Most of the obvious toxic chemicals (spills apart) are no longer discharged into our rivers. These toxic compounds include, organic compounds from the dying industry, petrochemicals, heavy metals (mercury, cadmium, lead etc), coal bi-products and anything else that you can think of from industrial processes. It is correct, as one member pointed out that there was less of a problem in the south due to a relative lack of industry. Any rivers near industrial areas will have copped it and about the only fish to survive the low oxygen conditions at the time, ironically, would have been eels. So there were two issues, straightforward poisoning and very low oxygen content of the water. Most of these pollutants are no longer present in our rivers.
What we have now are phosphates from our industrial/domestic washing machines, sewage works can't remove these, together with phosphates and nitrates run off from agricultural activities finding their way into the rivers. Some of the sheep dips include organo-phosphorus compounds (related to nerve gases) and insecticidal sprays from farming can all find their way into the watercourses. Phosphates and nitrates promote plant/weed growth like there's no tomorrow. As for the birth control discharge having an impact, I'd be a bit surprised but if that were the case then you could probably add antibiotics into the equation. Water sampling should "flush" out these two potential culprits.
Not exactly true...When they abstract and treat water for human consumption, the removed industrial waste products, heavy metals, pesticide residues, pathogens etc, which are filtered via sand or other, are flushed 'back' into the river from whence they came.... and in a more concentrated form. Yes, they should be removed from the cycle as a 'hazardous waste', but they aint i'm afraid. Alternatively, what they do, is discharge the possibly toxic wet sludge harbouring all the nasties into lagoons on farm land (as they do down here in Dorset) which then slowly seep into the feeder streams and again entering into the main river. When the lagoons are full of the said sludge (and someone complains at the smell or other), they then remove it and spread it on the fields where cattle graze and eat the grass etc! So it all eventually gets washed back into the river via runoff or enters the water table and/or enters into the food chain via the cattle, sheep etc...including the human food chain.
Again, most sewage works nowadays are equiped to remove phosphates, but only remove them 'partially' to a legal level required by the EA and the government, just like many other substances. Even in treated drinking water, there are always traces of the poisons left that have not been removed! They don't kill you outright though, but they are/can be 'accumulative' in ones body over a long period of time. Many people end up and die with cancers and problems usually later in life, and it aint all down to smoking and air pollution i'm afraid.
They may have also banned the usage of certain substances in recent times, but they are still present in our rivers settled out on the riverbed and in silt and mud, and often re-surface back into the river/canals. Food for thought!
Also the discharging by STW's of Raw Sewage is a legal licenced practice authorised by the EA, (the guardians of the river environment) in times of flood, but they do it at other times as well when no one is looking or monitoring them, and usually at night. Why, well it costs them money to treat it fully, so more in the pockets for the shareholders if they can get away with it...and they do!
Why do you think the EA cut down overhanging trees along our riverbanks and take out vegetation obstructions. It is because that when a STW discharges 'raw sewage' when the river rises as Graham says, tiolet paper, nappy liners, condoms, sanitary towels etc would get caught up in the branches and obstructions for all the public to see and expose the issue
