Willy Wonker Brown!

We received a message a couple of weeks ago at dripdriptamar@gmail.com from a local resident concerned about the state of the river that day. The Tamar had turned, in his words, the colour of Willy Wonka’s Chocolate River after heavy rain — thick, brown, and fast. What really worried him, though, was the foam collecting on the surface. It can look unnatural and alarming, and it’s easy to assume it must be some kind of chemical pollution.

But most of the time, post-storm foam is completely natural. When heavy rain washes leaves, soil, and other organic matter into the river, it releases tannins and natural compounds that lower the water’s surface tension. Fast-flowing water then churns these compounds, creating bubbles that gather as foam. It may look odd, but it’s usually a sign of a river full of organic material — not detergents or chemicals.

The real problem that day wasn’t the colour or the foam.

Our samples taken the following day revealed the true picture of the river. Bacterial pollution was almost off the scale, with Enterococcus recorded at 8,000 cfu/100ml at Calstock Quay (safe level is less than 400 cfu/100ml) . This is where the danger to human health really lies.

Appearances can be deceiving. Foam may look dramatic, but our professional lab results consistently show that the hidden, microscopic contaminants — not the visible ones — are the real risk to swimmers, paddlers, and wildlife.

After nearly a year of testing, we’re starting to see clearer trends. But one big question remains: what else is in the effluent entering our river that isn’t being tested for at all?

To explore this, and to set our priorities for the coming year, we’ll be hosting a People’s Assembly on 27th February. We’ll share more details soon, but for now: thank you to everyone who continues to report concerns, ask questions, and stand up for the health of our river.