From 1995, this Graywater Guide explains how to design and build a system of drip irrigation using reclaimed water from showers and laundry.
http://www.owue.water.ca.gov/docs/graywater_guide_book.pdf
Thanks to member Chateau_Prideaux!
It looks like that link is outdated. Here's an updated link.
http://faculty.ksu.edu.sa/zalam/Sustainability/graywater_guide_book.pdf
http://www.water.ca.gov/wateruseefficiency/docs/graywater_guide_book.pdf
I got a 404 with the 1st link. This one works, today...
Tom D. CT. USA