How can I find the drain barrel in backyard?
I live in a slab ranch,about 50 yrs old. My kitchen drain is clogged, we snaked it 50 feet, ran into nothing. Mind you the bathroom just off the kitchen is not affected, so we know that they are a separate drain system. Two years ago, kitchen clogged and plumber came and snaked it, saying we probably had a drain system in backyard for graywater from kitchen. He most likely just stirred things up a bit, getting the barrel to drain a bit. If I run the disposal while running water or the dishwasher(which isn't hooked up to disposal but goes into a branch of the same drain pipe as kitchen, it keeps water from backing up in the sink... A retired plumber said we need to pump out barrel in backyard. My problem is, no evidence of lid cover for said drain barrel is visible. How can I find it? (Without backhoeing the backyard?) and how much will it cost, roughly, to have it pumped out once I find it? I'm in New England?)