Safety and maintenance tips

Find and maintain your vapor traps, roof vents and floor drains. This can prevent sewer backups and exposure to sewer gas.
u-shaped pipe under a sink


Vapor traps 

Also known as P-Traps

How to identify

  • U-shaped pipes visible under sinks
  • Present in some form on all lines draining into the sewer system

What they do

  • Hold water and prevent gas from backing up from sewer


Maintenance tip

  • Periodically run water in all bathroom and utility room sinks so your vapor trap doesn't dry out.

If they dry out

  • Gases from the sewer system can enter your building 
silver vertical vent near the peak of a shingled roof


Roof vents

Also known as vent stacks or exhaust vents

How to identify

  • They will be located on the highest point of your roof

What they do

  • Allow air to flow in and out of your property's plumbing system
  • The air flow helps water flow through your pipes


Maintenance tip

  • Check roof vents periodically to make sure they are not blocked by leaves, snow or ice. 

If the vent is blocked

  • It can impact the flow in your sewer system.

round, brown drain on cement floor



Basement floor drains

How to identify

Drains are usually located near:
  • Water heaters
  • Furnaces and air conditioners
  • Washing machines

Maintenance tip

  • Once a month, pour a bucket of water down each floor drain to make sure it's working.



If the drain is clogged

  • You might hear gurgling noises in your drains or toilets
  • Water might begin to collect on the floor
  • Sewage can begin to back up

Never put fats, oils and grease (FOG) into pipes or drains

FOG can clog your pipes and lead to costly repairs. Use this tips for cleaning greasy dishes and cookware.

Contact us

Surface Water & Sewers

Public Works




Public Works
Surface Water & Sewers Division
309 Second Ave. S.
Minneapolis, MN 55401-2268


Monday – Friday
7 a.m. – 3:30 p.m.