In 2020, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected groundwater-level altitude data and water-quality samples from monitoring wells at the Petro-Chemical Systems, Inc. (Turtle Bayou) Superfund Site in Liberty County, Texas to evaluate the status of groundwater contamination at this previously remediated site. The dataset includes groundwater-level altitudes and field properties measured at 11 monitoring wells along with data from environmental and quality assurance/quality control water quality samples collected at each well. Water-quality samples were analyzed for a suite of volatile and semivolatile organic compounds.

In 2020, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected groundwater-level altitude data and water-quality samples from monitoring wells at the Petro-Chemical Systems, Inc. (Turtle Bayou) Superfund Site in Liberty County, Texas to evaluate the status of groundwater contamination at this previously remediated site. The dataset includes groundwater-level altitudes and field properties measured at 11 monitoring wells along with data from environmental and quality assurance/quality control water quality samples collected at each well. Water-quality samples were analyzed for a suite of volatile and semivolatile organic compounds.

In 2023, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected groundwater-level altitude and water-quality data from monitoring wells at the Petro-Chemical Systems, Inc. (Turtle Bayou) Superfund Site in Liberty County, Texas. The data were collected to obtain information that could be used to provide an update on the status of groundwater contamination at the site. This data release documents the groundwater-level altitudes, field properties, and water-quality data obtained in 2023 from six of the 11 monitoring wells where similar data were collected by the U.S. Geological Survey in August and September 2020 (Braun and Becher 2022). The environmental and quality-control data from the water-quality samples collected at each well that was sampled in April 2023 are included. Each water-quality sample was analyzed for a suite of volatile and semi-volatile organic compounds.

The Garland Creosoting Superfund Site in Longview, Texas is an abandoned wood treatment facility that used creosote to preserve wood products between 1960 and 1997. Previous remediation activities at the contaminated site included excavation of creosote-contaminated soil and the installation of an interceptor collector trench and groundwater treatment system to prevent the movement of contaminated groundwater into an intermittent stream, hereinafter referred to as the "unnamed tributary". The unnamed tributary drains into the Iron Bridge Creek after flowing along the southern boundary of the Garland Creosoting Superfund Site, and Iron Bridge Creek eventually drains into the Sabine River, a source of drinking water for thousands of Texas residents. The U.S. Environmental Protection Agency (EPA) is concerned with potential risks to human health from contaminated groundwater that may be flowing off-site either beneath or within the unnamed tributary. To evaluate the status of volatile organic compound (VOC) and semivolatile organic compound (SVOC) contamination, in November 2023 and January 2024, the U.S. Geological Survey (USGS), in the cooperation with the EPA, collected paired surface water and porewater samples from sampling locations along an unnamed tributary, and groundwater samples from monitoring wells at the Garland Creosoting Site. In total, nine paired porewater and surface water samples (along with one additional surface water sample) were collected from the unnamed tributary. Groundwater-quality samples were collected from five monitoring wells at the Site.

The Triangle Chemical Company Superfund site, in Orange County, Texas, was a chemical mixing and blending facility in the 1970s. According to the Environmental Protection Agency (EPA), poor waste management practices resulted in soil and groundwater contamination and fish-kills in Coon Bayou (U.S. Environmental Protection Agency, 2023). The Five-Year Review of the Triangle Superfund Site indicated groundwater in the upper water-bearing zone might be migrating off-site toward the southwest (U.S. Environmental Protection Agency, 2016). There are concerns regarding potential risks to human health from contaminated soil vapor in existing or future structures in the area. To evaluate the status of volatile organic compound contamination, the U.S. Geological Survey (USGS), in cooperation with the EPA collected passive soil-gas samples, indoor air quality samples, and groundwater-quality samples at the Triangle Chemical Company Superfund Site. In July 2021, passive soil-gas samplers were deployed at 12 locations which collected samples over a 22-day period and indoor air quality samples were collected at two locations immediately southwest of the Site. Samples for 1,4-dioxane were collected from eight monitoring wells at the site on June 1, 2022. To complement and expand on the July 2021 sampling, the USGS deployed passive soil-gas samplers at 22 additional locations over a 14-day period and collected indoor air quality samples at an additional two locations at the site in May 2023. Passive soil-gas and indoor air quality samples collected during these periods were analyzed for a suite of volatile organic compounds (VOCs). This dataset includes the environmental and quality-control data obtained from July 2021 through June 2023 from the passive soil-gas vapor, indoor air quality, and groundwater-quality samples collected at each sample location.

The Highlands Acid Pit Superfund site (hereinafter referred to as "the site") is located on a peninsula on the eastern bank of the San Jacinto River in the town of Highlands in Harris County, Texas. The site is bordered by Grennel Slough to the west, Clear Lake to the south, flooded former sand pits to the northeast and east, and private properties to the north. During the 1950s, industrial waste from refinery operations was disposed of in an excavated sand pit at the site, resulting in contamination of soil and shallow groundwater. Historical and ongoing groundwater monitoring at the site has revealed that arsenic and benzene are present and exceed protective concentration levels. It is unknown if vapor migration from contaminated groundwater is occurring or if the site poses a vapor intrusion concern for private properties adjacent to the site. To evaluate the status of soil-gas quality, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (EPA), deployed and retrieved soil-gas samples from 43 discrete locations at the site in April 2025. This dataset includes soil-gas sample locations and environmental and quality-control soil-gas data sampling results for a suite of volatile organic compounds at the site.

The Falcon Refinery Superfund Site (hereinafter referred to as “the Site”) is located in San Patricio County near Ingleside, Texas. The Site occupies approximately 104 noncontiguous acres that are divided into the North Site, the South Site, and a barge dock facility. Surface water drainage from the Site enters wetlands along the southeastern section of the property associated with this abandoned refinery. The wetlands connect to the Intracoastal Waterway and Redfish Bay, which connects Corpus Christi Bay to the Gulf of Mexico. In addition to the abandoned refinery, the site currently (June 2024) includes seven large (greater than 50 feet in diameter) aboveground storage tanks that are in the process of being disassembled and repaired or taken off-site. At full capacity, the refinery could process as much as 40,000 barrels of oil per day, and the primary products consisted of naphtha, jet fuel, kerosene, diesel, and fuel oil. Refinery activities and on-site waste disposal practices have contaminated the Site with hazardous chemicals (U.S. Environmental Protection Agency [EPA], 2017). To characterize the current status of groundwater quality, the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA), collected water-quality samples from 11 monitoring wells at the Site in January 2024. The samples were analyzed for volatile organic compounds, semivolatile organic compounds, metals (major ions and trace elements, including mercury), and total dissolved solids.

In September 2022, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected groundwater-level elevation data and water-quality samples from monitoring wells at the Many Diversified Interests, Inc. Superfund Site in Houston, Texas to evaluate the status of groundwater contamination at this previously remediated site. The dataset includes groundwater-level elevations and field properties measured at 12 monitoring wells along with data from environmental and quality assurance and quality control water-quality samples collected at each well. Water-quality samples were analyzed for arsenic, manganese, molybdenum, benzo(a)pyrene, and petroleum hydrocarbons.

The Ouachita-Nevada Wood Treaters Superfund Site is a former wood-treatment facility located on approximately five acres of undeveloped land along the west side of North Main Street in Reader, Arkansas in Ouachita County. The former facility used wood treatment products containing pentachlorophenol (PCP) and heating oil, a chromium-copper-arsenate solution, and a mixture of diesel fuel and motor oil. Releases of these wood treatment products resulted in soil and groundwater contamination in the shallow aquifer beneath the site (U.S. Environmental Protection Agency [EPA], 2021). In October 2024, the U.S. Geological Survey (USGS), in cooperation with the EPA, collected groundwater-level altitude data and water-quality samples from 18 monitoring wells at the Ouachita-Nevada Wood Treaters Superfund Site in Reader, Arkansas. These data were collected to evaluate the spatial distribution of semivolatile organic compounds (SVOCs) and dioxins and furans at the site. This dataset includes groundwater-level altitudes, field properties, and environmental and quality-control water-quality data. Water-quality samples were analyzed for a suite of SVOCs and for unfiltered (total) and filtered (dissolved) concentrations of dioxins and furans.

This dataset presents analytical results for laboratory and field tests conducted during 2015–19 as part of a bioremediation study in the wetland study area at Standard Chlorine of Delaware, Inc. Superfund site. Included in the dataset are (1) volatile organic compound and metal concentrations from field sampling in the wetland area, (2) results from in situ microcosms in the reactive barriers and control areas, and (3) volatile organic compound concentrations from laboratory experiments to test reactive mixtures for a barrier.