Water Quality Monitoring Program Data

The MassDEP-Division of Watershed Management, Watershed Planning Program (WPP) monitors surface waters throughout the Commonwealth in order to report on the quality of the water with respect to designated uses (e.g., swimming, boating, fish consumption, shellfish harvesting, aquatic life use) and to prioritize impaired waters for corrective actions, as required by Sections 305(b) and 303(d) of the Clean Water Act, respectively. Water quality monitoring data also inform a wide range of decision-making, including but not limited to identifying outstanding resource waters for special protection, development of water quality criteria, calibration and verification of predictive models for Total Maximum Daily Load (TMDL) analyses and evaluating the effectiveness of pollution control and watershed restoration measures.

Water quality monitoring data generated by the Watershed Planning Program are available back to 1994. Data collected since 2005 are provided below as downloaded files. For data prior to 2005 and for any other data requests, contact Tom Dallaire at Thomas.Dallaire@mass.gov, or Richard Chase at Richard.F.Chase@mass.gov. As newer data are processed and validated, these files will be updated. An interactive, geospatial data viewer that displays water quality and related data is also available (see below).

All data are collected under an EPA-approved Quality Assurance Program Plan.

A Water Quality Data Viewer is provided to access discrete and continuous surface water quality data, surface water quality standards classifications, and information on current/historic water quality assessments and impaired waters listings.  This viewer was developed using EPA Exchange Network grant funds.

Data Disclaimer - These data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and metadata have been reviewed for accuracy and completeness and approved for release by the Watershed Planning Program, no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

Data Dictionary
The data dictionary provides an explanation for each field presented in the Data Files, including any codes used.

Data Reporting Rules
WPP's data reporting rules that are used for results and other fields are described in this file.

Water Quality laboratory data, 2005-2020
This file includes water quality sample data generated via laboratory analysis, including nutrients (e.g., nitrogen, phosphorus), color, turbidity, bacteria, dissolved metals and other parameters collected at monitoring stations throughout the Commonwealth. By WPP convention, one sample from each field duplicate pair is reported along with the regular (Routine) samples. Complete quality control data (e.g., field duplicates and field blanks) are available upon request.

Water Quality discrete probe data, 2005-2020
These data result from the use of hand-held instruments placed in-situ during station visits for parameters such as dissolved oxygen, temperature, pH, and specific conductance.

Water quality continuous probe statistical summaries for deployments, 2005-2020
This file includes basic statistical summaries of the continuously-logged data (e.g., averages, maximums, minimums, etc., based on 30-minute interval readings) collected during each probe deployment for dissolved oxygen, temperature and specific conductance, depending on the type(s) of probe used.

Water quality continuous probe statistical summaries for monitoring stations, 2005-2020
This file contains summary water quality information based on multiple deployments at each individual station in a given data year for dissolved oxygen, temperature and specific conductance, depending on the type(s) of probe used.

Water quality continuous probe data, 2005-2020 (available upon request)
These data are the individual, 30-minute interval water quality readings from continuous probes deployed for durations from a few days to several months at each location. 

Biological data, 2005-2018 (available upon request)
These data are collected to assess aquatic life communities, including benthic macroinvertebrates, fish and periphyton.

Mount Hope Bay marine buoy continuous probe data, 2017-2020
Seasonal monitoring in Mount Hope Bay is part of the Narragansett Bay Fixed-Site Monitoring Network (NBFSMN) and provides water quality information for a sub-embayment of upper Narragansett Bay.