Basic assumptions (establishment of existing quality, determination of regulatory water quality, identification of desired quality, definition of special uses, and the expenditure determined in the public interest) in any water quality program are reviewed, and the tools to improve water quality and the design features that will accommodate such tools are described. Design phase provisions must include the utilization of every opportunity to adjust the highway alignment for favorable water quality. Drainage adjustments must be made which would improve water quality for highway runoff. Settling basins or detention ponds are described which can be multipurpose units and could be temporary or permanent devices. A standard catch basin which would provide a sump below the outlet for settleable solids is another feature of drainage design. The basin is equipped with baffles to prevent short-circuiting of flow and proper establishment of the retention time. A detention time of 2 hours allows suitable settlement characteristics. The treatment plant directed basically toward biological treatment is also outlined. In the area of design treatments, slope stabilization is important to reducing erosion and water pollution. Ditch or channel stabilization may be achieved with use of matting checks or wiers formed from concrete or wood as well as gravel or rock. Stepped slope treatment, the selection of suitable plant species, the farming of right of way are other aspects discussed. Attention is drawn to the need for alertness to sensitive issues, the establishment of the order of work, the restriction of operating time to accommodate special biological conditions, and the use of restricted methods. Bid items for temporary measures, force account time, and the provision of adequate right of way are other aspects covered. The need is indicated for aggressive leadership, education, staff communication, and improved state of the art studies in cost effective treatments to water pollution.

  • Corporate Authors:

    Western Association of State Highway & Transp Off

    AASHTO, 341 National Press Building
    Washington, DC  United States  20004
  • Authors:
    • Zirkle, J D
  • Publication Date: 1974-6

Media Info

  • Pagination: 13 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00260818
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Nov 27 1974 12:00AM