Imagine doing a load of laundry, collecting the water from the machine, and then using it to water your trees. Imagine that you’ve just finished taking a bath and instead of letting the water go down the drain as you normally would, you collect it and use it when you need to irrigate your lawn. Water, especially potable water, is beginning to run in short supply and we need to find creative ways to reuse it. There are already practical and safe ways to reuse water. For irrigation and landscape professionals, it is more important than ever to become informed about water sustainability. And though there are several approaches to reusing water, some of these approaches could prove to be the perfect fit for the irrigation industry. One such method is graywater reclamation.
What is graywater?
The answer to that question depends on where you live. Every state defines it differently, but graywater generally is considered to be untreated household water that comes from a sink, shower, dishwasher, or washing machine. Graywater is not toxic and is generally free from disease. It should never be confused with black water, which is unprocessed water that has come into contact with solid human waste.
Graywater and your garden
Capturing graywater for reuse is generally referred to as graywater reclamation. Because it often contains residue from soaps and food, graywater can be rich in nutrients that are beneficial to plants and soil. This makes it a no-brainer for use in the garden. Nitrogen, phosphorous, and potassium, three elements often found in fertilizer, are among the most common nutrients found in graywater. So, using graywater on plants and lawns can increase savings on costly utility bills, reducing the amount of potable water being used in a given home and ensuring that your plants and turf don’t get thirsty.
Essentially, there are two ways to irrigate with graywater: manually or via a method known as diversion. Manual irrigation is probably the easiest and most cost effective of these methods. Do you have a pail or bucket lying around your garage? Are your kitchen cabinets cluttered with unused pots and pans? If the answer to either question is yes, you have all the equipment needed to begin manually irrigating.
Simply fill the receptacle of your choice with graywater, haul it to the backyard, and spread it evenly over your plants and lawn. It’s as simple as that. This method, known as bucketing, can also be used when showering. By bringing a bucket into the stall with you when you shower, countless gallons of water that would otherwise be wasted are captured in the bucket and saved.
For those who don’t want to share their shower with a bucket, diversion may be a better approach. Diversion is a slightly more sophisticated way to use graywater and requires a few additions to your home’s existing plumbing. Typically, when water goes down a drain it flows directly to the sewage system.
Diversion prevents this from occurring. By installing a hand valve, water from the shower, washing machine, or sink can be diverted away from the sewage system into an alternate drainage system. Doing so keeps graywater and black water from mixing. Once diverted, graywater can be processed to a surge tank where it can be stored indefinitely. When the water is needed, it is pumped to an underground irrigation system. Your plants are watered—no bucket needed.
Because graywater can contain material capable of spreading disease, it is often viewed as a public health concern rather than a water conservation issue. It is important to note that studies have shown that graywater is not a threat to public health, and that there are no known cases showing illness as a result of contact with graywater. Despite these facts, only 13 of the 50 states currently allow the use of graywater. In several of those thirteen, strict and confusing regulations make the use of graywater prohibitively expensive and unnecessarily time consuming. It can deter homeowners from using graywater.
In Utah, for example, municipalities cannot issue permits for residential use of graywater until local health departments are cleared to do so by the state. Health departments must demonstrate that they can manage graywater systems in a way that sufficiently protects public health. This process can go on for months and months.
When it is finally completed, and municipalities are cleared to issue permits, individuals are then required to go through a rigorous permitting process. Potential builders must submit detailed plans for their graywater systems. The plan must include a plot plan drawn to scale, a log of soil formations and an estimation of anticipated groundwater levels. In addition, builders must hire authorized professionals to conduct required soil and groundwater tests. Lastly, local health departments will require written operation and maintenance procedures, including checklists and maintenance instructions from the designer. California places equally burdensome restrictions on those hoping to use graywater. Mandatory procedures for estimating soil irrigation capacity and discharge volume are required, and builders must submit soil percolation tests and detailed soil analyses. In addition, systems can be constructed using only approved material, which can increase costs.
Some experts feel that policies regarding graywater have to be simplified if people are to use it. Steve Bilson, CEO of ReWater systems and an authority on graywater, feels that many polices regarding graywater fail to focus on what really matters. “Most of the codes need to be simplified. We need to become concerned with the important things,” Bilson says.
For Bilson, focusing on soil samples and maintenance instructions is a waste of time. “Is the system using kitchen water? Is it being used to irrigate above ground? There has got to be common sense to the code,” he says. Bilson believes regulations regarding graywater do not have to be lengthy and complicated to be effective.
Short, practical statutes can encourage people to use graywater while simultaneously ensuring that they are not at risk. Arizona is a perfect example of this. Arizona is often considered the most forward-thinking state regarding graywater policy. Often admired for its simplicity, the Arizona code is being used as a model by other states such as New Mexico and Montana.
In Arizona, homeowners wishing to use graywater are not required to go through a lengthy permit process. No experts have to be hired to conduct soil samples and the types of materials used are left up to the individual.
Provided the home uses less than 400 gallons per day, residents wishing to use graywater need to follow a short and simple list of requirements. These common-sense conditions include stipulations that human contact with graywater will be avoided, that the graywater in question will not contain hazardous materials, and that the application of graywater is designed to keep standing water on the surface to a minimum.
Another user-friendly facet of the Arizona law is that installers are not required to follow specific design specifications. Although the design must be approved by the Arizona Department of Water Quality, regulators choose to focus on performance goals rather than design specifications. Such an approach allows for both technical innovation and affordability. It increases the likelihood that homeowners will comply with the law. It also creates a market for simple, affordable systems. According to the Water Conservation Alliance of Southern Arizona, these standards, which were issued in 2001, have increased graywater usage in Arizona by reducing costs and increasing convenience.
The graywater movement is still in its nascent stage. For some, it is a topic that generates great excitement. For this group of people, the expansion of graywater use cannot happen fast enough. Among others, graywater is a topic that illicits concern. These people believe that the spread of graywater use to the rest of the 50 states should be done slowly and with caution.
However, one thing both of these groups can agree on is that graywater is an exciting water conservation concept worthy of further exploration.