Does the Michigan Plumbing Code require a backwater valve? 

Yes. Section 175 of the Michigan Plumbing Code is dedicated to backwater valves on sanitary sewage drainage systems. If your home was constructed before the Michigan Plumbing Code required a backflow preventer, then you are not required to retrofit your home to install one. 

What should I check to see if a backwater valve is needed? 

Check to see if plumbing fixtures are lower than the street in front of your home and/or for a steep uphill street outside your home.

Who is responsible for the installation and maintenance of backwater valves? 

The property owners. 

How often should I check the backwater valve and what does it entail? 

You should check and maintain the valve at least once a year. Flush the mechanism and surrounding pipe with a hose during maintenance to clear any accumulated ebris from the area. 

Can backwater valves be used as a cleanout? 

No! Anytime a sewer snake passes through a backwater valve, damage can occur to the valve flapper or the finished seating surface against the flapper seal. 

Do I need a permit for a backwater valve? 

Yes. A plumbing permit is required. 

Where can I buy a backwater valve? 

Valves are sold through plumbing supply warehouses and sometimes, home improvement stores.