|What We Measure
All data discussed below may be accessed on the "Download Data"
section of this Web site.
In the Field - The following assessments are completed at all sampling sites:
- General Stream Site Assessment
The immediate surrounding landscape and the physical characteristics of the stream reach are reported
to provide a general description of the site. Observations and measurements include bank full width,
sediment substrate quality, and the perceived impact of local land use. This assessment is completed one time
prior to beginning water quality sampling.
General Stream Site Assessment Form
- Detailed Habitat Assessment & Physiochemical Parameters
The biological condition of a stream system is determined through a visual assessment of in-stream and riparian
habitat quality according to the EPA's Rapid Bioassessment Protocols. Key parameters such as epifaunal substrate,
channel sinuosity, and the frequency of riffles are measured to assess the site's ability to support aquatic life.
The site is rated numerically to provide an overall score of habitat quality, unlike the General Site Assessment
which is more of a narrative site description. This assessment is completed one time prior to beginning water quality
Detailed Habitat Assessment Form
- Water Chemistry
Stream water samples are taken for E. coli, total phosphorus, and total suspended solids. Blanks are taken for
E. coli and total phosphorus. Samples are stored on ice during transportation and are refrigerated or frozen
until analyzed. High school teams collect water quality samples biweekly.
Discharge and Water Chemistry Form
Discharge is measured by recording the time it takes a tennis ball to travel a specified distance.
High school teams measure discharge every time they collect water chemistry or macro invertebrate samples.
Discharge and Water Chemistry Form
Four replicates of benthic macroinvertebrates are collected from a representative riffle in the stream reach
by the hand-scrub method according to protocols used by the Biomonitoring and Aquatic Studies Section of the
VT Department of Environmental Conservation. Samples are collected once during the field season.
Macroinvertebrate Field Data Form
Macroinvertebrate Lab Data Form
In the Water Quality Lab - The water quality lab trains undergraduates in basic laboratory procedures and
water quality assays while maintaining a high quality dataset. Undergraduates analyze stream water samples collected
from the field under the direction of the Project Coordinator and Research Assistant. The following assays are completed
in the lab and the resulting data is available on the Streams Project database.
- Total Phosphorus
Samples are analyzed for total phosphorus via a persulfate digestion followed by analysis for orthophosphate
concentration using the ascorbic acid reduction method on a UV 1800 spectrophotometer. This assay was adapted
from "Standard Methods". The concentration of total phosphorus is measured in µg/L.
- Total Suspended Solids (TSS)
TSS is measured according to method 2540 D of the Standard Methods for the Examination of Water and Wastewater.
A known volume of water is run through a 0.45µm filter. Solids collected on the filter cause a change in filter
weight that is reported as total solids in mg/L.
- Total Coliform and Escherichia coli
Total Coliform and E. coli bacteria are analyzed within 24 hours of sampling according to the IDEXX Colilert® method.
Colilert reagent is added to 100mL samples that are incubated for 24 hours. Color change indicates the presence of
Total coliform and/or E. coli bacteria. The Most Probable Number (MPN) of bacteria per 100mL is determined.
In the Macroinvertebrate Lab - The macroinvertebrate lab trains undergraduate students in the sampling,
preservation, and identification of aquatic benthic macroinvertebrate specimens common to streams of the northeastern
United States. Students analyze samples with the goal of identifying most specimens to genus. However, due to the complexity
associated with their identification, the Chironomid order and many worms are only identified to family. The Guide to Aquatic
Invertebrates of the Upper Midwest and An Introduction of the Aquatic Insects of North America are the most commonly used keys.
- The primary indices used to assess the health of macroinvertebrate communities are:
- Total Abundance
- Species Richness
- EPT Richness
- EPT Abundance
- Abundance of hydropyschid caddisflies
Geographic Information Systems (GIS) Lab -
A new addition to the Streams Project database is a dataset of landscape-level variables derived using GIS.
Under the direction of the Streams Project GIS Specialist, undergraduate researchers help to create the dataset
from analysis of existing landscape-level datasets, in addition to analysis of data derived using a combination of
empirical field observations and aerial photo interpretation. Variables in this dataset are analyzed at the scale
of the catchment area, which is defined as all of the land draining to a given site along a stream. A complete list
of the available variables can be found at the download page.
The following list describes major categories of variables within the GIS dataset:
We identify the type of bedrock for each catchment area as well as the percentage of the catchment area covered
in highly erodible soils, and the average depth to bedrock.
In addition to the stream characteristics measured in the field (see above), we determine stream sinuosity,
stream slope/gradient, stream order, and upstream distance to a lake/pond greater than one acre for each monitoring
site. We add other variables to this list on an as-needed basis.
- Land Use
For each of the monitoring sites we measure amount of the catchment area in agricultural, urban, and forested
land use in acres and as a percentage of the overall catchment area.
- Built Infrastructure
Using several State spatial datasets, we calculate the upstream distances to dams, bridges, and culverts for each
monitoring site. E911 data are used to determine the total length of road network in each catchment area as well
as the length of road network by surface type. The E911 data are also used to provide a count of building structures
in each catchment area and to help determine the percentage of each catchment area in construction.