AN ECOLOGICAL ASSESSMENT OF A BRIDGE DEMOLITION

An ecological assessment in terms of stream macroinvertebrate samples and suspended solids measurements was made shortly before, shortly after, and eight months after a demolition of a bridge deck. The following conclusions were reached: (1) bridge demolition, while quite limited in extent, produces a significant level of suspended sediment (over 200 ppm in this case) which may persist for several days; (2) no effect on the downstream ecology of the stream was observed even though the EPA limits for suspended solids were exceeded during and for several days following demolition; and (3) the EPA proposed limits for suspended solids appear to be too low for short-term stream disturbing events. It was recommended that rock berms be used on similar projects with placement being made well before demolition. Also, a methodology was recommended for the monitoring of future bridge demolitions.

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 9 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00097220
  • Record Type: Publication
  • Report/Paper Numbers: VHTRC 75-R54
  • Files: NTL, TRIS, STATEDOT
  • Created Date: Oct 18 1975 12:00AM