We’ve explained how deep-rooted plants can damage a septic tank from the outside, but plenty of things can ruin it from the inside, too. For example, flushing bulky items (like paper towels, diapers, and wipes) can clog your septic tank. Cooking oil, grease, and household chemicals can also harm your system. And since a new septic system costs between $3,460 and $11,450, it’s worth following these guidelines.

Disposing of old paint, bleach, oil, and fertilizer should be handled by a company that specializes in this kind of waste. Many private junk removal companies do not dispose of these items. Because these materials are hazardous to the environment and dangerous to handle or dispose of improperly, you should confirm with your local municipality about places to take hazardous materials for safe disposal. 

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.

Depending on the home, wastewater either goes into a septic tank and seeps back into the backyard or is sent via sewer system to a local sewage-treatment plant. Septic systems naturally separate different components of the waste so that it can naturally and safely disperse it. They are usually reserved for homes not served by a municipal sewage department (like rural homes). A treatment plant, on the other hand, speeds up that process through screening and purification.