Drip irrigation isn't always good for trees to develop robust root system. Wastewater depends ... residential greywater can be used onsite if the residents are

Drip irrigation isn't always good for trees to develop robust root system. Wastewater depends ... residential greywater can be used onsite if the residents are careful about the type of detergents they use. There are methods to treat blackwater onsite (more than just a septic tank and a leech field). For trees, I think the biggest factor is if you use woodchips in a basin. Even a six-foot diameter with 1 ft depth, filled with arborist chips makes a huge difference in water retention and nutrition for the trees. These are rain water harvesting structures that do not require a drip system.