The General Law for the prevention and Integral management of waste (LGPGIR) has provided the reference for the implementation of the assessment of environmental risks (ERA) for contaminated sites; as a tool to determine the actions of remediation of contaminated sites. The Law defines the ERA as a "methodological process" to determine the probability or possibility of adverse effects resulting from exposure of humans to substances contained in infectious agents or hazardous waste that are occurring. The regulation published later is more accurate in the information ERA must contain. In July 2006, SEMARNAT publishes guide technique to guide the development of the ERA; which is the Guide document followed during the preparation of the ERA and will be admitted to the relevant authorities.

Application of the Era
In any anthropogenically contaminated with toxic compounds that affect human health or ecosystems, cleaning through this technical tool criteria should be established. SEMARNAT technical guide is very descriptive of the technical content that must comply with this type of study. It highlights the fact that for execution must have been just strict Characterization procedures to understand the magnitude of existing environmental liabilities. ERA considers in its evaluation present waste, its impact to the soil and/or ground waters taking into account the ecosystem in which the contaminant event occurred. In other words, as a result of the evaluation shall be defined the risk index and the factor of slope of cancer for every compound toxic to various possible human and ecosystem host. Based on these indicators will be established criteria for cleaning of each component and or their management to eliminate the risks of polluting compounds exposition.

Experience of CAM
CAM is a pioneer in the implementation and use of this tool; Therefore we consider it of great benefit to the environment and to the owners of contaminated land, in the sense that the criteria for management of environmental liabilities are based on information and comments specific to each particular case; in a way that avoids envelope or sub estimate impairment caused by contamination in the environment.

Since 1996, complying at the time the USEPA guidelines, we have been doing this kind of studies in Mexico.

Our experience includes the petrochemical, chemical, metalworking, pharmaceutical and textile industries, among others. Its implementation has enabled decision-making of the owners of each site with the support of the authorities.