How to report river pollution: who to call and what to say

Ring the environment regulator for the nation you are standing in, and do it while the pollution is still visible. The table has the numbers. England, Scotland and Northern Ireland share one number, so say clearly where you are if you are close to a border.

If there is an immediate threat to life, health or property, call the emergency services. SEPA's own page makes the same point about its reporting system.

Keep your distance from the water

Treat suspected sewage with care. The Rivers Trust explains that raw sewage can carry solid waste, and that even treated sewage can still contain chemicals, pharmaceutical products, harmful bacteria such as E. coli and enterococci, and excess nutrients that can cause toxic algal blooms. So do not paddle in to investigate, and keep children and dogs out of the water until you know more. If you have already been in and feel unwell, speak to a GP or NHS 111 and mention the river.

Step one: decide what you are looking at

You do not need test kit. The Rivers Trust points out that most sewage spills can be noticed by sight or smell, and it lists these signs:

• Wildlife in distress, including dead fish or fish gasping for air
• Unpleasant smells
• Discoloured water. Sewage is rarely brown, the Trust notes, and is usually grey or black
• Sewage-related litter such as wet wipes, sanitary items and tissue
• Sewage fungus, which can point to pollution even when nothing is flowing at the time

The Environment Agency's list of what to phone about is broader than pollution alone. It also includes collapsed or badly damaged river banks, people taking water illegally from a river or well, damage or danger to the natural environment, unusual changes in river flow, and incidents at regulated waste sites. If you are unsure, the operator can tell you whether it belongs with them.

Step two: write down the details

Pollution often passes quickly, so a report made from memory the next day is worth much less. Natural Resources Wales asks for what you saw, where it happened, when it happened, and whether it is still happening. It says location is essential. The Rivers Trust suggests a grid reference if you can get one and says a postcode should be enough otherwise.

Before you ring, try to have:

1. The date and time you first noticed it.
2. The precise location, including the river's name and which bank, if you know.
3. What you can see and smell, in plain words.
4. Whether it is getting better, worse or staying the same.
5. Photographs or video, if you can take them from a safe place.

Do not go into the water to get a better picture. The Riverfly Partnership tells its trained volunteers not to sample at all when there are visible signs of pollution, and they are not expected to put themselves at risk. The same sense applies to everyone else.

Step three: make the call, and keep the reference

You can report anonymously, but the Rivers Trust says that named reports carry more weight, and that visual evidence helps. Take down any incident number you are given. It is the simplest way to follow up, and if you are part of a local river group your coordinator will want it. Riverfly monitors are asked to pass it on in exactly this way.

Who does not deal with what

Regulators get calls about things they cannot act on. Natural Resources Wales publishes a useful division of labour, which is specific to Wales, though many of the categories will sound familiar elsewhere.

• Your local authority: fly-tipping of household waste, burning domestic or garden waste, smells from homes or small businesses, and dead animals.
• A utility company: burst water mains, unusual colour, taste or smell in drinking water, and blocked domestic drains and sewers.

In Northern Ireland, nidirect sends illegal dumping to the district council and land contamination from other activities to the council's Environmental Health Department. Suspected blue-green algae at a river, lake or the sea can be reported through the Bloomin' Algae app or by emailing photographs to the address in the table.

The Foyle and Carlingford areas also have the Loughs Agency, whose WaterWatch tool takes reports of illegal fishing and pollution.

Why a single report matters

A regulator cannot investigate what it does not know about, and short events leave little behind by the time anyone official arrives. A timed photograph with a location gives them somewhere to start. If you would like to see whether there is a known discharge point near the place you saw the problem, the Rivers Trust's Sewage Map shows where the sewerage network discharges and overflows into rivers. It does not prove where a particular spill came from, so report what you saw rather than who you suspect.

Do not be put off if nobody calls you back. Natural Resources Wales says it may contact you for more information but does not give individual feedback on every report, and that it ranks incidents by the risk to the environment, people and wildlife. Your report still goes on the record for that place and time.

What a report can do is add to the picture of a river over time. Our guide to how river health is measured looks at what official figures capture and how volunteers fill in the gaps. If what you saw was people fishing illegally rather than pollution, our licence guide explains where that report should go.