This data release presents water-quality and streamflow data from 12 streams on Cape Cod, Massachusetts, which were used to identify potential land areas that are sources of high nitrogen loading from groundwater directly to streams. The sources of nitrogen loading to groundwater in this region include wastewater from septic systems and fertilizer and stormwater runoff. Streamflow in the area is highly influenced by groundwater and not by direct outflows of treated wastewater. This dataset contains stream site information (CapeCodStreams_SiteInfo.csv), field and laboratory observations (CapeCodStreams_Field_Lab_QW.csv), and information on streamflow and calculated nitrogen loads (CapeCodStreams_Flow_and_Loads.csv). Additionally, the dataset provides information on simulated groundwater recharge areas contributing to individual stream reaches. Recharge area characteristics, including size, recharge quantity, groundwater travel time, nitrogen-yield characteristics, and land-use classifications, are provided (CapeCodStreams_RA_Char.csv and CapeCodStreams_RA_Wshed_Load.csv). A data dictionary (CapeCodStreams_Data_Dictionary.csv) is provided to describe column attributes and define attribute units.

A method to estimate the probable high groundwater level in Massachusetts, excluding Cape Cod and the Islands was developed in 1981. The method, commonly called the “Frimpter Method,” uses a groundwater measurement from a test site, groundwater measurements from an index well, and a distribution of high groundwater levels from wells in similar geologic and topographic settings. Historic groundwater-level statistics (maximum and 90th percentile groundwater level and annual groundwater-level range) were calculated for 153 wells in Massachusetts and nearby States to update the method inputs. In addition, as part of a comparison of approaches to determine the best index well for a given site, a multiple linear regression equation was developed to explore the relations between predictor variables and the correlations, with the goal of predicting the most highly correlated index well for each test site. This data release includes the calculated groundwater level statistics, the ancillary data used in the regression model, comparison of the data among well pairs, and predictions of the correlations among all well pairs.

A method to estimate the probable high groundwater level in Massachusetts, excluding Cape Cod and the Islands was developed in 1981. The method, commonly called the “Frimpter Method,” uses a groundwater measurement from a test site, groundwater measurements from an index well, and a distribution of high groundwater levels from wells in similar geologic and topographic settings. Historic groundwater-level statistics (maximum and 90th percentile groundwater level and annual groundwater-level range) were calculated for 153 wells in Massachusetts and nearby States to update the method inputs. In addition, as part of a comparison of approaches to determine the best index well for a given site, a multiple linear regression equation was developed to explore the relations between predictor variables and the correlations, with the goal of predicting the most highly correlated index well for each test site. This data release includes the calculated groundwater level statistics, the ancillary data used in the regression model, comparison of the data among well pairs, and predictions of the correlations among all well pairs.

Existing simulated groundwater head and water-budget output files from MODFLOW models for the Plymouth-Carver region (Masterson and others, 2009), the Hyannis Ponds Cape model (LeBlanc and others, 2019), and a SEAWAT model of lower Cape Cod (Masterson, 2004) were used in a new MODPATH version 6 (MP6) (Pollock, 2012) particle-tracking analyses. In the MODPATH6 analyses, endpoints associated with unique hydrologic receptors (model cells representing streams or drains, and ponds) were identified by forward tracking the particles through the simulated hydrologic system represented by each of the groundwater models. Each endpoint file is included in this data release. Shapefiles containing the unique zone identifier for each stream, drain, and pond model-grid-cell, also are included. Ultimately, the groupings found in each endpoint file were used to define areas contributing recharge, or contributing area, for each stream cell, drain cell, and pond in contact with a stream in the model area. This USGS data release contains the input and output files (https://doi.org/10.3133/sir2024xxxx). (See cross reference section of this metadata for full citation information).

Groundwater and estuary water levels near Mill Creek and the Herring River in Wellfleet, Massachusetts, were measured from June 2017 to August 2022. The data contained in these datasets consist of tables of updated statistics provided in the original work by Mullaney and others (2020, Appendix 2) and associated data release by Mullaney and Barclay (2020). The data include summary tables of water-level statistics and summary tables of updated statistical coefficients for the models in the original work. The data release also includes the underlying input data sets for these statistical regression models and an update of table 2 from the larger work, which consists of summary statistics of water levels for the period of data analysis from 2017-06-01 to 2022-08-05. Mullaney, J.R., and Barclay, J.R., 2020, Data on Tidally Filtered Groundwater and Estuary Water Levels, and Climatological Data Near Mill Creek and the Herring River, Cape Cod, Wellfleet, Massachusetts, 2017-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9T167II. Mullaney, J.R., Barclay, J.R., Laabs, K.L., and Lavallee, K.D., 2020, Hydrogeology and interactions of groundwater and surface water near Mill Creek and the Herring River, Wellfleet, Massachusetts, 2017–18: U.S. Geological Survey Scientific Investigations Report 2019–5145, 60 p., https://doi.org/10.3133/sir20195145.

Groundwater and estuary water levels near Mill Creek and the Herring River in Wellfleet, Massachusetts, were measured from June 2017 to August 2022. The data contained in these datasets consist of tables of updated statistics provided in the original work by Mullaney and others (2020, Appendix 2) and associated data release by Mullaney and Barclay (2020). The data include summary tables of water-level statistics and summary tables of updated statistical coefficients for the models in the original work. The data release also includes the underlying input data sets for these statistical regression models and an update of table 2 from the larger work, which consists of summary statistics of water levels for the period of data analysis from 2017-06-01 to 2022-08-05. Mullaney, J.R., and Barclay, J.R., 2020, Data on Tidally Filtered Groundwater and Estuary Water Levels, and Climatological Data Near Mill Creek and the Herring River, Cape Cod, Wellfleet, Massachusetts, 2017-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9T167II. Mullaney, J.R., Barclay, J.R., Laabs, K.L., and Lavallee, K.D., 2020, Hydrogeology and interactions of groundwater and surface water near Mill Creek and the Herring River, Wellfleet, Massachusetts, 2017–18: U.S. Geological Survey Scientific Investigations Report 2019–5145, 60 p., https://doi.org/10.3133/sir20195145.

Groundwater and estuary water levels near Mill Creek and the Herring River in Wellfleet, Massachusetts, were measured from June 2017 to August 2022. The data contained in these datasets consist of tables of updated statistics provided in the original work by Mullaney and others (2020, Appendix 2) and associated data release by Mullaney and Barclay (2020). The data include summary tables of water-level statistics and summary tables of updated statistical coefficients for the models in the original work. The data release also includes the underlying input data sets for these statistical regression models and an update of table 2 from the larger work, which consists of summary statistics of water levels for the period of data analysis from 2017-06-01 to 2022-08-05. Mullaney, J.R., and Barclay, J.R., 2020, Data on Tidally Filtered Groundwater and Estuary Water Levels, and Climatological Data Near Mill Creek and the Herring River, Cape Cod, Wellfleet, Massachusetts, 2017-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9T167II. Mullaney, J.R., Barclay, J.R., Laabs, K.L., and Lavallee, K.D., 2020, Hydrogeology and interactions of groundwater and surface water near Mill Creek and the Herring River, Wellfleet, Massachusetts, 2017–18: U.S. Geological Survey Scientific Investigations Report 2019–5145, 60 p., https://doi.org/10.3133/sir20195145.

This data release contains groundwater flux estimates from twelve locations in wetlands surrounding the Quashnet River in Cape Cod, located near Mashpee and Falmouth, Massachusetts. A VTP (i.e., rod with vertical temperature sensors with known spacings and depths) was also installed at a key groundwater discharge location to estimate 1D groundwater flux through time (Sohn et al., 2024). Vertical discharge flux patterns were estimated over time using the extended Kalman Filter (EKF) recursive estimation approach of McAliley et al. (2022). The EKF method was used to recursively estimate specific discharge in discrete time when temperature measurements were acquired (i.e., hourly) at each discharge location. The methodology used here has been previously tested on both synthetic and field data in McAliley et al. (2022) where EKF methods were shown to converge to step changes in synthetic discharge data on sub-daily timescales, and residuals between observed (i.e., field observations) and estimated (i.e., EKF predictions) temperatures were generally within 0.1°C, consistent with expected measurement precision. Further information on the numerical implementation, comparisons to synthetic and field observations, as well as links to open-source code can be found in McAliley et al. (2022). To complement these estimates, discrete measurements of groundwater discharge were taken using seepage meters directly coupled to the streambed interface. Vertical head gradients were also measured in some seeps and mean hydraulic conductivity values obtained from seepage meter measurements were used to produce estimates of 1D groundwater flux (m/d) from measured head differentials. This release covers data associated with the estimation of groundwater flux from these identified discharge zones using the methods above described above.

This data layer contains groundwater contributing areas for streams, ponds and estuaries in the Cape Cod and the Plymouth-Carver region. Contributing areas were delineated by using regional groundwater-flow models. The percent impervious cover of each contributing area was calculated by using a statewide 1-m resolution binary rater data layer of impervious surface in2005. This is one of three data layers in this data series publication.

This U.S. Geological Survey data release provides a comprehensive dataset of water-quality data and sampling-site characteristics collected in 1978–2018 during a study of the effects of land disposal of treated wastewater on groundwater quality in an unconsolidated sand and gravel aquifer on Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to rapid-infiltration beds at Joint Base Cape Cod for nearly 60 years before the disposal was moved to a different location in December 1995. The discharge formed a plume of contaminated groundwater that partly discharges to a glacial kettle lake about 1,600 feet from the beds and extends about 4.5 miles toward coastal saltwater bodies at Vineyard Sound. Water-quality samples were collected from monitoring wells, multilevel samplers (MLSs), continuous multichannel tubing samplers (CMTs), AMS gas-vapor sampling points (AMS, Inc., American Falls, Idaho), piezometers, temporary borings drilled by direct-push methods, and surface-water bodies to characterize the nature and extent of the contaminated groundwater and to observe the water-quality changes before and after wastewater disposal ended in 1995. Data are presented here for 604 wells (at 188 well-cluster locations), 1,155 MLS ports (at 61 locations), 42 CMT ports (at 6 locations), 13 gas-vapor points (at 1 location), 17 piezometers (at 5 locations), 536 depth intervals in direct-push profile borings (at 68 locations), 1 glacial kettle lake, and 1 wastewater-disposal discharge in and near the treated-wastewater plume. About 20,740 visits were made to individual sampling points between 1978 to 2018. This data release presents field water-quality measurements (specific conductance, pH, dissolved oxygen, turbidity and temperature; iron, MBAS and phosphate concentrations; and alkalinity); absorbance of ultraviolet/visible light; and concentrations of selected gases (including nitrous oxide, methane, dissolved inorganic carbon), dissolved organic carbon, selected nitrogen species (including nitrate, nitrite, ammonium, and total dissolved nitrogen), and selected inorganic solutes (including cations, anions, and minor elements). Information on sample collection and processing can be found in the Federal Geographic Data Committee (FGDC) metadata and “TableDefs CapeCodToxicsDatabase.xlsx.” The data are presented in two formats: Microsoft (MS) Access database (.accdb) and comma-delimited text (.csv) files. The MS Access version of the database (”DataRelease_CapeCodToxicsDatabase_v1.1.accdb”) contains 15 data tables linked by established relationships and 4 queries that repackage the data for the convenience of the user. Versions of the 4 queries and 15 tables exported from the MS Access database as comma-delimited text files have been zipped together by type (”tables” and ”queries,“ respectively). The text files are comma delimited, contain headings, and use double quotation marks to denote text fields. Numeric fields enclosed in double quotation marks are treated as text to preserve number formatting. Users not familiar with MS Access may prefer the text files to the MS Access database. The database can be reconstructed in Access or another relational data management platform from text-file tables in conjunction with the physical data model, the definitions of the table and field descriptions, and the Structured Query Language (SQL) commands described in a readme file zipped with the query text files. The table descriptions, field definitions, and significant figures for this database are documented by “TableDefs CapeCodToxicsDatabase.xlsx” and the FGDC metadata. The physical data model for this database is documented by “Relationships for CapeCodToxicsDatabase.jpg.” The relationships expressed in the .jpg file are further explained by an MS Word document titled “Relationships for CapeCodToxicsDatabase.docx.” Three types of data are included in the data tables: site and sample characteristics, water-quality data, and