When your drainfield is failing, the grass above the area will be overly bright and spongy, as the wastewater from the septic tank is fertilizing the lawn.
If the root of the problem is not addressed, raw sewage could eventually be on the lawn, which is an environmental hazard. Do not touch this kind of grass in the meantime.
If there aren’t clear sources of drain clogs, the tank might be too full to take in more water. Clogged drains can be inconvenient at best and sanitation issues at worst.
Septic tank gurgling is not the same thing as the knocking or clanging that plumbing pipes can make, and you’ll likely hear them more loudly when you flush the toilet or run water.
This gurgling will come from multiple drains and sounds more like a hollow, bubbling noise. It can be a red flag for a full tank or more serious issues.
Test your well water at least once a year for nitrate levels with a testing kit from a retailer or an accredited lab. If your well is contaminated, your septic tank may be full.
Non-biodegradable things like paper towels, diapers, plastic, and chemical drain cleaners should never be flushed. They can cause more problems in septic tanks or the pipes.