Homemade "valve box"
This "valve box", aka plastic mulch shield, was made using an old plastic pot. The greywater line enters through a hole drilled in the side of the pot. The greywater should discharge at least 2 inches below ground level and at least 2 inches above the mulch at the bottom of the valve box. Usually a paving stone covers this plastic mulch shield in the yard to mark its location.