industry, rivers and waste
Ref: W03

One way of controlling pollution is to discharge waste into the sewage system. The problem does not disappear entirely, but at least it goes to the sewage treatment works where the Water Company has installed the facilities to clean it up, before discharging it into the watercourse. Most industries in the South West do this - the tanneries, the abattoirs, the dairy processing plants and metal plating works.

A quarry

However, some works like paper mills and the china clay companies discharge direct into rivers in the Westcountry. Sewerage works themselves are also a major industry. All these operations have strict limits agreed with the Environment Agency on particles or chemicals etc. that they can discharge into the river. They have systems in place that clean up and check the water before it is discharged to make sure. In most cases the companies do a good job in discharging good quality water. Unfortunately, when something goes wrong these operations can be a real pollution threat, but because they are monitored the Environment Agency is able to punish the failure by prosecuting the offender in Court.

Clean stream meets china clay contaminated stream

Times change and we now demand much higher environmental standards by companies. For example, the china clay industry historically used to discharge clay waste, made up of very fine particles, into the rivers of mid-Cornwall. The river that ran through St Austell was called the "White River" because of the clay particles in it, and fish and animal life in the river was very limited. The River Fal used to run white quite often too, but because the levels of particles were less than in the White River, eels and brown trout were still able to survive. The solids (clay particles) released from this industry do not kill or poison directly, but they limit the amount of light able to get to the plants and creatures that live in rivers and streams, Now, the White River and the River Fal generally run clear, and there is much more life in the river as species are re-colonising the river bed.

In-stream habitat smothered by sediment

The solids also smother vegetation and riverbeds with a fine layer of clogging silt. This alters the habitat and interferes with the feeding of filtering animals like freshwater mussels and blackfly larvae (B09a). In Cornwall the washings from tin extraction at South Crofty, Camborne, contribute to the Red River. When you’ve got a river named after a pollutant, you’ve really arrived!

Tin mining creates another problem. The old tunnels, or adits, create underground watercourses. As the water level changes in them, oxidised metals are washed into nearby rivers such as the Carnon, these include arsenic and zinc, which are highly toxic. Problems such as this are practically non-solvable; it is a legacy from the past that we have to live with.

Heavy metal runoff

In the sediments of rivers lie many legacies of the way land has been used. We may not be able to alter the way the land was used in the past, but with an eye to the future steps can be taken to safe guard the environment for wildlife.

Industries these days can and do take precautions to reduce their harmful impact on the environment. Some industries take an especially active role in doing their bit for the environment by making sure their operations are carefully monitored and go beyond purely meeting requirements set out by law. For example, industries and businesses can look to gaining an ISO 14001 Accreditation.