I am going to cut a sewer pipe some 30 feet from the house to do some repairs. I live in area where big roaches are in the sewer. I wonder if they will actually run away once they hear the noise or if they will in my way. I don�t love roaches (who does?) but I wonder if there is a way to get them out of my way while I am doing the repair. I can access the inside of the sewer pipe from a cleanout, which is right by the house and I have some chemicals for killing roaches but I am not sure if that could hurt the environment. I know this is more pest control problem but I wonder if anybody has some experience with it. Thanks.