Ryan Griffin-Stegink
The graywater reuse system at the Doyles' home will cut their water bill by 27 percent.
MPC Research Assistant Matt Nichols authored this post.
Many people report that their best ideas come to them in the shower. In the case of Oak Park, Ill., homeowners Ana Garcia-Doyle and Jim Doyle, their great idea was the shower itself. Or more specifically, the thousands of gallons of water their family of five sends down the drain every year from their showers and tubs – water that could be reused for non-drinking purposes, such as flushing toilets.
Now, almost two years after first hearing about the concept of graywater reuse at a GreenTown presentation by the Metropolitan Planning Council’s Josh Ellis, Ana and Jim are turning that great idea into reality in their home, with one of the first residential graywater reuse systems in Illinois. The system’s installation was one component of a six-month renovation that increased the square footage of their 100-year-old home by almost 50 percent, while reducing water use by up to 27 percent.
Project manager Paul Saylor of Loop Construction walked MPC through the surprisingly simple mechanics of the graywater system. A separate set of PVC pipes – painted light purple to distinguish them from pipes for drinking water – carry water to and from a central holding tank in the basement. That 60-gallon tank receives water from the home’s showers and bathtubs, passes it through a mechanical filter to remove any loose material, and adds a mixture of chlorine diluted with fresh water to provide a basic level of disinfection suitable for flushing toilets. The filter must be replaced and the chlorine tablets replenished from time to time, just as a car requires regular oil changes.
Unfortunately, obtaining the necessary permits for the project was far less simple, due to Illinois’ current plumbing regulations, which prohibit reusing graywater for non-potable purposes. That permitting process forced the couple to submit a written request and make multiple phone calls over several months – first to the Village of Oak Park and later to Ill. Dept. of Public Health offices in Springfield and Chicago – before their application for a variance was finally approved. Largely because of increasing interest in reuse of alternate water sources, state officials are currently working to modernize Illinois’ plumbing code to make life easier – and permits simpler to acquire – for families like the Doyles.
With the new graywater system at Ana and Jim’s home, when any toilet in the house is flushed, an electric pump in the basement sends graywater from the tank to replenish the water level in the toilet. If the graywater tank is ever at risk of overflowing, incoming water will instead divert to the sewer. Conversely, if the tank ever runs low, the system can step in with potable water to flush the toilets. The system contains a safeguard called an “air gap” to prevent any possible backflow of nonpotable water.
Besides periodically replacing the tank’s filter and refilling the supply of chlorine tablets, the system is effectively maintenance-free. To reduce wear on the electric motor, a compressed air tank alternates with the electric pump to do the work of pushing water up two stories to the second-floor bathrooms.
While greywater reuse systems can be designed to capture water from laundry washing machines as well as showers, the Doyles and Saylor decided against including that option, as the family of five expects to generate more recycled water than the home’s high efficiency, 0.8 gallon-per-flush toilets can use. Even so, the retrofits should still reduce the family’s water use by up to 27 percent, a figure they intend to track on their monthly utility bills. Pending future changes to the Illinois plumbing code, they might be able to use some of the surplus graywater to irrigate outdoor landscaping.
And as for the question that many homeowners may be asking – how much did all this cost? – the answer may surprise you. The total cost of materials for the graywater system was roughly $2,000, a minor fraction of the overall cost of the Doyles’ renovation project. Labor was minimal, Saylor points out, since the house was already gutted and the plumbing exposed for the renovation. Thus, graywater systems likely make the most sense for new construction or homeowners already committed to a major remodeling project. Although the low cost of municipal water means that even cutting their monthly water bill by more than a quarter will not net huge savings, it is safe to say the project will pay for itself long before any of the components wear out, or the Doyles sell the house.
Ana and Jim have no plans to move any time soon. “We knew that we needed more space for our three kids and their grandmother who comes to stay with us, but we didn’t want to have to sell the house and leave the neighborhood that we love. So we decided to invest in the house and really make it the home we’ve always wanted,” says Ana. Now that vision has become a reality.
For Saylor, the project has also been rewarding. After a career in the film industry, Saylor only began working in construction management recently, and the Doyle’s project has been a learning opportunity for him about the possibilities of sustainable design. Loop Construction is one of only a few contractors in Illinois to have installed a graywater reuse system, positioning them advantageously when the state updates the plumbing code next year.
While the graywater reuse system is one of the home’s most unique features, the Doyles wanted to address multiple aspects of sustainability, considering that the nearly 100-year-old structure was far from efficient. Together, these design elements earned the home a 2012 Green Award from the Village of Oak Park and should merit Leadership in Energy and Environmental Design (LEED) certification once the evaluation process is complete.
A new geothermal well in the backyard circulates air from below ground – which is a constant 55 degrees Fahrenheit year-round – through a heat-exchanger in order to cut heating and cooling costs. In fact, it reduced the energy needed to heat the home during the winter so much that a natural gas furnace is no longer needed. A high-efficiency electric stove, clothes dryer, and water heater have also replaced their former gas counterparts. Finally, the house has been wired for photovoltaic panels to generate electricity, although Ana says installing the panels themselves may have to wait a few years until the family has the patience for another construction project.
Despite the effort involved in obtaining a variance from the Ill. Dept. of Public Health to install the graywater system – not to mention the inevitable delays that accompany any home remodel – Ana says they would do it all again if given the choice. Her advice to other homeowners interested in implementing water reuse technologies in their homes is straightforward. “Just do it!” she recommends. All those months of work and waiting netted a huge pay-off: a water- and energy-efficient home that will meet her family’s needs for years to come.