Sediment Source Assessment Using Sediment Fingerprints

Problem

Sediment is one of the most common causes of loss of stream-biologic integrity, whether in suspension in the water column, or as 

deposition on a stream or lake bottom. Fine-grained silts and clays are of particular concern because they can degrade habitat and often 

carry phosphorus and (or) other contaminants harmful to humans and aquatic life. Sediment-impaired water bodies, usually identified 

by fair to poor macroinvertebrate index scores, are placed on the 303(d) list of impaired waters, where a sediment Total Maximum 

Daily Load (TMDL) is developed under the Clean Water Act (https://www.epa.gov/tmdl). In order to effectively manage sediment, it 

is necessary to identify the sediment sources and locations of “hot spots” of erosion and deposition.

Procedure manual now available for fingerprinting sources of sediment in streams 

The U.S. Geological Survey (USGS) and the U.S. Environmental Agency (EPA) recently published a manual on sediment source 

identification that includes details on how to conduct a sediment fingerprinting study (Gellis and others, 2016). This Fact Sheet summarizes key points in the sediment fingerprinting approach.

What is Sediment Fingerprinting?

The sediment fingerprinting 

procedure establishes a minimal 

set of physical and (or) chemical 

properties (tracers) based on samples 

collected in upland or channel locations identified as potential sources 

of sediment. These properties are 

unique for each source within the 

watershed. Fluvial sediment samples 

(target sediment) also are collected 

that exhibit a composite, or “fingerprint” of source properties. Through 

statistical procedures, the target 

sediment properties can be matched 

to their respective upland or channel 

source “fingerprints” (fig. 1).

Erosion of source A

Routing to

channel and

sediment 

mixing

Sediment source 

apportionment

Erosion of source B

Erosion of source C

Suspendedsediment 

load

Comparison of source 

material and suspendedsediment samples using

fingerprint properties

Watershed

precipitation

and runoff

Figure 1. Outline of the sediment fingerprinting 

approach.

Properties of sediment that have been used as tracers in sediment fingerprinting studies 

include:

Elemental analysis, mineralogy, stable isotope ratios, magnetic properties, color, and 

radionuclides.

How Are Potential Sediment Sources Identified?

Potential sediment sources in the watershed can be identified through Geographic 

Information System (GIS) analysis, field reconnaissance of the basin, and photogrammetric analyses (such as aerial photographs). Sediment sources include, but are not limited 

to, upland areas (agricultural land, forest, construction sites, mining areas, urban sources) 

and the channel (streambanks, channel bed).

Source sampling generally requires 20 to 30 samples per source. In upland areas, 

samples are collected from the top 1.0 to 2.0 centimeters of the soil surface with a 

plastic hand shovel. To account for variability in the fingerprint properties at upland 

sites, sediment is collected across transects and composited into one sample. To obtain a 

representative sample of streambanks, eroding streambanks are sampled from the bottom 

to the top of the bank face. Three to five transects spaced 10 meters apart are sampled and 

composited into one streambank sample.

What Is Target Sediment?

Target sediment is the sediment that is being apportioned. This can include suspended 

sediment (fig. 2), bed sediment, flood-plain sediment, and reservoir or lake sediment.

Figure 2. Example of passive samplers used 

to collect suspended-sediment samples for 

target sediment. Prior to planning for the target 

sediment sampling design, it is important to 

contact the laboratory where the analyses of 

the various properties selected for the study 

will be performed to ask questions pertaining 

to sample mass and holding requirements; 

for example, whether the samples should be 

refrigerated. [Photo of Crow Creek, California by 

Allen Gellis, USGS, January 31, 2017]

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2018-3008

September 2018
How Can Sediment Fingerprinting Be Used?

• Targeting sediment sources for watersheds placed on the 303(d) list of impaired waters.

• Assessing the impact of land activities on sediment (construction areas, agricultural, mining, forest fires, timber harvesting, etc.).

• Determining the effect of best management practices (BMPs) on reducing sediment.

• In watersheds where the impact of streambank erosion compared to other sources needs to be determined.

How Are Sediment Sources Determined?

The USGS has developed a user friendly program (download at https://doi.org/10.5066/f76q1vbx; Sed_SAT) that takes the analyzed source and target sediment, calculates the statistics, and provides sediment-source allocation results with robust error analysis 

(fig. 3). Results from sediment fingerprinting are shown in figure 4.

Outlier evaluation

Source apportionment using an unmixing model

Size and organic corrections

Bracket test

Stepwise Discriminant Function Analysis

 Error analysis

Figure 3. Statistical steps used to apportion sediment in 

Sed_SAT (Gorman Sanisaca and others, 2017).

Streambank

Ditch bed

Crop

Forest

Construction

Percent

Streambank

Street

residue

Agriculture

Forest/

uplands

Percent 0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100

NA NA

NA NA

NA

Pocomoke River, MD-DE*

(157 km2

 agriculture, forest)

Mattawoman Creek, MD*

(135 km2

 agriculture, urbanizing, forest)

Little Conestoga Creek, PA*

(110 km2 agriculture, urban)

Anacostia River, MD-D.C.#

(188 km2

 urban)

Mill Stream Branch, MD#

(32 km2

 agriculture, forest)

Linganore Creek, MD*

(147 km2 agriculture, forest)

0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100

A

2008

June

16

2008

July

13

2008

July

23−24

2008

Sep.

6

2008

Dec.

11

2009

May

3−7

2009

May

15

2009

May

26

2009

Dec.

9−11

2010

May

18

2011

Apr.

16 3,000

2,000

1,000

Suspended sediment, in <63 microns, (mg/L)

0

17:4520:0021:4500:3014:4517:1522:4020:0022:1513:0017:3020:1522:1500:0000:3001:0002:1503:3004:3000:4501:2501:4502:1503:4504:4505:4505:3510:1504:1505:1505:4505:0020:20

SSC-Weighted 

Contribution 

(percent)

91

<1 8

Streambank

Forest

Road

Source type

EXPLANATION

B Figure 4. Example of sediment 

fingerprinting results from Chesapeake Bay 

studies. (A) From small watershed studies 

in the Chesapeake Bay. The target sediment 

was suspended sediment collected during 

several storms. [* indicates results were 

weighted by sediment loads for each storm; 

# indicates results were averaged over all 

storms; NA indicates source was not sampled 

(Gellis and Brakebill, 2013; Gellis and others, 

2015)]. (B) Sediment fingerprinting results for 

Upper Difficult Run, Virginia are displayed 

relative to the sediment concentration of each sampled event. [SSC-Weighted Contribution is the sediment-source contribution for all storms weighted 

by each sample’s sediment concentration; <, less than; mg/L, milligrams per liter; km2, square kilometers (Cashman and others, 2018)].

References

Cashman, M.J., Gellis, A., Gorman Sanisaca, L., Noe, G.B., Cogliandro, V., and Baker, A., 2018, Bank-derived material dominates fluvial sediment in a suburban Chesapeake 

Bay watershed: River Research and Applications, p. 1–13, DOI: 10.1002/rra.3325, accessed August 28, 2018, at https://onlinelibrary.wiley.com/doi/epdf/10.1002/rra.3325.

Gellis, A.C., and Brakebill, J.W., 2013, Sediment sources and transport in the Chesapeake Bay watershed: U.S. Geological Survey Science Summary, accessed January 23, 

2018, at https://chesapeake.usgs.gov/documents/ss-sedimentsourcesandtransport.pdf.

Gellis, A.C., Fitzpatrick, F., and Schubauer-Berigan, J., 2016, A manual to identify sources of fluvial sediment: U.S. Environmental Protection Agency report 

EPA/600/R-16/210, 106 p., accessed January 24, 2018, at https://clu-in.org/download/contaminantfocus/sediments/Sediment-sources-600R16210.pdf.

Gellis, A.C., Noe, G.B., Clune, J.W., Myers, M.K., Hupp, C.R., Schenk, E.R., and Schwarz, G.E., 2015, Sources of fine-grained sediment in the Linganore Creek watershed, 

Frederick and Carroll Counties, Maryland, 2008–10: U.S. Geological Survey Scientific Investigations Report 2014–5147, 56 p., accessed October 4, 2017, at http://dx.doi.

org/10.3133/sir20145147.

Gorman Sanisaca, L.E., Gellis, A.C., and Lorenz, D.L., 2017, Determining the sources of fine-grained sediment using the Sediment Source Assessment Tool (Sed_SAT): U.S. 

Geological Survey Open File Report 2017–1062, 104 p., accessed October 4, 2017, at https://doi.org/10.3133/ofr20171062.

Allen C. Gellis (agellis@usgs.gov), Lillian E. Gorman Sanisaca (lgormansanisaca@usgs.gov), and Matthew J. Cashman (mcashman@usgs.gov)

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)