Save Our South Coast Alliance                            WQR0024


Written evidence submitted by Richard C. J. Pratt, Environmental Planning Advisor for Save Our South Coast Alliance 



Sewage and other Polluting Discharges to Solent Harbours



We are submitting evidence for a group of individuals called Save Our South Coast Alliance ( This alliance has affiliates across parishes surrounding the Eastern Solent i.e. west and south of Chichester.




Summary Conclusions from the evidence in the following paper

  1. How effective are the planning policy and standards around sustainable drainage systems to reduce urban diffuse pollution in England?

At present it is not effective as infrastructure investment lags far behind consented new developments and water companies have historically underinvested in future growth and left inadequate historical systems.

  1. Should local authorities and highways agencies be given a duty to prevent pollution to watercourses without prior treatment?

LA should be given direct control

  1. How effective is Ofwat’s remit and regulation of water companies? Does it facilitate sufficient investment in improvements to treat water quality, including sustainable drainage system outflows and nature-based solutions such as constructed wetlands?

The experience of Chichester does not bode well.

  1. Is adequate investment being made in adapting water treatment systems to future climate change?

No. Currently in the Chichester District we have half a dozen Waste Water Treatment Works very close to High Water Spring Tides levels with a local plan proposing many hundred more connections. In addition we are facing wetter winters and drier summers.

  1. How could the designation of inland bathing waters by water companies affect the costs of achieving the associated water quality standards?

The bathing water designated areas have not kept up with all the new places where people now do wild swimming summer and winter.


Waste Water Treatment Works (WwTWs) surround Langstone, Chichester and Pagham Harbours, to the Eastern Solent. A similar configuration also envelops the Western Solent. As well as the outfall pipes from the WwTWs, there are Combined Sewer Outfalls (CSOs) and tertiary outlets. CSOs come into operation when WwTWs are threatened with being overwhelmed. This most commonly occurs during periods of prolonged rainfall, causing groundwater pressure to ingress sewer pipes and overload the system. Tertiary systems are often not fully charted and are historically not connected into the regulated waste water catchments.


The system was largely built between the Edwardian Period and the 1930s, when the area experienced significant growth on the back of improved rail and road connections to other regions.[1]


The actual WwTW have undergone numerous upgrades, in some cases the addition of nitrate filtering and UV treatment to protect water quality in designated protected zones. Nonetheless effluent remains a concern for bathing waters and areas covered by various protective designations.


The impact of effluent on harbour waters has been known since the tragic events of 1902 when four people lost their lives from typhoid after eating contaminated Emsworth oysters. The scandal obliterated the lucrative oyster trade of Chichester Harbour, which has never recovered.[2]


This event serves as a prequel to the current drama of anthropogenic degradation of the natural habitat. In 1989 the water utilities were privatised, promising new investment. But why is investment now failing to cope with the increasing demands on the sewerage system?


Investment is based upon a number of assumptions. The average use per household, around 150 litres per day, is obviously very important, but also consideration must also be given as to the separation of rainwater run-off from grey water, the integrity of the connecting pipes and the headroom of the WwTW themselves. The experience of people living in the catchments run by Southern Water has caused concern over the last 5 years or so, leading to a fine by Ofwat and more recently to a letter to Rachel Fletcher, head of Ofwat on 7 December 2020, from Chichester leaders. It reminded Ofwat of its duties under law namely to:


It is clear to the leader of CDC that Southern Water is saying that there is capacity, whilst it is a matter of record that there is not. This is being born out in planning applications which are on-going. The vulnerability of the coastal WwTWs to climate change/sea level rises is also noted in the letter. We have elsewhere drawn attention to this particular risk exposure.[3]


To give an idea of the variety in size and shape of the WwTW in a part of the sub-region, we reproduce the map from the Environment Agency.

Since this map was created there have been extensions to the various catchments and concomitant reduction in the headroom capacity of the WwTWs. For example, further developments since this 2005 map would have reduced the headroom of the Bosham WwTW from 400 households to virtually none. WwTWs in the Manhood peninsula also take the flow from the seasonal holiday homes which, whilst not in full-time occupation, may double the size of the population in summer. These units are no longer constrained by six-month occupancy restraints and not sufficiently accounted for in the headroom capacity. [4]


The ‘headroom’ spare capacity at the various WwTW appears not to have been re-calculated for several years, yet we know that planning consents for hundreds of new homes have been given in the meantime. The most recent document that we could find is Adopted Surface Water and Foul Drainage Supplementary Planning Document 20th September 2016 which certainly did not consider windfall site developments of the previous few years. [5] An added challenge for the capacity of the WwTW system is the mixing of storm and waste water from historically inherited and more recent unlawful connections.


Of equal concern is the chemical threat to the natural habitat (SSSIs) and the body charged with monitoring the quality of water from this perspective is Natural England.[6]

The latest assessments (28/02/20) for the intertidal littoral (the mud flats) show a worsening situation caused by nutrient enrichment.[7]


We have set out elsewhere our concerns for the nutrient enrichment contributed through waste water discharge.[8]


Some Hampshire LPAs have developed policies to deal with this. Chichester District Council has derogated policy reference to Natural England.[9] Whilst phosphates may be a powerful factor for eutrophication on inland/freshwater courses, it is nitrates that produce greater eutrophication on harbour/saltwater locations.


The discharge of nitrates and other nutrients to the waters of the harbour pose significant threats to water quality. Eutrophication within Chichester Harbour has led to a significant increase in algal growth. Each year from May, when water temperatures rise, this growth chokes lee shores where it piles up, covering intertidal mudflats, saltmarsh and mooring lines, floating in the navigation channels as dense mobile vegetative islands. The EA’s work on climate change impacts on Chichester Harbour in 2005 revealed a 50% loss of saltmarsh coverage since 1946. The dominant species of saltmarsh is spartina anglica, but also some small cord grass. Spartina is an important element of the landscape of CHAONB. A 2004 Natural England report notes it is also “an ideal agent for trapping and stabilising unconsolidated estuarine muds and balancing the erosion of muddy coastal shores (Martin, 1990)”. The salt marsh is also an important ‘damper’ of storm-blown tides, breaking the impact on lee shores, hence its importance in mitigating coastal erosion within Chichester Harbour.


Nitrates are the biggest single driver of eutrophication. Much of this nitrate is from previous agricultural run-off which has now been addressed, but the leaching of nitrates from the substrate will take up to 40 years to cease. Meanwhile the impact of outflows from the built environment continues to increase. Given the groundwater conditions exacerbated by intense periods of rainfall, there are many occasions when licensed discharges take place through the CSOs, rather than WwTWs. These flows are not scrubbed of nitrates. An example of the numbers even in dry conditions is the month from 27 March- 28 April (a very dry period) in which the Bosham Association received about 15 notifications from Southern Water advising of such discharges into the harbour. These intensify during periods of prolonged rainfall. Below is a graph provided by SW of their annualised ‘spills’, a euphemism for discharges via the CSOs.  These are not subject to nitrate scrubbing because they don’t pass through the WwTWs. [10]

No photo description available.







So what is at stake if planned developments are not made nitrate neutral in the Chichester District? Nitrate-neutral house building has belatedly become a concern and given considered thought in respect of the Solent’s sensitivities. EA maps from 2001 and 2004 show eutrophic alerts and nitrate sensitivity. Strikingly, Chichester Harbour features prominently. Whilst other Solent-surrounding LPAs are developing nitrate neutrality policies for development proposals, Chichester District Council has deferred to the Solent-wide policies of Natural England.[11]


The sensitivity of the Solent and its adjoining harbours has been charted for some time.[12] Charts published in 2012 show the entire Solent to be nitrate sensitive. The first chart from 2004 shows the legend, whilst the second gives an idea of the issues in the Southern Region.



Source: [13]


Numerous coastal WwTWs debouch to marine environments with a variety of protective designations including those at Apuldram and Bosham (Harts Farm). The protections and the explanation are set out simply in the Bosham Village Design Statement.[14]


It states:

“The mudflats, saltmarsh, grasslands, dune and shingle support substantial populations of overwintering waders, wildfowl and breeding seabirds, and other flora and fauna. For this reason, Chichester Harbour carries a number of international, European and national designations. At the national level the intertidal area and some of the land is designated as a Site of Special Scientific Interest (SSSI) which is designated under the Wildlife and Countryside Act 1981 as a national network of areas with the greatest value to wildlife or geological conservation.” (page 15).


Chichester Harbour has both port authority (navigation etc) and environmental management vested in a single body, that of the Chichester Harbour Conservancy (CHC). This body takes a keen interest in water quality.[15]


The importance of the saltmarsh as a significant contributor to carbon capture and sequestration has more recently been recognised. The suffocation and loss of the spartinas will remove such a valuable social good. [16] It is clear from the surveys by EN that the upper harbour is most affected by nitrate build-up and it is these areas that have lost the most spartina cover over the years.


The impact upon health of water users from effluent discharges remains a concerning issue locally. The latest readings of water quality (E.coli and enterococci) show that three locations - Dell Quay, Dell Quay north channel and Emsworth Quay - all failed the EU Bathing Water Directive on 13 January 2021. This is a matter of organic pollution causing risk to human health. These measurements were completed by CHC, which measures monthly in winter and bi weekly in summer. That there are no measurements in between and that there is no coordinated measurement with known discharges remains a concern for water users.


Water users in Chichester Harbour are particularly concerned that Southern Water is unable to deliver warnings of untreated discharges in a timely manner and there has been extensive correspondence between the EA’s James Humphrys and water user representatives. The problems focus upon the inadequacy of the BeachBouy notification system to which water users can register.[17] The CHC and local sailing/rowing/paddling clubs note the increased use of the harbour by immersive users, yet the harbour itself is not designated as a bathing water area, although main beaches at West Wittering and Hayling Island are designated. The EA requires bathing waters prone to pollution should under the following circumstances trigger public warnings:

  1. Heavy rain or tides washing pollution into the water that flows into a bathing water from the surrounding catchment. At sites where this is known to occur, this risk is assessed by daily Pollution Risk Forecasts (PRF) and if an increased risk is forecast, a pollution risk warning is issued along with advice against bathing and
  2. On rare occasions pollution incidents can occur which may affect water quality. If a pollution incident occurs that may affect bathing water quality we will issue advice against bathing. [18]

This does not appear to be happening with the frequency stipulated according to regular local water users, year-round swimmers and water sports enthusiasts.


We have no information on the take-up of the notification but it seems to be very patchy and doubts about its efficacy, timeliness and accuracy, may have caused clubs and user groups to hold back from endorsement as a reliable source.

Below are two examples of the notification in January 2021.



Another day in January 2021 reported even more prolonged releases, but many water users had not received adequate warning, even although there had been prolonged downpour.


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The letter to Rachel Fletcher, head of Ofwat on 2 December 2020, from Chichester leaders noted that the WwTWs discharged sewage into Chichester Harbour during 2020 for the following periods: Chichester = 107.2 Days. Thornham = 19.7 Days, Bosham = 41.8 Days and information from other combined sewer overflows together add another 10.1 days.


As well as environmental and health implications of the poorly performing regulatory systems and supply of water services, there are also long term economic implications. The CHC commissioned a study of the economic benefit of the high reputation of the Chichester Harbour environment. The Dasgupta Review has drawn attention to the measurement of economic value of such environments.[19]


In 2009 “the total value of Chichester Harbour has been estimated to be at least £2.78 billion. This cumulative figure is made up of individual valuation information from maritime businesses (£524M), residential property (£2,151M), tourism (£44M), land values (£52M) and recreation (£1.2M). [20]


Water quality clearly has a bearing on both the intangible and tangible assets of the Harbour and deterioration of these assets makes the area poorer. Two obvious features affected by the presence of E.coli and enterococci and nutrients (nitrates and phosphorus) are the attractiveness of the water sports and the landscape value of the Spartina/salt marsh.[21]


The loss of the sea grasses that fringe the harbour would have a major impact on attractiveness just as much as the loss of woodland and copses on land. The eutrophication engendered by nutrient enrichment also impacts boaters, paddle boarders and windsurfers whose craft get caught in the super-abundant algae and other plant life that form as a result. Sailors will recall the massive efforts made by the Chinese Government to clear their sailing area designated for the Olympic Games. It is not unimaginable that the problem could become as severe in our harbours. Deteriorating environmental conditions deter smart investment in enterprises, jobs, homes and social infrastructure. It is easy to tip into an unvirtuous spiral.


Can the Chichester District properly accommodate the number of houses currently being proposed in the local plan review and be sure that the water quality in our harbours can be maintained, let alone improved? ONLY if the water utilities could guarantee the investment necessary AHEAD of any development. This was a significant feature of the Conservative Party Manifesto 2019 which declared a government formed would ensure infrastructure is in place before homes are delivered.[22]


Much is laid at the door of Southern Water and the letter from Chichester District leaders to Ofwat has underlined this. Southern Water has a monopoly position on sewerage and waste water through the south coast from Hampshire, the Isle of Wight, West Sussex, East Sussex to Kent, although the supplier of fresh water in the west of this region is Portsmouth Water.[23]


Southern Water is regulated under the Water Industry Act 1991 and since 2007 has been owned by Greensands Holdings Limited, a consortium of investors representing infrastructure investment funds, pension funds and private equity.  Currently the largest shareholders are JP Morgan Asset Management (40%), UBS Asset Management (22%), Hermes Infrastructure Funds (21%) and Whitehelm Capital (8%).[24]


The company website shows its efforts at environmental compliance and is a convincing account of the company meeting its legal duties.[25] However, the experience of living in the area served by the company is that it will struggle if greater consumer demands are placed upon it. Wikipedia list the fines imposed on Southern Water between 2007 and 2019.[26] There are increasing examples of toilets backing up in new developments and excess waste having to be pumped out and taken away from sites by lorry.


SW is required to provide a service for all new development, yet the capacity of their current catchments is already severely stressed frequently, evidenced by the proven breaches of the regulations that resulted in fines and by the frequent resort to the full extent of their licences to discharge untreated waste to our harbours. The stream of investment funds from the receipts from Community Infrastructure Levy appear to lag far behind the requirement for such improvements that would meet and exceed minimum standards.


The issue for governance seems to be, can it sign off on developments unsure of the consequences for water quality on their doorsteps? The issue for the water utility must be, is it meeting its corporate social responsibility? The issue for the regulators is, are they doing their job?


February 2021