One area that often raises questions during underwriting and appraisal is the wastewater system, specifically whether the home uses a septic tank or a cesspool. While both are off-site sewage systems, they function very differently, and those differences can impact Michigan home loan approvals. Here’s what Michigan borrowers should know.
Septic Tanks: The Modern Standard
Septic systems are the most common and widely accepted private sewage systems in Michigan, especially in rural and lakefront areas. Modern septic tanks are typically constructed from reinforced fiberglass, though older systems may be made of concrete. These tanks are watertight and designed to treat household wastewater before it is properly returned to the environment. Here’s how a septic tank works:
- Wastewater flows from the home into the tank
- The contents are separated into three layers:
- Scum (organic matter) floats to the top
- Sludge (solid waste) settles at the bottom
- Clear effluent remains in the middle
- Bacterial action breaks down organic material over time
- The treated water slowly exits the tank and filters through the soil, safely returning to the water table
Because septic tanks actively treat waste and are sealed systems, they are generally acceptable for Conventional, FHA, and other Michigan home loan programs, provided they pass required inspections.
Cesspools (Cesspits): Older and Higher Risk
Cesspools, also known as cesspits, are far more primitive systems and are much less common in modern construction. Unlike septic tanks, cesspools are essentially holding pits for raw sewage. Key characteristics of cesspools include:
- Sewage collects in a pit and leaches directly into the surrounding soil
- Minimal treatment of wastewater occurs
- Solids are expected to decay at the base of the pit
- Because they are sealed holding systems, they require frequent pumping
- They are far more vulnerable to:
- Flooding from heavy rain
- Snow melt (a serious concern in Michigan)
- Groundwater contamination
Cesspools pose a greater environmental and health risk, which is why many lenders and municipalities view them unfavorably during the mortgage process.
Additional Risks with Cesspools in Michigan
Cesspools face unique challenges in Michigan due to climate and soil conditions:
- Tree root intrusion can penetrate the pit walls
- Root growth can cause blockages, overflows, or system failure
- Raw sewage may back up into the home
- Overflow can breach the hatch and flood the yard or the surrounding property
- High water tables increase the risk of contamination
Because of these risks, cesspools often trigger lender conditions, repair requirements, or outright ineligibility depending on the loan program.
How This Impacts Michigan Home Loans
For Michigan buyers and homeowners:
- Septic systems are generally acceptable with proper inspections
- Cesspools may:
- Require replacement before closing
- Trigger escrow holdbacks
- Limit financing options
- Be ineligible for certain loan programs
Knowing what type of system a property uses before you go under contract can save time, money, and stress. If you’re unsure whether a property uses a septic tank or a cesspool, or how it affects your Michigan home loan, it’s best to address it early, before underwriting does.
