A novel tracer method for estimating sewer exfiltration


Journal Article

A novel method is presented to estimate exfiltration from sewer systems using artificial tracers. The method relies upon use of an upstream indicator signal and a downstream reference signal to eliminate the dependence of exfiltration estimates on the accuracy of discharge measurement. An experimental design, a data analysis procedure, and an uncertainty assessment process are described and illustrated by a case study. In a 2-km reach of unknown condition, exfiltration was estimated at 9.9 ± 2.7%. Uncertainty in this estimate was primarily due to the use of sodium chloride (NaCl) as the tracer substance. NaCl is measured using conductivity, which is present at nonnegligible levels in wastewater, thus confounding accurate identification of tracer peaks. As estimates of exfiltration should have as low a measurement error as possible, future development of the method will concentrate on improved experimental design and tracer selection. Although the method is not intended to replace traditional CCTV inspections, it can provide additional information to urban water managers for rational rehabilitation planning. Copyright 2005 by the American Geophysical Union.

Full Text

Duke Authors

Cited Authors

  • Rieckermann, J; Borsuk, M; Reichert, P; Gujer, W

Published Date

  • May 1, 2005

Published In

Volume / Issue

  • 41 / 5

Start / End Page

  • 1 - 11

International Standard Serial Number (ISSN)

  • 0043-1397

Digital Object Identifier (DOI)

  • 10.1029/2004WR003699

Citation Source

  • Scopus