Gray water dump valve in bambi...

My Bambi only has one waste tank (black water tank). As you can imagine this is quickly filled up from shower and sink usage.



After reading many of the threads about the pros & cons of dumping gray water I've decided that I'd like to install an outlet valve for both the shower and sink. I'll primarily use this on my property. I'm okay with this...especially because California is currently in a drought and I can use bio-degradable soap.



I'm not looking to debate the pros/cons of dumping gray (touchy subject, I know).



I'm wondering - has anyone retrofitted a Bambi to make it possible to do so? If so I'd love to hear from them...