Conducting the Phase I Assessment - Historical Use
ASTM E 1527 lists the following eight standard historical sources: Aerial Photographs, Fire Insurance Maps, Property Tax Files, Recorded Land Title Records, Historical Topographic Maps, Local Street Directories, Building Department Records, and Zoning and Land Use Records. ASTM sets tests for those sources, the period of time over which those sources should be researched, and minimum search intervals.
The standard requires the collection and review of a considerable amount of information to determine whether or not recognized environmental conditions exist in connection with the subject property. How far does the assessor have to go in achieving this goal? Is it necessary to review every historical source? The answer is no! While the standard requires that the historical sources be reviewed, the standard affords a considerable amount of discretion on the part of the environmental consultant.
The ASTM standard requires the environmental professional to review the historical sources that are reasonably ascertainable and likely to be useful back to first developed use or 1940 whichever is earlier. For example, if a certain standard historical source is not reasonably ascertainable, then no further investigation of the particular source need be accomplished. If the source is reasonably ascertainable, but past experience suggests that the source is not likely to provide useful information, then it is not necessary to include the particular source in the historical investigation of the subject and adjoining properties.
A historical source is considered reasonably ascertainable if it meets the following criteria: 1) publicly available, 2) obtainable within a reasonable period of time and at a reasonable cost, and 3) practically reviewable. Publicly available means that the source is available to anyone upon request. Information that is obtainable within reasonable time and cost means that the information can be provided by the source within 20 calendar days of receiving a written, telephone, or face to face request, at no more than a nominal cost to cover costs of retrieving and duplicating the information. Historical information that can only be reviewed at the source is considered reasonably ascertainable if the review can be conducted within 20 calendar days of the request. Most databases and other forms of information, are practically reviewable if they can be obtained from the source by county, city, zip code, or other geographical information which permits the assessor to accurately locate the information in relationship to the subject and adjoining properties.
Developed use means agricultural use or the placement of fill. The standard requires the assessor to search historical information back to 1940 or when the property was undeveloped (e.g., woodlands), whichever is earlier, within the constraints of data failure.
Data failure occurs when a specific historical source is not reasonably ascertainable, not publicly available, not available within a reasonable time and cost, judged not likely to be useful, or does not meet either of the following: 1) coverage from the present back to 1940 or first developed use, whichever is earlier; or 2) coverage at approximately five year intervals. Date Failure must be documented in the Phase I Environmental Site Assessment Report.
ASTM states that the interval for historic research need not be at less than approximately five years. The standard does not specifically state what the appropriate interval should be for each source. Clayton has established the following intervals for the eight standard historical sources: all years available for Fire Insurance Maps, Property Tax Files, Recorded Land Title Records, Historic Topographic Maps, Building Department Records, and Zoning/Land Use Records; five year intervals for Aerial Photographs and Local Street Directories.
The following step by step process summarizes Clayton's historical research requirements:
1. Identify standard historical sources that are reasonably ascertainable and judged likely to be useful for the subject property.
2. Select the standard historical source with the greatest potential to provide a complete prior use history for the subject and adjoining properties.
3. Conduct standard historical source research.
4. Evaluate prior use of subject and surrounding (including adjoining) properties.
5. Has the standard historical source provided the following: Coverage from present back to 1940 or first developed use, whichever is earlier? Coverage at approximately five year intervals? If the answer to both questions is YES, then historical research meets the requirements of ASTM. If the answer to either question is NO, continue…
6. Document data failure.
7. Have all eight standard historical sources been search? If the answer is YES, then historical research meets the requirements. If the answer is NO, continue…
8. Is there a standard historical source remaining which is reasonably ascertainable and judged likely to be useful? If the answer is YES, then find that source and return to step three above. If the answer is NO, then return to step six.
9. Continue this process until the historical research requirements of ASTM have been met and data failure adequately documented.
Historic research is an integral part of any Phase I Environmental Site Assessment and should be conducted with great care. A large amount of professional judgement is afforded the consultant during historical research and many consultants shortcut the process. Clayton assessors, through proper training and written procedures, meet or exceed the ASTM historic search requirements.