As part of the Navajo-Gallup Water Supply Project, the Bureau of Reclamation was tasked with design and construction of infrastructure to treat and deliver potable water to the communities of Navajo Nation, parts of the Jicarilla Apache Nation, and City of Gallup. The Bureau of Reclamation has been evaluating the Public Service Company of New Mexico's (PNM) San Juan Generating Station (SJGS) reservoir as a possible water storage and sediment settling basin for the Navajo-Gallup Water Supply Project. The U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation, was tasked with collecting reservoir sediment cores and pore water from SJGS reservoir. This data release contains reservoir sediment organic chemistry results.

This study was done because elevated concentrations of metals including aluminum, arsenic, and lead were identified by Navajo Nation EPA staff in the San Juan River from below the Navajo Dam, through the Navajo Nation to Mexican Hat, Utah in the Four Corners Region of the United States (Colorado, Arizona, New Mexico, Utah). An interdisciplinary team applied approaches and principles of geology, geochemistry, geomorphology, hydrology, and statistics to gain a better understanding of the tributaries supplying the source(s) of metals to the San Juan River. Water samples were collected in single-siphon samples and by grab sample at 59 ephemeral and perennial tributaries to the San Juan River in 2021 and 2022. Eighteen surface water sites along the San Juan River were sampled as grab samples in 2021 and 2022 and fifteen sites along the San Juan River were sampled by equal width increment and composited in a churn during a baseflow synoptic sampling campaign in February 2021. A total of 765 unfiltered and 282 filtered samples were analyzed for major and trace cations. All samples were analyzed through the USGS Analytical Chemistry Laboratory in Denver, Colorado (Taggart, 2022; USGS, 2023 Method 37).

This dataset includes concentrations chloride and sulfate in porewater from piston and gravity cores collected in September 2019 offshore of south-central California aboard the R/V Bold Horizon. This dataset is one of several collected as part of the Bureau of Ocean Energy Management (BOEM)-funded California Deepwater Investigations and Groundtruthing (Cal DIG I) project. The purpose of the study is to assess shallow geohazards, benthic habitats, and thereby the potential for alternative energy infrastructure (namely floating wind turbines) offshore south-central California due to its proximity to power grid infrastructure associated with the Morro Bay power plant. These core data provide information about the geology of the seafloor and shallow subsurface offshore of the south-central California coast.

Sediment traps were deployed in tributaries to the San Juan River during 2021 and 2022. These traps collected sediment during storm events that typically occur as monsoonal convective storms from June to September. Because of the rural nature of the watershed, sediment traps were collected every 3 weeks so the sediment collected is a composite of that time period. The date listed is the date the trap was collected. This dataset includes the chemical concentrations of the sediment samples. Major ions are reported in weight percentage, while all other elements are reported in parts per million. Samples were fused at 750°C with sodium peroxide and the fusion cake dissolved in a dilute nitric acid. The resulting solution was analyzed by ICP-OES and ICP-MS. This method was done to include all of the rare earth elements. Results from this method may differ slightly from the results in the 49-element analysis because of the differences in digestion procedure. The 60 element dataset includes aluminum, calcium, iron, potassium, magnesium, phosphorous, sulfur, silicon, titanium, silver, arsenic, boron, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, dysprosium, erbium, europium, gallium, gadolinium, germanium, hafnium, holmium, indium, lanthanum, lithium, lutetium, manganese, molybdenum, niobium, neodymium, nickel, lead, praseodymium, rubidium, antimony, scandium, selenium, samarium, tin, strontium, tantalum, terbium, tellurium, thorium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zircon.

Sediment traps were deployed in tributaries to the San Juan River during 2021 and 2022. These traps collected sediment during storm events that typically occur as monsoonal convective storms from June to September. Because of the rural nature of the watershed, sediment traps were collected every 3 weeks so the sediment collected is a composite of that time period. The date listed is the date the trap was collected. This dataset includes the chemical concentrations of the sediment samples. Major ions are reported in weight percentage, while all other elements are reported in parts per million. Sediment samples in this dataset are digested using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids at low temperature. The resulting solution is analyzed by ICP-OES and ICP-MS. The 49 element dataset includes aluminum, calcium, iron, potassium, magnesium, sodium, sulfur, silicon, titanium, silver, arsenic, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, gallium, hafnium, indium, lanthanum, lithium, lutetium, manganese, molybdenum, niobium, nickel, phosphorous, lead, rubidium, antimony, scandium, selenium, tin, strontium, tantalum, terbium, tellurium, thorium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zircon.

Sediment traps were deployed in thirty-three ephemeral and perennial tributaries to the San Juan River during 2021 and 2022. This dataset includes the chemical concentrations of the sediment samples collected in sediment traps during storm events. These traps collected sediment during storm events that typically occur as monsoonal convective storms from June to September. Because of the rural nature of the watershed, sediment traps were collected every 3 weeks so the sediment collected is a composite of that time period. The date listed is the date the trap was collected. Major ions are reported in weight percentage, while all other elements are reported in parts per million. Each sample was split and analyzed following two different methods of sample preparation. In one method, the sample is decomposed using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids at low temperature. In the second method, samples are fused at 750°C with sodium peroxide and the fusion cake dissolved in a dilute nitric acid. The resulting solution for both methods is analyzed by ICP-OES and ICP-MS.

The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present laboratory measured spectral data associated with discrete surface water samples collected as part of both the CMS and boat mapping sampling efforts. All laboratory-based measurement presented herein were conducted by the U.S. Geological Survey (USGS) Organic Matter Research Laboratory (OMRL) in Sacramento, Calif. The machine-readable (comma separated value, *.csv) files presented herein include spectral data collected using two different instruments: 1) Laboratory-based absorbance and fluorescence measurements on filtered water using an Aqualog (Hansen and others, 2018) and 2) Laboratory-based absorption measurements using a Varian Cary spectrophotometer on particulate samples collected on glass fiber filters (Kishino and others, 1985; Roesler, 1998). The reported spectral data includes: 1) fluorescence intensities across a wide range of excitation (240 to 800 nm) and emission (250 to 800 nm) wavelengths expressed as an excitation-emission matrix (EEM), 2) absorbance of light (from 239 nm to 800 nm) due to dissolved and colloidal substances, and 3) absorption coefficients (from 350 nm to 715 nm) for particulates using the quantitative filter technique (QFT).

Elemental chemistry and weight percent of the less than 0.063 mm fine sediment fraction are reported for surface sediments from shoals, the ebb tide delta, local tributaries, and inland rivers that carry sediment to San Francisco Bay, California.

This dataset contains the results of batch experiments to evaluate the mobility of major and trace elements from the Aztec Drinking Water Reservoir #1 sediments. The sediments were exposed to 3 different environmentally relevant reagents, deionized water, bicarbonate, and acetic acid.

Elevated concentrations of metals including aluminum, arsenic, and lead were identified by Navajo Nation Environmental Protection Agency staff in the San Juan River from below the Navajo Dam, through the Navajo Nation to Mexican Hat, Utah in the Four Corners Region of the United States (Colorado, Arizona, New Mexico, Utah). An interdisciplinary team applied approaches and principles of geology, geochemistry, geomorphology, hydrology, and statistics to gain a better understanding of the tributaries supplying the source(s) of metals to the San Juan River. Water samples that were filtered with 0.45 micron filters were collected in single-siphon samplers and by grab sample at 41 ephemeral and perennial tributaries to the San Juan River in 2021 and 2022. Eighteen surface water sites along the San Juan River were sampled as grab samples in 2021 and 2022. Samples were chosen randomly for filtration to compare to unfiltered sample results. The samples were analyzed for major and trace cations by inductively coupled plasma emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) at the US Geological Survey Analytical Chemistry Laboratory in Denver, Colorado. A sub-set of samples includes data for pH and alkalinity as calcium carbonate. A total of 282 filtered samples were collected.