The Sample Record and Assessment Form provides a means for gathering and recording sample data and applying this data to make an assessment of stream-water quality. If a stream site is selected for long-term monitoring, the completed forms will provide documentation of changes in water quality that may occur over time.
The Sample Record and Assessment Form provides space for identifying the stream that is sampled, the specific location on the stream where the sample is collected, the date of sample collection, and the names of the sample collectors. The form also provides for recording general stream conditions at the time of sampling, including stream-water temperature and descriptions of stream-flow level and stream clarity.
The results of macroinvertebrate sampling should be recorded on the form by checking the box and entering the number of specimens collected for each of the listed macroinvertebrate types.
The water quality rating for the sample site is then calculated based on an index value that is determined by the number of macroinvertebrate types collected. The index value is calculated by multiplying 3 times the number of sensitive types, 2 times number of somewhat sensitive types, and 1 times the number of tolerant (nonsensitive) types. The three resulting values are then summed to provide a total index value which is compared to the values for excellent, good, fair, and poor water quality ratings.
The index values and water quality ratings are based on the number of different kinds of macroinvertebrates collected, rather than the number of individual specimens collected. Good water quality is indicated by a variety of different kinds of macroinvertebrates. Poor water quality may be indicated by large numbers of only a few kinds of macroinvertebrates.
Note that the methods established for the Save Our Streams Program call for collecting samples at 3 separate locations at a site and only recording the data for the sample with the best water quality rating. This provides a more reliable assessment for the site.
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