WHAT is a Sanitary Sewer Evaluation Study (SSES)?
An SSES is a thorough inspection of the sanitary sewer system to locate problems that may be occurring in your neighborhood.
WHY should we find and fix sanitary sewer problems?
Sewer pipes are designed to carry only wastewater to the treatment plant. However, many sewer pipes end up having to carry ground water and storm water that enters the system because of leaks, improper storm drain connections, breaks, and other faults. This excess water is called Inflow & Infiltration (I&I), and it takes up room in the sewer system that should be used for wastewater alone.
HOW is a Sanitary Sewer Evaluation Study (SSES) done?
Luckily, there are a wide variety of ways to evaluate a sewer system. One or a combination of the following evaluation tools will be used to evaluate the system:
Flow Monitoring: Monitors the flow of water through the system during wet and dry weather.
Smoke Testing: Identifies defects or improper connections by blowing odorless and non-toxic smoke into the sewer. When there are no problems, smoke will only be seen from the roof vents of each building that is connected to the sewer. When there are problems, smoke will be seen where there are defects. Since it can be unnerving to see smoke when it is not expected, 48 hours before testing door hangers will be placed on or given to the owners of buildings and homes that will be in the test area. Local Police and Fire officials will also be notified so they are prepared if citizens who have forgotten about testing happen to become alarmed.
Manhole Inspections: Allows information to be gathered on the direction of sewer pipes and also identify some I&I. Some manholes are located on private property. This may require inspection crews to enter your yard.
Internal & External Building Surveys: Identifies and evaluates drains, downspouts and sump pumps located on and within private property. Upon being given permission to enter private property at a convenient time, inspection crews will locate sump pumps and drains (usually located in the basement).
Closed Circuit Television (CCTV): Done by inserting a small robotic devices with a television camera through the sewer main or from a building cleanout toward the sewer main to locate and identify sources of I&I such as leaks, cracks and broken pipe.
Dyed Water Testing: Biodegradable and non toxic fluorescent dyes that are placed in downspouts, area drains and low lying lawn areas to identify sources that are deteriorated, broken or incorrectly connected to the sewer system.
Surveying: Collects elevation data about the sewer system as well as basement elevations throughout the project area, and is used to assist with developing a hydraulic model and proper construction methods if a new sewer system is needed.
Wet Weather Inspections: Conducted during heavy rainfall to determine areas that overflow or flood, and observe how the sewer system reacts. In other words, this particular inspection helps determine how well the sewer system is working during wet weather.