Water and Sewage
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Project description

Name of the case study
Nefyn, Morfa Nefyn and Edern Sewage Treatment works

Description of context
The legal obligation upon Welsh Water to carry out the scheme is highlighted below. Welsh Water obtain funding through an increase in pricing to customers over/above normal charges which is approved by OFWAT. Once funding is approved the scheme is then programmed to be carried out within Welsh Water´s Asset Management Plan (in this case the AMP3 programme which was 2000 to 2005).

• Section 121 of the Government of Wales Act made it a legal duty for the National Assembly for Wales to pursue sustainable development in all it does.

• Water related companies are affected by a list of legislations (specific to Wales):
- The Water Act 2003 works towards improving water conservation, protecting public health and the environment;
- The Water Industry Act 1991 covers the appointment and regulation of undertakers, protection of customers, general duties, supply duties and the domestic connection of water, as well as for sewerage- services, provision of service and general issues concerned with sewerage;
- The Water Industry Act 1999 set new water company charges;
- The Water Resources Act 1991 outlined the legislation for the control of the pollution of water resources and the land and works powers;
- The Anti-Pollution Works Regulations 1999, SI 1006 deals with compensation or notices to be served on works that are polluting;
- Water Resources (Environmental Impact Assessment) (England and Wales) Regulations 2003, SI 164 includes details on what projects need to have an Environmental Impact Assessment completed.
- The Water Supply (Water Quality) Regulations 2000, SI 3184 covers Regulatory Impact Assessment, the monitoring of water supplies, water treatment and legislation for enforcement;
- The Water Supply (Water Quality) Regulations 2001, SI 3911 looks at water supply, water treatment and enforcement.

• The third Asset Management Programme (AMP 3) is part of an investment programme known as the National Environment Programme. AMP3, the third phase in the programme since water privatisation, has been agreed by the Government following discussions with the Environment Agency, water companies and OFWAT (the UK water regulator).

• Dwr Cymru Welsh Water is the regulated company that provides water supply and sewerage services to over three million people living and working in Wales. The company has an Environment Management Group and a Quality and Environment Committee at board level. This committee reviews the performance of the Company (and its contractors) against key performance measures with particular regard to public health, health and safety and environmental impact. This ensures the environmental practices of the company and those contractors working on behalf of Dw^r Cymru Welsh Water.

Description of project - background
The villages of Nefyn, Morfa Nefyn/Edern in North West Wales are currently served by two distinct sewage systems or catchments.

One system covers most of Nefyn (popn of 1,359), and the second covers Morfa Nefyn/Edern (popn of 1,260).

The aim of the project, to improve the treatment of sewage in the area, was initiated as a result of the 1991 EU Urban Waste Water Treatment Directive (UWWTD) that was adopted into English and Welsh law through the Urban Waste Water Treatment (England and Wales) Regulations 1994. The regulation requires discharges to coastal waters from communities of between 2,000 and 10,000 population to receive ´appropriate treatment´, which is to be put into action by the end of December 2005. The area encompassed by Nefyn, Morfa Nefyn/Edern fall into this category. Dŵr Cymru Welsh Water were also required to undertake improvement works to combined sewer overflows in the sewer network to improve the quality of water in rivers.

The existing catchment system includes:
1) Nefyn catchment which drains by gravity to a macerating pump and tidal storage tank located in a steep gully. A lunar valve controls the discharge of sewage from the tidal tank. The sewage discharges to sea via a short outfall above the Mean Low Water Springs tide level, approximately 100m from the tank. The tank is shown below.

Location of the tidal tank at Nefyn
Location of the tidal tank at Nefyn

2) Morfa Nefyn/Edern catchment has four pumping stations. The sewage from these plus the remainder of the catchment drain by gravity joining together at Pont Edern, where the combined flow runs to Afon Geirch valley. The untreated sewage is discharged at Aber Geirch into the sea via a short outfall. Three combined sewer overflows (CSOs) operate only after heavy rainfall, these are connected to additional outflows, which in storm conditions may discharge diluted sewage into the river.

Existing Aber Geirch Outfall
The Existing Aber Geirch Outfall - below beech on north cliff

The proposed work involves the construction of one sewage treatment works to serve the two catchment areas covering Nefyn, Morfa Nefyn/Edern. This is to replace the two systems currently in place. The chosen site is located on agricultural land just outside an Area of Outstanding Natural Beauty, close to the existing sewage system for Edern/Morfa Nefyn with easy access for maintenance from the main road. The preferred location of the pipeline to the treatment works will follow the main road, the B4417.

Further development will occur for the Nefyn pumping station, which is to be built behind a farm near Nefyn fire station. This is located downstream of the Nefyn catchment to collect all the flows from the catchment.

Description of project - objectives/aims
The sustainability objectives are the same as the project driver: to improve the standard of treatment required for sewage discharges into coastal water adopted as part of the European Union (then European Economic Community) 1991 Urban Waste Water Treatment Directive (UWWTD). This objective is supported by the selection of a site that incorporates the most suitable method and location of sewage treatment with regards to sustainability.

Description of project - time interval and stages
Following the Urban Waste Water Treatment (England and Wales) Regulations 1994, a feasibility study was commissioned to investigate the most appropriate options for providing sewage treatment for the areas of Nefyn, Morfa Nefyn/Edern. This study was completed in 1997 and identified that the most appropriate option was to merge the two catchment areas. Two public exhibitions took place in March and November 2003, and following positive public feedback planning applications were submitted for the development. Dŵr Cymru Welsh Water‘s Asset Management Plan 3 (AMP3) requires that Nefyn, Morfa Nefyn/Edern will be provided with full biological treatment by March 2005 at the latest.

Description of project - financing
More than £3 million is being invested into the project, to be carried out by Dŵr Cymru Welsh Water Alliance North Wales Delivery Team, a strategic partnership between Dŵr Cymru Welsh Water, Galliford Northern and EC Harris.

Description of project - other sectors involved

What tools were used to assess sustainability?

A feasibility study

Welsh Water Treatment Works Site Selection Matrix

More information

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