If you experience a sewer backup, please call MAWC to report it as soon as possible. Reports must be made within 72 hours of the backup.
724-834-0966 (Monday – Friday 7:00 a.m. – 3:00 p.m.)
724-755-5800 (24 hours a day/7 days a week)
A MAWC employee will investigate to determine if there are any problems in the main sewer line, such as a blockage. If there is a blockage, the MAWC employee will take action to restore normal flow in the main sewer line as quickly as possible.
In some cases, the investigation may show that the backup was caused by an issue in the homeowner’s lateral line, such as root intrusions or grease buildup. If so, the homeowner is responsible for calling a plumber to resolve the problem.
In some instances, the MAWC employee may determine that the backup was caused by a surcharge of the main sewer line due to a rain event. This means that the main sewer line was hydraulically overloaded beyond its design capacity due to the inflow and infiltration of stormwater.
To prevent sewer backups due to a surcharge or a blockage in the main sewer line, one option that you may want to consider is the installation of a backflow device on your lateral line. Backflow devices (sometimes referred to as backflow preventers or backwater valves) are designed to prevent sewage backups. Backflow devices are available for installation by licensed and insured plumbers.
The following two videos illustrate what happens during a sewer surcharge without a backflow device. The first one shows a house with good plumbing (the lateral does NOT have inflow or infiltration of stormwater) and the second one shows a house with bad plumbing (the lateral DOES have inflow or infiltration of stormwater).
All video animations are courtesy of the Metropolitan St. Louis Sewer District, used with permission
Sewer Surcharge No Backflow Device (Good Plumbing)
Sewer Surcharge No Backflow Device (Bad Plumbing)
The next two videos illustrate what happens during a sewer surcharge with a backflow device installed on the lateral line. The first one shows a house with good plumbing (the lateral does NOT have inflow or infiltration of stormwater) and the second one shows a house with bad plumbing (the lateral DOES have inflow or infiltration of stormwater).
Sewer Surcharge with Backflow Device (Good Plumbing)
Sewer Surcharge with Backflow Device (Bad Plumbing)
Please note that if stormwater is getting into your lateral line behind the backflow device while the device is in the closed position, this stormwater can fill up the capacity in your lateral line and then back up into your basement. Allowing stormwater into the sanitary sewer system is prohibited. Not only can it cause problems for you if you have a backflow device installed, but it contributes to problems that may be experienced by your downstream neighbors. Just think – if every house had good plumbing that did not allow any stormwater into the sanitary sewer system, then the main sewer line would not surcharge and cause backups during heavy rain events!
MAWC would like to respectfully notify you that property damage resulting from sewage backing up into your home is the responsibility of the homeowner, not the Authority. Most insurance companies offer products to cover homeowners in the event a sewer backup. You can protect yourself from the unanticipated costs of a sewer backup by contacting your insurance agent.
We hope you will take the time to consider your risks and select any options that you feel best protect your property.