Roots from trees and shrubbery protruding above the tank or drainfield could clog and/or rupture them. Trees that are right inside the vicinity of the concrete septic tank hold the likely to penetrate the tank because the system ages and also the concrete starts to develop cracks and tiny leaks. https://www.prlog.org/12986538-mastering-septic-tank-cleaning-expert-tips-for-healthy-home-and-environment.html