Previous Site Use Scenarios

Previous

Metal Finishing Sites

Metal finishing facilities may use solvents or emulsion solutions (for example, solvents dispersed in an aqueous medium with the aid of an emulsifying agent) in the degreasing tanks to clean and prepare the surface of metal parts. Wastewaters generated from cleaning operations are primarily rinse waters, which are usually combined with other metal finishing wastewaters and treated on site by conventional chemical precipitation. These wastewaters may contain solvents, and solid wastes such as wastewater treatment sludges, still bottoms, and cleaning tank residues (EPA, 1999).
Not all releases are related to the industrial processes described above. Some releases result from the associated services required to maintain the industrial processes. For example, electroplating facilities are large consumers of electricity, which requires a number of transformers. At older facilities, these transformers may have been disposed of in unmarked areas of the facility, which makes it difficult to know where leaks of polychlorinated biphenyl (PCB)-laden oils (used as coolants in transformers) may have occurred. Similarly, large machinery requires periodic maintenance. In the past, chemicals used for maintenance operations such as solvents, oils, and grease, may have been flushed down drains and sumps after use. Stormwater runoff from paved areas such as parking lots may contain petroleum hydrocarbons and oils, which can contaminate areas located downgradient. When conducting initial site evaluations, planners should expand their investigations to include these types of activities (EPA, 1999).
In addition, metal finishing facilities may have been located in older buildings that contain lead-basedpaint and asbestos insulation and tiling. Any structure built before 1970 should be evaluated for the presence of these materials. They can cause significant problems during demolition or renovation of the structures for reuse. Special handling and disposal requirements under state and federal laws can significantly increase the cost of construction. An overview of the Technical Approaches to Characterizing and Cleaning Up Metal Finishing Sites Under the Brownfields Initiative can provide decision makers with:
  1. An understanding of common industrial processes at metal finishing facilities and the relationship between such processes and potential releases of contaminants to the environment
  2. Information on the types of contaminants likely to be present at a metal finishing site
  3. A discussion of characterization, screening and cleanup levels,and cleanup technologies that can be used to assess and cleanup the types of contaminants likely to be present at metal finishing sites
  4. A conceptual framework for identifying potential contaminants at the site
  5. Information on developing an appropriate clean-up plan for metal finishing sites where contamination levels must be reduced to allow a site's reuse
Resources for Metal Finishing is available in the Links to Resources for Metal Finishing Exhibit.
Exhibit: Links to Resources for Metal Finishing
Previous
Top