Buying a Home With a Septic System? Here's What Buyers Should Know
A home can look great during a showing while one of its most important systems is completely out of sight.
More than 1.3 million Michigan homes and businesses rely on septic systems. For buyers, especially those considering acreage, lake properties or homes outside municipal sewer areas, understanding the septic system should be part of the due diligence before closing.
A septic system isn't necessarily a negative. The important thing is knowing what you're buying.
How Does a Septic System Work?
A conventional septic system has two main components:
Septic tank: Wastewater enters an underground tank where solids settle to the bottom as sludge and oils and grease rise to the top as scum.
Drainfield: Liquid wastewater leaves the tank and is distributed through the drainfield, where the surrounding soil provides additional treatment.
Some properties have more complex systems with pumps, alarms, controls or alternative treatment components.
Because most of the system is underground, its condition can't be determined simply by walking through the house or checking whether the toilets flush.
What Happens During a Septic Inspection?
The exact process depends on the property and type of system, but a septic evaluation can include:
Reviewing permits, installation records, pumping history and previous repairs
Locating the tank and drainfield
Opening and inspecting accessible tanks
Measuring sludge and scum levels
Checking the tank, inlet and outlet piping for deterioration or damage
Inspecting the effluent filter when present
Testing pumps, alarms and controls when the system has them
Examining the distribution system
Walking the drainfield for standing water, wet soil, odors or other signs of failure
Michigan EGLE recommends pumping when a tank is more than one third full of sludge and scum. EGLE also recommends inspecting tanks, filters, pumps, alarms and the drainfield as part of routine system evaluation.
A recently pumped tank alone shouldn't be confused with proof that the entire septic system is functioning properly.
Don't Forget the Drainfield
The tank gets most of the attention, but the drainfield is a critical part of the system.
Warning signs can include standing wastewater, unusually wet or spongy ground, sewage odors, plumbing backups and unusually lush vegetation over the system.
What is above the drainfield matters too. Vehicles, heavy equipment, structures and certain landscaping can interfere with its operation. Michigan EGLE identifies root infiltration as one of the leading causes of septic system failure in the state.
Ask for the Records
Before or during the inspection period, buyers should try to obtain whatever documentation is available.
Useful records may include:
Original permit or system design
Approximate installation date
Tank size and system type
Location of the tank and drainfield
Pumping history
Repair and maintenance records
Previous inspection reports
Local health departments may have septic permits, drawings and other historical information that isn't immediately available from the seller.
Septic Requirements Can Change by County
One of the most important things Michigan buyers and sellers should understand is that septic and well requirements aren't necessarily the same from one community to another.
Some counties have Time of Sale, point of sale or property transfer programs involving septic systems, private wells or both. Other counties don't require an evaluation simply because ownership is changing.
In Southeast Michigan, requirements and programs can differ among counties including:
Wayne County
Washtenaw County
Macomb County
Livingston County
Requirements can also change over time and may depend on the property, type of system and local jurisdiction.
For that reason, buyers and sellers should check with the county or local health department responsible for the property early in the transaction. They can provide current information about required evaluations, permits, records, water testing, septic requirements and any procedures associated with transferring the property.
Don't assume that the process used for one Michigan property will automatically apply to another.
A government required evaluation also shouldn't automatically be considered a replacement for a buyer's own due diligence. The purpose and scope of a required evaluation may be different from the inspection a buyer wants when deciding whether to purchase the property.
What If the Property Has a Private Well?
Many septic properties also rely on a private well.
Michigan EGLE recommends private well owners inspect their wells and routinely test their drinking water. Buying or selling a home with a private well is specifically identified by EGLE as a reason to test the water.
The relationship between the well and septic system also matters because wastewater must be properly treated while the well needs protection from potential contamination sources.
Buyers can review Michigan EGLE's private residential well information for additional guidance.
Questions to Answer Before Buying a Home With Septic
Before the inspection period ends, try to answer:
Where are the tank and drainfield?
How old is the system?
What type and size of system is installed?
When was it last pumped?
Are maintenance and repair records available?
Has the system ever backed up or failed?
Does it have pumps or alarms?
Does the property also have a private well?
Has the drinking water been tested?
Does the local health department have system records?
Are there local Time of Sale, point of sale or transfer requirements?
Has a qualified septic professional evaluated the system?
The General Home Inspection May Not Be Enough
A general home inspection and a septic inspection aren't necessarily the same thing.
Different properties can require different specialists. Depending on the home, that might include septic, well and water testing, sewer scope, chimney evaluation, structural evaluation or another specialized inspection.
Understand What's Underground Before You Buy
A septic system can provide decades of service when it is properly designed, used and maintained. The risk for a buyer is not simply that a property has septic. It's buying without understanding the system's condition, history and local requirements.
The kitchen, layout and backyard may get your attention during a showing, but some of the property's most important components are the ones you can't see.
If you're considering a home in Metro Detroit or Southeast Michigan, search homes for sale with SoldByCaleb and make property due diligence part of the buying process.
You can also explore recently sold homes throughout Southeast Michigan when researching neighborhoods and property values.
Sources: Michigan Department of Environment, Great Lakes, and Energy, U.S. Environmental Protection Agency, and local Southeast Michigan health departments.