It is generally safe to stay in a house that smells like sewage for a short time, but you should get the problem fixed as soon as possible. While the level of sewer gas is usually low enough to only cause minor symptoms, prolonged inhalation can lead to headaches, nausea, or respiratory irritation. High levels of gas exposure can be more dangerous, and high concentrations of methane—a component of sewer gas—can pose an explosion risk in enclosed spaces. If you smell sewer gas in your home, ventilate the area and call a professional to locate, assess, and fix the problem, as it will not go away on its own.

No, you typically cannot use metal detectors to find your sewer line. Most sewer lines are made of non-metallic materials such as PVC, clay, or cast iron, which are not detectable by standard metal detectors. Metal detectors are designed to locate metallic objects, so they won't be effective for identifying the path of a non-metallic sewer line. To locate your sewer line accurately, it's best to use other methods.

The cost to repair a main sewer line clog is about $3,110 on average. The average cost range is  $1,310 to $4,950, but it can go as low as $215 and as high as $9,300 or more. The cost factors for this repair include the severity of the clog, pipe accessibility, video inspection, removal method, permits, pipe material, labor rates in your area, and time of year. Repairs made from outside during the winter can be more difficult due to the frozen ground or during the spring if the ground is saturated from a lot of rain and snow melt.

If you don’t have a sewer cleanout, clearing out clogs can be extremely difficult. You would need to try to clear the clog from sink drains, but it can be harder to reach the clog all the way in the drain line. A sewer cleanout makes it much faster and easier for pros to clear clogs from your main sewer line.