Plumbing for a Greywater System (Plus Some Money Savings!)

Reader Contribution by Jennifer Kongs

The Small Home, Big Decisions series follows Jennifer and her husband, Tyler, as they build a self-reliant homestead on a piece of country property in northeastern Kansas. The series will delve into questions that arise during their building process and the decisions they make along the way. The posts are a work in progress, written as their home-building adventure unfolds.

Customization is the name of the house-building game, and we are taking advantage of all available options by including as many eco-friendly features as possible and laying out the house to fit our lifestyle. One part of this effort is our customized plumbing — our goal is to build-in a greywater system that will rely on gravity to feed water from our washing machine and a washbasin (both in the basement) to outside water-storage tanks. In the photo above, you can see the pipes that have been installed that will run under our concrete basement floor. The pipes in the top/back of the photo are the ones that will connect into our future greywater system. Runoff rainwater collected from the roof will also be piped to the same storage tanks. (We will take a closer look at the full system and the rainwater collection in later posts.)

As a quick background, greywater encompasses all used household water except the water from toilets, which is called “blackwater.” The average U.S. resident uses close to 40 gallons of water every day performing basic household chores and cleaning, including bathing, washing dishes and laundering clothes. As long as the water you work into a greywater system has not been mixed with toxic chemicals, it is considered safe to reuse in home landscapes.

Tyler makes our laundry soap with nontoxic ingredients, and we have decided that the chemical risks from rainwater that runs off of our roof are not significant enough to prevent our using the water for irrigation. Each laundry load will deliver about 10 to 20 gallons of water to the storage tank, and the amount of collected rainwater will obviously depend upon how much precipitation we receive. The water will flow downhill to be stored in tanks, which will allow overflow to run out. We will water trees and nonedible plants, and after we are sure the dilution rate of the laundry soap in the greywater combined with the rainwater is enough to not cause any unintended damage to our plants, we may use the water in the vegetable garden via soaker hose and/or drip tape (after some filtering to prevent clogs and buildup). 

Even though we will be using well water for irrigation and so don’t need to worry about saving on our water bill, collecting and reusing greywater will divert water from our septic system, thus extending its life. This system will also save energy and be more secure during times of drought. As a bonus, our contractor is “employing” Tyler to assist in installing this custom plumbing, so we will be saving money on the installation of our greywater system, too.

Whether you’re building a new home or are interested in incorporating greywater harvesting into your existing house, check out these resources for some ideas. The first link was our inspiration for setting up our greywater system:

From Laundry to Landscape: Tap into Greywater
Greywater Systems: A Way to Save Water at Home
Flushing the Toilet with Greywater

Photo of foundation and plumbing by Jennifer Kongs.

Next in the series:Home Construction Timeline: Plans vs. Reality
Previously in the series:An Educational Visit to Four Season Farm

­­­Jennifer Kongs is the Managing Editor at MOTHER EARTH NEWS magazine. When she’s not working at the magazine, she’s likely in her garden, on the local running trails or in her kitchen instead. You can connect directly with Jennifer and Tyler by leaving a comment below!

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