5 Signs You Need Trenchless Sewer Repair ASAP

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Trenchless technology is a type of subsurface construction work that requires few trenches or no continuous trenches. It is a rapidly growing sector of the construction and civil engineering industry. It can be defined as "a family of methods, materials, and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities."^[1][2]

Trenchless construction includes such construction methods as tunneling, microtunneling (MTM), horizontal directional drilling (HDD) also known as directional boring, pipe ramming (PR), pipe jacking (PJ), moling, horizontal auger boring (HAB) and other methods for the installation of pipelines and cables below the ground with minimal excavation. Large diameter tunnels such as those constructed by a tunnel boring machine (TBM), and drilling and blasting techniques are larger versions of subsurface construction. The difference between trenchless and other subsurface construction techniques depends upon the size of the passage under construction.

The method requires considering soil characteristics and the loads applied to the surface. In cases where the soil is sandy, the water table is at shallow depth, or heavy loads like that of urban traffic are expected, the depth of excavation has to be such that the pressure of the load on the surface does not affect the bore, otherwise there is a danger of the surface caving in.^{[citation needed]}

Trenchless rehabilitation includes such construction methods as spiral wound lining, sliplining, thermoformed pipe, pipe bursting, shotcrete, gunite, cured-in-place pipe (CIPP), grout-in-place pipe, mechanical spot repair, and other methods for the repair, rehabilitation, or replacement of existing buried pipes and structures without excavation, or at least with minimal excavation. Mechanical spot repair is applied where damaged pipelines require the reinstatement of structural integrity. Sliplining, CIPP, and thermoformed pipe lining involve pulling or inverting a new liner into an existing pipe, then applying heat and/or pressure to force the liner to expand to fill the pipe. CIPP technologies combine a carrier (felt or fibreglass) impregnated with heat, ultraviolet light, or ambient curable resin to form a "pipe within a pipe". Pipe bursting fractures a pipe from the inside and forces the fragments outwards while a new pipe is drawn in to replace the old.^[3] The other methods are primarily for fixing spot leaks. Trenchless rehabilitation methods are generally more cost-effective than traditional exhume (dig) and replace methods.

The trenchless technology industry is represented by several industry associations in addition to standing committees within almost every water and sewer related industry association. The International Society for Trenchless Technology, established in 1986, has 25 active national trenchless technology societies associated with it.

In the UK, the United Kingdom Society for Trenchless Technology (UKSTT) was established in 1993. UKSTT offers a Trenchless Enquiry Service to assist people in all area's of trenchless technology.

In the US, The National Association of Sewer Service Companies (NASSCO) was established in 1976 and is the oldest such association with a trenchless focus. The North American Society for Trenchless Technology (NASTT) was established in 1990.

Several organizations bring out technical Journals for sensitizing the readers about such techniques.

• Trenchless Technology Magazine
• United Kingdom Society for Trenchless Technology
• How Trenchless Technology Works
• Center for Underground Infrastructure Research and Education CUIRE
• China Hong Kong Society of Trenchless Technology CHKSTT
• Trenchless repair in Canada

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A drain is the primary vessel or conduit for unwanted water or waste liquids to flow away, either to a more useful area, funnelled into a receptacle, or run into sewers or stormwater mains as waste discharge to be released or processed.

In most systems, the drain is for discharge of waste fluids, such as the drain in a sink in which the water is drained when it is no longer needed. In the UK, plumbers refer to waste water as "bad water", under the premise that the water they are moving from one area to another via the use of a drain is not needed and can be removed from the area, like a "bad apple" being removed from a fruit bowl.

Drain design and installation parameters are engineered to ensure drain functionality for its intended purpose, allowing for variances in volume, matter to be conveyed and maintenance requirements. Drain installation takes into account principles related to gravity, vacuum, grade, health hazards from biological agents, and resistance to functional failure. Also incorporated in drain design are requirements to allow drain maintenance and repair of a blocked drain, such as cleanout access.^{[citation needed]}

In systems such as swimming pools or fountains where waste fluid is recirculated, the drain is the input to the Recirculating Pumping machine. These fixtures can be very dangerous because people do not expect to encounter more than the head pressure of water above the drain when contacting a drain. When there is a recirculating pump, the force of suction consists of the head of water, plus the suction of the pump (up to a maximum of 1 atmosphere).

Fatalities have occurred around drains as a result of suction entrapment (also known as pool suction-drain injury). In these situations, a portion of the body, hair, or clothing may become stuck against the drain and may become impossible to release, resulting in drowning. For example, in 1994, Cristin Fitzpatrick drowned in a Variety Village swimming pool when her hair became entangled in a water funnel.^[1]

Properly designed drains in swimming pools and spas mitigate this hazard by either adding multiple drains, or increasing the surface area of the drain opening with the use of many holes or safety covers. Since drain suction increases rapidly when a portion of the drain flow is blocked, having two drains or a larger drain inlet allows alternative suction paths for the inflow. Also, swimming pool safety devices are available to automatically turn off an operating pump if a rapid increase in suction is detected, as could happen during a suction entrapment incident.

While fear of the drain may be counterproductive, children should be taught not to intentionally touch or attempt to block components of a swimming pool recirculation system.^{[according to whom?]}

Since children often play in public fountains, the use of multiple drains is a mandatory safety feature, regardless of whether or not the architect or planner intends that the fountain be used as an aquatic play feature. This is to ensure minimal risk of plumbing entrapment, but vandals can sometimes break into drains in the night time and remove the covers (commonly known as "drain mugging"), leaving them in a hazardous condition.

On December 17, 2007, the national Virginia Graeme Baker Pool and Spa Safety Act was passed into law in the US. This law seeks to bring an end to suction entrapment related injuries and deaths by incorporating consumer protection regulation of pool and spa drains.

A drain cover is a cover with holes (e.g. a manhole) or a grating used to cover a drain, to prevent unwanted entry of foreign objects, or injury to people or animals. It allows drainage of liquids but prevents entry from large solid objects, and thus acts as a coarse filter. A sink drain cover is a drain cover used to cover the sink drain.^{[citation needed]}

• 
  A metal grating covering a storm drain
• 
  A stone drain cover, ancient Roman architecture at Vindobona, Austria.
• 
  A sink drain cover and a plastic sink plug

Blocked drains are a common problem in bathrooms and kitchens. In some cases, a chemical drain cleaner can clear the blockage, or a drain snake or augur can be used to mechanically clear the blockage. Disassembly of drain pipes can be an effective method of clearing severe blockages, especially if caused by the presence of a solid object. Sometimes, a licensed plumber is needed to rectify more fundamental issues with the installation.^{[citation needed]} Blocked drains, if left long enough, can develop into a health hazard as the presence of mold and bacteria increases.^{[citation needed]}

The American Society of Mechanical Engineers publishes the following standards:

• A112.6.3 – Floor and Trench Drains
• A112.6.4 – Roof, Deck, and Balcony Drains