Sewer lateral work is where high value search and real revenue meet
The queries worth building a program around are the ones attached to a replacement, not the ones attached to an hour of drain cleaning.
Drain cleaning searches are the most contested phrases in the trade. Franchises bid them, national brands rank for them, and the customer often has no memory of who came out. You will get some of that work anyway. You should not design a content program around it.
Replacement work is different. Sewer lateral replacement, cast iron and galvanized repiping, water service line replacement, backwater valve installation and camera inspection all have searchers who read before they call. Those pages can be won by a local shop because the answers are local. What the line is made of, where it runs, how it is reached under a raised house, and what a camera actually shows are all questions a national template answers vaguely or not at all.
Give each of those jobs its own page. Describe the work in order, say what changes when the house sits on piers versus a slab, and explain what a homeowner should ask before signing anything. Ranges and allowances are fine if they are yours and you keep them current. Do not publish a number you would not honor.
Then link the cheap pages to the expensive ones. A homeowner who searched for a slow drain in Mid-City and read your page about repeated backups is one internal link away from the page that sells a camera inspection.