"When drainfields become saturated with water, they can't efficiently drain the wastewater from the holding tank" said Barbara Wright, Manager of Wastewater at Public Health - Seattle & King County. "Poor drainage may mean slow fixture drainage, sewage back-up or even total system failure."

What to do during a major rain or flood:

• Eliminate all non-essential water use
• Reduce toilet flushing
• If your drainfield is covered with water, do not use the system until the water has receded
• Avoid contact with sewage if there is a sewage back-up. Contaminated water can cause disease

Call an OSS (on-site sewage) professional immediately if you notice any of these problems:

• Water on the drainfield that does not subside after the rain stops
• A bad odor/sewage smells
• Wastewater backs up into house
• Slow running drains, especially after laundry loads
• Sewage surfacing anywhere

Typical winter rains and even additional seasonal water use add extra stress to septic systems that may lead to premature system failure or costly repairs. A well-maintained septic system is better able to withstand the stresses of heavy rains or flooding.

Take advantage of these tips for optimal system functioning:

• Get the septic tank pumped every 3-5 years
• Hire an On-site System Maintainer to regularly monitor your OSS
• Reduce water use to minimize impact on drainfield
• Don't use a garbage disposal
• Don't use septic additives
• Use "eco-friendly" household cleaners
• Flush only toilet paper
• Run full loads of dishes and laundry and spread usage throughout the week

More information about OSS operation and maintenance may be found at: www.metrokc.gov/health/wastewater