Adding a washer drain to septic system plumbing help!

[WildBill]

I want to add a washer drain to my septic sewage system. I know code says the drain can't be more than 30" from the floor but this is impossible as my septic tank is higher than the basement. In the first photo the two 4" Ts are the existing plumbing to the septic tank. The T on the right is for graywater, the T on the left is blackwater from the toilet. I was going to add the 3" T and plumb as shown (bottom left side), only on the backside of the pipe as shown in picture #3. Photo #2 shows the washer hook up on the right, to a P trap, then to a check valve represented by the small length of pipe. What do you think? I can add it higher, the washer is currently draining into the very top of the graywater Y fitting (pic 1) but I thought it would be best for the washer to drain as low as possible.

Pic 1

Pic 2

Pic 3

 

[johnjh2o]

The washer drain needs to be vented. I don't understand your comment about having a gray water and a black water system as they are both connected to the same main line.

 

[WildBill]

I didn't mean seperate systems, only what those pipes are carrying. Does the washer still need a vent even if the 4" T on the far right will be vented at the top? Would that be a wet vent? Does the vent have to be right after the p trap?