Three-way diverter valves for greywater-harvesting systems should be placed where they are very convenient to use—so you use them…
Incentivize yourself to do the right thing. Thus, I strongly recommend you put them in the same room as the source of your greywater. That way, you can easily turn the valve’s handle to direct the greywater where you want it to go. For example, you can direct your bubble-bath water to the sewer/septic (its high salts are toxic to soil and plants in arid environments), then turn the valve back to direct your benign shower water to vegetation in your landscape without having to leave the bathroom. Below are some stellar examples. See the greywater harvesting chapter of Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition for more, along with essential greywater-harvesting information.
Greywater three-way diverter valve installations conveniently accessible in the room where the greywater originates:
1. Access hatch (closed) for three-way valve that diverts greywater from bathtub/shower2. Access hatch (open) for three-way valve that diverts greywater from bathtub/shower3. View inside access hatch for three-way valve—labeled so you know where you are directing the greywater. Greywater directed to landscape goes to mulched basins via a gravity-fed branched-drain greywater distribution system. Design by Brad Lancaster. Carpentry by Steve Bull. Plumbing by Clay Brown.4. Access hatch (closed) for three-way valve that diverts greywater from bathtub/shower. Note how the top of the access hatch is purposely sloped, so urine will run off, rather than collect atop it. (The access hatch is beside the toilet, and some guys miss when they try to urinate in a toilet.) Design by Brad Lancaster. Carpentry by Steve Bull. Plumbing by Clay Brown.5. Drain plumbing with three-way diverter valve beneath a bathroom sink. Design by Brad Lancaster. Plumbing by Clay Brown.6. Drain plumbing with three-way diverter valve beneath a bathroom sink. Drain water goes through the sink drain, through P-trap, down the vertical pipe/vent stack (a one-way air vent (or air-admittance vent) sits atop the vent stack), to the 3-way valve. The vent creates an air break so water won’t siphon out of the P-trap. Jandy Valve-brand 3-way valves are available from pool and spa suppliers and OasisDesign.net. Design by Brad Lancaster. Plumbing by Clay Brown.
Greywater three-way diverter valve installed outside the house:
A bathtub/shower greywater “spring” directs drain water to a well-mulched and vegetated infiltration basin. A three-way valve (downstream of the P-trap and vent) in a valve box allows for distribution of greywater to either the landscape or the sewer. The end of the greywater pipe discharges 2 to 3 inches (5 to 8 cm) above the mulch in the basin to prevent roots from growing into the pipe and solids from backing up and clogging the pipe. Greywater immediately infiltrates beneath the surface of the mulch into the soil of level-bottomed basins to be used by plants. Image reproduced with permission from “Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition” by Brad Lancaster
Greywater three-way diverter valves NOT accessible in the room where the greywater originates, but made accessible with and electric switch conveniently located in the room where the greywater originates:
7. Diverter switch for three-way valve (for shower/bathtub greywater) in linen cabinet (closed) beside bathtub. Design by Leslie Buerk, KalyxStudio.com.8. Diverter switch for three-way valve (for shower/bathtub greywater) in linen cabinet (open) beside bathtub. Design by Leslie Buerk, KalyxStudio.com.9. Close-up of diverter switch for three-way valve (for shower/bathtub greywater) in linen cabinet beside bathtub. Design by Leslie Buerk, KalyxStudio.com.10. Closer-up of diverter switch for three-way valve (for shower/bathtub greywater) in linen cabinet beside bathtub. Design by Leslie Buerk, KalyxStudio.com.11. Electric actuator on three-way Jandy Valve that diverts shower/bathtub greywater. This actuator is connected to the switch in linen cabinet beside bathtub. Design by Leslie Buerk, KalyxStudio.com.12. Trap door (closed) to access hatch for three-way Jandy Valve which diverts shower/bathtub greywater and is wired to switch in linen cabinet and actuator on valve. Due to constricted space under bathroom floor (bathroom is on 2nd floor of house), the three-way valve could not be ideally installed with access hatch in the bathroom. Instead the access hatch is in the closet beside the bathroom. Design by Leslie Buerk, KalyxStudio.com.13. Trap door (open) to access hatch for three-way Jandy Valve which diverts shower/bathtub greywater and is wired to switch in linen cabinet and actuator on valve. Due to constricted space under bathroom floor (bathroom is on 2nd floor of house), the three-way valve could not be ideally installed with access hatch in the bathroom. Instead the access hatch is in the closet beside the bathroom. Design by Leslie Buerk, KalyxStudio.com.14. Trap door (open) to access hatch for three-way Jandy Valve which diverts shower/bathtub greywater and is wired to switch in linen cabinet and actuator on valve. Due to constricted space under bathroom floor (bathroom is on 2nd floor of house), the three-way valve could not be ideally installed with access hatch in the bathroom. Instead the access hatch is in the closet beside the bathroom. Design by Leslie Buerk, KalyxStudio.com.15. View within access hatch of three-way diverter valve with actuator switch
