Contaminated land is an emotive subject, lending itself to sensationalist images of danger signs and mass evacuations of housing estates.

The truth is generally much more mundane.

Lawyers who advise regularly on contaminated or potentially contaminated land issues must learn to live with uncertainty: uncertainty as to the law, how it will change and how it will be enforced; uncertainty as to the attitudes of the market to actual or perceived risk; and uncertainty as to the fundamental issue of when land is to be regarded as 'contaminated'.Small wonder then that many property lawyers must have heaved a large sigh of relief when, on 24 March last year, the government announced its intention to withdraw its proposal for statutory registers of contaminative uses of land under s.143 of the Environmental Protection Act 1990 - less than three years from the initial announcement of the proposal.

However, the proposed registers were only ever concerned with the collection and availability of information: the absence of a statutory register will affect neither the actual condition of land nor the contingent liabilities for that con dition.

Those liabilities, in particular, are currently in a state of flux.

For example:-- The decision of the House of Lords in Cambridge Water Company v Eastern Counties Leather plc (unreported, December 9, 1993) indicates that liability for historic contamination can be strict, though foreseebility will be relevant to recovery of damages.

The case also gives the rule in Rylands v Fletcher a new lease of life.-- The Cambridge Water case deals with the liability of the original polluter; the law as to the liability of a subsequent owner or occupier of land is obscure, but there is authority on which such liability could arguably be based.-- It remains to be seen whether the government will ever implement s.61 of the Environmental Protection Act 1990 which creates potentially very onerous obligations on owners of land where there are potentially harmful deposits of waste - waste being a concept which UK law defines extremely widely.-- In withdrawing its proposal for the contaminative use registers, the government's attention appears to have shifted to the issue of liability, which forms a major component of the 'wide-ranging review' currently being undertaken.-- From the point of view of the water regulator (the National Rivers Authority) its powers to deal with pollution of groundwater - principally contained in s.161 of the Water Resources Act 1991 - are unsatisfactorily weak.

Pressure can be anticipated for more effective powers to enforce clean-up.-- The EU has embarked on a general review of compensation and remedial mechanisms for impairment of the environment, following the Commission communication of March 1993 on 'Repairing damage to the environment'.Put all of these factors together and it should become apparent that we are probably in line for some potentially far-reaching changes.Applying this to current property transactions, it will be appreciated that these changes may well come about during the purchaser's ownership of property now being acquired, or during the term of leases now being granted.

There is thus a need for conveyancers to face up to these problems, register or no register.Much nonsense is spoken and written about due diligence in property transactions which, in the context of the vast majority of such transactions, is utterly unrealistic.

In an ideal world it might well be possible to follow a logical sequence of investigation, monitoring, risk assessment, contractual negotiation and risk allocation as between the parties.

In the real world, vendors do not co-operate, purchasers do not like spending money on consultants, and the cost of even a basic site investigation may be prohibitive in the context of the transaction.

Even the most basic 'walk-over' investigation is likely to cost more than £1000.

Where investigations including soil sampling are involved, a site investigation in accordance with DD:175 (the draft British standard for such investigations) the cost is likely to be in the order of £12,000 to £15,000 per hectare, excluding the costs of analysis - which can themselves be very significant.Realistically, rigorous and scientific site investigation is going to remain limited to the 'set piece' high value and high risk transactions: those involving superstores on reclaimed tips; industrial parks on former steel works sites; reclamation of military land and the like.

Even in such transactions, practice remains variable and there are great discrepancies in the quality of information available to purchasers, tenants and funders.

The key points for solicitors to bear in mind in such cases are:-- Use good consultants, instruct them in good time and ensure that their brief is adequate and that their conditions of engagement are satisfactory.-- Do not be fobbed off with site reports which may have been commissioned for some other purpose, eg geotechnical reports on ground stability.-- If the client is relying on reports of previous consultants, or if such reports are to form the basis of a later report, ensure that the earlier consultant's duty of care extends to the client.-- Read the reports carefully yourself, in draft and in final form.-- Remember that there is a great difference in practice between the investigations which can be undertaken before a site is developed and what can practically be achieved given the physical and operational constraints on a developed site.In some cases, such as those mentioned above, the need for assessment of potential contamination and associated liabilities will be obvious.

In other cases there is a difficult decision to be made as to how much (if at all) investigation should be made.

Clearly, had the statutory contaminative use registers been introduced, a search of the register would have been a clear and inexpensive step which solicitors could have taken - and doubtless would have been negligent not to take.

What solicitors and their clients would have made of the results is of course quite another matter - especially bearing in mind that the contamination potential not only of the land being acquired, but also adjoining and nearby land, may need to be considered.Short of retaining a consultant there are two obvious sources of information as to possible contamination: the local authority and the vendor.

Extracting information from either of these will not necessarily be easy, though at least in the case of public authorities there are statutory rights of access to information under the Environmental Information Regulations 1992 (SI 92/3240).

Many local authorities will hold information which could help to determine whether there is any real risk from contamination.So long as the caveat emptor rule remains the basis of conveyancing practice, it will inevitably be difficult to achieve a satisfactory position in relation to enquiries as to possible contamination.

The most carefully drafted pre-contract enquiries can all be met with the simple response that the purchaser must rely on his or her own inspection and investigations.

The House of Commons environment committee in its 1989 report on contaminated land urged the reversal of the rule in relation to contamination, but unfortunately the government did not pursue the proposal once it had decided to institute the subsequently ill-fated public registers.

Nonetheless, there is nothing to prevent the purchaser's solicitors trying to obtain such information as the vendor may have, particularly if there are other circumstances which are indicative of possible contamination.The transfer of land will inevitably involve the transfer of at least some element of risk to the purchaser in relation to contamination.

Such risk can be allocated by way of contractual provisions, particularly by covenants and indemnities.

Again, however, such indemnities seem unlikely in the near future to form part of the mainstream of property transactions.

Their drafting raises many difficult considerations, such as where the risk should fall in relation to subsequent, and maybe unforeseeable, changes in the law; and of course the indemnity is only as effective in protecting the purchaser as is the strength of the vendor's covenant.

Nor are the risk issues all one way: there may well be circumstances which justify the vendor in seeking an indemnity from the purchaser in relation to future contamination.

In short, indemnity provisions certainly have a role to play, particularly in commercial transactions, but it would be unrealistic to suggest that they can ever be the complete answer to the problem.Leases present difficulties of their own in relation to possible contamination, both for landlords and tenants.

From the tenant's point of view, there will be an understandable wish to avoid financial responsibility for rectifying pre-existing problems of contamination.

Danger areas for the tenant are the repairing covenant, covenants as to payments of outgoings and compliance with statutory requirements and the service charge.

A common approach to problems of site contamination when reclaiming land has often been to avoid construction on the most highly contaminated areas and to use these for hard-surfaced areas such as car parking.

These may well be common areas under the lease, maintainable at the tenant's expense.

Such a commitment for a term of 20 years or more should not be undertaken lightly, and unfortunately there is very little case law to suggest how standard lease drafting might apply to contamination problems.From the landlord's viewpoint, the main potential problem is possible contamination of the premises by the tenant, particularly where the tenant is engaged in industrial activities or is storing contaminative substances.

Such risks may be minimised by the exercise of discrimination in selecting a tenant, by appropriate drafting in the lease and by vigilance during the term.

In particular, for 'high risk' tenants it may be highly advisable to conduct investigations for contamination at the commencement and end of the term, to establish exactly what effect the tenant's activities may have had.Contamination is, unfortunately, a field where it is far easier to state the problems than to give clear advice.

A degree of discrimination is needed, together with an awareness of steps which can be taken to minimise risk.

At the very least, the solicitor who is aware that his or her client's proposed purchase is built on or near to a former landfill site (for example) can draw that fact to the client's attention and can warn of the potential risks of proceeding without further investigation.

Mercifully, contamination will not arise as a significant issue on the vast majority of transactions, but the practitioner should be vigilant for it as a possibility in all cases.