A site assessment is a process by which investigators determine if there are any contaminants on or directly under a piece of real estate, the exact location of those contaminants, and the extent to which those contaminants are present. If there are pollutants or contaminants at the site, a further study is done to determine what potential dangers those substances pose to the public, and how they may be exposed to them. It is common to do a site assessment before property transfers, loans or new construction, but one may be done at any point during the life of the property.
An environmental site assessment is often broken down into two phases. The first phase seeks to identify what contaminants might be present, and produces a report based on those possible contaminants. In the second phase, a more concerted effort to specifically identify and characterize the potential problems is undertaken. Given the specialized nature and training required for a second phase, many choose this phase only if conditions demand it.
Commonly, the first phase involves researching the past uses of a property. If, for example, a location was a gasoline station, the assessment may seek to determine if there were any underground storage tanks left at the location. Those could be corroded, or have otherwise degraded over time, and present a risk. Also key is a visual inspection to determine if there is anything that may be a cause for concern, such as areas without vegetative growth or asbestos-containing materials.
If there is cause for concern, the report issued for the first phase of the environmental site assessment should note what those concerns are in detail. Though at this point there may be little evidence that a real problem actually exists, the main concern is whether the potential is there. If there is potential, the need for the second phase of the environmental assessment is greater.
In this phase, there could be extensive excavation, or simply having some samples taken from the ground. The extent of the excavation mainly depends on the past uses of the property and the potential dangers that are there. These samples are then taken to a laboratory for further analysis. If a problem is verified, then it becomes up to the property owner to find a suitable solution. In some situations, the government may require a property owner to take some action to clean up the problem.
When a clean-up operation is necessary, the second phase of the site assessment should provide some guidance. While the report may not indicate or recommend contractors to help, it often suggests or defines the scope of the project. This should help when getting bids or estimates for the job.