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MassGIS Data: MassDEP Ground Water Discharge Permits

November 2023

The Ground Water Discharge Permits datalayer (formerly known as Groundwater Discharge Points) is a statewide point dataset containing approximate locations of permitted discharges to groundwater. Current as of November 16, 2023.

Table of Contents



The Massachusetts Department of Environmental Protection (MassDEP) Bureau of Water Resources (BWR), Groundwater Permitting Program is responsible for regulating the discharge of pollutants to the groundwaters of The Commonwealth (314 CMR 5.00).

The MassDEP Groundwater Discharge Permits layer includes “Active”:

  • Facilities that discharge 10,000 gallons per day or more of sanitary wastewater*
  • Facilities that discharge any amount of industrial wastewater to the ground
  • Facilities that use reclaimed water in conjunction with a discharge to the ground.

Groundwater discharge permits are issued primarily for domestic and commercial wastewater, carwashes, laundromats, and certain industrial facilities. The type of discharge and the amount being discharged will designate which permit application should be filed.

*Please note: There may be instances where site constraints would require a discharge of
less than 10,000 gallons per day of treated sanitary wastewater to obtain a groundwater
discharge permit

See the MassDEP Groundwater Discharge Permitting website for details.

In ArcSDE the layer is named GWP_PT.


Locations contained in this layer are primarily based on MassDEP Groundwater Discharge Permit Program staff interpretation of site plan maps that accompany the Groundwater Discharge Permit applications.  In certain cases, locations may be based on address information associated with the permit.

Associated attribute information is provided by the MassDEP Groundwater Permits database.


The point attribute table for the MassDEP Ground Water Discharge Permits datalayer contains the following fields:

PER BWR Permit Number, Unique site ID
PERR BWR Permit Number plus Renewal Number, Unique site ID
NAME GWP Name, according to the Ground Water Permits database
ADDRESS GWP Address, according to the Ground Water Permits database
TOWN Standard (1-351) MassGIS town name in which the GWP is located
REGION Standard (1-4) DEP Region ID in which the GWP is located:
 1 = Western
 2 = Central
 3 = Northeast
 4 = Southeast
BASIN Basin (watershed) in which the GWP is located
TYPE Status / type of discharge according to WMP:
 C = Car Wash
 = Industrial
 L = Laundromat
 RU = Reclaimed Water
 S = Sanitary Discharge
 O = Other
Note: a small number of features are coded with the combined TYPEs of L/C or S/C.
FLOW Metered flow of discharge; in gallons per day (GPD) according to the Ground Water Permits database

Related Datalayer

  • Location Documentation Table (GWP_PT_LDT) - See MassDEP Standards for Point GIS Data.
  • Unlocated Sites List (GWP_PT_USL) - This table lists the active permit sites that are unlocated and not contained in the layer.  This table is empty when all active permit sites in the MassDEP Groundwater Permits database are located at the time the layer is updated at MassGIS.


MassDEP GIS and Groundwater Discharge Permitting Program staff maintains this data.  Updates to this data are provided to MassGIS on a semiannual basis. A standard component of the update includes the addition of new active permit sites, the removal of permit sites that are no longer active permits.  Updates may also include refinements to existing, active permit site locations and updates to associated attribute information to reflect changes in the MassDEP Groundwater Permits database.

Questions regarding this data should be referred to the MassDEP Groundwater Discharge Permitting Program.

Last updated: November 20, 2023

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