Contents
About D ˆ
wr Cymru Welsh Water
How Welsh Water is managed
How water resources are
managed
How water is treated
and distributed
How wastewater/sewage
is managed
Water and the customer
Water in Wales
Health and Safety at
D ˆ
wr Cymru Welsh Water
8 6 7 5 4 3 2 1
1
number of household customers – water 1,300,000
number of household customers – wastewater 1,250,000
number of business customers – water 110,000
number of business customers – wastewater 76,000
average amount of water produced every day (megalitres) 840
length of water mains (km) 27,400
length of sewers (km) 19,000
number of water treatment works 68
number of sewage treatment works 833
number of water pumping stations 714
number of sewage pumping stations 1861
number of combined sewage outfalls 3,200
number of impounding reservoirs 65
number of service reservoirs 654
Key facts about
D ˆ
wr Cymru Welsh Water is a regulated ‘not for profit’ company, that provides
water supply and sewerage services to more than three million people living
and working in Wales and some adjoining areas of England.
as with all other UK water companies, welsh water’s spending and maximum customer bill levels are determined by industry regulator Ofwat. Other regulators include the welsh assembly Government, the Drinking water inspectorate and the environment agency. The company has 1.3 million household customers and over 100,000 business
customers, making it the sixth largest of the 23 water companies in england and wales.
it may seem that providing water to people’s homes is a simple matter as it only involves capturing the rain and piping it to homes. But in reality the water industry is much more complex. To ensure a constant supply of water, man has created his own water cycle by
tapping into the natural one. welsh water takes water from rivers, lakes and boreholes. it is then cleaned and treated before being delivered to its 3 million customers.
welsh water has two key responsibilities: to provide a high quality water supply to customers and to take away wastewater and return it to the environment safely. These functions require billions of pounds of
equipment and other assets, and cost hundreds of millions of pounds to operate each year. To replace all of welsh water’s assets at today’s prices would cost £25 billion.
To provide a water supply, welsh water has 65 impounding reservoirs – that is, water storage areas mainly created by building dams across river valleys in upland areas. The company has 68 water treatment works, where reservoir water is treated so it can be drunk from the tap, and it supplies an average of 840 million litres of water every day through a network of 27,400 km of water mains. as many reservoirs and water treatment works are on high ground, gravity helps supply much of the water our customers consume. This means less energy is needed to pump water around the system and this benefits the environment by reducing the company’s carbon footprint.
Taking away wastewater from customers’ homes and businesses – from sinks, baths, toilets and industrial activities - is also a major task. we collect this wastewater together with rainwater that runs into drains from roadways, roofs and other surfaces and it is all carried through a network of 19,000 km of sewers. The wastewater is treated to make it biologically safe at 833 wastewater treatment works located next to rivers and along the coast of wales.
about D ˆ
wr Cymru welsh water
3
Welsh Water is not like other UK water and sewerage companies in the way it is
operated, as it is not run to make a profit.
it is owned by Glas Cymru and has no
shareholders. its only purpose is to deliver the best possible service to customers at a fair price. if welsh water makes a financial surplus then it is reinvested for better services.
welsh water also differs from other water companies in that it employs relatively few people. instead it outsources key functions such as maintaining its equipment, building new assets and providing customer services, to
other companies that are expert in each of these activities. in this way welsh water aims to get the best service for its customers.
welsh water and its partner companies work together in what is called the asset
Management alliance.
How welsh water is managed
How water resources are managed
3
The water cycle
The earth has a finite amount of water, which is naturally circulated in what is called the "water Cycle". This cycle starts with evaporation of water from seas, lakes and rivers and
transpiration from plants. The evaporated water condenses and falls as rain. The rainwater collects in streams and rivers that starts the process over again. after use, the dirty wastewater or sewage is taken away, cleaned and returned to the natural cycle.
it is an amazing fact that 99% of the world’s water is unavailable for us to use. 97% is saltwater in the oceans and the seas and 2% is frozen in the polar ice caps, leaving only 1% as fresh water for us to use which is the equivalent of only ten days’ rainfall!
Water supply
sources of drinking water have changed little over the centuries. it is still drawn from springs, rivers and lakes, all of which are replenished by rainfall. This process of taking water from the environment is called abstraction.
in many cases, the natural water supply is insufficient to meet demands of the community – particularly in densely populated areas. To overcome this deficiency, dams are built to create reservoirs. also, major transfer schemes are used to move water from areas where there is a surplus, to others where there may be a shortfall. For example, the large city of Birmingham is supplied from the elan Valley reservoirs of Mid wales.
The area served by welsh water receives more rain overall than most other parts of the UK. The wettest area is snowdonia with up to 6000mm rainfall a year. The driest is Herefordshire with an average of only 700mm.
although there is a generous supply of rain in wales, the demand for water from customers increases every year. This requires careful management of resources at every stage if the company is to ensure a high quality, constant supply of fresh, clean water. so to satisfy the ever increasing demands of customers, welsh water is constantly investing in, improving and extending its water supply network.
Water in Wales
The region’s high annual rainfall and natural geographical features of hills and valleys favour the catchment and storage of water.
Of welsh water’s water supplies: 97% comes from surface water 3% comes from ground water
River flow
Various factors affect the surface drainage pattern and extent of river flow within a particular region. These combine to determine the ways in which water resources are
managed.
Climate – amount of precipitation received,
evaporation and transpiration (evaporation of water from plants) rates.
Catchment – size and shape of catchment
area.
Slope – the steeper the degree of slope the
greater the run-off into streams and rivers.
Valley form – glaciated, U-shaped valleys hold
more water and reduce evaporation losses.
Geology – permeable rocks such as chalk allow
water to percolate through to the water table below.
Soil & Vegetation – thin soil and sparse
ground cover over impervious rocks greatly increase surface run-off and therefore river flow. Conversely, thick soil and extensive vegetation will transpire water and reduce the volume of run-off.
Farming – grazing animals deplete the natural
vegetation which increases surface water run-off. arable farming needs a reliable supply of water and often involves irrigation or drainage schemes which take water from rivers and reduce flow.
Urban Development – tarmac and concrete
surfaces greatly increase run-off rates. if treated wastewater is pumped back into a river, flow is increased from that point.
7
How water is treated and distributed
4
Water quality
By the time it reaches rivers, reservoirs or aquifers, water already contains a wide variety of substances which determine its quality. it absorbs dirt, dust and gases from the air, debris and bacteria from the ground, and soluble minerals from rocks.
at a water treatment works the main objective is to destroy the bacteria and remove as many unwanted substances as possible. although water treatment techniques vary widely depending on local factors, the end result will always be water that complies with the current drinking water directives. However, its character will vary greatly from one area to another. in Britain today people take access to a regular, reliable and safe supply of ‘pure’ water very much for granted. water from our taps is expected to be safe, clean and pleasant to drink. water is a natural resource, but it has to be purified before you can drink it. The water
you see in the reservoirs is raw water – in its natural state. The water needs to be cleaned and treated at the treatment works to a high quality, and delivered 24 hours a day, 365 days a year. This requires a high degree of
engineering and scientific skill.
Clean water
The natural water we see around us almost everywhere often appears to be clean but this is rarely the case. water has the ability to
accommodate a huge range of substances which can make the water unsafe to drink without any change in its appearance. natural waters are a mixture of chemicals, micro-organisms, and suspended material. The exact composition of water varies from one area to another and even from day to day. water sources throughout wales can vary in it’s make up dependent on its source and the
SLUDGE TO SLUDGE DRYING LAGOONS RETURN TO WASH WATER RECOVERY TANKS TO SLUDGE PUMP HOUSE SLUDGE PUMP HOUSE SLUDGE FROM WASH WATER RECOVERY PLANT
TO SLUDGE THICKENING PLANT WATER OVERFLOW FROM SLUDGE THICKENING PLANT AFTER SETTLEMENT CYCLE, CLEAN WATER IS RETURNED TO RAW WATER CONTACT TANK FOR
REPROCESSING DIRTY WASH WATER FROM GRAVITY FILTERS Polyelectrolyte is dosed and mixed to help the wash water separate into
clean water for recycling and sludge for disposal
POLYELECTROLYTE
Cleaning water
as the quality of water received by water treatment works varies according to where it has come from, the amount of treatment it receives must also vary.
◗ water from underground is usually the
purest form of natural water having been filtered though rocks and soil. Often, all it needs is disinfection to kill harmful bacteria.
◗ water from lakes and reservoirs requires
additional treatment and often a series of processes to remove or destroy any unwanted substance.
◗ The water abstracted from rivers can be the
most variable in quality and usually needs the most treatment. This includes screening, clarification, filtration and disinfection.
Methods of treatment
Screening – this is the first step in the
treatment process where mechanical screens remove some of the larger debris that can be found in rivers and reservoirs ie floating material such as branches, twigs, leaves etc.
Clarification – a treatment chemical
(coagulant) is added to the water which causes
Above:
Clarification process.
Above:
Clarification, removal of clumps from clearer water (Floccuation tanks).
Above:
RECYCLED WATER FROM WASH WATER RECOVERY TANKS TO GRAVITY FILTERS FROM COCODAFF PLANT
By addition of Chlorine and Lime
MANGANESE REMOVAL
BALANCING TANKS SUPERNATENT RETURN BALANCING TANKS
WASTE WATER
NORMAL OPERATION WATER LEVEL
TO FILTERED WATER CONTACT TANKS 150mm GRANULAR ACTIVATED CARBON FROM COCODAFF PLANT VIA MANGANESE REMOVAL STAGE 280mm ANTHRACITE 425mm SILICA SAND 75mm FINE GRAVEL (2.5 - 6.4mm) 75mm COARSE GRAVEL (6.7 - 13.2 mm) DIRTY WATER TO WASH WATER RECOVERY TANKS FOR RECYCLING
NORMAL OPERATION WATER LEVEL
FROM WASHWATER TANKS 150mm GRANULAR ACTIVATED CARBON 280mm ANTHRACITE 425mm SILICA SAND 75mm FINE GRAVEL (2.5 - 6.4mm) 75mm COARSE GRAVEL (6.7 - 13.2 mm) AIR SCOUR Above: PH Adjustment. Above: Disinfection, chlorine.
to remove by allowing them to settle and fall to the bottom of the tank leaving cleaner water above.
Filtration – this is in effect an attempt to
recreate nature’s own purification process. The water is percolated down through a series of filters made up of a layer of fine sand and supported on layers of coarse sand and gravel. as the water passes through the filters, any remaining material is retained and the clear, filtered water is collected at the bottom. The filters are regularly cleaned and the resulting sludge which has collected is removed for disposal.
pH adjustment – sometimes it may be
necessary to add chemicals to adjust the pH of the water. Chemicals are added to correct the ph value and maintain consistent quality.
Disinfection – finally, the water must be
disinfected to kill any remaining bacteria. This is usually done by adding chlorine or sodium hypochlorite and occasionally ozone.
Quality control
Before drinking water reaches the tap, every drop is cleaned and purified. To make sure it is wholesome and fit to drink, detailed laboratory tests are carried out at different points in the water supply system, including customer’s taps.
naturally occurring iron and manganese which may cause ‘discoloured’ water. Old water pipes, often made of iron, can add to the problem. all of these are measured prior to and during the treatment process to ensure their removal.
The quality of treated water is constantly monitored –welsh water analyses more than 60,000 samples every year.
Service reservoirs
The cleaned water is then stored in totally enclosed tanks made of concrete, metal or fibreglass called service reservoirs, before being piped to customers. These reservoirs also ensure a supply to the customer’s taps during periods of peak demand and maintain pressure within the system.
Water distribution systems
Delivering great volumes of water to virtually every domestic, agricultural and industrial premises in the land requires a vast network of pipes and mains. Much of the network in welsh water’s region covers rural areas with small populations where it is much more costly to supply each resident than in high density urban areas.
Maintaining a water supply network presents many problems. as the mains are underground, detecting fractures or cracks is not easy and even when minor leaks are detected it is very expensive to dig up the ground to repair them. water from the service reservoir (where treated water is stored) passes through pipes, usually by gravity flow, until it reaches the customer. in some areas it is necessary to build tall water towers to maintain pressure. it is this pressure that makes water pour out of the tap when it is turned on. water mains have to be designed and constructed to withstand this pressure. Many different materials have been used in the past, but today mains tend to be made of ductile iron or PVC, depending on the nature of the ground. Ductile iron is very strong and can resist ground movement, but plastic is more resistant to corrosion.
11
How wastewater/sewage is managed
5
What is wastewater/sewage?
we tend to think of sewage as the water poured down the drain after washing dishes, taking a bath or flushing the toilet. in fact, wastewater includes all waste water. This contains a variety of substances, some dissolved and some in the form of solids which will float, sink or stay suspended in the water.
◗ Domestic water from baths, washing up,
toilets etc.
◗ industrial waste water that may contain
animal and human waste, oils, sand and sometimes harmful chemicals.
◗ Rainwater that runs off roofs, roads and
pavements.
Wastewater collection
Collecting this enormous amount ofwastewater and getting it to a treatment works is a major engineering task requiring a vast network of sewers spreading out to virtually every home, office, shop, school and factory in the country. in the region covered by welsh water, this amounts to approximately 19,000km of pipes and drains.
This network has been developed over many years and in some parts of Britain the sewers in use today were designed and built during the 19th century. Many of them are in a poor state of repair and badly need replacing.
Carrying out maintenance work on such a large underground network is both difficult and costly. apart from deterioration through normal wear and tear, sewers can be damaged by the weight of traffic moving above them, by ground movement or subsidence in the soil. a major break in a ‘foul’ water sewer can lead to serious problems. it is therefore essential that the sewage network works efficiently and is maintained to the highest possible standard.
Sewage network types
There are two main types of sewage network:
Combined sewers – single pipes which carry
both domestic and industrial ‘foul’ water as well as surface rainwater.
Separate sewers – one pipe that carries ‘foul’
water and another pipe that carries rainwater run-off.
wherever possible, separate sewers are
preferred because rainwater and ‘foul’ water can be kept apart and in storm conditions rainwater can be easily discharged directly to rivers or the sea. (for more info – see page 16)
Industrial effluent
The quality of domestic sewage is fairly predictable and unlikely to contain any highly toxic substances. industrial effluent however varies greatly and companies need consent before any discharge into public sewers can take place.
The sewerage company needs to be sure that the effluent:
◗ is safe and will not be a health risk to service
engineers
◗ will not damage either the fabric of the pipes and sewers or the equipment at the sewage treatment works, and
◗ Has been sufficiently treated before discharge to remove any toxic substances.
Screened water forwarded for grit and grease removal Raw sewage from inlet chamber
Screening conveyor Screenings removed to macerator tank Screen brush To primary treatment Grease to grease concentrator Grit pumped to grit classifiers Grit removal Grit settles to base
of the tank and is scraped to the grit pumps Turbine aerators – to float grease to the surface From screening plant Grease removal
Grease skimmed from the surface into the channel
Travelling bridge
From primary lamella tanks
Wastewater treatment
The purpose of wastewater treatment is to remove enough impurities from the
wastewater to enable it to be returned safely to a river or the sea where it can again become part of the natural water cycle. wastewater treatment is a complex process and methods used vary within the company’s areas. However, the key processes are as follows:
Screening – metal screens remove large,
floating objects such as paper, wood, cans and plastics which could block pipes or damage equipment.
Grit channels – wastewater flows slowly along
wide channels allowing grit and heavy particles to fall to the bottom.
Settling tanks – fine, solid particles settle out
of the sewage, falling to the bottom of the tank to form sludge. This process is called sedimentation.
Biological filters – partly treated wastewater
is spread over large beds of rough stones or clinker where colonies of bacteria have formed. The bacteria remove harmful waste by feeding on organic matter in the sewage converting it to carbon dioxide, water and nitrogen compounds. This biological activity
Above:
Inlet and grit removal.
Above:
First stage - primary settlement.
Above:
13 Water Spray Plastic Media Filter To Secomam Unit Plenum Chemical Dosing Water Water From aeration tanks To ultra violet disinfection
To raw sludge holding tank Sludge settles to base of hopper-bottomed tanks
Lamella plates
Treated clean water to sea outfall From secondary
lamella tanks 160 medium pressure ultra violet lamps in two banks of 80
Activated sludge – this is an alternative to
biological filtration where a culture of bacteria (activated sludge) feeds on the sewage. The air the bacteria need is pumped in under
pressure by surface aerators and fine bubble diffusers.
Final settling tanks – even after final
sedimentation the cleaned water, or effluent, still contains organic material. if this is discharged into a river with low natural flow pollution could occur. also, the water may not be clean enough to be safely abstracted downstream. in these cases ‘polishing’ treatments such as pebble bed clarifiers, sand filtration and micro-straining are used. The treated effluent then flows over weirs to rivers and streams where it rejoins the natural water cycle.
Monitoring
as technology creates new, more advanced materials and substances such as chemical compounds or even biological washing powders, water services companies and the environment agency need to match these developments with sophisticated monitoring techniques to ensure thorough and safe wastewater treatment for their customers.
Above:
Final settlement tanks.
Above:
Wastewater disposal
when people have finished using water, it is expected that the wastewater produced will be taken away and cleaned up properly before it is put back into rivers and the sea. However, the more water people use, the more wastewater is created and as environmental protection becomes increasingly important, traditional methods of disposing of wastewater come under close scrutiny.
Sewers
welsh water’s network of sewers takes away the wastewater produced by households and businesses as well as the rainwater that runs off roofs and streets into drains. Much of the network is old, often dating back to Victorian times and some sewers are too small to cope with the sheer volume of today’s wastewater. as our climate is changing sometimes flooding occurs when there is heavy rain or flash floods.
Surface Water
surface water is the rainwater that runs from roofs, highways and paved areas into the public sewerage system. For a number of reasons, including more frequent storms and the growth of built up areas, welsh water’s sewer network has to deal with increasing flows of surface water. Occasionally, the capacity of the network is exceeded in some areas and results in incidents of sewage flooding of homes, gardens and roadways and can cause pollution incidents in streams and rivers.
Storm overflows
There are 3,200 storm overflows on welsh water’s sewerage system. These are structures on a sewer designed to discharge excess surface water directly into rivers during periods of heavy rainfall
River discharge
welsh water has 833 sewage treatment works across its region, most of which are located inland next to towns and villages and discharge into local rivers or the sea. all the inland works use biological processes to clean the waste water collected from customers so that it can be safely returned to local rivers.
environment agency wales sets clear, well defined standards to protect the river
15
water and the customer
6
Each person in Britain uses an average of 150 litres of water a day - about 15
bucketfuls. Our great grandparents would have managed with about 18 litres
or two bucketfuls!
Water in the home and garden
in recent years domestic consumption of water has increased dramatically, and as living standards rise and more people buy washing machines, dishwashers, hot-tubs and even swimming pools, so the demand for water increases. The average household uses 420 litres of water every single day. The largest domestic use is for flushing toilets followed by baths, showers and washing machines. although all this water has to be treated to a standard that makes it fit to drink; only 1% is actually used for drinking purposes. The rest is used for a wide variety of other activities in and around the home.
Welsh Water customer campaigns
welsh water is keen to involve its customers in understanding how their behaviour affects the water and wastewater network in their area, and has a number of customer campaigns designed to draw attention to customers’ activities and how they impact on the performance of its systems.also, welsh water is rising to the challenges that climate change is bringing to the water
industry. with more long, hot and dry summers predicted, together with more frequent and intense winter storms, welsh water is asking its customers to look at how small changes in their everyday lives can help to combat the effects of climate change.
Be Waterwise – water efficiency
The ‘Be waterwise’ campaign was launched in March 2007 and is designed to inform customers that whilst they can use all the drinking water they need, water, even in wales,is a finite resource and wasting it is bad for the environment. Our message –
‘Use as much drinking water as you
need but please don’t waste it’
Using water wisely is one of the everyday activities we can all do to help manage the effects of climate change.
wales is not immune from the threat of future water shortages and we can all play an important part in conserving resources. it is in everyone’s interest to avoid wasting water and advice is being made available on how to achieve this in the home and garden. water efficiency tips include having a shower instead of a bath, and not leaving the tap running when washing hands or brushing teeth. The biggest user of water in the home is garden sprinklers, using as much water in an hour as an average family will use over two days - use a watering can or handheld device instead.
How your water is used in the home
33% flushing the toilet 22% using the washing machine and dishwasher 16% using the kitchen sink 13% taking a bath 9% using a handbasin 4% taking a shower 3% using the outside tap 33% 22% 16% 13% 9% 4% 3%
Green Space Wales – surface water
run-off
welsh water’s Green space wales campaign is focused on the management of surface water run- off to prevent flooding and pollution by maintaining as much Green space as possible. Climate change is predicted to bring more heavy rainfall on an increasingly developed urban landscape of roads, car parks, buildings and paved front gardens. with reduced green areas for drainage, rainfall is increasingly channelled into public sewers, sometimes overloading them and causing sewer flooding and pollution incidents. The company is asking people to consider the following practical examples of things that will help, such as using porous paving or gravel for new or altered paths, driveways or patios, so instead of rainwater running off, it soaks through to the ground underneath. also, if people are building an extension to their house or a complete new build, the layout can be designed so that it allows drainpipes to run straight into the garden to water plants directly.
Drains awareness Wales – keep FOG
out of the sewers
welsh water’s ‘Drains awareness wales’ campaign aims to prevent the build up of fats, oils and grease (FOG) in sewers across wales, by discouraging customers from pouring them down the sink. Coagulated FOG builds up in sewers, causing blockages which can result in flooding pollution, and overflowing drains, sinks and toilets. This can be an expensive problem not only for welsh water, but also for
householders if they have a blockage on their own system and need to call out a plumber to clear it.
in the UK there are approximately 200,000 sewer blockages, and 75% of these are caused by fats, oils and grease disposed of into the sewer system.
welsh water encourages customers to ‘stop and think. not down the sink!’ instead offering customers tips on how to dispose of FOG correctly, including collecting FOG in a container to dispose of with the refuse. Or, make fat balls
17
The ‘Dirty Dozen’ –
don’t use toilets as bins
welsh water is asking its customers not to use toilets as bins, and is drawing attention to the ‘Dirty Dozen’ items that cause most problems when they are flushed down the toilet, instead of being disposed of with the household waste. Flushing inappropriate objects causes thousands of blocked sewers every year, sometimes resulting in pollution of water courses and sewage flooding of homes. even small items that are flushed away can build up and cause obstructions, or pass through sewage works and end up as litter on beaches and river banks. For more information visit our website on
www.dwrcymru.com/TheDirtyDozen/
WaterAid in Wales
welsh water and its alliance partners are fully committed to supporting national charity wateraid’s aim to use practical solutions to provide safe water, effective sanitation and hygiene education to the world’s poorest people. wateraid also seeks to influence policy at national and international levels.
welsh water re-launched wateraid in wales on world water Day (22nd March) 2004 and set the ambitious target of raising £1 million in ten years. a wide range of large and small fundraising activities are organised every year and fundraising is on track to achieving its ambitious target.
Education and Welsh Water
welsh water is keen to provide a hands on learning experience for its future customers. since the launch of the education strategy, over 100,000 pupils have visited one of its 4 award winning education centres. Teachers are seconded into the business on a professional development opportunity to deliver key business messages on the vital role of water. Pupils are able to experience first hand how the water is cleaned at the treatment works. They can also discover how the climate is changing and how this is affecting the water cycle along with river study lessons, water efficiency and many other exciting practical outdoor lessons. all lessons are linked to the national Curriculum and fully risk assessed.Paying for water services
Rainwater may be free but water from the tap is certainly not and customers have to pay for their supplies. industrial users have a meter to measure the amount they use. new homes must have a water meter, and other domestic
customers can also choose to have a water meter installed free by their water services company, but most householders choose to pay for an unmeasured supply of water at the standard annual rates.
water in wales
7
Welsh Water provides most of Wales and some bordering areas of England with
water and sewerage services, supplying customers with clean, safe drinking
water and taking away wastewater 24 hours a day, 365 days a year.
Location of Welsh Water assets
welsh water sites are found all over wales. its reservoirs are generally located on high ground. Rainfall is higher and the water can then be gravity fed to the treatment works and on to the settlements where water is used. welsh water’s water treatment works are also generally located on higher ground and near to reservoirs. This also means that it is possible to take advantage of gravity to move water and minimise the company’s use of electricity and consequently reduce the environmental impact and its carbon footprint.wastewater treatment works are located near to settlements where much of the wastewater is produced. welsh water has 10 times as many wastewater treatment works as it does water treatment works. This is because it is not possible to take advantage of gravity to move wastewater to the treatment works from people’s houses and it would not be efficient to pump wastewater great distances. There is also more wastewater to treat because of the surface water (or rainwater) going down the drains from roofs, roads and driveways.
1
water Treatment works
ECledd au Usk Tywi Con wy Wy e Severn Dee Alw en Bangor Pwllheli Llandudno Rhyl Denbigh Mold Chester Wrexham Dolgellau Machynlleth Aberystwyth Llandrindod Wells Hereford Chepstow Monmouth Brecon Newport Pontypridd Bridgend Swansea Llanelli Tenby Lampeter Carmarthen Haverfordwest Fishguard Holyhead Llyn Alaw Cwmstradllyn Llyn Brenig Elan Llyn Brianne Usk Llandegfedd Llys-y-Frân Pontsticill Talybont Llwynon Crai Alwen Celyn 1-10 Ml/d 10-50 Ml/d 50-100 Ml/d > 100 Ml/d Water boundary 14 largest reservoirs Wastewater boundary
wastewater Treatment works
ECleddau Usk Tywi Con wy Wy e Severn Dee Alw en Bangor Pwllheli Llandudno Rhyl Denbigh Mold Chester Wrexham Dolgellau Machynlleth Aberystwyth Llandrindod Wells Hereford Chepstow Monmouth Brecon Newport Pontypridd Bridgend Swansea Llanelli Tenby Lampeter Carmarthen Haverfordwest Fishguard Holyhead Water boundary Wastewater boundary 2,000 - 10,000 10,000 - 25,000 0 - 250 500 - 2,000 25,000 + 250 - 500 Population21 The company aims to create a positive health
and safety culture in which everyone believes that health and safety is an integral part of the way welsh water manages its business, and understands and accepts their responsibilities and actively seeks to minimise the risk to themselves, and to those who may be affected by the company’s undertaking.
Hazard and risk
a hazard is any source or situation with a potential for harm in terms of human injury or ill health, damage to property, damage to the workplace environment, or a combination thereof.
a risk is the combination of the likelihood and consequence(s) of a specified hazardous event occurring.
People face hazards and risks everyday, (crossing the road for example) and make their own judgement on the potential risks in this situation. However, in the workplace
businesses have to make a formal judgement on whether any significant level of risk is acceptable as part of its work. at welsh water we do this through a formal process of risk assessment.
This process is quite simple, it involves:
◗ looking for hazards in a task
◗ identifying anyone or anything that may be harmed or damaged
◗ Deciding how likely and how serious the
harm or damage will be
◗ Deciding the best ways to reduce the likelihood and severity of the harm or damage.
This is often achieved by adopting safe
working practices.
