If you're not on a municipal sewer line, you need to keep a regular eye on your septic system. Basically, it consists of a tank that collects wastewater from your house. Inside the tank, solids settle to the bottom and bacterial action starts to break down the waste. Liquid waste flows out of the tank and into the ground through a series of perforated pipes (your septic field), which further filters the water (it may also flow into a second holding tank, where it's pumped out into the field). Eventually, the semisolid sludge at the bottom of the tank will need to be pumped out by a sewage contractor.

The key to maintaining a healthy septic system is to limit what goes into it. No products other than toilet paper should be flushed (even if they say they're flushable), kitchen scraps should be composted (not put through the garbage disposal), and chemicals or kitchen grease should never be put down the drain (not even drain cleaners; use augers instead). You should also be aware that bacterial “boosters” for the tank haven't been proved to work and, in fact, can throw off the bacterial balance.

Too much water flowing through the system can take solid waste into the liquid waste pipes, so fix any running toilets or leaking faucets, and don't overload the system with too much water at any one time. For this reason, water from gutters and swimming pools should never be directed into the septic system.

You need to check the sludge level in the tank at least annually. Open the tank access and place a long stick or piece of thin lumber into the tank. When you bring out the stick, it will be wet up to the level of the liquid in the tank, but it will be stained up to the level of the sludge in the tank. If the sludge level is higher than one-third or halfway up the tank, call a contractor to pump it out.

If water isn't draining into the septic system properly, and an auger doesn't find any drain blockages, call in an expert immediately. The problem may be a blocked pipe, a full tank, or bacteria levels that have dropped too low. Fixing the problem right away might save you from cleaning up sewage backup.

To help your septic field stay healthy, keep trees and large shrubs away from it (their roots can break into the pipes), and don't allow heavy trucks to drive over it. If you notice a sewer odor in your yard, or unusual grass growth or murky water sitting in or near where the pipes drain into the septic field, call in an expert. Your field may have failed or become blocked, contaminating the ground with sewage.

Keeping your outdoor spaces well maintained, from driveways to decks, makes your house feel welcoming. Unfortunately, the great outdoors brings some unwanted guests, ranging from carpenter ants and termites to rodents and even deer. While this chapter helped you make your house and yard welcoming to people, Chapter 9 will help you make your house unwelcome to pests of the animal variety.