Transport of Cryptosporidium parvum oocysts through vegetated buffer strips and estimated filtration efficiency

Appl Environ Microbiol. 2002 Nov;68(11):5517-27. doi: 10.1128/AEM.68.11.5517-5527.2002.

Abstract

Vegetated buffer strips were evaluated for their ability to remove waterborne Cryptosporidium parvum from surface and shallow subsurface flow during simulated rainfall rates of 15 or 40 mm/h for 4 h. Log(10) reductions for spiked C. parvum oocysts ranged from 1.0 to 3.1 per m of vegetated buffer, with buffers set at 5 to 20% slope, 85 to 99% fescue cover, soil textures of either silty clay (19:47:34 sand-silt-clay), loam (45:37:18), or sandy loam (70:25:5), and bulk densities of between 0.6 to 1.7 g/cm(3). Vegetated buffers constructed with sandy loam or higher soil bulk densities were less effective at removing waterborne C. parvum (1- to 2-log(10) reduction/m) compared to buffers constructed with silty clay or loam or at lower bulk densities (2- to 3-log(10) reduction/m). The effect of slope on filtration efficiency was conditional on soil texture and soil bulk density. Based on these results, a vegetated buffer strip comprised of similar soils at a slope of <or=20% and a length of >or=3 m should function to remove >or=99.9% of C. parvum oocysts from agricultural runoff generated during events involving mild to moderate precipitation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Buffers
  • Cryptosporidium parvum / physiology*
  • Filtration
  • Oocysts / physiology*
  • Rain

Substances

  • Buffers