Better fertilize them with some black water!

I have several volunteer tomatoes growing along the banks of my creek right now. I dumped some freezer burned frozen tomatoes into my creek in the spring. It is actually more of a storm water runoff ditch but usually has some water in it.

True that. They'd probably be better fertilized if they came down the bathroom drain.

Better fertilized, but possibly less safe for eating. There's good reasons why untreated human waste isn't used on food crops.

By the same token, I'm not particularly interesting in eating food that is irrigated with grey water. Grey water itself is not considered potable. Though this grey water is not showered on the plants. It is delivered directly in the ground. That's safer.

I had a HUGE garden at our first house 50 some years ago. Our laundry water discharged into a sump that was pumped into the not-so-good drainfield. I discovered that by turning a handle I could discharge that water to the outside instead. A hose quickly sent all that lovely water to the garden instead. I had the biggest, healthiest, heavily-producing plants in the whole rural area.

So, I think there might be more fertilizer in that water than you imagine. 😄

The question wasn't about fertilizer in grey water. Laundry detergent has loads of N and P. But grey water also has the potential to carry bacteria and viruses, so not good to eat what you spray it on. But if delivered to the roots, it can serve well.