March 2017

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Overview

The Federal Clean Water Act (CWA) directs states to monitor and report on the condition of their water resources. The Water Quality Monitoring Station data layer was compiled by staff within the Massachusetts Department of Environmental Protection (MassDEP) Division of Watershed Management (DWM), Watershed Planning Program (WPP) in fulfillment of CWA mandates.

Approximately 2,400 unique predominantly surface water stations in this datalayer have been visited sometime between 1994 and 2014. Each station, stored as a single point in the layer, represents a location where general field characteristics were observed, where in-situ probe measurements were made, or where discrete water quality samples were collected by WPP staff or their agents.

Learn more about the DWM-WPP water quality monitoring program.

In ArcSDE the layer is named DWMWPP_WATER_QUALITY_STATIONS.

Methodology

The data layer was created using field descriptions recorded by DWM-WPP staff or using coordinates generated following a systematic random point selection process developed by the Environmental Protection Agency (EPA) Office of Research and Development, Western Ecology Division.

When geo-referencing began in the 1990s, using Geographic Information Systems, station points were placed on water features as represented on the 1:25,000 U.S. Geological Survey (USGS) topographic quad images maintained by MassGIS. If a water feature was not depicted on the quad, then orthographic images were used to place the point and documented in the descriptor (e.g.”…stream not apparent on quad…”). Points depicting stream monitoring stations are representative of a potential 100 foot sampling reach. This reach is essentially the same water with no obvious changes to water quality from other water sources (e.g. tributaries or pipes). Points depicting pipes are placed at the mouth of the pipe, with pipe outflow samples taken before mixing with receiving surface water.

After initial station placement, field staff reviewed mapped points to ensure placement agreed with field notes. The systematic random point selection process was used when a probabilistic wadeable stream monitoring project began in 2010. The 2010 sampling points were generated from the 1:100,000 National Hydrography Dataset Plus coverage (NHD-Plus-coverage), while the 2011-2014 probabilistic wadeable stream project sites were generated from the higher resolution 1:24,000 NHD-Plus-coverage, following the EPA protocols. Those points were not adjusted to fall on quad-imaged waters, therefore some of those stations may appear to be “on dry land” when stations are overlaid on the quad images.

Attributes

The layer's point attribute table contains the following fields:
VINTAGE The date the 1994 through 2014 station information was extracted from the station database.
WPP_BASIN Text of the MassDEP DWM WPP watershed and or coastal drainage area name that identifies where the station is located which is based on the MassGIS Major Basins layer but modified to reflect surface drainage areas used with the MassDEP Integrated List of Waters report by the WPP.
UNIQUEID Unique identifier code assigned by DWM-WPP for the monitoring location.
WATERBODY Station water body name based on MassDEP’s SARIS, PALIS, and/or CAMIS.  SARIS = Stream and River Inventory System, PALIS = Pond and Lake Inventory System, CAMIS = Coastal and Marine Inventory System. (Note: names are separated by ‘/’ if, for example, a monitoring station is on a named impoundment on a stream)
STADESCRIP Station location description.
MLTYP_NA Monitoring Location Type Name, is the characterization of station location type (e.g., lake, river, discharge pipe, etc), consistent with EPAs Water Quality Exchange (WQX) domain values used for submitting data to the Storage and Retrieval (STORET) Data Warehouse.
WATERCODE Unique water body code based on MassDEP’s SARIS, PALIS, or CAMIS inventory coding systems. Note: if a waterbody is not listed in any of the published inventories then the watercode is the “Basin Code” followed by zeroes (with SARIS having a total of seven digits and PALIS or CAMIS having a total of five digits).
ESTABLISH The year the station was first registered (i.e. tracked systematically in a database and in GIS) by DWM-WPP staff.  [Note: stations sampled prior to 1994 are not necessarily included in this coverage.]
BASINCODE Numeric basin/watershed code assigned that identifies where the station is located (SARIS, PALIS basin derivation).
WATERSHED Text basin/watershed name that identifies where the station is located (SARIS, PALIS basin derivation).
LONGITUDE Longitude (decimal degrees; North American Datum (NAD), 1983; Massachusetts State Plane Coordinate System)
LATITUDE Latitude (decimal degrees; North American Datum (NAD), 1983; Massachusetts State Plane Coordinate System)
The water quality monitoring stations should be displayed with the MassDEP DWM WPP watersheds data (included in the download at the top of this page). Fields in the IL_DWMWPP_WATERSHEDS_POLY attribute table are as follows. (Note: these delineations are based on MassGIS 'Major Basins' shapefile but modified by the DWM/WPP to reflect surface drainage areas for use with the Massachusetts Year 2014 Integrated List of Waters report by the WPP.):

DWM_Name

 

The MassDEP DWM WPP watershed delineations are based on the MassGIS Major Basins layer, but modified to reflect surface drainage areas for use with the MassDEP Integrated List of Waters report by the WPP. For example, a portion of the Cape Cod Watershed Area was changed to reflect its drainage into Buzzards Bay, resulting in shape changes for both the Cape Cod and Buzzards Bay watershed delineations. In general, the watershed name is based on the Massachusetts Stream and River Inventory System (SARIS) that includes all Massachusetts river basins and coastal drainage areas (Halliwell et al. 1982). The WPP watershed name Boston Harbor (Proper) does not appear in the MassGIS Major Basins layer or the SARIS list of watersheds; it refers to the harbor itself. Three drainage area types are further described in SARIS as follows: River Basin: Major inland river basin. River Basin and Coastal Drainage Area: Major inland river basin coupled with smaller areas draining directly to coastal waters within the general geographic area of the associated river basin. Coastal Drainage Area: Subdivisions of the coastal drainage system that have been partitioned into specific geographic areas. These areas all drain to coastal waters but may have multiple small-scale drainages.

DWM_Code

 

The watershed identification code used by the DWM/WPP for assigning water body segments (assessment units) to a watershed. These codes are assigned according to the Massachusetts Stream and River Inventory System (SARIS) -- the first two numbers of which assign 1. the major drainage system and 2. the river basin and coastal drainage area (the sub-basin) (Halliwell et al. 1982).

Drainage

 Three drainage area types are further described in SARIS as follows: River Basin: Major inland river basin. River Basin and Coastal Drainage Area: Major inland river basin coupled with smaller areas draining directly to coastal waters within the general geographic area of the associated river basin. Coastal Drainage Area: Subdivisions of the coastal drainage system that have been partitioned into specific geographic areas. These areas all drain to coastal waters but may have multiple small-scale drainages (Halliwell et al. 1982).

References

Halliwell, D.B., W.A. Kimball and A.J. Screpetis. 1982. Massachusetts Stream Classification Program Part I: Inventory of Rivers and Streams. Massachusetts Division of Fisheries and Wildlife, Department of Fisheries, Wildlife, and Recreational Vehicles and Massachusetts Division of Water Pollution Control, Department of Environmental Quality Engineering. Westborough, MA.

Maintenance

The MassDEP DWM-WPP is maintaining this datalayer. Periodic updates are anticipated as monitoring years are completed and station mapping is verified by sampling staff. For further information about this coverage and other data associated with these stations, contact Richard Chase (Richard.F.Chase@state.ma.us, 508-767-2859) in the MassDEP DWM-WPP.

This data layer replaces DWMSTATIONS_PT and its four related tables (STAID, FIELD, LAB, HYDRO).


Last Updated 3/28/2017