The drainage industry and the environment

The drainage industry is key to long term environmental sustainability in a multitude of ways, many of which would not be immediately apparent. This article by the National Association of Drainage Contractors aims to identify these, as well as set out how the industry is addressing them

This paper does not comment on the well-documented issues that surround the water companies’ discharge of waste into rivers and the sea and the damage that is being done to our environment due to underinvestment in sewage infrastructure. Rather, it focuses on everyday drainage issues that do not form part of the water company sewer estate.
    
The most obvious impact that drainage can have on the environment is in respect to pollution. Illegal dumping of waste has been a problem for many years with irresponsible contractors avoiding the cost and inconvenience of using designated waste sites. This can take a number of forms, from simply lifting up manholes and discharging waste illegally into public sewers to emptying tankers into farmers’ fields. Such behaviour damages the environment with human waste entering water courses. It also damages the industry, both by disadvantaging responsible contractors who take the time and trouble (not to mention cost) of discharging waste legally, and by bringing the drainage contractor industry into disrepute.
    
Then there is the issue of mixed and cross connections whereby clean and foul water waste are either combined or directed to the wrong drainage system. Simply this may result in foul waste entering clean water run off systems, and vice versa, or the systems simply being combined for the sake of expediency. Of course, it is not the drainage contractor industry that causes these problems; generally it is developers and the construction industry. However, the drainage industry does have the opportunity to identify such problems and either correct them, or report them to their customers for them to address. Indeed in some cases, contractors may report such issues to relevant authorities for action such as on large scale residential or industrial developments.
    
Off grid drainage systems are also an issue with either inappropriate sewage management system installations and poor (sometimes completely absent) maintenance. There are of course legal provisions in play here (which differ in England and Wales), but there are few outside of the drainage industry who can identify these issues, and know how to correct them.
    
Of course, there is the more visible impact of backed up drains through blockages in homes, public buildings and commercial premises which can cause their own environmental damage, not to mention health issues. The drainage industry routinely deals with such challenges using ever more sophisticated equipment and technology, such as CCTV, high pressure water jetting, electromechanical repair and patching and lining. In such circumstances there are some that refer to it as the fourth emergency service, and there is no doubting the industry’s position as the fourth vital utility alongside water, gas and electricity.
    
But it doesn’t end there. The drainage contractor industry also covers such disciplines as highway and gully maintenance, oil separator and interceptor maintenance, road sweeping and large site (such as airport) sweeping and cleaning. Many of these activities require the extraction of water from water hydrants, and this is an environmental issue in its own right.
    
Highway and gully maintenance is very topical at this time. It has become customary, using advanced tanker vehicles, to clear gullies on highways and separate solid and polluting substances from ‘grey’ water, and then to use that water to flush down the gullies after clearing them - this is known as decanting. The solid and polluting waste is then disposed of at an approved waste centre. As the nearest approved centre can be many miles away, this technique saves many long and unnecessary tanker journeys reducing cost, but more importantly, carbon emissions. The reason that the subject is topical is that current Environment Agency rules do not permit grey water decanting, probably because the rules were put in place before vehicle technology enabled grey water separation from solid and polluting waste. More about this later!
    
Oil and interceptor waste management is something that the average person would know nothing about! Petrol stations and restaurants are required to have separators/interceptors to separate water from oil to limit pollution from waste from these sources. In effect, the devices trap the oil and store it to be removed through regular maintenance.

Unfortunately, whilst there are some responsible petrol station operators and restauranteurs who are conscientious about maintenance, the vast majority are not. This results in unnecessary pollution, and can be attributed to a total lack of enforcement of what is a legal requirement. The UK can learn from countries like Ireland that are very proactive in ensuring compliance with maintenance regulations.
    
Sweeping activities are more straightforward, but to avoid environmental damage, operators must dispose of waste in a responsible manner.
    
And so on to the issue of hydrant use. Water accessed from hydrants does of course belong to the water companies, and they generally prescribe the standpipes that contractors must use to extract water, which should take place with the appropriate license. Unfortunately, there is substantial water theft that takes place with irresponsible contractors using unauthorised standpipes to take water illegally without a license. Whilst this in and of itself is not damaging to the environment, it is the case that improper standpipe use can result in foul water contamination of clean water supplies, which is a real problem for the water companies.
    
The other environmental impact from the drainage industry is from vehicle carbon emissions. The industry employs thousands of vehicles varying from small vans to very substantial tankers which are on the road all the time. There is limited use of electric vehicles now emerging, but the reality is for large tankers, the battery power required to propel them make them impractical. The industry believes that hydrogen power will provide much greater opportunities to move away from fossil fuel powered vehicles, as has been demonstrated by JCB.
    
So how has the industry been addressing all these issues? Well, a little over ten years ago two small contractors in London formed a body called the National Association of Drainage Contractors (NADC). With encouragement from Defra, NADC set about establishing a training and certification regime primarily to ensure that all contractors and their engineers and operatives became aware of health and safety issues which can impact on them and the general public. The regime also set about certification in the use of all the services that contractors provide and the equipment and vehicles that they use.
    
As the Association grew, some four years ago, it established an Environment and Waste (E & W) Committee to focus on the issues that have been highlighted above. In addition, a new approved contractor scheme called DrainSafe was launched in 2021 which was unashamedly modelled on the existing Gas Safe and Water Safe schemes. The E & W Committee engages with Government and other appropriate stakeholders to address issues such as gully maintenance and hydrant use. It also issues guidance to contractors on issues such as oil separator/interceptor maintenance, off-grid sewage management systems and mixed/cross connections.
    
DrainSafe, as the approved contractor quality mark, exists to uphold the highest standards in the drainage industry with the intention of stamping out illegal activities and poor quality service. It is there to support responsible contractors to operate on a level playing field and to eliminate ‘cowboy’ operators from the industry. As a by-product of this, there will be substantial benefits to the environment by policing of the issues for which the E & W Committee is responsible. DrainSafe will also enable customers (residential, commercial and private sector) to identify those contractors who act responsibly towards the environment.
    
There is a long way to go in ensuring that all avoidable environmentally damaging activity caused by drainage issues is addressed, but the drainage industry is determined to play its part.