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Buying a Home

What To Look For in a Septic System When Buying a Home

If you're buying a home in Alaska, you're likely to be purchasing one with a septic system. A septic system is effective, cost efficient, and easy to maintain. However, failing systems are a major source of groundwater pollution, cause waterborne illnesses, such as dysentery and hepatitis, and are expensive for homeowners to replace.

Educate Yourself Before Purchasing a Home

The Department of Environmental Conservation put this guide together to introduce you to some of things you should do to protect yourself from an unforeseen expense and the surprise of having to replace your newly purchased home's septic system.

For starters you'll want to visually inspect the septic system, get a copy of the design and construction records from the department's online SEPTS and review the previous owner's maintenance records.

The top warning signs of septic system failure:

  1. Slowly draining sinks and toilets
  2. Gurgling sounds in the plumbing
  3. Plumbing backups
  4. Sewage odors in house or yard
  5. Ground wet or mushy underfoot over the drainfield
  6. Grass growing faster or greener in one area of the yard
  7. Drinking water tests showing presence of bacteria

None of these warning signs is a sure indicator that a system has failed, but you should investigate further if one or more of these signs is present!

Check The Record

Unlike the other parts of a house, the septic system is difficult to see! However, you can check the records on a home's septic system by contacting your local Department of Environmental Conservation office, or if you live in Anchorage, you may check with the Municipality.

These records should reflect:

  1. The age of the system. If properly designed, installed, and maintained, a septic system can effectively treat household wastewater for up to 20 years or more. Look to see if the house has a system that is near the end of its life-span.
  2. The size of the system. Size is important because graywater (laundry water, sink water) and blackwater (toilet water) need to be retained in the tank for at least a day or more to allow solids to separate from the liquids and begin breaking down. If wastewater is pushed through without proper settling, the solids can clog the drainfield, stressing and possibly damaging the system. Adequate tank size is 1,000 gallons for a home with up to three bedrooms plus 250 gallons for each additional bedroom in the home.
  3. The location of the system. Knowing where the tank and drainfield are will help you visually check the area for obvious signs of failure. In addition, poorly sited drainfields can result in septic system failures. Location of the system in relation to wells, other septic systems, slope of the land, natural drainage patterns, underlying soil conditions, and lot boundaries may indicate potential problems with the septic system and should be reviewed by you or a professional.

Tip: Keep an eye out for previous certifications from the Department; these should indicate that the system is in compliance with good septic system standards, or will indicate any waivers that were granted and why.


Proper maintenance can add years to an older system. Even well-designed and properly installed septic systems can fail earlier than expected if previous homeowners did not perform routine maintenance.

Try to determine how frequently the tank has been pumped from the realty agent or owner. Ask to see maintenance records. Keep in mind the necessary pumping frequency depends on the size of the household and the size of the tank. For example, a four-bedroom home with a 1,250 gallon tank should be pumped approximately every 2.6 years. Modern conveniences such as garbage disposals, hot tubs, or whirlpools will increase the necessary pumping frequency.

Special thanks to PIPELINE, a quarterly publication of the National Small Flows Clearinghouse, for providing information used in this guide.

How to maintain your system

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