The septic system industry is a fragmented one, filled with contractors married to the traditional gravel-style systems, and lots of mom-and-pop gravel pits for them to choose from, Newbold said.

• 化粪池系统的行业是一个零散的，充满了承包商已婚传统砾石式系统，以及大量的妈妈和弹出砂石坑让他们选择，纽伯德说。