Maryland Department of Natural Resources
Maryland Tributary Water Quality Project
Project Summary
Data in this data set falls into one of three major sampling programs:
Chesapeak Bay Tributaries, Core and Trend, or Patuxent Monitoring. Each program is described separately below. For all programs the Maryland Department of Natural Resources (MDNR) is conducting the sampling in conjuction with the Maryland Department of Health and Mental Hygiene Baltimore Laboratory, which analyses chemical parameters and chlorophyll.

Bay Tributaries
Water quality is sampled at 33 stations in Maryland tributaries of the Chesapeak Bay. Sampling frequency is once monthly for all stations and twice monthly from March through October for 12 stations. The entire sampling network is normally covered in four consecutive days. Stations were located to provide a characterization of the Chesapeake Bay segments identified by the EPA Bay Program. Additional factors that were considered were critical areas such as those experiencing anoxic conditions, those located near important fisheries,those experiencing severe anthropogenic impacts, and/or riverine-estuarine transition areas.

The following parameters are profiled at each station beginning at a surface depth of 0.5m and ending 1.0m above the bottom. Depth intervals are normally 1.0m.

  • Water tempterature
  • pH
  • Dissolved oxygen
  • Specific conductance
  • Salinity
  • Oxidation-reduction potential
Grab samples are collected for analysis of the following parameters at 0.5m and 1.0m above the bottom. At stations where stratification occurs, two additional sample are taken, one above and one below the pycnocline.

  • Total Kjedahl nitogen (filtered and whole)
  • Nitrate plus nitrite (filtered)
  • Nitrite (filtered)
  • Ammonium (filtered)
  • Total organic carbon (whole)
  • Dissolved organic carbon (filtered)
  • Reactive silica (filtered)
  • Total suspened solids
  • Total dissolved phosphorus (filtered)
  • Total phosphorus (whole)
  • Orthophosphate (filtered)
  • Active Chlorophyll-a
  • Phaeophytin
Additional parameter measured at each station are:
  • Total depth
  • Secchi depth

Resource Assessment Service.
Copyright © 1997 Department of Natural Resources. All rights reserved.