Save The Grey: Should You Choose A Greywater Diversion Or Treatment System For Your Business?
With environmental concerns becoming a hotter topic seemingly every day, more and more businesses are looking to reduce their environmental impact in any way they can. One of the best and most achievable ways to do this is by recycling greywater, the relatively clean water that drains from sinks, showers, dishwashers and other sources uncontaminated by sewage or fecal matter.
However, greywater can be recycled in one of two ways; greywater diversion, which directs untreated greywater directly towards useful functions, or greywater treatment, which uses an array of chemical processes to clean greywater before it is reused. Each of these options comes with its own costs, advantages and disadvantages, so you should thoroughly assess the needs of your business (not to mention your budget) before you decide on a greywater recycling system.
Greywater diversion systems
Greywater diversion systems are relatively simple and widely used and can be used to collect greywater from various sources as well as rainwater collection tanks. These systems do not attempt to clean or decontaminate greywater in any way before it is used, and are generally use to provide water for functions where potable water is not required, such as flushing toilets.
Because these systems are not required to clean greywater (although most systems contain fine filters for removing particulate matter), they are generally much less complex and, crucially, much less expensive. In many cases, a simple pump and a surge tank for temporarily storing excess greywater are the most complicated components of a diversion system, so they are also much simpler and easier to maintain. Despite this simplicity, however, greywater diversion systems can be highly efficient, and can lower your business's water bills significantly if used extensively.
However, because diverted greywater is untreated and may be laced with bacteria and chemical contaminants, there are strict limits placed on how it can be used. For instance, while untreated greywater can be used to irrigate a flower planter or decorative lawn, they cannot be used to provide water to sprinkler systems or indoor potted plants due to the risks posed to passersby, and they can only be used in subterranean systems. For similar reasons, untreated greywater can only be stored or a very limited time before it must be flushed away, to prevent holding tanks becoming breeding grounds for water-borne diseases. As such, greywater diversion systems are forced to direct much of what they collect directly to the sewers during times of low water usage, and larger businesses with greater water consumption may only see a very slight decrease in the amount of mains water they use.
Greywater treatment systems
As the name would suggest, a greywater treatment system uses chemical treatments and filters to partially cleanse collected greywater. While the water expelled from a greywater treatment system is not fully clean and is by no means drinkable, the treatment process removes dangerous pathogens and contaminants, before releasing the water for a variety of uses.
This treatment process makes greywater from a treatment system much more versatile than that which comes from a diversion system, and it can be safety used for a wider variety of tasks, including those which involve human contact with the greywater such as window cleaning and providing water for sprinkler systems. Treating the greywater also allows it to be stored indefinitely, as the removal of organic contaminants during the treatment process prevents the water from stagnating.
However, the addition of what essentially amounts to a small-scale treatment plant to your greywater system naturally increases costs, and treatment systems cost significantly more to purchase, design and install than simple diversion systems. Choosing a treatment system also gives you more maintenance headaches -- maintaining a supply of treatment chemicals for replenishing the system is essential, as is periodic cleaning to remove the sludgy byproducts of the cleaning process. As such, greywater treatment systems tend to have a much higher upkeep cost than diversion systems, which may not be defrayed by water bill savings if your business uses low-to-moderate amounts of water.