If your home has a septic system, everything that rinses down any drain in the house—from the laundry sink to the bathtub to the toilet—finds its way into that tank. Avoid pouring cooking grease into a sink drain. It can clog your system. Photo by Tan Wei Ming

That drip-drip-drip from a leaky bathroom faucet or running toilet does more than waste water and annoy your family. If your house has a septic system—and thousands in northern Arizona do because they’re not hooked up to a city sewer system—a leaking faucet could be flooding your drainfield.

The drainfield—also called a leachfield—is the area on your property where your septic system’s pipes deposit the water from the tank into the ground. The water sinks deep into the soil, where natural bacteria break it down and convert it into nutrients. The remaining liquid evaporates or penetrates far beneath the surface.

That is, unless the surface is saturated. If your drainfield is taking on more water than it can absorb, it never has a chance to dry out and make room for more water.

As long as your family is awake, you’re sending water to that drainfield. Every time you flush the toilet, take a shower, brush your teeth, rinse the dishes or wash a load of laundry, water is flowing down a drain someplace in your house.

Fix dripping faucets as soon as you notice them. Not only do leaks waste water, they keep your septic system’s drainfield saturated, which can flood your yard.

That water—along with the waste, food scraps, grease and soap that wash down the drain with it—flows to your septic tank, where it sits for a few days. Natural, beneficial bacteria in the tank break down and liquefy the solid waste before your tank sends the liquid through pipes to the drainfield, where it soaks into the soil.

When your family clears out of the house for a day of school or work, or when everybody tucks in to sleep overnight, you give the drainfield a break. Sure, someone might wake up for a quick trip to the bathroom, but for the most part, nobody’s using much water for hours at a stretch, so the drainfield has a chance to dry out.

A running toilet or a leaking faucet, on the other hand, sends a steady drip of water down the drain all day and all night. All of that water winds up in the drainfield, so it stays saturated all the time. By the morning, when everybody wakes up and starts taking showers and rinsing the breakfast dishes, the drainfield just can’t absorb any more water.

When the drainfield overflows, you’ll have a soggy yard and you might even see standing water. This isn’t healthy; that water came from your drains and toilets. Plus, standing water in your yard can create a disaster if it finds its way under your house, where expansive clay soil is supporting your foundation. When that soil gets wet, it tends to swell, and the swelling can push on your foundation enough to crack it.

Trust me: It’s cheaper and easier to fix a leaky faucet than it is to repair a cracked foundation.

Don’t throw any personal or household products into a toilet that empties into a septic system. Items like paper towels and baby wipes are slow to biodegrade, so they linger in the system and can clog the pipes and cause problems.

A trickling toilet very often is simple to stop by replacing the flap inside the tank. A leaking faucet often is caused by a worn-out washer, which will cost you about $1 to replace.

Your house will tell you when something is wrong. Pay attention to that drip-drip-drip. It might not be as innocent as it sounds.

For more do-it-yourself tips, go to rosieonthehouse.com. Rosie Romero is an Arizona contractor who has been in the Arizona home building and remodeling industry for 35 years. He has a radio program from 8-11 a.m. Saturdays on KAZM (780 AM) and KQNA (1130 AM).