Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:°C = (°F-32)/1.8 Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (µg/L). Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).