The series has followed property expert Sarah, her husband Graham Swift and their four sons as they build a new home on a former dairy farm in Somerset, surrounded by 220 acres of farmland.
 
Like thousands of other UK rural properties, their new building plot is not connected to a mains sewer. 
 
To ensure that waste from the kitchen sink, washing machine, bathroom and WCs was correctly disposed of, Sarah’s team contacted Klargester to set up a site review to establish the best wastewater treatment system to serve both the family’s new home and the adjoining annexes. 
 
Klargester has more than 70 years’ experience in drainage management and the company employs a nationwide team of off-mains engineers to support its market-leading range of Klargester private drainage solutions.  It adds up to a best-in-class support package for homeowners that have to manage their wastewater within the boundaries of their properties. 
 
An old, failing, septic tank that had served the occupants of the original farmhouse but was now clearly redundant gave an early indication of the site’s likely requirements.
 
Chris Yeates, Klargester’s Sales Director conducted a site visit.  He explains: “We established fairly quickly that this site would not support a septic tank.
 
“Septic tanks only allow the settlement of solids; most of the work of cleaning the wastewater of its pollutants and removing any remaining suspended solids is done by its drainage field.  However, this cleansing process can only happen if the ground conditions allow the waste effluent to be filtered as it seeps downwards through the soil.  That cannot happen if the drainage field is based on a clay substrate and/or the water table is less than a metre from the surface. In this case, we were faced with both clay soil and a high water table.
 
“We advised the family to install a sewage treatment plant – in this case a Klargester BC BioDisc.  A sewage treatment plant is highly effective at treating wastewater, removing up to 95 percent of pollutants before discharging the effluent into a drainage field to finalise the process.” 
 
The team also found the ideal location for the treatment plant, 20 metres from the house and close to a stream. 
 
Chris continues: “It’s important to say that a septic tank cannot legally discharge into a flowing water course because the effluent is too polluting.  But a sewage treatment plant is permitted to do so because the effluent is very clean. It’s also important to opt for a wastewater treatment plant which is EN 12566-3 compliant, such as the Klargester BioDisc."

Klargester Accredited Installer Mark Ward from Ward Environmental Services was contracted to project manage the installation in line with Environment Agency requirements.  He applied for permission to put in a wastewater treatment plant and this was granted under the General Binding Rules. 
 
Mark explains: “The family wanted a solution that met all the current regulations and therefore would have a minimal impact on the environment.  Private drainage solutions have to deal with complex waste that may include cleaning products, residue from cooking, as well as human waste. They can be highly polluting if they are incorrectly specified and not looked after, so for this reason they should never be considered as ‘flush and forget’ installation.”
 
Chris also made certain that the treatment plant was sized in accordance with the needs of the household and its annexe accommodation.  He advises: “Sizing a treatment plant correctly is vital to its future effectiveness. You must consider the numbers of individuals who will be creating the waste, and the loading that will be placed upon it.  An off-mains drainage system which is too small, for example, will quickly become overwhelmed.
 
The family’s drainage now meets all the requirements of the General Binding Rules which govern off-mains drainage in England and, finally, there is a service plan in place for annual maintenance, all of which will be logged as part of an on-going asset register.” 
 
The sewage treatment plant and its pipework were installed in late 2020.