Mulch basin question

[woodlumn]

Hi there,

I've had your Build An Oasis With Graywater book for a few months now and have been planning my laundry-to-fruit tree system. I'm confused about a couple of things, and am hoping you can help.

It seems that the mulch basin is the best design for our young fig trees. I will be testing the perk this weekend, but expect it to be average, based on the digging and gardening observations I've made over the years. My surge is about 18 gallons, depending on laundry load size. This will be a gravity system. Here are my questions:

- Do I need to use multiple outlets, or can I just have one pipe that empties to the pit?

- Is it preferable to have the pipe 2" above the surface of the pit, or should it be submerged within the pit into a 5 gallon pot or otherwise?

I think that's it for now, but I'm sure I'll have more questions. Thanks for your advice, and nice work with the book. It's a great resource on our reference shelf!

[oasis]

- Do I need to use multiple outlets, or can I just have one pipe that empties to the pit?


Multiple outlets are better as they distribute the water more evenly, however it depends on the overall context. If the perk is slow, the water will spread more, and if you have a dozen fruit trees to water with a Laundry to Landscape system, maybe each one only gets one outlet

- Is it preferable to have the pipe 2" above the surface of the pit, or should it be submerged within the pit into a 5 gallon pot or otherwise?

Submerged is now legal in CA, laying on the surface of the mulch is easier and more serviceable.

Good luck!

Art

[woodlumn]

Thanks for the reply, Art.

Does the volume of the outlet covers (flower pots or buckets) need to add up to the volume of the surge?

- John

[oasis]

No, the volume of the basin needs to be about 4x the surge volume, min., (half of the volume is mulch, and they wear down to half as deep over time). The outlet shields should be porous enough that the water flows nearly full speed into the mulch.

[woodlumn]

Thanks again, Art.

One more, if I may: When calculating surge, would I look at water use per day, per hour, or just per laundry load regardless of whether we do back-to-back loads?