I had to do something similar to trace about 1/4 mile of 2" irrigation line. The product I used was a armadatech pro290 and 150' metal fish tape. The fish tape was sent up the pipe, and the pro290 transmitter was connected to the exposed fish tape. Then I used the pro290 receiver to find where the fish tape was.

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https://armadatech.com/upcp_product/pro290/

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edit: check your local tool rental company to see if they have something similar