Because many industries discharge their wastes through the sewage system, sewage sludge fertilizer may be contaminated with heavy metals, whilst the use of pesticides also poses a major threat. Thus, dichloropropene-dichloropropane (DD), used to k i l l worms, was believed to degrade rapidly in the environment without major problems, until it was discovered that the use of other pesticides together with DD can inhibit its degradation. In The Netherlands, some 30,000 hectares of agricultural land in Drentre province are now so polluted with DD that drinking water supplies may have to be treated by air stripping until the year 2050.

In some cases, the damage is immediate and obvious. As the material dumped in old landfills breaks down, for example, explosive levels of gases such as methane can build up. In 1986, an explosion at Loscoe in Derbyshire caused by gas moving underground from a domestic waste landfill destroyed a bungalow, severely injuring the occupants. There have been several deaths, particularly in the US, caused by similar explosions. A British government report indicates that at many sites, landfill gas had "migrated 300 to 400 metres, and on some occasions, further."19 Because even landfill sites that have been licensed to accept only demolition and "inert" waste have generated hazardous concentrations of landfill gases, another government study concluded that "i t would be a sensible precaution to assume that every site, whatever its category, has the potential to produce methane . . . in significant quantities."20

There are about 4,000 landfill sites21 currently operating in Britain, in addition to an estimated 6,000 closed sites.22 Little official action has been taken to pinpoint high-risk sites, despite a flurry of planning guidelines and technical papers about landfill gas after Loscoe. A survey by the government Inspectorate of Pollution23 listed over 1,000 gassing sites but failed to identify their location, while Friends of the Earth were told by several waste regulation authorities that "information on closed sites cannot be divulged."24

Derelict industrial land in Wolverhampton. At the end of the 1980s, approximately half of all new building in Britain was taking place on redeveloped land, most of which was suspect in terms of contamination.

Land may also be contaminated through airborne pollutants. The incineration of toxic wastes — ironically touted as a preferable option to landfill — is a potent source of such contamination. It has recently been shown "beyond reasonable doubt" that the Rechem toxic waste incinerator at Pontypool, Wales, has contaminated land within 500 metres with PCBs and dioxins. The highest dioxin level ever recorded in scientific lit erature was found on this site.29

The ash residues from municipal waste incinerators also cause problems both by leaving toxic heavy metals in a form that readily leaches from landfill sites and as a direct hazard. Residents living close to the Red Moss landfill site in Horwich, Greater Manchester, complained that their health was being affected by wind-blown ash from the site which

Old and current landfill sites are also major sources of surface and groundwater pollution, a recent government-commissioned study of 100 landfills revealing over half of them to be polluting.25 In many cases, the effects only become evident over longer periods of time or manifest themselves far from the site of origin. For example, a borehole in the quiet village of Blewbury in Oxfordshire was closed in 1992 when the level of carbon tetrachloride exceeded maximum permitted levels in drinking water. The only potential source for the contamination was the Atomic Energy Authority (AEA) laboratories at Harwell, four kilometres away, where tonnes of chlorinated solvents, typically used for industrial cleaning, have been dumped onto chalk above the regional aquifer.26 The AEA is now spending over one million pounds on an air stripping plant at Harwell to clean the solvents, chlorobenzenes, pesticides and PCBs from the groundwater which may reduce the very high concentrations within the laboratory boundary, but is unlikely to restore the aquifer and may turn water pollution into air pollution. The total bill over the 10 or more years' operation is likely to run into millions of pounds.27

accepted 16,000 tonnes of residues from the Bolton municipal waste incinerator each year. A campaign by local residents and Bolton Friends of the Earth resulted in a ban on the deposit of fly ash (the most contaminated part) on the site and pledges to investigate full treatment by solidification of the ash. 3 0

Local Action

•

With increasing public awareness of environmental pollution, local citizen groups have sprung up around Britain in the last five years, focusing on problems associated with contaminated land. Women from Craigneuk in Scotland formed the Craig Anti-Pollution Group in 1991 with the backing of Friends of the Earth Scotland. They are concerned about their children playing on the open waste tips from the Ravenscraig steelworks, Britain's largest single site of contaminated land which ceased production in summer 1992.

Contaminants from tailings of abandoned lead mines can affect large areas as well as travel long distances. In central Wales, drainage from mine entrances and shafts, and erosion of spoil heaps has led to high concentrations of lead, cadmium and zinc in streams, depleting aquatic life in many rivers. Productivity of at least 1,200 hectares of agricultural land on the river flood plains has been reduced because of the high levels of metals in the soil.28

Agricultural practices may also lead to contamination.

Waste from Ravenscraig, including several million tonnes of coke oven-wastes and pickling acids, was dumped down old mine shafts. Groundwater contaminated with ammonia, cyanide, phenols and oil is now surfacing within the site and in a tributary of the river Clyde which runs within the site boundary. Cleaning up such a heavily contaminated site could cost an estimated £200-£240 million.31 The Craig Anti-Pollution Group' s demands for full details about contamination levels have not been met, and British Steel is threatening to close a nearby steel works i f they are forced to clean up Ravenscraig. The residents

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How Safe is Safe?

In 1810, the J. J. White factory bought a 414 acre site of a 17th century steel works near Glasgow and another 12 acres as a waste materials dump, to produce soap and soda, but by 1820, it was producing chrome salts. It went on to become the largest producer of chrome in the world. In 1899, the horrific working and health conditions at the White's factory became a national scandal when Labour leader Keir Hardie published the first of his "White Slave" series of pamphlets on the Rutherglen works, entitled "Chrome, Charity, Crystals and Cant". In many of the workers, the chrome, both liquid and dust, had created holes in their arms and noses. "They told me of John Campbell who had to wear a cage to cover his belly it was so eaten away with chrome poisoning," wrote Hardie.

By the turn of the century, the company had become British Chrome Chemicals Ltd, which started manufacturing chromium oxide in 1919, followed in 1945 by bichromate crystalizing. The waste products changed accordingly from chrome ore dust, to a contaminated liquor, to residue deposits. In the mid-1950s, factory records detail complaints from residents about the chromium dust levels in the street. Other by-products included heavy metals, acids and poisons such as cyanide, arsenic and benzene. After more mergers and amalgamations, the factory finally closed down in 1968 when the production of bichromate was moved to Cumbria.

The 12 acres of land set aside for waste disposal had quickly become inadequate in the 148 years of the factory's working life. Expansive ponds and lagoons formed and regular but indiscriminate dumping took place day and night. In April 1991, chromium waste was discovered on land acquired for the development of a nursing home. A driver, Mr McLeary, employed by the chemical factory to transport the waste to the various dumps, came forward, after local and national publicity, to reveal more sites — and the names of other drivers. Soon toxic dumps were discovered throughout the built-up areas of southeast G l a s g ow— Cambuslang, Carmyle, Rutherglen, Toryglen and Eastfield.

An October 1991 public meeting, convened by the district council, revealed that the local people knew far more about the extent of dumped carcinogenic hexavalent chromium waste than the authorities. Rutherglen maternity hospital has been constructed on top of a toxic waste dump, while an industrial site — with at least four food-related factories — has been built on the site of the former White's chemical works.

Most of the contaminated areas that have been found have been children's play areas and football pitches, which, although fenced off with warning sites, children still play on. Some of the toxic waste seeping through the football park cannot be seen in daylight but glows clearly at night.

Dust and direct human contact with contaminated material seem to be the major immediate threats. Levels of child leukaemia in the area are high, as is the number of children with asthma and people with skin problems.

After several months of official reports, including health reports, members of the public involved in supplying information to the authorities formed the Cambuslang, Carmyle and Rutherglen Against Pollution (CCRAP) group in March 1992 to campaign against and publicize the toxic waste. The group are now opposing plans of Celtic Football Club to build a new stadium on an area believed to have high levels of contamination from the chemical works, and demanding proper remedial action, not just the fencing off of contaminated sites, in addition to surveys to find the full extent of contamination.

Cambuslang, Carmyle and Rutherglen Against Pollution are lobbying hard to ensure that the site is not simply covered over with concrete.

Mary Ferrie of the Craig Anti-Pollution Group expresses the frustrations of many similar groups and concerned individuals when she says, "We're not scare-mongering. We're scared. Why aren't our councillors and MPs shouting the odds about this? We're just housewives, but we have to do it ourselves. We have to say something," a plea that has been echoed around Britain by groups who have found little local or central government interest in land contamination.

Clean-Up

The most effective way to remove the stigma of contamination would be a credible — but expensive — clean-up operation. The cost of remedial work to prevent landfill gas, for example, can range from £50,000 to £500,000 depending on the site, while remedial work for groundwater pollution may reach

£1 million.32 The total cost of cleaning-up contaminated land in the UK has been estimated at £10-30 billion.3 3 Environmental groups argue that a tax on the more polluting industries, such as landfill sites, steel works, chemical factories and even petrol filling stations, could fund the clean-up and reduce further contamination.

In the meantime, on-site containment — covering contamination with earth or tarmac — and cheap waste disposal in landfills is undermining remedial treatment, and the little remedial work that is carried out is often of a low standard. In a 1988 survey of 29 sites which had been redeveloped, contaminated ground in 22 of them had simply been covered over, while in the remaining seven, contaminants had been removed for disposal off-site, shifting the problem elsewhere. A more detailed assessment of seven of the sites indicated that reclamation on only four of them had prevented hazards to human and animal health, and to the environment. Waste tips, especially those containing drummed or bagged waste, were described as " a contamination time bomb."34

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