How a Sanitary Sewer System Works
A sanitary sewer system carries sewage (from sinks, toilets, showers/bath tubs, washing machines) from homes and businesses through privately-owned sewer laterals or pipes to publicly owned sewer mains, which are usually in the street, and then to the wastewater treatment plant located on North Washington Street.
The sewer mains and the wastewater treatment plant are owned and operated by the Evans City Water & Sewer Authority.
A storm water sewer system carries rainwater from streets, parking lots, sidewalks, and roof leaders (or downspouts) to publicly owned sewer mains, which are owned and operated by the Municipality of Evans City and not the Authority.
Infiltration and Inflow
This extra flow may not seem like a major problem, but when Evans City experiences a heavy rainfall it can cause sewage to backup into homes or overflow manholes and run down our streets.
During heavy rainstorms large amounts of water, which is supposed to flow into the normally separate storm sewer system, instead often finds its way into the sanitary sewer
Homes that have downspouts connected to the lateral are contributing Inflow by bringing rainwater directly into the sewer system. Likewise, floor drains and sump pumps connected to the laterals are also sources of Inflow. Even the curb vents or cleanouts in your yard or sidewalk may play a role. If the vent is loose or lies below grade, rainwater can enter and flow into the sanitary sewer system.
Infiltration is a less obvious problem because its source is underground. Tree roots can cause breaks or cracks in your lateral, allowing water in the ground to seep into the broken pipe. Sections of sewer pipe under your yard or sidewalk may have separated over time, providing another way for water to enter into the sewer system.
Most people don’t realize how minor sources of I&I can add up to a major problem. One or two downspouts connected to laterals doesn’t seem like a big deal, but when downspouts from hundreds of homes are tied into the sewer system, they can create a major surge during a rainstorm. And even if I&I is not having a direct impact on your property, it could be contributing to a sewer backup into your neighbor’s basement down the street.
I&I is not limited to private homes. Public sewer mains also become broken and cracked, and rainwater can seep through the pipe as well as the joints in manholes. So, the solution to I&I can only come through the efforts of both the Authority and the residents and businesses of Evans City.
This issue is more important now than ever. The costs of operating the treatment plant are rising and are to a large extent dependent on the amount of sewage flowing through the facility. As a result of I&I, it is not unusual for the flow during a heavy rainfall to be six or seven times the normal flow. Higher flows from I&I mean higher operating costs, which in turn mean higher sewer rates.
One of the ways the ECWSA is tackling the problem of I&I is by requiring Dye Testing and Video Lateral Camera Inspection of homes at the time of transfer or sale.
What is Dye Testing?
A dye test is conducted to determine whether or not your home plumbing is properly connected to your city’s sewer system. Colored, florescent dye is added to various areas where storm water might flow into the sanitary sewer system.
Dye testing is a simple procedure where storm drains, yard drains, and the outside of the foundation walls of a house, or other areas are flooded with water to simulate a heavy period of rainfall.
During inspection, the inspector checks your yard drain, driveway drain, subsurface drain, and ensures that they are not connected to a sanitary only sewer.
If colored dye shows up on the camera in the building lateral, then it is evident that there is a defect in a given area in the private sanitary sewer line.
What is a Lateral Video Inspection?
During a lateral inspection, a camera attached to a cable (pictured below) is inserted into the inspection tee where the interior of the building lateral can be seen on a monitor.
An operator monitors the camera to see if any water infiltrates and drains into the building lateral.
The operator is able to see if there is any root infiltrations or cracks in the sewer line. During the inspection, the inspector will also dictate and create a graph drawing to help locate the lateral and main for any necessary repairs.
Why is testing so important?
Everything wears out!
Even though all of these items are completely unrelated in their uses,
they all have something in common. Cars, roof shingles, and socks are all items that everyone purchases and replaces when they get old.
Why should your private home’s sanitary sewer lines be any different? As a homeowner benefiting from the public wastewater treatment system, it is your responsibility to make sure the sewage lines in your home are properly maintained and not contributing infiltration to the public sewer system.
Infiltration into the sanitary sewer line can be caused by many different things.
Tree roots can grow into the pipe joints and cause small cracks which eventually expand and become worse over time.
Removing the tree might prevent future damage from getting worse, but any existing damage will remain.
Deteriorated joints in the pipe can also be a source of infiltration. In addition, stress causes the pipe to warp and crack allowing infiltration to enter the sewer.
Infiltration of storm water and groundwater into the sanitary sewers is the biggest problem the Evans City Sewer Authority faces.
The problem is important enough that the federal government has ordered the states to ensure every house passes dye testing.
Selling or Buying a Home
If you’re selling your home you will be required to schedule a dye test and lateral video inspection. Typical fees range from $150.00 – $800.00. ECWSA’s inspection fee is $200.00. Tests are typically ordered by closing companies, but applications are also available at our office or at www.ecwsa.net
Having a sewer line inspection prior to purchasing a property is proactive in making educated buying decisions, planning for any upcoming maintenance, budgeting for necessary repairs, or to gain valuable purchase price negotiation.
What to Do If You Fail a Dye Test / Inspection
The ECWSA Sanitary Sewer Rules & Regulations provides valuable information about how to proceed should your home fail inspection. Information such as application procedure and specific materials and construction methods for lateral replacement, as well as other important information is available there.