DEEP: General Guidance on Development of Former Agricultural Properties

General Guidance on Development of Former Agricultural Properties

(March 1999)

The Department of Public Health and the Department of Energy & Environmental Protection have become aware of a number of site development projects on former agricultural land in which persistent pesticides (primarily dieldrin, DDT and breakdown products, chlordane, arsenic) remain in soil at concentrations that approach or exceed the Connecticut Remediation Standard Regulations (RSRs). While such development projects do not specifically fall under the RSRs, concerns have been raised that the residual pesticides constitute a health risk. In light of this, DPH and DEEP offer general guidance for such sites as described below. This guidance is meant to provide an approach that is protective of public health and that also leaves a degree of flexibility. We expect municipal officials and site developers to consider our input together with other factors in deciding how best to handle site re-development projects.

  • Evaluate site history and sample surface soil (ideally 0-3 inches depth) in areas where pesticides were applied, handled, and stored. A limited number of deeper samples are also recommended, particularly in areas where there is evidence of substantial surficial contamination. Total mass concentrations and leaching tests should be performed, with consideration given to analyses for newer pesticides if the site is currently agricultural.
  • Evaluate detected pesticide concentrations against RSR values. If the concentrations are below the RSR values in all cases, there is no need for further consideration of pesticide contaminant issues at the site. If some concentrations are above the RSRs, the following options for managing the affected soil should be considered:
  1. Keep affected soil separate from other soils and use it on-site as fill under buildings, parking lots, or access roads or dispose of the soil in an approved landfill off-site.
  2. Mix it with unaffected soils to decrease the effective soil concentration. In this case, representative samples should be taken from the mixed soil piles following RCRA protocols regarding the number and location of samples from soil piles. If the mixed concentrations are below the RSRs, the soil pile can then be used anywhere on-site. If the mixed concentrations are still above RSR values, then the soil pile could be used as fill material below grade (but not topsoil) in parts of the site where digging will not occur (i.e., areas where children will not play; non-residential areas; uses as described under Option 1).
  3. Depending upon the degree of RSR exceedance, consideration should be given, in consultation with DPH and DEEP, to removal of specific hot spot areas.
  4. If affected soils are in some manner kept on-site, an additional precautionary step would be post-construction surface soil sampling to ensure that the practices described above have successfully reduced the potential for direct exposure.
  5. If any soils containing pesticides above RSR values remain on-site, the location of these affected soils should be recorded on a site map which is on file at the local health department.

Site-specific data can be provided to DPH (860-509-7742) and DEEP (860-424-3705) to make sure that a particular site does not present unique risks and that the data are suitable for comparing against RSR values.

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Content Last Updated: November 2006