Updated: Dec 1, 2021
Diminishing water supplies is a world-wide problem. In the United States, with population increase and an increasing decline in water supply, the best current solution is a reduction in water use. To address this problem, many states and communities are imposing water use restrictions. Restrictions to landscape watering is the most common. A great solution to reducing water use in landscaping is greywater irrigation! Using water twice makes sense!
WHAT IS GREYWATER?
Greywater is all wash-water waste generated by a home or business. This is water from the washing machine, the sinks, bathtubs and showers and can be reused! Blackwater, on the other hand, is toilet waste and waste from garbage disposals and dishwashers and contains high levels of nitrogen and pathogens and cannot be used in irrigation.
GREYWATER CAN BE USED FOR IRRIGATION:
Yes, greywater can be used for irrigation; but the codes and regulations on this process varies from state to state. Californians, for instance, have used greywater irrigation systems illegally for many years. Due to these practices, the California Greywater Code was re-written with significant changes. This code designates three types of greywater systems:
Clothes Washer System: This is probably the most commonly used as it is the easiest to implement, but there are restrictions on its use. It can use only a single washing machine in a family dwelling, and must be a domestic, not a commercial machine. This system may only use gravity or the pump from the washing machine itself to irrigate the desired areas in the yard or garden. The washing machine system may use up to 15 gallons per day per person in the household. It does not require a construction permit as long as it does not require cutting of the pipes that exist.
Simple System: This system also serves a one or two family residence. The discharge of greywater is greater than the clothes washer system, and discharges up to 250 gallons per day. A construction permit is needed for a simple system.
Complex System: This is a greywater system that uses over 250 gallons per day, and also requires a construction permit. The simple and complex systems are subject to inspection and possible percolation tests until they are approved.To install a whole-house system is a fairly simple matter in new construction, but is difficult in existing buildings.
BASIC REQUIREMENTS FOR USING GREYWATER:
Two inch covering regulation: The irrigation system using greywater must be covered by 2” of material to avoid contact with the greywater.
Drip system of greywater irrigation: The drip system works the best with greywater irrigation. Spray irrigation is not to be used with greywater. Also, greywater is not to have run-off or ponding, and cannot reach any body of water or storm drain.
No irrigation of crops intended for human consumption: Greywater may not be used for this; and, in addition, human contact with the system should be minimized.
GREYWATER IN THE GARDEN:
Plants can respond better to greywater and the nutrients within than potable water
Don't store greywater for more than 24 hours
Distribute graywater evenly across the garden, don't over water any one area, drip systems are perfect for greywater
Avoid any cleaners containing Boron or high levels of salt, this is toxic for plants.
If using a water softening system, opt for adding potassium instead of salt.
CALIFORNIA'S GREYWATER CODE:
California’s greywater code is found in Chapter 15 of the California Plumbing Code (CPC). (You can download it here: https://greywateraction.org/wp-content/uploads/2014/12/Chapter-15-CA-Plumbing-Code-2016.pdf)
It includes regulations for both “HCD” – the residential code, and “BSC”- the commercial code.
Pacific Vista Landscape Services is focused on water conservation. Re-using your greywater to irrigate your landscape can not only result in water reduction, but is a great way to keep a beautiful garden during drought conditions. Our professional team are experts with the latest irrigation technology and can implement a greywater system for your property. We will even evaluate your current system for free! Contact us and see how we can save you water AND money now AND in the years to come!