Unfortunately, many human activities and their by-products have the potential to pollute water. Industrial enterprises, the water industry, housing, agriculture, horticulture, transport, discharges from abandoned mines, recreation and deliberate or accidental pollution incidents all affect water quality. Pollutants from these and many other activities can enter surface or groundwater directly, may move slowly within the groundwater to emerge eventually in surface water, may run off the land, or may be deposited from the atmosphere. Any water pollution can be exacerbated by adverse weather conditions. Whilst some pollutants would have an obvious and rapid toxic effect upon the flora and fauna of the river, others such as microbial contamination are invisible to the naked eye but might present a hazard to human health if ingested. Some pollutants may be overlooked because they have a more insidious, long-term effect – for example, causing slow siltation of the river. All these threats are well recognised and are covered by a variety of official advisory publications which the ACA wholeheartedly endorses.
On the Avon, pollution can arise from point sources, such as discharges through pipes or spillages, or diffuse pollution which is more dispersed. The most likely cause of pollution from point sources is domestic waste. The problem is described in more detail in the following document – (click here to view) THE THREAT OF SEWAGE POLLUTION.
The most likely source of diffuse pollution is run-off from the land of animal waste, of soil, and of horticultural and agricultural chemicals – made worse where grazing cattle cause riverbank erosion. The ACA was instrumental in gaining the incorporation of the Avon, as an Associate Project, into DEFRA’s first Catchment Sensitive Farming Initiative to reduce agricultural run-off into the river. We provided some seed money of our own to combine with money from the AONB’s Sustainable Development Fund. The project ran for 18 months, starting in October 2006 and is described in outline in the following file – AVON CSFI Introduction Oct 06 – and Powerpoint presentation – AVON-CSFI. The second phase of this initiative is now underway and we are delighted that, somewhat belatedly, the Avon has been included in the primary scheme covering the rivers Erme and Yealm partially as a result of the ACA’s lobbying but, primarily, as a result of the exemplary performance of all those involved in Phase 1 and on the demonstrable improvements in the Avon’s water quality resulting from participation. In Phase 2, which will run until 2015, farms in the Avon catchment will be eligible for more capital funding in addition to manure and soil management advice, as set out in the following document – csfdi2008_2015. A video summary of the Catchment Sensitive Farming Initiative is available here – https://youtu.be/JZytPcpBvrA .
A review of the Environment Agency’s monitoring of organic pollution in the Avon for the years 2000-2010 is presented in a document which can be read by clicking here:- Avon WQ observations 200111 Operation of the programme has some severe shortcomings which render the programme useless as a means of environmental protection.
In the lower reaches of the river, uncontrolled discharges into the river or the sea of miscellaneous boating wastes such as fuel, lubricants, paint and solid debris pose a different challenge. If we are to protect our river, conservation must be paramount in the thoughts and actions of all user groups.
Also in the lower estuary, litter and waste from various sources are a perennial problem which the ACA attempts to tackle by regular clean ups of the shoreline. For instance, Cockleridge beach at Bigbury on Sea is part of the Marine Conservation Society’s (www.mcsuk.org) Adoptabeach and Beachwatch campaigns which ACA members actively support in conjunction with Learn to Sea (
The Rivers Trust has provided a helpful map indicating likely sources of pollution in the Avon and other local rivers:-
CEFAS (Centre for Environment Fisheries and Aquaculture Science) produced a sanitary survey report on water quality in the Avon Estuary in 2014, which includes a mass of data on potential sources of pollution and the possible effects on shellfish production :- https://www.cefas.co.uk/media/js5efegk/bigbury-and-avon-sanitary-survey-2014-final-table-issues-untagged-figuresdj.pdf