Comparability of river suspended-sediment sampling and laboratory analysis methods
Scientific Investigations Report 2018-5023
Prepared in collaboration with the Minnesota Pollution Control Agency, Clean Water Fund
- Joel T. Groten and Gregory D. Johnson
Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.
Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.
Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.
Groten, J.T., and Johnson, G.D., 2018, Comparability of river suspended-sediment sampling and laboratory analysis methods: U.S. Geological Survey Scientific Investigations Report 2018–5023, 23 p., https://doi.org/10.3133/sir20185023.
ISSN: 2328-0328 (online)
Table of Contents
- Methods of Data Collection and Analysis
- Field Sampling and Laboratory Analysis Method Comparison
- References Cited
Additional publication details
- Publication type:
- Publication Subtype:
- USGS Numbered Series
- Comparability of river suspended-sediment sampling and laboratory analysis methods
- Series title:
- Scientific Investigations Report
- Series number:
- Year Published:
- U.S. Geological Survey
- Publisher location:
- Reston, VA
- Contributing office(s):
- Minnesota Water Science Center
- Report: vi, 21 p.; Appendix
- United States
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