SBS™ - Small Bore Sewer™

The Small Bore Sewer ™ (SBS™) is a watertight small diameter wastewater collection system that provides servicing with superior operational and environmental performance at a significantly lower cost as compared to historic gravity sewers.

Clearford’s patented effluent sewer systems have successfully been in operation throughout North American communities since 1989, and all of these SBS™ serviced communities are positive references.

Key among its unique and value-added features, the SBS™ system:

• Operates effectively in various climate and water flow conditions, and is an ideal servicing option for challenging installations in communities with extremely low daily water usage rates and/or low sewage generation flows;
• Produces an effluent quality which enables treatment to a potable standard;
• Eliminates groundwater infiltration and inflow, and prevents aquifer contamination by ex-filtration, due to the thermally sealed materials stipulated in the system design;
• Is installed at shallow depths allowing for a reduced need for heavy equipment, less disruption to the community and its existing infrastructure, and the ability to employ local labour;
• Has been designed to convert waste solids to an alternative fuel source, biogas (methane), resulting in a reduction in the overall volume of sludge to be treated and elimination of the requirement for solids delivery, handling and disposal;
• Allows for captured biogas (methane) to be used to generate electricity; thereby reducing greenhouse gas emissions by eliminating the discharge of biogas (methane) into the environment;

With the SBS™ as the enabling foundation technology, Clearford delivers, on a global basis, turnkey, fixed-price wastewater collection, treatment, and energy generation solutions.

Clearford’s Distributed Digester:

Clearford’s Distributed Digester is a decentralized primary wastewater treatment and methane capture and conversion facility. The Digester produces bio-gas as a result of the conversion of bio-solids to biogas (methane). The design of the digester has been optimized for hydraulic mixing to achieve maximum conversion, and uses non-mechanical, passive processes to collect and convey the methane to the collection hub or methane conversion facility.

The Digester separates solids from liquids, and contains and directs a predominantly solids-free liquid effluent by gravity through small diameter pipes to the treatment plant. The quality of the effluent is reflected in significantly reduced contaminant concentrations – with total suspended solids reduced by 80%, biological oxygen demand by 29%, total Kjeldahl nitrogen by 25% and total phosphorus by 14%.

The Digester has unique attributes that promote anaerobic digestion and methane generation including passive hydraulic mixing, passive heat retention, and higher interaction between new substrate and old anaerobes. All of this means that solids are effectively eliminated at source.

As well, proprietary attenuation devices buffer surge flows, resulting in fewer design requirements for collection and treatment, and a resulting reduction in cost for these components.

High Density Polyethylene (HPDE) Piping

Clearford’s SBS™ uses small diameter, fused-joint High Density Polyethylene (HPDE) piping for its collection mains, laterals and clean-out access points. This pipe is stronger, more resilient and more flexible than conventional PVC sewer pipe, and has a design life of over100 years, compared to 35 years for PVC. HPDE requires minimal bedding, offering a more flexible range of layout possibilities. One roll of HDPE delivers up to 350 meters of pipe. All connections, bends and appurtenances are welded on-site to create a sealed, leak-free piping system that completely eliminates groundwater infiltration into the sewer system and the potential for sewage leaching into the environment, and ensures consistent and predictable operation and maintenance costs – the lowest of any sewage collection system.

Installation of Piping

HPDE piping allows two simple installation options – open cut (digging small, shallow trenches) or trenchless technology (TT) using horizontal directional drilling (HDD).

Both installation options cost significantly less than traditional sewers, can be installed in a fraction of the time using local labour, and have a minimal impact on the environment. In addition, the open cut method and the sealed nature of the HDPE piping allows common trenching to be used for both water and wastewater.

Clean-Out Access Holes

SBS™ maintenance clean-out access holes are vertical extensions of the HDPE sewer main system and are designed along the sewer routing for future access for flushing the piping system. The clean-out housing is constructed with high-grade, durable HDPE ribbed culvert materials, and a secured cast iron bolt-on lid. The maintenance access holes can be installed in any accessible location along the piping route. There is no scheduled maintenance of the pipe network for the life of the system. The only elements of routine maintenance are the effluent pump stations which are installed on an as-required basis to deal with gradient requirements.