Wastewater Treatment

As you are aware. Southern Water is the statutory sewerage undertaker in Rother District. In line with paragraph 162 of the National Planning Policy Framework (NPPF) and the National Planning Practice Guidance (PPG), we have updated our site-by-site assessment of the sites with 20 or more dwellings identified in the draft Development and Site Allocations Local Plan (DeSA) to determine whether capacity in the local sewerage network is sufficient to meet the anticipated demand.

That assessment reveals that additional local sewerage infrastructure would be required to accommodate the proposed development, involving making a connection to the local sewerage network at the nearest point of adequate capacity.

a) Insufficient capacity

A lack of capacity is not a fundamental constraint to development however new or improved infrastructure would need to be provided in parallel with the development.

Connection to the sewerage network at the nearest point of adequate capacity is the mechanism by which the development can provide the local infrastructure required to service the sites. Southern Water has limited powers to prevent connections to the sewerage network, even when capacity is insufficient. Planning policies and planning conditions, therefore, play an important role in ensuring that development is co-ordinated with provision of necessary infrastructure.

Unless planning policies support delivery of necessary underground sewerage infrastructure there is a risk that it will not be delivered in parallel with the development, leading to an unacceptable risk of foul water flooding in the area to both new and existing residents. This situation would be contrary to paragraph 109 of the NPPF, which requires the planning system to prevent both new and existing development from contributing to pollution.

It is likely that investment would be required to deliver additional wastewater treatment capacity. This strategic infrastructure, such as extensions to wastewater treatment works, can be planned and funded through the Price Review process, and coordinated with new development. Last year's (2015) price determination will fund the investment programme for the period to 2020. There will be another price review in 2019, covering the investment period 2020 to 2025. Adoption of development plan documents provides the planning certainty required to support investment proposals to Ofwat, the water industry's economic regulator.

We have therefore proposed policy provision below to secure delivery of necessary local sewerage infrastructure in parallel with development. Our proposed policy provision would be in line with paragraph 157 of the NPPF which states that Local Plans should 'plan positively for the development and infrastructure required in the area to meet the objectives, principles and policies of this framework', and paragraph 177 of the NPPF outlines that it is important to ensure that planned infrastructure is deliverable in a timely fashion.

Furthermore, it is important to give early warning to prospective developers regarding the need to connect off-site, as it could add to the cost of development. Early warning will facilitate delivery of the necessary infrastructure as this infrastructure requirement can then be incorporated into the planning process at an early stage.

b) Proximity to treatment works and requirement for odour assessment

A few of the sites identified in the DeSA are in close proximity to our treatment works. Southern Water endeavours to operate its wastewater and sludge treatment works efficiently and in accordance with best practice to prevent pollution. However, unpleasant odours inevitably arise as a result of the treatment processes that occur.

New development must be adequately separated from wastewater treatment works to safeguard the amenity of future occupiers/users. Paragraph 109 of the National Planning Policy Framework (NPPF) requires that the planning system should prevent new development from being put at unacceptable risk from, or being adversely affected by unacceptable pollution. Annex 2 of the NPPF established that pollution includes odour and noise. Paragraph 120 of the NPPF states that 'To prevent unacceptable risks from pollution and land instability, planning policies and decisions should ensure that new development is appropriate for its location. The effects (including cumulative effects) of pollution on health, the natural environment or general amenity, and the potential sensitivity of the area or proposed development to adverse effects from pollution, should be taken into account'. Paragraphs 4.3.1 and 4.3.1 of the National Policy Statement for Wastewater state that 'Odours from waste water infrastructure can have a significant adverse impact on the quality of life of individuals and communities. Waste water infrastructure generates odour emissions during all stages of conveyance, treatment and storage. At waste water treatment works odours may arise from the inlet works; primary settlement tanks; during secondary treatment; and particularly from sludge treatment, transfer and storage'.

Proposed amendments

In line with the NPPF and National Planning Practice Guidance and to ensure a sustainable development, we propose that the following criteria are added to the list of considerations for the policy detailed above.

* A connection is provided to the local sewerage system at the nearest point of adequate capacity, in collaboration with the service provider.

This site is in close proximity to Preston Farm, Sidley Wastewater Pumping Station.

* The masterplanning of the site should take account of nearby wastewater pumping stations to minimise land use conflict