How is Water Quality Measured?


Stormwater Quality Monitoring Program

MSD collects over 3 million individual water quality records each year. This monitoring program provides a detailed picture of the health of streams in Jefferson County. Monitoring results are summarized on an annual basis in the Stormwater MS4 Annual Report, and complete data are provided electronically annually to the Kentucky Division of Water (KDOW). Every two years, MSD publishes a Synthesis Report, called the State of the Streams, that summarizes water quality trends.

Types of Stream Monitoring 

In 1988, MSD established the Stream Program. The program was developed for the purpose of gathering and evaluating water quality and biological data from Jefferson County streams. A cooperative water sampling agreement was formed between MSD and the United States Geological Survey (USGS). Presently, twenty-seven sampling stations in Jefferson County, two sites barely over the county line, and two control stations in Meade and Nelson Counties, are monitored on a regular basis.

The Stream Program performs physical, chemical, and biological analyses. Physical analysis includes Water Temperature, Air Temperature, Stream Flow, Dissolved Oxygen levels, Specific Conductance, Barometric Pressure and pH. Chemical analysis includes Biological Oxygen Demand, Chemical Oxygen Demand, Total Suspended Solids; Total Volatile Suspended Solids, Total Dissolved Solids, Alkalinity, Ammonia, Nitrates, Nitrites, Organic Nitrogen, Total Phosphorus, and Soluble Reactive Phosphorus are performed on a monthly basis. In addition, 18 metals, herbicides, and pesticides are monitored quarterly. Microbiological analyses for fecal coliforms and fecal streptococcus are performed monthly. Biological analyses using macroinvertebrates are currently conducted twice a year, every other year. Macroinvertebrates are invertebrates (insects, crayfish, etc.) that are large enough to be seen with the naked eye. The different types of macroinvertebrates and numbers of individuals in each type are used to provide a picture of relative stream health and impact over long periods of time.

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