Constituents Measured or Computed Continuously in Maryland
Continuous measurements of constituents (water-quality parameters) can be obtained by direct measurement using sensors, or by indirect computation using models.
Below is a list of constituents continuously measured or computed by the USGS in Maryland. Click on a constituent for more detailed information, including a list of where it is measured or computed.
| Constituent Name | Units | Criteria |
|---|---|---|
| Computed discharge | cubic feet per second (cfs) | |
| Dissolved oxygen | milligrams per liter (mg/L) | 5 mg/L |
| Escherichia coli bacteria | colonies per 100 milliliters (cfu/100mL) | |
| pH | standard units (std units) | 6.5 std units, 8.5 std units |
| Specific conductance at 25 degrees Celsius | microsiemens per centimeter (uS/cm) | 400 uS/cm |
| Suspended sediment | milligrams per liter (mg/L) | |
| Suspended sediment concentration, water, unfiltered, estimated by regression equation | milligrams per liter (mg/L) | |
| Total nitrogen, water | milligrams per liter as nitrogen (mg/L-N) | |
| Total nitrogen, water, filtered, estimated by regression equation, milligrams per liter | milligrams per liter as nitrogen (mg/L-N) | |
| Total phosphorus | milligrams per liter (mg/L) | |
| Total phosphorus | milligrams per liter as phosphorus (mg/L-P) | |
| Turbidity, measured as NTU or FNU | formazin nephelometric units (FNU) | 150 FNU |
| Water temperature | degrees Celsius (°C) |