Question of the week

This is a good opportunity to do some simple math that can help you understand how useful a greywater system can be for you and how changing your landscaping can help much more substantially!


My last water bill used 46 HCF for 61 days.  If we could skim at least 22 HCF off per cycle, that would keep me in the bottom two price ranges (tiers).

…We do about 10 HE laundry loads per week.  Would just setting up grey water from the washer be enough to cover those 22 HCF

The answer to this is twofold.  First of all, a high efficiency washing machine uses about 10 gallons per load these days.  So 10 loads would equal 100 gallons per week.  That adds up to 400 gallons per month.  You could be watering 3-4 mature fruit trees with that water!  Learn how to do this yourself at our upcoming workshop.

On the other hand, 1 HCF (hundred cubic feet) is 748 gallons.  So you would only chip into your water use by just over 1/2 HCF a month which isn't really going to make a dent in your water bill!

Now, if you consider lawn (the biggest water user in our landscape), which can't really be watered with this greywater without substantial investment in pumps, filters, and specialized irrigation ($5K +), you'll find that 500 square feet of lawn uses 13,000 gallons of water a year.  That's over 1K gallons a month, which is about 1.5HCF.

So getting rid of just this much of your lawn (which is free if you sheet mulch it) will save you 3 times the amount of water the above greywater system ($600-$800) will save you.

The key point here is to start with a good landscape design.  Know what you absolutely want in your yard.  And put the elements in efficient relationship to each other and to water sources.  Things that are going to be using shower greywater will rely on gravity and need to be placed downhill from the shower.  Things that are going to be using laundry greywater can be higher because of the pump on the washing machine.  And make sure there's places that can catch water falling off the roof in a rainfall and allow it to absorb in!  That's free water!

There's so much more to it than this.  This is why consulting with an expert can save you a lot of money and time in the end.  Before you implement an expensive system, reducing your consumption and efficient placement will get you off to a better start!

For more information, call or email me for a consultation.