The repair estimates for our public water infrastructure are high. The EPA estimated in July that we’ll need to spend $655 billion to keep the water flowing for just the next decade. If we want to have a topnotch water system, the American Society of Civil Engineers puts the price tag at $3.4 trillion by 2020.
Given how unlikely it is that such major spending will occur, we might do well to ask ourselves if there’s anything we can do to safeguard our clients and make their properties more resilient. The answer is that there’s much that the green industry can offer, and loads of underused water sources we can tap to irrigate landscapes.
Whether it’s called water reclamation, water recycling or water reuse, programs to filter and re-use wastewater have gotten something of a bum rap in the media. Branding efforts like ‘toilet-to-tap’ don’t help, but the fact of the matter is that all water is re-used. Earth isn’t getting a fresh supply of H 2 O piped in from the moon. The only question is whether we wait around for nature to clean it up for us, or do we take on the job ourselves?
The least intrusive form of water reuse is when it is offered by the municipalities themselves. The wastewater treatment plants for most cities are already required to treat the sewer water to a fair degree before they release it back to the environment. In states like Florida, Colorado, Texas and California, some municipalities now offer recycled water to local property owners.
So why isn’t everyone doing it? Because all cities and municipalities have codes protecting their potable water supplies; you can’t use the same pipe that is used to transmit potable water to send recycled water. Also, laying pipe is expensive. Using the regular pipes to carry recycled water would contaminate the potable supply, so water purveyors who offer recycled water have to lay a separate set of pipes, colored purple, just to carry that water. If a city in your area has purple pipes, you may want to ask for a map of their layout, because the water purveyor might be up for extending their system if you ask.
“We are willing to entertain a request to expand the system from anyone,” said Damian Higham, recycled water compliance technician with Denver Water in Colorado.
It makes sense for them to want to expand; every user they supply with recycled water is less of a strain on their potable water system. When it comes to adding recycled water customers, bigger is better, according to Higham. “If you have multiple users in an area, it becomes more attractive. It’s worth the capital expenditure to get it there,” he said. “If it’s just an individual user, often the burden of extending infrastructure to their property will be on them.” For most, the extra cost is high enough to take that option off the table.
It’s very localized, and recycled water programs differ from city to city and state to state on how close to potable the water is, how it can be used, and what reporting or training is required to use it. You may have to post signage after hooking up a client’s system, or get certified with the local water provider, so they can be certain you won’t do anything crazy.
However, there are options that don’t rely on the city at all, and these are often attractive to property owners looking for disaster resilience, sustainability, or those who simply don’t want the city water. One such option is a graywater system.
Graywater is gently used water, which has not been contaminated with heavy chemicals or dangerous bacteria. Water from showers and bathroom sinks is usually a safe bet, while water from toilets is not. Other sources are on more of a case-by-case basis.
Kitchen sinks generally have too much bacteria from food waste, and local codes may rule them out; however, dishwasher water is fine, so long as the owners use a low-salt detergent. Laundry water is usually good, but provisions must be made in case the property washes diapers.
Water from washing machines works especially well for graywater, as a rule. There are lots of detergents that make laundry water actually more nutritious for plants than the potable supply, for one thing. For another, laundry-to-landscape systems use the washing machine’s own pump to move the water, avoiding the usual design difficulties of a gravity feed.
It’s important to remember to include a three-way valve in the system when installing. “If you’re installing a laundry-to-landscape system, it’s important to remember to include a three-way valve in the system. That valve is required by law so the user can divert water to either the landscape or the sewer system,” said Daniel Wilson, founder and president of Wilson Environmental Contracting in Santa Barbara, California. Any water that may have touched human feces is automatically considered blackwater.
Contractors who get into graywater will, sooner or later, find customers asking them to hook up a graywater system directly to their sprinklers. Maybe your city will allow it, but most regulations stem from plumbing codes that didn’t originally distinguish between gray water and blackwater. The local ordinances may allow pumping graywater through sprinklers with sufficient filtration and backflow prevention, but they may require that graywater be distributed through subsurface systems only.
There are a lot of reasons to implement graywater systems. They provide common sense resiliency to your clients’ landscapes, because they rely on water that’s already used and budgeted. It reduces their landscape’s footprint on the nation’s water supply, and since Americans’ water-use is only going to come under closer scrutiny as time goes on, that’s a good thing.
Both graywater reuse and recycled water ultimately rely on a single source—the public water supply. If that central source is having trouble getting the funds to keep their infrastructure up to snuff, is there anything that landscape contractors can do? The answer is still yes, and it’s as old as the hills.
People have been practicing rainwater harvesting since the dawn of time, and though our modern potable water system has rendered cisterns and water tanks largely unnecessary, that doesn’t mean they aren’t useful. According to Wilson, modern rainwater harvesting systems come in one of three types.
“The first is above-ground storage or tanks, the second is below-ground storage or cisterns, and the third one is simply storage in the soil, with the soil being a kind of leaky tank,” he said. While swales and rain gardens are valuable landscape additions that can store water, you can’t actively pull water out of those leaky tanks to irrigate lawns, so we’ll leave that subject for another article.
For the purposes of our discussion, there are only two types, and al though there are significant differences between the two, they share one common trait: they both function by storing abundant rainwater for later use.
Of course, storing water is easier said than done, and contractors looking to offer rainwater harvesting installations need to know a thing or two before they start. “It’s one thing to push water through a pipe or a sprinkler nozzle,” said Wilson, “but it’s another thing to take 5, 10 or 100 thousand pounds of water, store it next to a structure, or on a slope.” Even a 500-gallon tank weighs more than the average car when filled up, so it’s best not to take chances with your design.
Another risk from rainwater harvesting that also deserves your consideration is the risk of drowning.
Every year, a few families suffer the worst kind of pain because their cistern wasn’t sufficiently childproofed. Making sure your tank has a strong lid and a good filter can be enough to banish that nightmare.
Good filtration has other benefits, too. “Without filtration, mosquitos, rats, skunks and possums can fall in, drown, then rot and contaminate your water,” says Wilson. If the client is just looking to use the tank for landscape irrigation, it doesn’t have to be clean enough to drink or wash with, but it does have to be clean enough to avoid clogging up sprinkler nozzles or drip emitters.
Even if you keep insects and animals out, leaves, dust, bird droppings and other debris may be washed into the tank with every storm. That’s why including a firstflush diverter into your design is probably a good call, even on the cleanest roofs. A certain amount of bacteria is unavoidable, but so long as the stored water doesn’t get any sunlight, it won’t flourish and gunk up the tank.
Some property owners will be looking to use their new rainwater supply indoors as well as on the lawn, and most indoor uses will require extra filtration. Adding in extra screens down to the one micron level, and either ozonation or UV disinfection may be necessary, depending on whether they want to drink it, or just flush toilets with it.
Getting versed on indoor use requirements is particularly helpful for landscape contractors in rural markets. For property owners building hunting cabins or second homes in secluded areas, rainwater harvesting may be more cost-effective than digging a well or paying for a hookup to the municipal supply.
Steve Krieger, owner of Rainwater Harvesting Supply Company in St. Louis, Missouri, says that he’s noticed a trend in rainwater harvesting installations. “We’re seeing a few more requests from preppers,” he said.
‘Preppers’ are people who believe that society might collapse within their lifetimes, and are getting ready to subsist without outside help. That means farming their own food, generating their own power (or living without) and, yes, storing rainwater.
For urban properties, however, rainwater harvesting can’t compete economically with the potable supply. For example, in St. Louis, situated between the Mississippi, the Missouri and the Illinois rivers, the water companies can offer water at four gallons per penny. Given that, you might think Krieger is crazy for selling his irrigation company and keeping his rainwater supply business, but according to him, the interest in urban rainwater harvesting is still likely to grow.
“From a stormwater mitigation perspective, most sewer districts view it as a desired practice,” he said. “They just have less experience with it than they do with plant-based mitigation processes like rain gardens and bioswales.” Where landscape techniques for slowing stormwater may lose effectiveness over the years due to soil compaction, a tank or cistern will hold the same amount of water now or ten years from now.
In 2007, the EPA sued the Metropolitan St. Louis Sewer District (MSD) over its failure to mitigate stormwater, and reached a settlement to the tune of $4.65 billion.
After the MSD’s attempt to pass on the costs to ratepayers was ruled an illegal tax, the district began looking into different infrastructure improvements that could reduce stormwater, right down to encouraging rainwater harvesting.
Many U.S. cities have suffered from similar suits, and according to Krieger, it’s very likely that sewer districts will start offering rebates for rainwater harvesting installations. “The MSD needs the money, and the people who use the stormwater system, and the sanitary system, are the ones who are going to pay for it,” he said. So if your market has stormwater troubles, it may be worth checking to see if there aren’t already financial incentives in place.
At the end of the day, it comes down to a fairly simple equation. Populations continue to grow, but the amount of fresh water does not. Water is going to be a hot-button issue in the years to come, and contractors who know how to reuse water will be well-positioned to thrive in good times, and survive bad ones. We’re going to have to think hard about our water sources eventually, so why not start now?