SEWER SEALS
The Envirosafe Sewer Seal is a patented device that retrofits existing catch basins and pump drain hubs, thereby eliminating the necessity for major modifications to existing sewer system that may be required in order to attain compliance with EPA Air Quality regulations on emissions of hydrocarbon and toxic gases from sewer systems. The Envirosafe Sewer Seal, when installed in an existing catch basin, establishes a water seal at grade level that prevents the escape of hydrocarbon and toxic vapors to the atmosphere, thereby complying with EPA requirements for water seals on sewer systems.
Sand, dirt and gravel that wash into catch basins during normal day-to-day operations can plug sewer systems and generate an enormous amount of solid/hazardous waste that requires disposal. With disposal cost continuously rising, millions of dollars will be spent annually disposing of hazardous waste. The Envirosafe Sewer Seal, when installed in an existing catch basin, provides a means for trapping and collecting 70% to 90% of any sand, dirt or gravel before it has a chance to enter the underground sewer system. Trapping these solids at grade level allows for easy removal and reduces the cost of cleaning catch basins and sewer lines. The Envirosafe Sewer Seal, by helping to prevent the generation of solid/hazardous waste, can save companies millions of dollars annually.
The Envirosafe Catch Basin, also patented, not only incorporates all the advantages of the Envirosafe Sewer Seal, but also can be used as an alternate or replacement for concrete catch basins and pump drains currently in use. Concrete catch basins, over a period of time, will normally develop cracks that allow hazardous materials to leach out and contaminate the surrounding soil. Depending on the area of the country, pilings or other means of support may be required to support the weight of a concrete catch basin. The Envirosafe Catch Basin, being lightweight, eliminates the need for supports.
Environmental issues more often overshadow safety. The Envirosafe Sewer Seal and Catch Basins, when utilized to comply with EPA Air Quality Regulations, provides safety features unequaled by anything currently available for sealing catch basins and pump drains prior to performing hot work. Sealing combustible gases from the atmosphere using the Envirosafe Sewer Seal or Catch Basin virtually eliminates the possibility of an ignition source igniting the combustible gases and causing a sewer explosion.
Envirosafe Sewer Seals or Catch Basins Versus P-Traps
P-traps are accepted by EPA as a means of establishing a water seal. However, there are many problems associated with using a p-trap. The water seal in a p-trap is normally not visible, making it very difficult to determine if a proper water seal is present. In fact, some state regulatory agencies are now requiring that the water seal in a p-trap be visible. Should a line with a p-trap become plugged for any reason, it can become a major maintenance problem to unplug the line. A p-trap, in most cases, will not allow use of a “snake,” commonly used with hydro blasting equipment to unplug lines. The Envirosafe Sewer Seal or Catch Basin places the water seal at grade level where it is always visible for inspection, thus eliminating the guesswork about whether there is a proper water seal. Lines that become plugged are very easily cleaned by simply removing the weir cover.
Hydrocarbons will float on the water seal of a p-trap and the Envirosafe Sewer Seal or Catch Basin. Hydrocarbons floating in a p-trap are extremely difficult to remove. This poses a safety as well as environmental problem prior to hot work or an environmental inspection. Since the p-trap is underground and not visible, hydrocarbons floating on the water seal may go undetected and emit combustible gases and/or hazardous air pollutants. Flushing a p-trap is not always successful, because it requires a large quantity of water to create enough turbulence to mix the hydrocarbons with water, so they can be flushed through the p-trap. Water treating is a very costly process, therefore, the less water required to flush a pump drain could result in a significant savings in water treating cost.
The Envirosafe Sewer Seal or Catch Basin takes advantage of the fact that hydrocarbons float on water. Additionally, the Sewer Seal or catch basin is easy to clean. Simply remove the cap, run water into the trough and the floating hydrocarbons are washed over the weir. Since the water seal in the Sewer Seal or catch basin is at grade level and visible, you can easily see when all the hydrocarbons have been flushed through the drain, thereby reducing the amount of water required. Replace the cap and you have a safe, hydrocarbon-free water seal.
Locating the water seal at grade level not only provides the required water seal against hydrocarbon emissions, but it also provides an excellent safety feature by eliminating the possibility of a spark igniting combustible sewer gases and resultant sewer explosion. P-traps have a shallow water seal that allows combustible or toxic sewer gases through the water seal because of pressure surges in the sewer system. When this occurs, combustible and toxic gases can build up leaving the pump drain out of environmental compliance and putting it in the category of an “accident waiting to happen.”
Design new sewer systems to meet EPA and state compliance regulations for QQQ, B-1, HON and for API Standard API RP 500 Type 1 Open Drain utilizing ESSCO area drains.
Design new sewer systems to meet EPA and state compliance regulations for QQQ, B-1, HON and for API Standard API RP 500 Type 1 Open Drain utilizing ESSCO area drains as junction box or manhole.
Venting the Sewer System
Sewer systems have always been designed as open channel flow. EPA regulations such as QQQ, B-1 & HON requiring the sealing of sewer systems from the atmosphere have changed the sewer design to closed channel flow. Closed channel flow design makes venting of the sewer system more critical to maintain flow. Venting normally occurs at junction boxes throughout the system, but additional vents may need to be installed to maintain proper flow. Some refineries vent to a carbon canister system and some vent to a scrubber and flare system Other refineries vent to the atmosphere. Sewer systems not properly vented can vapor lock and stop flow. The sewer system must be able to get air (breathe) in order to flow properly. A sealed sewer system can pull a vacuum and cause seals at grade to fail, leaving the drain out of compliance. ESSCO has developed a vent seal system that allows the sewer system to breathe during normal operating conditions, while not emitting VOCs to the atmosphere.
