This series describes the process of designing and building a sustainable home, which is passing tests for airtightness and proved to retain heat in winter. This installment focuses on water sustainability design and practices.
While it might be the perception that a high-performance home mainly focuses on the energy footprint, incorporating water sustainability practices into the house design is also part of the equation. And this was an even more important aspect of the design because even though Minnesota is known as the Land of 10,000 lakes, it has experienced significant drought conditions, including less rainfall and lower underground water table levels.
With this in mind, the first aspect of water usage to consider was how to bring water into the house. With the land located in a rural area, a city water and sewer connection was not available. This meant digging a well for water access and installing a septic system. It was originally planned that the well would be 120 feet deep, but the water table was lower than expected, perhaps from groundwater overuse, so in the end the well depth was 190 feet. In terms of the septic, the soil in Minnesota is generally unsuitable for a conventional drainfield septic system, so instead a mound system was installed. Then wildflowers and wheat were planted on the mound to prevent erosion. Decentralized septic systems are a more sustainable way to manage water waste compared to centralized sewage plants.
With the water coming directly from the well, an in-home filtration system was installed, consisting of:
- Filter 0: Spin-down filter
- Filter 1: PHO filter (polyphosphate to reduce scale)
- Filter 2: KDF filter (for heavy metals)
- Filter 3: ACB filter (activated carbon filter for chlorine, pesticides, and other chemicals)
- Filter 4: A water softener
In order to confirm safe water levels and efficacy of the water filtration systems, water samples were taken both of the water directly from the well pump and then after the filtration units and sent to an approved lab to test for various containments, including:
- E. coli Bacteria
- Nitrate
- Nitrite
- Arsenic
- Lead
- Manganese
Fortunately, the testing came back to show that the samples meet EPA guidelines for safe drinking water and no additional treatment efforts were necessary.
In terms of water conservation, the dishwasher, washing machine, toilet faucets, and showerhead were EPA WaterSense certified and the appliances were also Energy Star certified. These are all standard water management techniques that are easily implantable in any home, but I wanted my home to be above average in terms of water sustainability. As an example, I wanted to take advantage of greywater for second use, but this proved harder than I had hoped.
I searched around for experts who would be able to help install a greywater system. One of the more popular options was a laundry-to-landscape solution, but most of the options were DIY that were far outside my capabilities. In addition, many of these greywater systems are not part of standard plumbing practices and do not always meet code. (On a different note, I found out during my research that even if all my detergents and soaps are eco-friendly, microplastics in most clothing are problematic for laundry-to-landscape greywater, especially when growing food.)
Because of these hurdles, I needed to settle for some lower hanging fruit. One of the easiest greywater solutions I implemented was with the toilet. My builder, Paltrin, recommended and installed a dual-flush toilet to save water. And then I topped it off with a sink that sits on top of the tank. When the toilet is flushed, the fresh water automatically comes out of that faucet for handwashing and then drains directly into the toilet tank to then be used to rinse out the basin during the next flush. (This was such an easy upgrade, that all I had to do was order the specialized sink online and install it myself in under 5 minutes. Any house can do this!) In order to ensure a comfortable hand washing temperature, my builder installed a hot-and-cold-water mixing valve to feed tempered water to the toilet.
Another way that I was able to incorporate water sustainability practices was by installing 4 rain barrels and connecting them to my gutters to store water for gardening purposes. As part of this, my builder calculated the gallons of water that would need to be managed using this equation: roof sq feet x inches of rain x 0.623 gallons per inch.
For example, a 3,000 square foot roof would have 3,738 gallons of water to manage with only 2 inches of rain. Taking this amount of potential water flow into account, a partial diverter was installed to prevent the barrels from overflowing. Then to manage the rest of the water from the gutters, my builder had rain gardens designed and installed to direct water flow away from the house. Raingardens are shallow, landscaped depressions designed to collect and absorb rainwater runoff, and are a more natural way to manage stormwater runoff that creates habitat, improves water quality, and reduces irrigation needs.
In terms of irrigation, I am not installing a sprinkler system on the nearly 4 acres of land. Instead, in the future, I plan to create swales and berms for water management and grow native plants that can thrive in Minnesota’s climate. In my upcoming articles, I’ll dive into the process of planting for this first season and the progress of adding a PV system, including the considerations of adding a backup battery for the well.
Jessica Fishman is director of renewable energy at Kiterocket, is a strategic marketing leader with nearly 20 years’ experience, including seven years as head of global public and media relations at inverter maker SolarEdge. Passionate about addressing climate change by accelerating the clean energy transition, she has worked at leading renewables companies, building marketing and communications departments.
Read the first in the series of Building not your average dream home.
The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
Popular content
