Working together - a pioneering approach to rural river improvement

A healthy river can provide us with a host of benefits, and clean water is only part of it. The river catchment land itself provides us with flood management, produce from agriculture, biodiversity and scenery to keep us fit in body and mind. All these benefits are interlinked and there’s an increasing awareness that if we are to improve our rivers we need to be thinking about both the water and the catchment as a whole.

Better tap water and cleaner rivers have long been the key drivers of investment for water companies. And the solutions have traditionally come in the form of major civil engineering and energy- or chemical-intensive new treatment processes.

But is this really the best way to tackle the problem, especially in a rural area? Are we over-engineering the solution – using a sledgehammer to crack a nut? Are we building expensive assets and leaving a legacy of big future operational costs for our customers?

There is another way, and it’s one that United Utilities is considering for the Petteril project in Cumbria. Based on partnership working, it will deliver more effective interventions and reduce the burden of investment costs on customers.

The River Petteril begins at Motherby near Penrith and flows north through farmland and rural communities until it joins the River Eden in Carlisle. There are 10 wastewater treatment works along its course, 10 combined sewer overflows and 12 wastewater pumping stations. There are also more than 100 farms, numerous private septic tanks and one motorway service station.

The biggest issue affecting the river is phosphorus which can lead to algal blooms, impacting on fish and wildlife. So where does the phosphorus come from? It’s found in soaps and detergents so wastewater assets are one source. Phosphate removal processes at wastewater treatment plants would be a traditional solution.

But phosphorus is also found in fertilisers and animal waste which washes off farmland. In a rural area like the Petteril catchment this is a significant factor. According to the Environment Agency only 30 per cent of the phosphorus in the catchment comes from wastewater assets so it became clear that a non-traditional approach was needed. We decided it was worth carrying out accurate modelling to understand exactly where the most effective interventions could be made. We wanted to see how innovative treatment solutions and catchment solutions might provide a better option in the round.

This is where we have built on best practice and case studies from other parts of our region. Since 2005 we have been restoring moorland landscape in parts of the Pennines to help improve reservoir water quality. Over the last four years in Cheshire we’ve been trialling schemes with farmers to encourage the use of alternative fertilisers, and techniques like the growing of cover crops to reduce run-off during the winter months. In the Wyre area of Lancashire we’ve funded grants to help farmers with tree planting, fence installation and buildings improvements, all aimed at keeping livestock out of watercourses, helping maintain improvements to the local bathing waters.

Through the Petteril project, working with partners like the Environment Agency, the Eden Rivers Trust and Carlisle City Council we’re getting the buy-in to bring all these ideas together into one approach with multiple benefits.

We still need to address our own wastewater assets so we’ve also been trialling innovative new small scale phosphorus removal technologies at Calthwaite WwTW. The results have been encouraging and they show that the necessary levels of phosphorus reduction can be achieved using a sustainable media filtration technique rather than the traditional chemical coagulation process. In this way, when the media is changed, the phosphorus can be recovered and recycled for fertiliser and other uses.

And what does this mean for our customers? The original cost of installing and operating traditional phosphate removal technology at all of our assets along the Petteril would have come in at £14 million and would have missed 70 per cent of the river’s problem. The cost of the integrated catchment management strategy comes in at closer to £4 million. And what’s more, the pilot scheme may well show that additional benefits are delivered at the same time, such as carbon capture, slowing the flow of floodwater, and reduced risk of pollution at nearby Bowscar borehole.

It’s early days and this is a three year pilot scheme, but it shows how working in partnership can bring exponential improvements. And according to our stakeholder groups in the area, this is exactly the sort of innovative thinking water customers want to see ahead of the next price review in 2019.

DEFRA’s current 25 year plan sets out “to be the first generation to leave the environment in a better state than we found it.” Part of its approach, “Pioneer”, brings different agencies together to tackle environmental challenges in a new way, to get the best possible outcomes for the least cost. We’re going to be sharing what we learn from the Petteril project with Pioneer, to help shape the UK’s environmental policy for years to come.

Read our recent article on Phosphate Management on one of the UK's leading process engineering magazines'