The main cause of septic failures is too much water. It overflows the tank and forces solids into the septic field where it clogs. Low-flow faucets, toilets, and other fixtures are a great way to reduce this risk. If you do laundry at the cottage, stagger loads over several days. You could also consider installing a no-flush urinal.
You should minimize the amount of fats and oils that go into any drain system, as these materials will slowly build up and block the pipes. Once in the septic tank, that can bind with other solids making it harder for the bacteria to break things down. Also, don’t use a garburator at the cottage. Your septic system won’t be able to break the material down and you’ll need to have the tank pumped out more frequently.
Limit the use of antibacterial products at the cottage, particularly things such as soap and household cleaners that will get flushed into the septic. Large amounts of these products—or other strong disinfectants such as bleach or toilet bowl cleaners—can actually kill off the essential bacteria in the tank and render your system inoperable.
Anything that isn’t biodegradable should not get flushed down the drain. These things will accumulate in the tank or clog the weeping bed if the get flushed out. This includes feminine hygiene products, condoms, diapers, “disposable” wipes, and other plastics. Also, don’t flush cigarette butts for the same reason.
Yep, you read that correctly. In some circles, there’s a rural legend that if you have a seasonal cottage you should drop some raw meat—often in the form of roadkill—to “kickstart” your system for the start of the season. That’s not only not true, but the fur and bones could clog up the system.
Never flush unneeded medications down the drain (at the cottage or at home). Not only do you risk impacting the bacteriological activity in the tank, if they flush all the way through the system, they can end up in the lake where research has shown that some drugs have negative impacts on local wildlife. Most pharmacies will collect and safely dispose of surplus or expired medicine.