The United Kingdom is one of relatively few nations to have privatised its provision of water and treatment of wastewater, thereby turning water into an industry.

Water industry regulation

The services provided are still subject to government regulation: in the case of the United Kingdom, by the Drinking Water Inspectorate, The Water Services Regulation Authority (still familiarly referred to as “OFWAT”, after being known for some years as the Office of Water Services) and by the Environment Agency. These bodies issue directives for the management of water both as a safe and standardised product and as a resource, and therefore the industry must concern itself not only with providing water for consumption, but minimising its over-all use in the interest of environmental sustainability.

Major UK water companies

Municipal water industry work is shared by what are referred to as the “Water Companies”, public limited companies (PLCs) who govern geographic areas within the UK. The ten major water PLCs are:

• Anglian Water
  
• Dwr Cymru (also known as Welsh Water)
  
• Northumbrian Water
  
• Severn Trent
  
• Southern Water
  
• South West Water
  
• Scottish Water
  
• Thames Water
  
• United Utilities
  
• Wessex Water
  
• Yorkshire Water
  

These companies subcontract work to specialised consultancies and contractor companies.

 

Water resources

Because of the requirements of environmental protection, and the inescapable need to exploit water as a resource, a wide variety of roles have come to exist with the industry. The most profound human impact on water today involves extraction: the taking of water from both surface bodies and underground sources such as aquifers. Water may be taken directly from natural sources such as rivers and lakes, or from man-made collection points, such as reservoirs. River dam and reservoir construction requires the expertise of civil engineers, who are capable of calculating the physical stresses that will be tolerated by these structures. The extraction of water from underground sources calls upon not only the skill of these engineers, but also the knowledge of geologists and hydrogeologists, who understand the difficulties of evaluating and accessing the resource below.

Sustainable water consumption, reducing water pollution and lessening the effects of floods and droughts all help to preserve water as a resource, not just for humans, but for the entire ecosphere. These demands require the expertise of scientists from a variety of disciplines. Ecologists work from the perspective of what our actions are doing to the ecosphere, while biologists in turn look at how the deterioration of the environment will impact upon us. Much work is done to protect and improve aquatic and wetland habitats, and it is not only the water industry that is required to make provision for the natural environment. Studies are undertaken to gauge the impact of irrigation and the run-off of agricultural fertilisers and pesticides into waterways. Contaminant modelling can reveal pollutants in groundwater, stemming from both agricultural and industrial sources. Surface water modelling, undertaken by hydrologists, can reveal how extraction may lead to low water levels, or how rainfall may contribute to flooding and infiltration of water courses. Consultancies extend advice to contractors and the privatised water companies (PLCs) to whom they supply services, ranging from ecological surveys and environmental impact assessments of intended building sites, to assembling building proposals which conform to industry requirements.

Water treatment

Water must first be purified before being distributed to consumers. The initial process of pumping water into clean water treatment works (WTWs) draws upon the skills of civil, mechanical and electrical engineers, who construct pumping stations, as well as building treatment facilities. Telemetry systems lend a certain degree of automation to these plants, requiring installation by specialist engineers, and later monitoring by technicians.

Water is treated to remove both biological and chemical contaminants before its supply to consumers. It is within water treatment that chemists and chemical engineers often work under the title of Process Technician or Process Engineer. Potable water treatment is done in three stages: primary, secondary and tertiary. The primary stage involves screening, which separates coarse materials from the water, but also provides pre-conditioning if the water itself is considered “hard” (i.e. has a high level of calcium carbonate). The secondary stage can entail further mechanical separation on a much finer scale (sand or membrane filtration, for example), as well as chemical treatment. Causing contaminants to “fall out” of the water as precipitate is a process known as sedimentation, and this can be done through filtration or encouraged through chemical means including coagulation and flocculation, which bond contaminants together for easier removal. Research, development and particularly sales of water treatment chemicals are integral parts of the industry.

The tertiary stage of clean water treatment is largely concerned with disinfection. Disinfection, too, can involve the addition of chemicals such as chlorine, but may also involve further physical processes such as UV radiation and subjecting the water to ozone in an effort to kill micro-organisms. Minimum standards dictate that water is safe for consumption, but consumer demand often requires that water be further improved in terms of appearance, smell and taste. Water may again be conditioned to adjust for relative “hardness”, or subject to the addition or extraction of fluoride. As with any industry, customer satisfaction is an important issue, and water companies employ inspectors and customer services staff to liaise with the public over any concerns.

Water distribution

Once treated, potable-quality water is distributed to end-users through a network of mains. Monitoring of flow and detecting any possible loss through leakage can be undertaken through dataloggers and meters, which are installed along the networks. Any leakage is addressed by engineers who have a variety of means for its detection, some of which are non-invasive, such as acoustic monitoring with the aid of “listening sticks”. The installation, maintenance and operation of the distribution network generate several fields of employment, which may fall under the remit of utility companies, or of specialised contractor companies and consulting engineers.

Consultancies provide expertise in mapping networks and helping to set up DMAs (District Metering Areas), as well as analysing water consumption patterns for the information of water companies. GIS operatives, network modellers and statisticians all have roles to play within this aspect of water usage. Computer modelling is undertaken throughout many stages of water engineering, and may be applied to water supply and distribution, sewerage and drainage, treatment processes, and even used to anticipate the potential behaviour of rivers in times of heavy rainfall and flood. Because of the wide range of applications for modelling, demand for capable staff is traditionally high in this area.

Waste water treatment

We have been discussing roles that relate to water before it reaches the consumer, but it must not be forgotten that owing to the cyclical nature of water use and its return to the environment, the effective treatment of wastewater is also an important industry. Wastewater is not merely that which we use and return to the system via sewerage pipes, but also includes the domestic “grey water” which leaves our homes and the rain water which finds its way into storm drains as surface run-off.

Primary treatment again filters out large or insoluble components from wastewater. Contrary to potable water treatment, however, the objective of the secondary phase is to biologically break down solids, rather than to chemically encourage their cohesion. Micro-organisms are introduced to digest organic material and may be used to populate filter media through which the wastewater is made to pass. The sludge which remains after the break-down process is dewatered and can then be disposed of, or oxygenated to form an “activated sludge”, which can be used as a catalyst to further digestion. Wastewater and sewage treatment plants (WWTWs and STWs) are increasingly including tertiary treatment in their processes, allowing for discharge of better quality water back into the environment. The science behind these processes yields opportunities for research into new and improved methods of treatment, particularly as government guidelines bring discharge into close scrutiny.

A relatively new area within wastewater research is examining the particular problems posed by fats and greases, which impact on water mains, as well as water treatment. Because of the rigors that drainage and sewerage pipes are made to withstand, technology also continues to evolve around laying pipes and maintaining those already in situ. “Trenchless technology”, pipe-bursting and slip-lining are techniques making the work of sewerage engineers less invasive, and in many cases, less costly.

As with any industry, cost-effectiveness is always a concern, and many roles within water have a commercial element to them. The building of water or sewage infrastructure and plant draws upon the skills of estimators, quantity surveyors and buyers to project costs, but water industry work must first be awarded by water companies to subcontractors and consultancies who tender for the business. This is done in accordance with the AMP, or Asset Management Plan; a five-year programme to ensure needed work is undertaken in a manner that is cost-effective for consumers. Hence bid managers and proposals engineers who can calculate costs not only in materials but also man-hours (allowing also for a profit margin) are an integral part of the industry.

Once the work is secured, design, contracts and projects teams progress the contract from the proposal stage. Site managers, resident engineers, site and commissioning staff put the design into realisation. The project and contracts team will continue to have involvement at this stage, in order to ensure the work is completed to prescribed time, budget and safety standards. The commissioning stage of treatment plants may see the return of process engineers who help with start-up, ‘trouble-shooting’ and in some cases, run the works for a trial period after hand-over.

Equipment companies provide a wide range of items to the industry as a whole, ranging from pumps to scientific equipment such as analysers, with some providing single package solutions such as skid-mounted plant which can be used in locations where large-scale treatment works would be too costly to consider. They may also supply spares and on-going servicing agreements.