water – Water that is not fit for drinking.
recycled/reclaimed water – Any non-potable water which has been treated for reuse as greywater.
What color is it?
greywater – This water originates from the bathroom (sinks, tubs, showers) but not the toilet. It may also come from washing machines. Since graywater is not contaminated by as many pathogens and as much nitrogen as other forms of water, it does not need as much treatment before reuse. In fact, if the water contains only ecological cleaning products, it can be reused “as is”. For example, water from the washing machine can be collected in a container and used for watering the garden. If an on-site water treatment system is present, greywater can be reused for the toilet – a saving of lots of potable water.
blackwater – According to definition, this is water from toilets, kitchen sinks, and dishwashers. Such water usually requires a significant amount of treatment before being able to be resused. As it is not practical for individuals or businesses to do so, blackwater is mostly sent to municipal treatments plants.
Having said that, water from kitchen sinks and dishwashers could be considered greywater. When only “green” soap products are used, this water could be reused for the garden or as the first stage in washing the car – the final rinse being clean or drinking-quality water. With regard to kitchen sinks, it is possible to have a dual-drainage system. That is, the sink drainage pipe can have two routing possibiliies - the main sewage system or a smaller “greywater” container. The water user preselects the water channel via a valve or other option depending on what is being washed. For example, rinsing vegetables and fruits after purchase but before using can most certainly be considered greywater.
All these “colored” waters deserve special piping, no? Of course, they do, and the plumbing industry has risen to the occasion. According to the P&M article, “Purple piping is the industry standard color designating that the water flowing through the pipe is recycled”. (P&M 2)
If your home does not reuse any water at the moment, why not seek advice from the experts, The Gentlemen Plumbers.