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 identify and 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.

map of Massachusetts watersheds
(Click on image to enlarge)

Water quality monitoring data generated by the Watershed Planning Program are available back to 1994. Data collected since 2005 are provided below. For data prior to 2005 and for any other data requests, contact Tom Dallaire at, or Richard Chase at As newer data are processed and validated, these files will be updated. An interactive, geospatial data viewer that displays data by monitoring station location is PENDING.

The data provided here may also be summarized and described in WPP Technical Memoranda.  

All data are collected under an EPA-approved Quality Assurance Program Plan (DWM-WPP QAPP).

Data Files:

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.

Water Quality Monitoring Stations  xlsx format of Water Quality Monitoring Stations
- MassGIS data: MassDEP-DWM-WPP water quality stations
This file contains water quality monitoring station information for sites visited at least once by the Watershed Planning Program staff since 1994. Metadata for each monitoring station are presented, including waterbody name, site location (lat/long), watershed, town, etc.  This reference file links the data in the files below to a specific place or waterbody using the field called UNIQUEID.

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

Data Reporting Rules  pdf format of 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, 2005-2014  xlsx format of Water Quality laboratory data, 2005-2014
file size 11MB
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 attended probe data, 2005-2014  xlsx format of Water Quality attended probe data, 2005-2014
file size 2MB
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, 2005-2011  xlsx format of Continuous probe statistical summaries 2005-2011
This file includes basic statistical summaries of the unattended, continuously-logged data (e.g., averages, maximums, minimums, etc.) collected during each probe deployment for dissolved oxygen and/or temperature.

Water quality continuous probe statistical summaries for monitoring stations, 2005-2011  xlsx format of Monitoring stations statistical summaries 2005-2011
This file contains summary water quality information based on multiple deployments at each individual station in a given data year.

Water quality (continuous probe) data, 2005-2011 (PENDING)
These data represent discrete water quality readings from continuous probes deployed for durations from a few days to several months at individual stations. Most deployments include data collected every 30 minutes for dissolved oxygen and temperature.

Biological data, 2005-2015 (PENDING)
These data are collected to assess aquatic life communities, including benthic macroinvertebrates, fish and periphyton.