Site Contamination

WHAT IS A CONTAMINATED SITE?

A contaminated site is one at which hazardous substances occur at concentrations above background levels and where assessment indicates it poses or is likely to pose a hazard to health or the environment.

WHY CONDUCT AN ASSESSMENT?

Common reasons for investigating a site are:

• Required by council to gain development consent
• Part of prepurchase or vendor technical due diligence

The processes of assessment of a site for planning approval are set out in SEPP55 and its Guidelines. The trigger for Council’s request for an assessment is the application for Development Consent.

HOW IS AN ASSESSMENT CONDUCTED?

Different elements of the assessment process may be followed depending on the reason for the investigation. Usually the purpose is to determine the type, level, and extent of any contamination and the action necessary to monitor, manage or remediate the site. The typical process is:

Site Inspection

The purpose is to become familiar with the site, understand the topography and to note any relevant features such as possible contaminant sources either on the site or nearby.

Site History

A thorough site history provides an understanding of past usage, particularly of any potentially contaminating activities. The site history provides a guide to further investigation, particularly what contaminants to test for. It is not practical to test for all contaminants.

A site history normally includes discussions with past occupants, local identities, a study of aerial photographs, council records, Land Titles Office records, Environmental Protection Authority (EPA) records and other such sources.

Sampling / Drilling

The sampling / drilling program will depend on the site inspection and site history. In theory if there is no indication of contamination then sampling / drilling is unnecessary. In practice on virtually every site a detailed drilling and sampling investigation will be necessary if the report is to be accepted. If ground or surface water is present this may also have to be sampled. A report is usually prepared at this stage.

WHAT HAPPENS NEXT?

REMEDIATION

This can be the most costly element in the process.

There are numerous remediation strategies depending on the nature of the contamination and the time frame allowed for the clean up. It may involve removing the contaminated soil to specially licensed depots and in some cases stabilising it with concrete before removal, and/or on site remediation by various specialised processes. The ground water may also require remediation. The process includes preparation of a Remediation Action Plan and the provision of notice to council.

VALIDATION

After remediation it is necessary to validate that the site is now clean. This usually involves a soil sampling program and may also include monitoring of surface and ground waters. There are detailed EPA Guidelines regarding the number of samples, quality assurance procedures and related matters.

AUDITING

In some cases the consultant’s report will need to be audited. Some audits must be conducted by an independent EPA accredited auditor, while in some cases the Councils conduct the audit themselves, or it may be audited by an independent consultant.

THE PLAYERS

As with most human activities there are numerous laws, regulations, guidelines and codes of practice governing contaminated sites and as would be expected each state and council has its own regulations. Fortunately however they have largely relied on the same information source when formulating policies.

It is not intended to discuss legal issues but to briefly provide an overview of how the regulatory process works for full site investigations which might be, eg required by a council as a condition of issuing a Development Consent.

Only the NSW situation is outlined here, each state is somewhat different.

THE REGULATORS

The EPA

The Contaminated Sites section of the NSW EPA sets the guidelines for the assessment and remediation of contaminated sites. In most cases they do not directly approve a particular investigation or remediation program.

The Australian and New Zealand Guidelines for the Assessment and Management of Contaminated sites by the Australian and New Zealand Environment and Conservation Council (ANZECC 1992 Guidelines), and the NEHF A, D, E and F levels provide the basis for most contaminated site investigations.

Different levels of contamination are allowable for different site uses. Eg the maximum allowable level of lead in the soil for a single dwelling residential site is much lower than that allowed on an industrial site. See How Clean is Clean?

The ANZECC and NEHF Guidelines set out how an investigation should be undertaken, what levels of contamination are acceptable for a particular site usage, and what levels require further investigation and or remediation action. Generally the NSW EPA draws on these Guidelines when preparing the State Guidelines.

The Hazardous Chemicals and Waste section of the NSW EPA control the transport and disposal of contaminated soil to EPA approved depots. They have classifications for particular depots regarding what type of contaminant can be accepted. See Disposal of Waste.

The EPA can declare a site as contaminated land and direct remediation action at the owner’s expense.

The Councils

It is the councils that actually approve development and building applications. It is these applications that frequently trigger a demand for a site assessment. Thus it is the councils who approve an investigation and/or remediation by approving a development application.

The councils rely on consultants for environmental reports and validation reports. The councils may require that the report be audited. For simpler sites they may review the consultant’s report themselves.

The Consultant

They undertake the assessments, supervise the remediation and validate the site once it has been cleaned up.

In some instances the consultant and the remediation contractor may be the same organisation. There is a potential conflict of interest in this situation as the consultant has a responsibility to represent the client’s interest and not that of the clean up contractor. The argument in favour of a combined consultant/contractor is that it offers a package deal. A package which contains both the supervisor and operator in the one role may not be a satisfactory solution for the client.

The Auditor

If the council does not wish to review the consultant’s report themselves then they may require that the consultant’s report is audited by another consultant or by an independent EPA accredited auditor. The auditors provide an independent review of the consultant’s investigations and/or validation. They are not and must not be the ones that undertake the investigation or validation. There are detailed EPA Guidelines covering how the audit should be undertaken and an accredited auditor must report to the EPA on the audits they have undertaken.

An accredited auditor is a person, not a Company. They cannot audit their own reports nor those of the organisation for whom they work. Thus if an audit is required by Council you must have two separate organisations - one to do the assessment, and one to do the audit. An auditor must not be the one who undertakes the investigation or remediation. The system parallels the financial regulations. The accountant (Environmental Consultant) prepares the financial reports (site assessments) and the auditor audits them.

The system described relates only to contaminated land. There are other types of audits such as site or process audits to determine whether a site or process meets the Environmental and/or Occupational Health & Safety standards. These Environmental and/or Occupational Health & Safety audits should not be confused with the contaminated land assessments and audits discussed above.

Confidentiality & Responsibility

The relationship between the Client and Consultant is governed by the normal client professional relationship rules. The Consultant’s relationship is one of confidentiality and responsibility to the client.

The relationship between a client and an accredited Auditor is quite different and is dealt with in the NSW Contaminated Land Management Act. The Auditor has a legal obligation to the Council and the EPA, which includes notification in a prescribed format. Even when a non statutory audit is conducted by an accredited auditor, the auditor must notify the EPA who may then request further details. Even though the auditor may be paid by the client their responsibilities are at least in part to the Council and the EPA.

It is important not to confuse the words assessment or investigation with the word audit as they are two distinct processes. Audit has the conventional meaning of review of another’s presentation, the Consultant’s, against preset criteria.

The Contractor

The contractor undertakes the remediation program under the supervision of the consultant. The skills required will depend on the particular situation. Some projects are largely earth moving projects while others require specialised technology.

The Owner/Developer

The owner/developer finances the operation and has overall responsibility.

HOW CAN NEW ENVIRONMENT HELP?

The above information is a simplified summary.

New Environment can provide detailed advice, site sampling and consultancy.