1/2 too small, you want minimum 3/4 inches, better yet searc
1/2 too small, you want minimum 3/4 inches, better yet for sewer lines, go search rigid brand sectional c11 and up, 1 1/4 works best, usually they go around $3-4000 but on ebay there is company sells a xerox version, comes in yellow instead of gray, with 100 fts of cable, for about 1600$