Evaluating systems to reduce road improvement impacts on mountain streams.

Details

• Creators:
  McLaughlin, Richard A. ; Jennings, Gregory D. ; King, Scott E.
• Corporate Creators:
  North Carolina State University. Soil Science Dept. ; North Carolina State University. Department of Biological and Agricultural Engineering
• Subject/TRT Terms:
  • Streams
  • Rivers
  • Environmental impacts
  • Highway design
  • Roads--Design and construction--Environmental aspects--North Carolina
  • Rivers--North Carolina
• Publication/ Report Number:
  FHWA/NC/2006-44
• Resource Type:
  Tech Report
• Geographical Coverage:
  North Carolina
• Edition:
  Final report; July 1, 2004-June 30, 2007.
• Corporate Publisher:
  North Carolina. Department of Transportation. Research and Analysis Group
• Abstract:
  Sediment is the most common pollutant affecting North Carolina’s waterways, impacting a range of aquatic organisms, reducing ; reservoir capacity, and hurting their aesthetic value. Construction activities, including roadway projects, are a significant ; contributor of state-wide sediment loading. The NC DOT program of widening and paving rural roads in the mountain region ; provided an opportunity to evaluate new types of roadside erosion control BMPs with the goal of protecting the particularly ; sensitive trout streams commonly found there. ; Two roadway paving projects were each divided into experimental sections installed with either 1) the standard DOT BMPs ; consisting of narrow sediment traps and rock checks, 2) the new fiber wattle check dams (consisting of a mix of straw wattles and ; coir logs) with 100 grams of granulated polyacrylamide (anionic PAM 705) added to each, or 3) the new wattle check dams alone ; (no PAM added). ; The results suggest a significant advantage to the use of the new BMPs. At the first site, from June 2006 to March 2007, the ; average turbidity values (in NTUs) for the stormwater runoff for were 4,198 for the Standard BMPs, 30 for the Experimental ; BMPs with PAM, and 187 for the Exp. BMPs alone. The second site showed similar results with average turbidity values of 64 ; for the Exp. BMPs with PAM, as compared to 852 for the Standard BMPs. Sediment loading at both sites was similarly skewed ; with dramatic decreases in sediment discharged off site from the new BMPs. At the first site, the Standard BMPs lost an average ; of 944 lbs (428 kg) of sediment per storm event as compared to just 1.93 lbs (0.88 kg) for the BMPs with PAM and 6.53 lbs (2.96 ; kg) for the Exp. BMPs alone. At the second site, the Standard BMPs lost an average of 8.84 lbs (3.63 kg) per storm event ; compared with 1.67 lbs (0.76 kg) for the Exp. BMPs with PAM.
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17179/dot_17179_DS1.pdf
• File Type:
  [PDF - 2.09 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:171f59a48425fd83370b04f9139ad837ebcbc76bc6855005823d497e3143befd