About septic systems

Tips to save water and maintain your septic system 

Household chemicals

Don't pour household chemicals or medication down the drain.

Chemicals destroy bacteria in your system that are necessary to break down solids.

Call the Public Health Hazardous Waste Line at 206-296-4692 to ask about chemical disposal.

Long-term use of medications, such as antibiotics, may also destroy important bacteria in your septic tank and drainfield. Visit the Washington State Medicine Disposal Program site for safe disposal of unwanted medications.

Don't use septic tank additives.

These products may be harmful by adding extra solids to the system that can clog your drainfield. The chemicals can also pollute groundwater and surface water. If you feel you must use additives, be sure to use only those that have received written approval from the Washington State Department of Health. It is unlawful to use any non-approved additive.

Don't drain water from hot tubs into your septic system.

Large volumes of water can 'drown' your drainfield, and chlorine can destroy important bacteria in your septic tank and drainfield. Drain hot tubs away from the system, especially the drainfield.

For disposal options, call King County's Water and Land Resources Division at 206-477-4800 or email them at WLRCustomerService@kingcounty.gov.

Bathroom

Did you know that residences use the most water for flushing toilets? Each person flushes 18.5 gallons per day!* Toilets, showers, and faucets represent more than 70% of indoor water use.

You can lower your water use in the bathroom by following these easy tips:

• Repair leaky faucets and toilets. Slow leaks, such as a dripping faucet, can generate 15 to 20 gallons (57 to 76 liters) of wastewater per day.*
• Use "low flow" fixtures on faucets and shower heads (available at most hardware stores)
  • Faucet insert: slows water flow
  • Faucet aerator: adds air to spread water flow
  • Reduced flow faucet: faucet built for low water flow
  • Mixing valves: one fixture that regulates hot and cold water
• Take shorter showers.
• Turn off water while brushing teeth or shaving. Fill your sink halfway with water to rinse your razor.

Flush only bodily wastes and toilet paper down the toilet. Products labeled as "flushable" may not be suitable for a septic system.

Think before you flush

It's important to keep a careful eye on actions that may affect your sewer or septic system.

Download flyers to learn more:

• Think Before You Flush (658 KB)
• Piensa antes de bajarle (Spanish) (552 KB)

Kitchen

Helpful tips to save water in the kitchen:

• Run only full loads in the dishwasher.
• Don't run the dishwasher and washing machine at the same time.
• Keep water in the refrigerator to avoid running water until it gets cold.
• Don't run the water while washing dishes.
• Rinse fruits and vegetables through a colander into a bowl, then use leftover water to water your houseplants.
• Keep faucets tightly closed.
• Use 'low flow' fixtures on faucets.
• Fix leaky faucets.

Laundry

Helpful tips to save water in the laundry room:

• Use the load size setting and proper water temperature.
• Run full loads in the washing machine.
• Don't run the dishwasher and washing machine at the same time.
• Consider a water efficient washing machine.

Does it matter what kind of laundry soap I use?

Current research indicates that it doesn't matter which you use, powder or liquid. What matters:

• How much detergent you use per load.
• How often you wash clothes or dishes.

An important way to maintain your system is to do loads of wash over several days rather than all in one day. Use the dishwasher sparingly, too.

Remember: the system works best when wastewater has time to separate, and the bacteria have time to break down the organic matter. Too much water going into the system too often rushes water through the system too fast.