Managing water quality and wastewater

Planning development and managing water quality and waste water in the Chichester local plan area

This factsheet has been produced to provide a clear explanation on the roles and responsibilities of the organisations involved in planning development and managing water quality and wastewater in your local plan area.  A list of common Frequently Asked Questions is also included.

Organisations' role and responsibilities

Chichester District Council

Planning Policy

Chichester District Council is the Local Planning Authority (LPA) responsible for planning to meet the development needs of the Plan Area, primarily through production of the Local Plan, supported by relevant documents including an Infrastructure Delivery Plan, Sustainability Appraisal and Habitats Regulations Assessment.  The Local Plan Area includes the Chichester District but excludes the area falling within the South Downs National Park.

Planning applications

The LPA is responsible for managing the development of land and buildings which includes anything from an extension to a house to a large scale residential/ commercial development.  More minor development proposals often benefit from deemed permission automatically granted within nationally governed legislation and for this, there is no need to apply for planning permission locally although permitted development rights may typically be subject to conditions and limitations to control their impact.  Where a planning application is required however, the LPA will be responsible for making a decision on the proposal in the first instance.  There is a presumption in favour of granting sustainable development, unless the LPA is able to produce demonstrable evidence of a significant harm that would occur as a result of granting permission.

Environment and Health Protection

Environment and Health Protection within Chichester District Council covers pollution and environmental protection, food (including shellfish production), biodiversity and climate change, sustainable construction as well as land drainage and the management of coastal waters.  Building Control ensures that new development complies with minimum standards for design and construction.  As a consultee of the planning system, advice is provided in relation to sustainable construction, biodiversity, emissions (such as noise and air pollution), contaminated land, discharges from private sewage plants, land drainage and coastal defence.  

Southern Water

Southern Water is the statutory sewerage undertaker for most of Chichester District, responsible for collecting, conveying and treating wastewater. Southern Water also supplies clean water to the north east of Chichester District. Southern Water has a statutory duty to serve new development and to meet environmental limits set by the Environment Agency. Investment in strategic infrastructure such as Wastewater Treatment Works is planned in 5-year periods and is informed by a plan-based population forecast, alongside monitoring of the LPA's Local Plan, and other relevant data. Reinforcement of the local wastewater network (eg pipes and local pumping stations) to cater for new development is funded through the New Infrastructure charge to developers once planning permission is granted. Compliance by Southern Water with its statutory responsibilities is overseen by the statutory regulatory body, OFWAT, whilst compliance by Southern Water with its environmental permits is overseen by the Environment Agency - the LPA has neither the legal remit, capacity, expertise, nor access to relevant network data to perform an overview function.

Portsmouth Water

Portsmouth Water provides water supplies to a domestic population exceeding 698,000, as well as many industries, large defence establishments and varied commercial businesses.  The area supplied by the water company extends through South East Hampshire and West Sussex from the River Meon in the west to the River Arun in the east. It encompasses 868 square kilometres.  The water that Portsmouth Water supply to their consumers has to meet strict drinking water standards.  These standards provide specific limits on a number of pollutants, including nitrates and pesticides. The water company carefully monitors levels and strictly follows the advice of the Government's Drinking Water Inspectorate who regularly audit their work.  

Environment Agency

The Environment Agency is responsible for protecting and improving the environment, managing the risk of flooding from main rivers and the sea, and promoting sustainable development. The Agency discharges these duties through a range of activities. In particular, the Agency regulates discharges into the environment in accordance with legislation and provides advice and guidance as a statutory consultee in relation to planning matters. 

Natural England

The organisation is responsible for conserving, enhancing and managing the natural environment including monitoring and protecting important habitat sites such as sites of special scientific interest (SSSIs) and restoring these to a favourable condition.  Natural England works collaboratively with other organisations to protect biodiversity and also advises as a statutory consultee on relevant policy and planning matters. An explanation of the joint role that the Environment Agency and Natural England hold in managing impacts on habitats through the Habitats, Water Environment and Environmental Permitting Regulations is available to view.

 NE and EA Roles in Planning and Permitting (PDF, 154 KB)

Chichester Harbour Conservancy

The Conservancy has a duty to conserve, maintain and improve Chichester Harbour (an Area of Outstanding Natural Beauty (AONB)) for recreation and leisure, nature conservation and natural beauty.  The Conservancy works with a wide range of stakeholders including landowners, local businesses and local authorities in managing the AONB.  The Conservancy regularly tests the water quality at 12 different sites around the Harbour with administrative support from the Council who publish the results of analysis on their website.

Frequently Asked Questions

Q. Can a Moratorium be imposed on planning applications?

A. Whilst a particular issue may make it less likely that planning permission would be granted, each application must be assessed on its individual merits taking account of the harm that might occur but also the suitability of any proposed mitigation.  As an individual assessment is required in each case, it is not possible to impose a blanket moratorium on all planning applications for housing development.  However, if a statutory provider raises issues which are not able to be satisfactorily mitigated, this will be afforded significant weight in the determination of an application.

Q. When are planning conditions relating to wastewater imposed?

A. A Grampian style condition can only be imposed where there is sufficient confidence that its requirements can be achieved by the developer.  Such conditions can be imposed by the LPA to enable Southern Water to manage the timing of a connection to the public sewer.  This allows the legal right to connect to be sensibly managed prior to occupation of the development.  The condition might enable Southern Water to agree a drainage strategy with the developer, the preferred point of connection as well as consider existing capacity and to programme any necessary upgrading work to the sewerage system.  If an existing wastewater network does not have capacity for flows from a new development, then the LPA may impose a condition on a planning permission which requires that new wastewater infrastructure enabling sufficient capacity in the wastewater network, is put in place to accommodate the new development prior to occupation.

Q. What is the statutory right to connect and what is non-mains drainage?

A. Developers have a statutory right to connect new sewers to existing public sewers under section 106(1) of the Water Industry Act 1991 and sewerage undertakers do not have the ability to refuse a connection on the grounds of capacity in the local sewerage network and/or sewage treatment works. In some circumstances however, it may be the case that the sewerage undertaker requires drainage systems to be constructed in a manner which better protects the existing public sewerage and/or sewage treatment systems, such as requiring a developer to connect at an alternative location.  Identified works are funded through the Infrastructure Charge which is levied by Southern Water on all new development.

Government guidance identifies that the presumption must always be to discharge into the public (mains) sewer. This is defined as a sewer system that is managed and operated by an OFWAT appointed sewerage undertaker.   Non-mains drainage refers to a range of privately owned and operated wastewater treatment solutions, including private treatment plants and individual septic tanks.  The Environment Agency considers that a mains connection is always the most sustainable and certain way of dealing with wastewater from new development and expects developments discharging domestic sewage to connect to the public foul sewer.  The Agency will not normally grant a permit to discharge for a private sewage treatment system where it is deemed reasonable to connect to the foul sewer.

Q. How are the risks from climate change and population growth on the sewerage capacity being managed?

A. All of the organisations are working together to understand and manage the current and future risk to sewerage capacity. The LPA are aware there are issues at some locations where tide lock and/or a high water table inundates the foul sewer network.  Evidence collected from ongoing studies will indicate where actions are necessary and these will be addressed through measures available to each organisation.  These measures include Southern Water's Drainage and Wastewater Management Plan (DWMP) which is working towards adoption in late 2023, Environment Agency regulation, as well as the LPA's new Local Plan, also planned for adoption in 2024. 

Q. How is the quality of wastewater managed?

A. Southern Water has three Wastewater Treatment Works (WwTW) which discharge directly into Chichester Harbour at Apuldram, Bosham and Thornham. The Environment Agency sets discharge consents for each WwTW to minimise the pollution of receiving waters such as Chichester Harbour.  Depending on the location of the WwTW, the consents will specify the total volume of treated water permitted as well as consented levels for various chemical effluents such as ammonia, phosphate and nitrates. Coastal discharges (for example, Apuldram) are often limited by nitrogen whilst inland discharges (for example, Tangmere) are often limited by phosphorous. The Environment Agency also audit permit compliance to assess whether the permit conditions are being complied with. The LPA has no enforcement powers in relation to permits and the appropriate body to raise concerns about discharge events to is the Environment Agency, which is the relevant enforcement agency for WwTWs. Suspected pollution incidents should be reported to Southern Water's emergency reporting line: 0330 303 0368.

Q.  Why is Dry Weather Flow used to calculate wastewater treatment headroom for new development?

Dry Weather Flow permitting is the standard water industry-wide regulatory means of understanding a catchment population to enable the Environment Agency to set the level of discharge of treated effluent that is returned to the environment, in conjunction with any additional environmental permits (e.g. for nitrate or phosphate removal) that may be needed to safeguard water quality objectives. Dry Weather Flow is a good measure of effluent coming from homes and businesses (i.e. the population), and therefore contains the greatest concentration of organic matter and pollutants that require treating before returning to the environment, rather than rainfall (which is clean and acts as a dilution to wastewater). The way of calculating Dry Weather Flow is set out in government guidance from the Environment Agency: Calculating dry weather flow (DWF) at waste water treatment works (opens new window).

Wet weather flow is factored into FFT (Flow to Full Treatment) (opens new window). Flow to full treatment refers to the total level of rain and wastewater, or flow, that a WWTW must treat before it is permitted to discharge excess flows to storm tanks or, if the tanks become full before rain subsides, the environment. A WWTW must treat all flows up to a threshold specified in permits. Usually, FFT is set at three times DWF - this is decided by the EA when they set the permit levels for both DWF and FFT.

Q. When are combined sewers and overflows used?

A. During dry weather, wastewater from development is treated at the Wastewater Treatment Works (WwTWs) and then released into the rivers, harbours or sea.  In wet weather, surface water and rain runoff infiltrates the sewerage system and combines with wastewater. The storm tank holds the excess ready to be treated after the high flows subside. In large storms or sustained showers, once the storm tanks are full, overflows to rivers or sea are used to prevent backing up of the network which could lead to the flooding of homes, businesses, hospitals and schools. 

During or following a period of heavy and sustained rainfall, the WwTWs might need to discharge stormwater (a mix of rainwater and wastewater) to the harbour. Storm effluent is not discharged without treatment - permits typically require 6mm 2-dimensional screening to remove solids plus retention within a storm tank to allow settlement of finer solids, which results in a significant reduction in Biological Oxygen Demand (BOD) prior to discharge. These discharges are more likely where infiltration and inundation occurs such as groundwater ingress into the sewer pipes and when wrongly connected surface water drains are connected to the foul drains.  This flows as excess capacity to the WwTWs.

Flow beyond the processing capacity (the permitted FFT) of the plant is at first directed to the large storage tanks mentioned above for processing later, however, if the excess flow continues beyond the storage capacity of the tank, then basic screening of the waste is carried out (at Apuldram, this includes UV disinfection) before it is discharged into the harbour.  Every year, the Environment Agency collect Event Duration Monitoring (EDM) data from all companies, providing greater transparency around the frequency and duration of spills from all storm overflows - both those on the network and at sewage treatment works. The vast majority of these are compliant with their permits and should only have been used when rainfall risks the network or sewage treatment works from being overwhelmed or sewage backing up into people's homes or discharging into the environment. Defra has also set up a new Storm Overflows Taskforce committed to eliminating harm from storm overflows so that our waters continue to be safe for humans and wildlife. The Taskforce comprises of experts from the Environment Agency, OFWAT, Consumer Council for Water, Water UK and Blueprint for Water. Southern Water has also set up its own Clean Rivers and Seas Taskforce (opens new window) dedicated to reducing the use of storm overflows. 

Q. What is the groundwater infiltration issue at Apuldram (Chichester) Wastewater Treatment Works (WwTW)?

A. The Chichester catchment is affected by high levels of groundwater infiltration into the sewer network.  When groundwater levels are high, water leaks into the sewer system and causes the Apuldram WwTW to operate its storm overflow.  In winter months, significant rainfall and high groundwater levels frequently leads to the prolonged use of storm discharges and for this reason, Apuldram WwTW is considered to be at environmental capacity.

An enforcement notice served on Southern Water in 2013 requiring further investigation of the flows to Apuldram WwTW was incorporated into the Environmental Permit in 2014 with improvement conditions to enable schemes to reduce infiltrations/storm discharges.  In 2014 UV disinfection was installed on the storm overflow which limits its impact on the water quality in the Harbour.  Southern Water have also identified Apuldram WwTW as a priority for long-term investment in their 25-year Drainage and Wastewater Management Plan based on storm overflow performance and nutrient neutrality risks.  To manage development in the Apuldram WwTW catchment, both the Environment Agency and Southern Water have produced a position statement which was endorsed by Chichester District Council's Planning Committee in December 2018.
 Apuldram WWTW Position Statement (PDF, 284 KB)

Q. How is the water quality monitored in Chichester Harbour?

A. Chichester Harbour is the largest natural estuary in the South East.  The Harbour is a recreational water, much like lakes and rivers, whereas water at many beaches is designated as Bathing Waters and has to achieve a higher standard of water quality in relation to human health.

The Harbour is a natural system with many features that may cause it to have variable water quality. Wildlife, surface water run-off, agriculture and livestock, discharge from private sewage treatment plants, connected ditches and leisure activities all add to the bacteriological and chemical load in the water. This is always the case regardless of any Waste Water Treatment Works' input which in any case, only contributes around 10% of nitrogen pollution.  Nevertheless, water sampling and analysis is carried out on a regular basis (twice a month in the summer and once a month in the winter) at twelve locations around the Harbour to inform recreational users.  In recent years, the water quality has consistently complied with bathing water standards even though the Harbour is not designated as a 'Bathing Water'. The current Harbour water results are published at Chichester Harbour Conservancy (opens new window), whilst historical results can be accessed on the LPA's water quality webpage.  There is no targeted water sampling undertaken, for example, following a storm water discharge.  Recreational users of the Harbour should therefore consider the results as being specific to the date and time of the sampling, that there is likely to be spatial variation in the harbour water quality, and that the results should be treated as indicative only. 

All recreational users of the Harbour are recommended to use good hygiene practices before and after coming into contact with Harbour water, for example, covering cuts with a waterproof plaster, washing hands after contact with the water and avoiding hand to mouth movements before they clean their hands. Southern Water run a notification service called Beachbuoy (opens new window) which alerts subscribers or visitors to their webpage when there has been untreated waste water treatment plant discharges into the Harbour. Swimmers and other users of the Harbour are advised to use this free service to best assess the risk and protect their own and their families' health when planning to come into contact with the Harbour water.

Q. What is the nutrients issue in Chichester Harbour?

A. In Chichester Harbour, both nutrients (nitrogen, mainly as nitrates) and faecal bacteria are significant water quality issues. They enter the catchments as a result of runoff from farmland and urban areas and as discharges from the sewerage system. They affect the ecology, amenity and commercial use of the water. The Harbour is shallow and not well flushed by either the tide or by freshwater (there are no large rivers) so these nutrients remain in the Harbour and encourage algae to grow, forming the dense green mats over the mudflats that we see every summer, and that would not normally occur naturally. These algal mats reduce oxygen levels in the mud and so reduce the populations of small invertebrates that birds feed on.  Chichester Harbour is an internationally important site for the bird populations who live and overwinter there and is protected under the Habitats Regulations 2017.  The legal protection of the Harbour is of a high standard and its ecological importance is recognised through a suite of national and international protective designations. 

As a result of the occurrence of nitrates in Chichester Harbour, the Environment Agency has implemented a range of measures to reduce nutrient inputs. These include nitrogen permits on key WwTWs around the Harbour and the introduction of nitrogen reduction measures by farmers in the catchment, including those required in Nitrate Vulnerable Zones. In addition, following Natural England's assessment during 2019/20 which suggested that more than 3000 hectares of the intertidal parts of Chichester Harbour is now classified in an "unfavourable - declining" condition, the LPA now has to be certain that any planning proposal would not adversely affect the Harbour. Consequently, planning permission will only be granted by the Council where it can be certain that nutrient levels will not increase, even by a small amount, as a result of the planned development. 

Q. How does a planning proposal achieve nutrient neutrality? 

A. Natural England has produced a standard methodology, available on the LPA's nutrient neutrality  webpage, to calculate what the impact of a proposed development would be. Residential development will likely lead to less nitrates entering Chichester Harbour than many agricultural land practices that involve the spreading of fertiliser.  Therefore, some developments will, through their change of land use, naturally result in a permanent reduction in nutrients from the site.  However, others will not and for these, some form of linked mitigation is required to balance out their nutrient increase.  Often this will take the form of a separate piece of land where the use can be changed from a high nitrogen input use to a lower-level use such as woodland, wetland or a country park.  Developers are free to arrange their own mitigation provided this can be legally secured for the lifetime of the development (this is often only feasible for larger developments).  To facilitate smaller developments and to make sure previously developed sites in urban areas are not discouraged, the LPA is working with other local planning authorities across the Solent to look at approaches to mitigation, including the potential for LPAs to purchase a small amount of credits from existing mitigation providers, which could then be sold on to smaller developers less able to purchase mitigation on the open market.  It is anticipated that such a solution may only be needed in the short term, until a nitrogen trading platform being developed by DEFRA and the DLUHC is up and running. In any scenario, the cost of any mitigation required would be met by the developer, not by the Council-Tax payer.