It's plumbing, but you're also expected to know where the water came from, the exact specifications of the treatment plant that cleaned it, exactly what is in t

It's plumbing, but you're also expected to know where the water came from, the exact specifications of the treatment plant that cleaned it, exactly what is in the water down to the parts per billion, and have ideas for what kind of faucet will make everyone trust the water the most. Also bonus if you know how to run a business and give guidance on what type of house to buy before putting in pipes.