Cleaning up our rivers

© Linda Pitkin - 2020Vision

Ali Morse, Water Policy & Catchment Technical Specialist, sets out why we need to think smarter about our wastewater

Often described by people as ‘quintessentially English’, our chalk rivers are rare and important habitats. However only 12 are protected and many are not in good condition.

Over three quarters of our 200-plus chalk rivers are failing to meet the ecological or chemical standards set for healthy rivers, the majority because of pollution. A range of chemicals, contaminants, sediment from a variety of sources - industry, agriculture and households – all create problems for wildlife.

The most common reason for rivers falling into poor condition is the chemical phosphorus. While useful on land as a fertiliser, when found in our rivers it feeds algae which out-compete the more delicate aquatic plants like water crowfoot, thus destroying the habitat and food source of aquatic insects and fish.

Similarly, nitrates find their way into our rivers and are transported downstream, where they are taken up by hungry marine algae in estuaries and harbours. The resulting algae smother coastal mudflats, suffocating the insects that are an essential food source for wading birds. Other chemicals (such as the hormones found in human contraceptives) disrupt the breeding cycles of fish, preventing them from reproducing, whilst other pollutants are completely toxic to aquatic life.

Traditionally we have relied on what are called ‘end of pipe solutions’, which require industrial waste to be treated before being released into our rivers. Water companies, who treat our sewage, and industrial businesses have made significant advances in removing key chemicals from waste water. For example, Southern Water is currently redeveloping Woolston Treatment Works in Southampton – state of the art ultrafiltration membranes will reduce solids, bacteria and viruses entering the River Itchen, and the site will be the UK’s largest plant of its kind when complete.

Over three quarters of our 200-plus chalk rivers are failing to meet the ecological or chemical standards set for healthy rivers

But in many cases we are now reaching the limits of what is technically or financially feasible. Treating our waste water before discharge is only one part of the picture. If sewers become blocked, waste water containing raw sewage and chemicals from our homes can escape directly into rivers.

Water companies are encouraging customers to only put ‘the three Ps’ down the loo – paper, pee and poo. Most of our personal healthcare and beauty items are not flushable, despite what their packaging may state, and environmental and water-related organisations are campaigning to have these items marked as “Do Not Flush”.

The risk of sewer flooding can also be reduced by controlling the amount of water that enters our sewers. In many areas, the public sewer takes both household water and rainwater. Termed ‘combined sewers’, these pipes can be overwhelmed during heavy rainfall; so redirecting your downpipes to a water butt or soakaway will take pressure off our sewers.

Chemicals used in the home also impact our rivers. Phosphates in cleaning products such as dishwasher detergents ultimately end up in our rivers, so choosing phosphate-free products eliminates this risk. We’ve been working with partners in river catchments across Hampshire and the Island to encourage householders to make the switch.

For some households, waste is not dealt with by the water company but through private systems like septic tanks. These systems do not actively remove phosphate, so switching to eco-friendly products is even more important if your home is served by one of these systems.

Pollutants from land management are the other most significant source affecting our rivers. Sediment from fields, nitrates and phosphates from fertilisers and animal and crop waste, as well as agricultural chemicals, can all find their way into our waters. Our land advisors work with farmers to help them reduce the loss of chemicals and sediment from their land.

Through our Loddon Farm Advice Project in north Hampshire we are working in partnership with Affinity Water, South East Water and Catchment Sensitive Farming to help farmers in the Loddon catchment reduce these impacts.

Through our work with our partners, we are continuing to deliver projects to tackle all of these issues and more. With the Wessex Chalk Stream & Rivers Trust, we are currently developing an ambitious project which will see the Test & Itchen Catchment Partnership members tackling the pressures facing the headwaters of these two iconic chalk rivers.

Changes in land management practices, pollution, climate change and invasive species all threaten the biodiversity and man-made heritage of these rivers, and we are developing a bid to the Heritage Lottery Fund which would support us in tackling these issues over the coming years.


What you can do

  1. Choose your products carefully. As well as going phosphate-free, choose products that say ‘suitable for septic tanks’, as harsh chemicals like bleach can kill the friendly bacteria that break down the waste in your tank. Do not dispose of paints, medicines or other chemicals down your sinks and toilets, as these too may upset the balance. 
  2. Reduce your water use. Much of our water is drawn from our rivers – and growing demands means that water levels and conditions for wildlife drop. Take a short shower instead of a bath, install a water-saving toilet flush, or install water butts to use in the garden.
  3. Keep the drains clear. Be careful about what you put down your sinks and toilets. Sanitary items and wet wipes can cause blockages, causing untreated waste water to overflow into homes or rivers. Perhaps surprisingly, less bulky items can also be a problem – fats, oils and grease poured down the kitchen sink can congeal in pipes, causing blockages. 
  4. Show your support for environmental improvements. Water companies must prove to the industry regulator that there is customer support for investments in environmental improvements. All companies will soon be consulting on their next round of plans, so if you think a few extra pennies on your bill is justified in order to protect our precious chalk streams, let them know. Look out for information on your bill or keep an eye on company websites.