The Chesapeake Bay Program established the nontidal water quality monitoring program in 2004 to better estimate nutrient and sediment loadings in Chesapeake Bay watersheds >1000 km2. The nontidal monitoring program includes the nine River Input Monitoring stations, for a total of 85 monitoring stations throughout the watershed. Routine samples are collected monthly with an additional eight storm-event samples per year to obtain a range of discharge and loading estimates. Stations are located near USGS stream-flow gages to permit calculations of pounds per day of nutrients and sediments flowing downstream.
The Chesapeake Bay Nontidal Water Quality Workgroup coordinates the implementation of this monitoring program to ensure comparability among participants. Sampling is performed by 10 agencies in five states, with five laboratories analyzing the samples. Participants follow standard operating procedures that conform to Chesapeake Bay Nontidal Network protocols which are based on USGS sampling methods and EPA-approved analytical methods. Each organization has an approved quality assurance plan that describes field and lab methods, quality control specifications, data management and reporting procedures.
The accuracy and comparability of data are independently evaluated through the Chesapeake Bay Split Sample and Blind Audit Programs. Laboratories also participate in the USGS Standard Reference Sample Program. Non-tidal data are available on the CIMS network; River Input data may be downloaded directly from USGS.