Ian McAulay, CEO of Southern Water has announced a package of investment and an offer to host a summit of senior leaders aimed at helping to improve the water quality and important natural habitats of Chichester and Langstone Harbours.

Part of the investment is a new £5m environmental improvement fund. Central to the company’s commitment to the harbours is an undertaking that a proportion of this £5m will be invested with partners on initiatives that deliver both nature-based solutions and environment net-gain for both harbours.

The announcement follows a series of top level meetings with local campaigners and political leaders including Gillian Keegan MP for Chichester and Alan Mak MP for Havant.

Southern Water is investing £1.7 billion over the next four years across the south-east to improve the capacity and efficiency of the waste water network and reduce the number of releases from Combined Sewer Overflows (CSOs).

Chichester and Langstone Harbours are among the locations where permitted releases from CSOs of diluted wastewater happen.

This includes £13 million to be invested to improve instrumentation and data capture that further reduces the risk to the environment from storm overflows, including at Budds Farm, which releases into Langstone Harbour.

A major £6.5 million scheme to reduce groundwater infiltration into the vast Chichester sewer network is also planned. The water company said that every drop of groundwater that can be kept out of the network reduces the need for storm overflows.

Action already taken to reduce the contribution that wastewater treatment works make to nutrient enrichment in the harbours includes:

A 90 per cent reduction in the nitrates going from wastewater treatments works into the harbours. These works now contribute less than 10 per cent of the overall nitrate levels in the harbours and all operate within nitrate permit conditions.

CSOs contribute just one per cent to the nitrates in the harbours and all works operate well within nitrate permit conditions.

Creating one of the few CSOs in the UK with UV treatment to sterilise storm releases at Chichester.

An online storm release notification system, Beachbuoy that helps customers and partners by providing near real time information about CSO activity at designated bathing waters and recreational watercourses. Beachbuoy will cover all 83 designated bathing waters and Chichester Harbour and Langstone Harbour by the end of May.

A roll out of Event Duration Monitoring (EDM) technology across 98 per cent of the network since 2017 to build a clearer and more detailed picture of the use of CSOs, that helps to target future investment and operational activity. Further investment to ensure 100 per cent coverage by 2025 is in place. Southern Water led the industry in the roll out of EDM technology.

One of the first published Pollution Incident Reduction Plans (PIRP) which details a programme of activities to deliver a sustainable reduction in pollution incidents.

Ian McAulay said:

“Saving the internationally important and threatened habitats at Chichester and Langstone harbours is incredibly important to us, our customers and our stakeholders. We are absolutely committed to playing our part by reducing the harm to the harbours’ waters from Combined Sewer Overflows (CSOs).”

He added:

“Our new £5m environmental improvement fund, as part of our overall spending plans for 2021/22 and beyond, clearly demonstrates Southern Water’s commitment to being an active and involved member of the newly formed Chichester Harbour Protection & Recovery of Nature group (CHaPRoN). This emerging group is a very welcome and positive step forward in forging a powerful partnership to save our harbours.

“Working together with a shared action plan we truly believe we can make significant strides to improve the water quality of our harbours, this will benefit the environment, water users and support the local economy.

“As part of our commitment to working within this partnership, we are offering to host a summit of senior leaders at which I hope we will agree a shared action plan.”

Gillian Keegan, Member of Parliament for Chichester commented:

“I welcome Southern Water’s investment plans, which are definitely a step in the right direction, and their efforts to improve community engagement. However, it is of course important that it leads to tangible results.

“I will continue to work closely with Southern Water, all the statutory agencies, my neighbouring MPs and Government Ministers to address the current declining state of the harbour. I’m looking forward to hearing more detail on the proposals to ensure we develop a solution-focused approach.”

Alan Mak, Member of Parliament for Havant said:

“Southern Water will play a key role in reducing discharges and ending storm overflows, and this investment is a good first step. I look forward to their detailed plan setting out how they will meet the new legal obligations set by the Government.”

The issue of Combined Sewer Overflows (CSOs) and storm overflow releases into the environment have become a growing issue of concern as a result of greater transparency of Event Duration Monitoring (EDM) data. Southern Water said the company has been at the forefront of this growing openness and transparency of information about releases from wastewater treatment sites since 2017.

Southern Water is embarking on a project to reduce infiltration into the sewer network and to reduce the incidence of spills commencing in 2021. The project will involve the monitoring of flows in the sewer network relative to groundwater levels and rainfall.

This will inform where to target concentrations of flow monitoring devices to home in on areas of particular concern. Once hotspots have been identified the utility will progress to the next stage of surveying individual sewer runs by scanning equipment which will check for leaking joints and pipe defects which are allowing flow into the system.

Once the weak points are identified it will use no-dig techniques which have been enhanced in recent years, to create a permanent seal to the pipes.

Nutrients also enter the harbours’ waters from sources other than CSOs. Southern Water said that Environment Agency figures show that wastewater from wastewater treatment works is a relatively small source of these nutrients.

In Langstone Harbour wastewater treatment works direct to the harbour account for four per cent of the nutrients - in Chichester Harbour the figures are 12 per cent from wastewater treatment works,