“Drain carry” is a catchy term for the more technical phrase “The Drainline Transport of Solid Waste in Buildings.” Plumbing contractors and drain-line specialists will understand the challenges associated with clogged drains better than anyone since they are the ones who get the calls and see what gets put down the drain. Plumbing engineers may not always understand the implications of a design if they strictly adhere to the code, especially if they are under pressure to use low-flow fixtures for conservation measures.
As a foundation for public health, plumbing codes outline basic principles that public health is achieved “through properly designed, acceptably installed, and adequately maintained plumbing systems.” Plumbing systems should “… be installed, designed, arranged, constructed and maintained to protect against fouling, deposit of solids, and stoppages.”