CSO attributes and location information are from a variety of datasets for each state: Connecticut: Beginning with GIS data compiled by the Connecticut Department of Energy and Environmental Protection (“CT DEEP”) and displayed on their CSO Right-to-Know site (https://portal.ct.gov/DEEP/Municipal-Wastewater/Combined-Sewer-Overflows-Right-to-Know), EPA filtered the data for the purposes of this map and made corrections based upon updated information available in EPA’s files. EPA’s map only displays municipalities with CSO outfalls, whereas CT DEEP’s map includes municipalities with CSO-related bypasses at their Wastewater Treatment Facilities (but no Combined Sewer Collection System CSO outfalls). EPA’s map only displays CSO outfalls – the point at which CSOs are discharged to the receiving water - whereas CT DEEP’s map includes CSO regulators (the structure through which wastewater and stormwater exits the conveyance pipe towards the Wastewater Treatment Facility). Maine: Service containing both facility and outfall locations permitted under the Maine Pollution Elimination System (MEPDES) and administered by the Maine Department of Environmental Protection (MEDEP). The data has been collected using multiple methods over 2 decades under the direction of the Maine DEP GIS Unit. All location data was quality checked by MEDEP MEPDES Inspectors and GIS Unit staff in 2018. Massachusetts: Attribute and location information from a combination of MassDEP CSOs(https://mass-eoeea.maps.arcgis.com/apps/webappviewer/index.html?id=08c0019270254f0095a0806b155abcde) (metadata - https://mass-eoeea.maps.arcgis.com/home/item.html?id=0262b339c2c74213bdaaa15adccc0e96) and NPDES permits(https://www.epa.gov/npdes-permits/massachusetts-final-individual-npdes-permits). New Hampshire: Active CSO outfalls collected from NH NPDES permits(https://www.epa.gov/npdes-permits/new-hampshire-final-individual-npdes-permits). EPA made corrections based upon updated information available in EPA’s files. Rhode Island: RI CSO Outfall Point Features. The outfalls managed by the Narragansett Bay Commission are downloadable from a GIS file through RIGIS (Rhode Island Geographic Information System https://www.rigis.org/datasets/nbc-sewer-overflows/explore?location=41.841121%2C-71.414224%2C13.57&showTable=true). Data was intended for use in utility facility engineering structure inventory. Last updated: 2019. Downloaded: 11/19/2021. Metadata (https://www.arcgis.com/sharing/rest/content/items/2108bab269df47f988e59c18a556f37d/info/metadata/metadata.xml?format=default&output=html) Vermont: Attribute and location information from Vermont Open Geodata Poral (https://geodata.vermont.gov/datasets/VTANR::stormwater-infrastructure-point-features/explore?location=43.912839%2C-72.414150%2C9.29). Point, line, and polygon data was collected and compiled through field observations, municipal member knowledge, ortho-photo interpretation, digitization of georeferenced town plans and record drawings, and state stormwater permit plans. Accuracy of all data is for planning purposes and field verification is at the user’s discretion. VT Layer: Stormwater Infrastructure (Point Features) Metadata (https://www.arcgis.com/sharing/rest/content/items/5c9875ee609c4586bd569dbacb2d92f1/info/metadata/metadata.xml?format=default&output=html).

CSO attributes and location information are from a variety of datasets for each state: Connecticut: Beginning with GIS data compiled by the Connecticut Department of Energy and Environmental Protection (“CT DEEP”) and displayed on their CSO Right-to-Know site (https://portal.ct.gov/DEEP/Municipal-Wastewater/Combined-Sewer-Overflows-Right-to-Know), EPA filtered the data for the purposes of this map and made corrections based upon updated information available in EPA’s files. EPA’s map only displays municipalities with CSO outfalls, whereas CT DEEP’s map includes municipalities with CSO-related bypasses at their Wastewater Treatment Facilities (but no Combined Sewer Collection System CSO outfalls). EPA’s map only displays CSO outfalls – the point at which CSOs are discharged to the receiving water - whereas CT DEEP’s map includes CSO regulators (the structure through which wastewater and stormwater exits the conveyance pipe towards the Wastewater Treatment Facility). Maine: Service containing both facility and outfall locations permitted under the Maine Pollution Elimination System (MEPDES) and administered by the Maine Department of Environmental Protection (MEDEP). The data has been collected using multiple methods over 2 decades under the direction of the Maine DEP GIS Unit. All location data was quality checked by MEDEP MEPDES Inspectors and GIS Unit staff in 2018. Massachusetts: Attribute and location information from a combination of MassDEP CSOs(https://mass-eoeea.maps.arcgis.com/apps/webappviewer/index.html?id=08c0019270254f0095a0806b155abcde) (metadata - https://mass-eoeea.maps.arcgis.com/home/item.html?id=0262b339c2c74213bdaaa15adccc0e96) and NPDES permits(https://www.epa.gov/npdes-permits/massachusetts-final-individual-npdes-permits). New Hampshire: Active CSO outfalls collected from NH NPDES permits(https://www.epa.gov/npdes-permits/new-hampshire-final-individual-npdes-permits). EPA made corrections based upon updated information available in EPA’s files. Rhode Island: RI CSO Outfall Point Features. The outfalls managed by the Narragansett Bay Commission are downloadable from a GIS file through RIGIS (Rhode Island Geographic Information System https://www.rigis.org/datasets/nbc-sewer-overflows/explore?location=41.841121%2C-71.414224%2C13.57&showTable=true). Data was intended for use in utility facility engineering structure inventory. Last updated: 2019. Downloaded: 11/19/2021. Metadata (https://www.arcgis.com/sharing/rest/content/items/2108bab269df47f988e59c18a556f37d/info/metadata/metadata.xml?format=default&output=html) Vermont: Attribute and location information from Vermont Open Geodata Poral (https://geodata.vermont.gov/datasets/VTANR::stormwater-infrastructure-point-features/explore?location=43.912839%2C-72.414150%2C9.29). Point, line, and polygon data was collected and compiled through field observations, municipal member knowledge, ortho-photo interpretation, digitization of georeferenced town plans and record drawings, and state stormwater permit plans. Accuracy of all data is for planning purposes and field verification is at the user’s discretion. VT Layer: Stormwater Infrastructure (Point Features) Metadata (https://www.arcgis.com/sharing/rest/content/items/5c9875ee609c4586bd569dbacb2d92f1/info/metadata/metadata.xml?format=default&output=html).

Stormwater, wastewater, and drinking water data from a variety of sources is being compiled. Stormwater data has (is) been collected for many urbanized town and village centers statewide. Wastewater data is available for some towns and is currently being developed more fully as data becomes available. Drinking water data is rarely available. Point, line, and polygon data was collected and compiled through field observations, municipal member knowledge, ortho-photo interpretation, digitization of georeferenced town plans and record drawings, and state stormwater permit plans. Accuracy of all data is for planning purposes and field verification is at the users discretion. Subwatershed Drainage systems were mapped to establish the connectivity of the stormwater features, and to show where runoff from impervious surfaces in various subwatersheds within an urbanized area eventually enters the receiving water. Subwatershed boundaries were drawn by hand using a variety of elevation data and corelated to each towns Stormwater Infrastructure report.

This dataset contains the locations of municipal and industrial direct discharge wastewater treatment facilities throughout the state of Vermont. Spatial data is not maintained and therefore, this dataset may not be complete. Current facility specific information can be accessed by the Wastewater Inventory URL field. Data within the Wastewater Inventory is current and maintained by Wastewater Program staff.

This data was created through the modification of an existing sewer service dataset from the CT Office of Policy and Management (OPM), in addition to sewer data from the Southeastern Connecticut Council Of Government (SCCOG) and the Town of Stonington. It also includes data from the Sewer Service Area 2018 file in areas where the OPM dataset was not as current.,

This geospatial dataset depicts a sewage no-discharge zone established under Clean Water Act Section 312. The area(s) depicted are zones where the discharge of any sewage, treated or untreated, from vessels is prohibited. This layer was created using information from the corresponding Federal Register notice and is created for informational purposes, not to be used for enforcement.

A dataset of well information and geospatial data was developed for 426 U.S. Geological Survey (USGS) observation wells in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. An extensive list of attributes is included about each well, its location, and water-level history to provide the public and water-resources community with comprehensive information on the USGS well network in New England and data available from these sites. These data may be useful for evaluating groundwater conditions and variability across the region. The well list and site attributes, which were extracted from USGS National Water Information System (NWIS), represent all of the active wells in the New England network up to the end of 2017, and an additional 45 wells that were inactive (discontinued or replaced by a nearby well) at that time. Inactive wells were included in the database because they (1) contain periods of water-level record that may be useful for groundwater assessments, (2) may become active again at some point, or (3) are being monitored by another agency (most discontinued New Hampshire wells are still being monitored and the data are available in the National Groundwater Monitoring Network (https://cida.usgs.gov/ngwmn/index.jsp). The wells in this database have been sites of water-level data collection (periodic levels and/or continuous levels) for an average of 31 years. Water-level records go back to 1913. The groundwater-level statistics included in the dataset represent hydrologic conditions for the period of record for inactive wells, or through the end of water year 2017 (September 30, 2017) for active wells. Geographic Information Systems (GIS) data layers were compiled from various sources and dates ranging from 2003 to 2018. These GIS data were used to calculate attributes related to topographic setting, climate, land cover, soil, and geology giving hydrologic and environmental context to each well. In total, the data include 90 attributes for each well. In addition to site number and station name, attributes were developed for site information (15 attributes); groundwater-level statistics through water year 2017 (16 attributes); well-construction information (9 attributes); topographic setting (11 attributes); climate (2 attributes); land use and cover (17 attributes); soils (4 attributes); and geology (14 attributes). Basic well and site information includes well location, period of record, well-construction details, continuous versus intermittent data collection, and ground altitudes. Attributes that may influence groundwater levels include: well depth, location of open or screened interval, aquifer type, surficial and bedrock geology, topographic position, flow distance to surface water, land use and cover near the well, soil texture and drainage, precipitation, and air temperature.

A dataset of well information and geospatial data was developed for 426 U.S. Geological Survey (USGS) observation wells in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. An extensive list of attributes is included about each well, its location, and water-level history to provide the public and water-resources community with comprehensive information on the USGS well network in New England and data available from these sites. These data may be useful for evaluating groundwater conditions and variability across the region. The well list and site attributes, which were extracted from USGS National Water Information System (NWIS), represent all of the active wells in the New England network up to the end of 2017, and an additional 45 wells that were inactive (discontinued or replaced by a nearby well) at that time. Inactive wells were included in the database because they (1) contain periods of water-level record that may be useful for groundwater assessments, (2) may become active again at some point, or (3) are being monitored by another agency (most discontinued New Hampshire wells are still being monitored and the data are available in the National Groundwater Monitoring Network (https://cida.usgs.gov/ngwmn/index.jsp). The wells in this database have been sites of water-level data collection (periodic levels and/or continuous levels) for an average of 31 years. Water-level records go back to 1913. The groundwater-level statistics included in the dataset represent hydrologic conditions for the period of record for inactive wells, or through the end of water year 2017 (September 30, 2017) for active wells. Geographic Information Systems (GIS) data layers were compiled from various sources and dates ranging from 2003 to 2018. These GIS data were used to calculate attributes related to topographic setting, climate, land cover, soil, and geology giving hydrologic and environmental context to each well. In total, the data include 90 attributes for each well. In addition to site number and station name, attributes were developed for site information (15 attributes); groundwater-level statistics through water year 2017 (16 attributes); well-construction information (9 attributes); topographic setting (11 attributes); climate (2 attributes); land use and cover (17 attributes); soils (4 attributes); and geology (14 attributes). Basic well and site information includes well location, period of record, well-construction details, continuous versus intermittent data collection, and ground altitudes. Attributes that may influence groundwater levels include: well depth, location of open or screened interval, aquifer type, surficial and bedrock geology, topographic position, flow distance to surface water, land use and cover near the well, soil texture and drainage, precipitation, and air temperature.

In summer in Massachusetts, USA, preferential groundwater discharge zones are often colder than adjacent streambed areas that do not have substantial discharge. Therefore, discharge zones can efficiently be identified and mapped over space using heat as a tracer. This data release contains fiber-optic distributed temperature sensing (FO-DTS) data collected along the streambed interface of the main channel and tributaries of the upper Quashnet River, within approximately 1 km of Johns Pond, from June 14 to June 20, 2020. For these deployments a Salixa XT-DTS control unit (Salixa Ltd, Hertfordshire, UK) was used, and measurements were made over several day increments at 0.508 m linear resolution. Specific locations for collected data are located within the data files, and additional details are contained in the ‘readme’ files within each zipped data directory. Measured data in the form of Salixa instrument files are located in the 'Raw' data directory, including data collected along lengths of optical fiber that were not installed in the streams. The 'Processed' data directory contains data that have been aggregated from the original machine output files, spatially trimmed, and georeferenced. Additionally, simple summary streambed interface temperature statistics (mean, max, min, standard deviation) are listed by streambed location.