Gray Water Flows Green
Seventy years ago, there were approximately 150 million people living in this country. Today, that number has more than doubled. The population explosion has taken its toll on our nation’s water supply. As a result of increased demand, many of our aquifers are at low levels, and wetlands throughout the country have gone dry. A dilapidated water infrastructure has exacerbated the problem.
Year after year, millions of gallons of clean drinking water are wasted due to broken water mains and leaking pipes. Climate change is also playing its part in the current water crisis. According to a recent report by the U.S. Government Accountability Office, 36 states will face catastrophic water shortages within five years due to a combination of drought and rising temperatures.
The water crisis is affecting the landscape contracting industry in a very real way. Outdoor water use is estimated to account for up to 50 to 70 percent of a household’s total water consumption. In light of the nation’s water woes, many officials find this to be an unacceptably high percentage. As a result, more and more municipalities are implementing mandates restricting or totally eliminating the use of water for irrigation.
These restrictions have created a number challenges for those who work in the industry. It is clear that these challenges must be met head-on. The only question is how to best do that? We can’t stop the population from growing. We can’t make it rain, and we can’t create new sources of water. All we can do is be smart about how we use the water we already have.
One of the most promising new ways to use water intelligently is graywater reclamation. Although it is defined differently by each state, graywater is generally 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 wastewater that has come into contact with solid human waste.
Capturing graywater for reuse is generally referred to as graywater reclamation. Once it has been reclaimed, graywater can be applied in a number of ways. It can be used to flush toilets, wash cars, and most importantly, irrigate landscapes.
Graywater accounts for roughly 50 percent of the total wastewater produced in a given household. In an average home in the U.S., that translates into 90 gallons of water per day, or more than 30,000 gallons per year. “The water-saving properties of graywater are just remarkable,” says Steve Bilson, chairman and CEO of ReWater Systems, Inc., San Diego California. “When you look at the big picture, you’re talking about hundreds of thousands of gallons of water that can be reused annually. If you add that up year after year, you’re talking about millions of acre feet of water being saved and reused.”
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 landscape. “Graywater has carbon and nitrogen constituents and those are both present in a lot of fertilizers,” says Sybil Sharvelle, an assistant professor at Colorado State University who is currently studying the long-term impacts of landscape irrigation using household graywater.
Although the study is still in its early stages, so far it has revealed some exciting results. “At some of our test sites, plants are doing better with graywater. These plants, which tend to be the more robust varieties, get more nutrients from graywater than they would from fresh water, and they really benefit from that.”
Irrigating with graywater is remarkably easy. Simply grab one of the pots taking up space in your kitchen, fill it with dishwater and head to the backyard. Once there, distribute the water over the desired plant material. That’s all there is to it. Just remember to spread the water evenly, as you want to avoid puddling. This method, commonly referred to 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.
Of course, there are more sophisticated ways to irrigate using graywater. One such method is known as diversion. 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, the graywater is then 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. Irrigating with graywater means that homeowners don’t have to rely on expensive potable water to nourish their landscapes. By some estimates, using graywater for this application can reduce a household’s dependence on city water by up to 50 percent, a significant savings on costly utility bills.
Nationwide municipalities, including cities in North Carolina, California and Florida, are implementing or considering implementing water rate increases.
“What’s happening is that water districts throughout the country are out of water and to control usage, they’re increasing their prices,” says Bilson. “As a result, we’re seeing a geometric increase in the overall interest in graywater systems. People are a lot more interested in graywater this year than they were last year, and they were a lot more interested last year than they were the year before that. The increase in water rates is really making graywater systems a lot more attractive, and that appeal is just going to continue to grow as far as the consumer is concerned.”
Although graywater is generally considered to be safe and is more often than not free from disease, it can come into contact with small amounts of fecal matter. Because of this fact, it is often viewed as a public health concern rather than a water conservation issue. This is disconcerting to many graywater advocates. “There are eight million unpermitted graywater systems in the United States. Yet, even in this totally uncontrolled environment, people are not getting sick,” says Art Ludwig, an ecological consultant from Santa Barbara, California. “When it’s used in sub-surface applications, graywater is just not a threat to public health.” Ludwig’s position is certainly not without merit. According to the Centers for Disease Control and Prevention (CDC), there has not been a single documented illness caused by exposure to graywater. Sharvelle’s research has been consistent with the findings of the CDC. “It’s really too early to tell conclusively, but there haven’t been reported illnesses from people irrigating with graywater,” she says. “That’s something I can say. I have interviewed a lot of people with graywater systems and talked to a lot of different agencies, and there just aren’t people getting sick as a result of applying graywater for irrigation.”
Despite these facts, the statutes regulating graywater are often strict and confusing, making the use of graywater prohibitively expensive and unnecessarily time consuming. In short, these rules often deter homeowners from using graywater legally.
In Utah, for example, municipalities cannot issue permits for residential use of graywater until local health departments have signed off. The state health department has to be satisfied that public health is sufficiently protected. This process can go on for months and months.
When the process 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 ground water levels. In addition, builders must hire authorized professionals to conduct required soil and ground water 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.
California’s graywater code is so strict because the state views graywater systems as a means to dispose of wastewater rather than as a means to irrigate.
“The current code assumes that graywater is not being used to water landscapes, which is stupid,” says Bilson. “It treats these systems as a means to dispose of wastewater and not as a means to irrigate. But that’s not what people want from a graywater system, and that’s not what the code is supposed to be about. It should be about helping people to reuse water and irrigate efficiently and safely. It should be about reducing wastewater, eliminating pumping costs and reducing irrigation runoff.”
Bilson is not the only one frustrated by the current California code. “The code is so unrealistic and so widely ignored—it is at best ineffective and at worst undermines the credibility of codes,” says Ludwig. “All the current regulations do is prevent anyone who may know what they’re doing—plumbers, builders or landscape contractors—from building these systems. The law needs to get out of the way.”
Bi lson bel ieves regulat ions regarding graywater do not have to be lengthy and complicated to be effective. “Is the system using kitchen water? Is it being used to irrigate above ground? These are the type of things the code should focus on, not soil samples. There has got to be common sense to the code,” he says.
There are states that have graywater regulations that are far less restrictive than those found in California and Utah. Arizona’s graywater code, which has been used as a model by states across the country, is generally considered to be among the best of any found in the U.S. In Arizona, homeowners wish ing to use graywater are not required to go through a lengthy permit process. The health department plays no regulatory role, and no experts have to be hired to conduct soil samples. In addition, the types of materials used are left up to the individual, which reduces costs and encourages technical innovation.
Provided the home uses less than 400 gallons per day, all residents wishing to use graywater must do is follow a short and simple list of requirements. These straight-forward conditions include stipulations that human contact with graywater will be avoided, that the graywater in question will not contain hazardous materials, that graywater will be applied using only flood or drip irrigation and that the application of graywater is designed to keep standing water on the surface to a minimum.
One of the most commonly praised aspects of Arizona’s graywater law is that installers are not required to follow specific design specifications. Designs must be approved by the Arizona Department of Water Quality; however, regulators choose to focus on performance goals rather than design specifications. Such an approach increases the legal use of graywater and helps to create a market for the sale and installation of affordable graywater systems.
In any situation, there are risks and rewards. Of course, this is true of graywater. However, so far it seems that the rewards far outweigh the risks. Graywater is incredibly water efficient; it is incredibly cost efficient and it poses almost no threat to public health. But, best of all, because it saves so much potable water, we can all do our part for water conservation.