Hi,

In my basement, the drain pipe to the septic system looks like the attached picture (I apologize for the poor picture quality here).

We had the vertical pipe capped prior to moving in at the recommendation of the home inspector. However, the pipe is/was was the drain pipe for the washing machine. The previous owner simply fed the outlet of his washing machine into the open end of this pipe.

For history, the home is 30 years old; we are the second owners. The washing machine has always been in the basement in this configuration.

(1) Is it safe to uncap this drain pipe and connect a small sump pump+check valve to it in a sealed fashion (where it's sealed to past the check valve)?

For example, am I likely to experience any dramatic changes in backpressure with a closed system that I wasn't likely to experience with the previous open system?

(2) Is it to ICC 2006 plumbing code to do (1)?

Thank you for your time in advance.

(1) Is it safe to uncap this drain pipe and connect a small sump pump+check valve to it in a sealed fashion (where it's sealed to past the check valve)?

Small detail - the sump pump would only be used to expel washing machine wastewater and dehumidifier water from a basin; e.g. a Drainosaur.

After talking with the plumber who capped the pipe, he noted that capping it in the first place was a bit of a silly thing to do, and that he'd feel like a crook for coming out to saw off the end of the pipe. For now, we're just going to saw off the end where the cap is.