Low-Pressure dosing or LPD is a common alternative to having an aerobic septic unit. These systems use the conventional anaerobic septic tanks with the addition of a pump tank. The state of Texas allows these systems to be installed in heavy clay soils. The disposal field is much like a gravity-fed conventional septic system in that it has a ditch with rock in it. But typically speaking, the ditches are 1 foot wide and the distribution pipe is 1-inch schedule 40 with a hole drilled every 5 foot down the length of the pipe. These systems use an effluent pump to pressurize the lines and also have valves in place to balance the flow of effluent to ensure even distribution. The downside to these systems is high installation cost and if a water table is detected then these systems are no longer a viable option. As with any in-ground system overloading the disposal field with too much water in too short a period may result in a wet yard to say the least.