Author: Newfoundland. Water Resources DivisionPublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 29
Book Description
Environmental Guidelines for Bridges
Author: Newfoundland. Water Resources DivisionPublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 29
Book Description
Environmental Guidelines for Bridges
Author: Chapter 4
Author: Environmental Guidelines
Author: International Labour OfficePublisher:
ISBN: 9789221242901
Category :
Languages : en
Pages : 138
Book Description
Abstract
Assessment of the Environmental Effects Associated with Wooden Bridges Preserved with Creosote, Pentachlorophenol, Or Chromated Copper Arsenate
Author: Kenneth M. BrooksPublisher:
ISBN:
Category : Wood preservatives
Languages : en
Pages : 108
Book Description
Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced transportation infrastructure costs and increased public safety. However, the preservative used to treat the wooden components in timber bridges is lost to the environment in small amounts over time. This report describes the concentration of wood preservatives lost to adjacent environments and the biological response to these preservatives as environmental contaminants. Six bridges from various states were examined for risk assessment: two creosote treated bridges, two pentachlorophenol-treated bridges, and two CCA-treated bridges. In all cases, the largest bridges located in biologically active environments associated with slow-flowing water were selected to represent worst-case analyses. Sediment and water column concentrations of preservative were analyzed upstream from, under, and downstream from each bridge. The observed levels of contaminant were compared with available regulatory standards or benchmarks and with the quantitative description of the aquatic invertebrate community sampled from vegetation and sediments. Pentachlorophenol- and creosote-derived polycyclic aromatic hydrocarbons (PAHs) were not observed in the water near any of the selected bridges. However, low levels of PAHs were observed in the sediments under and immediately downstream from these bridges. Pentachlorophenol concentrations did not approach toxicological benchmarks. Sediment concentrations of naphthalene, acenaphthylene, and phenanthrene exceeded the probable effect level. Metal levels at the bridges treated with CCA were less than predicted effect levels, in spite of questionable construction practices. Adverse biological effects were not observed in the aquatic invertebrate community or laboratory bioassays conducted on water and sediments sampled at each of the bridges. Results of this study reveal the need to follow the construction information found in Best Management Practices for the Use of Treated Wood In Aquatic Environments published by Western Wood Preservers Institute. Regulatory benchmarks used in risk assessments of this type need to be indexed to local environmental conditions. The robust invertebrate communities associated with slow-moving streams over soft bottoms were not susceptible to the concentrations of PAHs that would be expected to affect more sensitive taxa, which typically are located in faster moving water over hard bottoms. Contaminants released from timber bridges into these faster systems (where more sensitive taxa are located) are significantly diluted and not found at biologically significant levels.
Meeting Environmental Requirements After a Bridge Collapse
Author: Publisher:
ISBN:
Category : Bridge failures
Languages : en
Pages :
Book Description
"This report is intended to assist transportation and environmental professionals in the event of a bridge collapse or similar emergency. It analyzes the environmental review process in five cases of bridge reconstruction following collapse in Florida, Minnesota, Mississippi, and Oklahoma. The report describes how the key elements of the environmental review process in the cases reviewed were completed comparatively quickly. It finds that when emergencies occur they create a sense of urgency on the part of all stakeholders that leads to a consensus on the prioritization of the project. This report identifies several effective practices that allowed sponsor agencies to expedite the environmental review process. They include: Implementing processes and agreements that lead to regular dialogue among state and Federal transportation and resource agencies and establish strong working relationships before emergencies occur; Limiting the scope of projects to reduce the potential for new environmental impacts or disagreements; Using contracting mechanisms that offer opportunities to quickly respond to emergency situations; Maintaining up-to-date inventories of historic, cultural and natural resources to quickly identify the potential impacts of proposed designs; Establishing formal and informal emergency procedures that clearly identify roles and responsibilities helps to expedite the environmental review process; and, Networking with peers from other states."--Abstract.
Increased Attention Needed to Insure that Bridges Do Not Create Navigation Hazards, United States Coast Guard, Department of Transportation
Author: United States. General Accounting OfficePublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 56
Book Description
Guidelines on Engineering and Environmental Practices
Author: Australia. National Capital Development CommissionPublisher:
ISBN: 9780642143815
Category : Bridges
Languages : en
Pages : 201
Book Description
Guidelines for Historic Bridge Rehabilitation and Replacement
Author: Mary Elizabeth McCahonPublisher: AASHTO
ISBN: 1560514302
Category : Technology & Engineering
Languages : en
Pages : 66
Book Description
This report presents a literature search, findings of a survey on the current state of historic bridge rehabilitation or replacement decision making by state and local transportation agencies, and nationally applicable decision-making guidelines for historic bridges. The guidelines are intended to be used as the protocol for defining when rehabilitation of historic bridges can be considered prudent and feasible and when it is not based on engineering and environmental data and judgments. The guidelines include identification of various approaches to bringing historic bridges into conformance with current design and safety guidelines/standards, and the effect or implications of remedial action on historical significance. There are currently no such nationally applicable decision-making guidelines, but there are a variety of state and local processes and policies for managing historic bridges. Effective practices for the various processes inform the nationally applicable guidelines. The guidelines are in narrative and matrix format.
Policy Analysis and Recommendations for Environmental Protection for Montana Department of Highways Bridge and Construction Projects
Author: William David RoutzahnPublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 146
Book Description