anybody got problems with roots getting into sewage pipes, water, and gas line?
what fruit trees would have the most aggressive root system?
A friend of mine had a Lychee tree with root getting into the main sewage pipe. If you don't have better information, plant fruit trees at least 5 feet away from sewage pipes and keep the trees small by pruning them every year.
If you really want to plant some near the pipes, try the dragon fruit plants (their roots stay around 1 foot deep). Dragon fruit plants grow very well in OC and the fruits are 1000 times better than the imported ones from supermarket.