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USGS2015

Control of nitrogen and phosphorus transport by reservoirs in agricultural landscapes

Reservoirs often receive excess nitrogen (N) and phosphorus (P) lost from agricultural land, and may subsequently influence N and P delivery to inland and coastal waters through internal processes such as nutrient burial, denitrification, and nutrient turnover. Currently there is a need to better understand how reservoirs affect nutrient transport in agricultural landscapes, where few prior studies have provided joint views on the variation in net retention/loss among reservoirs, the role of reservoirs apart from natural lakes, and differences in effects on N versus P, especially over time frames >1 year. To address these needs, we compiled water quality data from many rivers in intermediate-to-large drainages of the Midwestern US, including tributaries to the Upper Mississippi River, Great Lakes, and Ohio River Basins, where cropland often covers >50 % of the contributing area. Incorporating 18 years of data (1990–2007), effects of reservoirs on river nutrient transport were examined using comparisons between reservoir out- flow sites and unimpeded river sites (N = 869, including 100 reservoir outflow sites) supported by mass balance analysis of individual reservoirs (n = 17). Reservoir outflows sites commonly had 20 % lower annual yields (mass per catchment area per year) of total N and total P (TP) than unimpeded rivers after accounting for cropland coverage. Reservoir outflow sites also had lower interannual variability in TP yields. The mass balance approach confirmed net N losses in reservoirs, suggesting denitrification of agricultural N, or N burial in sediments. Net retention of P ranged more widely, and multiple systems showed net P export, providing new evidence that legacy P within reservoir systems may mobilize over the long-term. Our results indicate that reservoirs broadly influence the downstream transport of N and P through agricultural river networks, including networks where natural lakes and wetlands are relatively scarce. This calls for a more complete understanding of agricultural reservoirs as open, connected features of river networks where biogeochemical processes are often influential to downstream water quality, but potentially sensitive to changes associated with sedimentation, eutrophication, infrastructure aging, and reservoir management.

Biogeochemistry↗

USGS1982

Dams, reservoirs, and withdrawals for water supply; historic trends

The U.S. Geological Survey (USGS) from time to time has published an inventory of major reservoirs and controlled natural lakes. The latest available USGS report indicated that as of 1963, usable capacity in major reservoirs (those having 5 ,000 acre-ft of usable capacity) totaled 359 million acre-ft. The growth rate for total capacity averaged about 80%/decade until the early 1960's. Since then, reservoir capacity has increased at a markedly slower rate, the effects of approaching an asymptotic limit on capacity in some areas, compounded, by increasing public aversion toward reservoir construction. The trend toward non-structural measures places greater dependence on management skill and on better forecasts. At some point, the potentials of conservation and better management will become less effective than reservoirs and there will again be an upward trend in reservoir capacity. (Lantz-PTT)

Open-File Report↗

USGS2013

Chronological history of zebra and quagga mussels (Dreissenidae) in North America, 1988-2010

An unprecedented invasion began in North America in the mid-/late-1980s when two Eurasian mussel species, Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel), became established in Laurentian Great Lakes. It is believed that Lake Erie was the initial location of establishment for both species, and within 3 years, zebra mussels had been found in all the Great Lakes. Since 1986, the combined distribution of two dreissenids has expanded throughout the Great Lakes region and the St. Lawrence River in Canada and also in the United States from the Great Lakes to the Mississippi Basin including Arkansas, Cumberland, Illinois, Missouri, Ohio, and Tennessee river basins. The distribution of dreissenid mussels in the Atlantic drainage has been limited to the Hudson and Susquehanna rivers. In the western United States, the quagga mussel established a large population in the lower Colorado River and spread to reservoirs in Arizona, California, Colorado, Nevada, and Utah. Overall, dreissenid species have been documented in 131 river systems and 772 inland lakes, reservoirs, and impoundments in the United States.

Book chapter↗

USGS2018

Development of new information to inform fish passage decisions at the Yale and Merwin hydro projects on the Lewis River, Washington—Final report, 2018

The reintroduction of extirpated salmonids to historically occupied areas is becoming increasingly common as a conservation and recovery strategy. Often, reintroductions are implemented after the factors that originally led to species extirpation have been reduced, eliminated, or mitigated. For anadromous Oncorhynchus spp. (Pacific salmon) and O. mykiss (steelhead), addressing barriers to migration, which have been a primary factor in the decline and extirpation of many populations, has been an integral component of recovery efforts. Mitigation has included barrier removal, developing fish passage opportunities, and (or) actively trapping and hauling juvenile and adult anadromous salmonids around barriers. With any reintroduction, there are a number of concerns regarding the ecological impact of the reintroduction efforts. Three of the main tenets to consider when assessing reintroductions are (1) the potential benefits if reintroduction is successful, (2) the biological risk through interactions of reintroduced strains with existing populations, and (3) the factors potentially limiting a successful reintroduction. This report focuses on information and data to address the second and third factors as they apply to the upper Lewis River in Washington. The upper Lewis River historically contained wild populations of O. tshawytscha (Chinook salmon), O. kisutch (coho salmon), and steelhead. These populations were extirpated after completion of hydropower facilities on Lake Merwin in 1932, Yale Lake in 1953, and Swift Reservoir in 1958, which prevented fish from migrating to and from ocean environments. However, recent licenses issued by the Federal Energy Regulatory Commission require the installation and operation of an upstream fish passage facility at Lake Merwin and a downstream fish passage facility at Swift Reservoir. The licenses were developed in consultation with the National Marine Fisheries Service and the U.S. Fish and Wildlife Service. The overarching goal of this fish reintroduction project is to establish viable, self-sustaining, naturally reproducing, harvestable populations of spring Chinook salmon, winter steelhead, and coho salmon at levels higher than minimum viable populations. This report uses a combination of field data and existing information to address six key objectives related to the reintroduction in order to inform decisions about passage at the Yale Lake and Lake Merwin hydropower projects. The objectives are (1) a review of information relevant to anadromous fish reintroduction and full fish passage; (2) a habitat assessment of tributaries to Swift Reservoir, Yale Lake, and Lake Merwin; (3) a field study to assess adult potential for spawning success; (4) an assessment of juvenile production and outmigration success; (5) a Lake Merwin predator impact study; and (6) a set of studies assessing interactions between anadromous and resident fish.

Washington↗

USGS2025

Framework developed for geomorphic mapping of Fern Ridge Lake, Oregon, 2023

The construction and operation of large reservoirs in the Willamette River Basin, Oregon, influences important cultural, biological, and other natural or economic resources in affected river corridors. The present-day landforms and cover within the reservoirs have been shaped by a variety of processes, including the pre-dam valley setting and geomorphic processes related to dam operations. Maps of reservoir geomorphic process domains, landforms, and cover provide a foundation for understanding how erosion and deposition processes in or near the reservoirs may affect cultural resources. Detailed geomorphic mapping of Fern Ridge Lake in 2023 provides a basis for evaluating geomorphic processes and patterns of sediment transfer within the reservoir. These processes are related to geomorphic and hydroclimatic conditions as well as annual lake level fluctuation for seasonal flood-control operations. This geomorphic mapping also provides an inventory of existing landforms from which to evaluate the spatial and temporal geomorphic change over time. Digital maps based on high-resolution digital surface models and orthophotographs acquired during low-pool conditions in 2023 extend over an area of about 30 square kilometers (km) upstream of the Fern Ridge Dam. The mapping framework has 3 main components consisting of several subtypes: 5 process domains, 18 landforms, and 7 cover categories. The overarching classification structure is tied to the process domains, which correspond to dissimilar regions of the reservoir that have distinct landforms and broadly similar suites of geomorphic processes. This document describes the geomorphic mapping framework for the reservoir at Fern Ridge Lake and provides mapping unit descriptions including delineation criteria, hypothesized formation processes inferred from remote-sensing and field observations and the literature, and relevance during drawdown operations.

Oregon↗

USGS1991

Physiological response of largemouth bass to angling stress

The physiological effects of catch-and-release fishing on largemouth bass Micropterus salmoides from Lake Powell and Mantua Reservoir, Utah, were evaluated, and an estimate of the time needed for recovery from hooking stress was obtained. Fatigue in Lake Powell fish, as indicated by elevated blood lactate, was directly proportional to hooking time (1–5 min) and water temperature, but recovery from the hyperlacticemia was relatively rapid (about 24 h). Hyperglycemia, an indicator of stress hormone production, did not occur in largemouth bass hooked and played for 1–5 min in the coldest water (11–13°C), was moderate in fish hooked and played at l6–20°C, and was severe in fish played for 5 min at 28–30°C. Fish held for recovery in live cages suffered further hyperglycemia, presumably because of the stress of confinement. Ionoregulation, as indicated by relatively stable plasma chloride values, was not immediately affected in largemouth bass caught at water temperatures of 11–13°C or 28–30°C, but an unusual hyperchloremia developed in fish hooked and played at 16–20°C. During recovery, the expected progressive hypochloremia developed. Plasma osmolality was somewhat affected by hooking at all water temperatures tested, but recovery was almost complete within about 8 h. Mantua Reservoir fish were hooked and played only at water temperatures of 23–26°C. The hyperlacticemia and hyperglycemia that occurred were generally more severe than in the Lake Powell fish hooked and played at either 16–20°C or 28–30°C. However, effects on plasma chloride and osmolality were similar to those occurring in Lake Powell fish.

Transactions of the American Fisheries Society↗

USGS2013

Estimation of reservoir storage capacity using multibeam sonar and terrestrial lidar, Randy Poynter Lake, Rockdale County, Georgia, 2012

The U.S. Geological Survey, in cooperation with the Rockdale County Department of Water Resources, conducted a bathymetric and topographic survey of Randy Poynter Lake in northern Georgia in 2012. The Randy Poynter Lake watershed drains surface area from Rockdale, Gwinnett, and Walton Counties. The reservoir serves as the water supply for the Conyers-Rockdale Big Haynes Impoundment Authority. The Randy Poynter reservoir was surveyed to prepare a current bathymetric map and determine storage capacities at specified water-surface elevations. Topographic and bathymetric data were collected using a marine-based mobile mapping unit to estimate storage capacity. The marine-based mobile mapping unit operates with several components: multibeam echosounder, singlebeam echosounder, light detection and ranging system, navigation and motion-sensing system, and data acquisition computer. All data were processed and combined to develop a triangulated irregular network, a reservoir capacity table, and a bathymetric contour map.

Georgia↗

USGS2016

The Water-Quality Partnership for National Parks—U.S. Geological Survey and National Park Service, 1998–2016

The U.S. Geological Survey (USGS) and the National Park Service (NPS) work together through the USGS–NPS Water-Quality Partnership to support a broad range of policy and management needs related to high-priority water-quality issues in national parks. The program was initiated in 1998 as part of the Clean Water Action Plan, a Presidential initiative to commemorate the 25th anniversary of the Clean Water Act. Partnership projects are developed jointly by the USGS and the NPS. Studies are conducted by the USGS and findings are used by the NPS to guide policy and management actions aimed at protecting and improving water quality. The National Park Service manages many of our Nation’s most highly valued aquatic systems across the country, including portions of the Great Lakes, ocean and coastal zones, historic canals, reservoirs, large rivers, high-elevation lakes and streams, geysers, springs, and wetlands. So far, the Water-Quality Partnership has undertaken 217 projects in 119 national parks. In each project, USGS studies and assessments ( http://water.usgs.gov/nps_partnership/pubs.php ) have supported science-based management by the NPS to protect and improve water quality in parks. Some of the current projects are highlighted in the NPS Call to Action Centennial initiative, Crystal Clear, which celebrates national park water-resource efforts to ensure clean water for the next century of park management ( http://www.nature.nps.gov/water/crystalclear/ ). New projects are proposed each year by USGS scientists working in collaboration with NPS staff in specific parks. Project selection is highly competitive, with an average of only eight new projects funded each year out of approximately 75 proposals that are submitted. Since the beginning of the Partnership in 1998, 189 publications detailing project findings have been completed. The 217 studies have been conducted in 119 NPS-administered lands, extending from Denali National Park and Preserve in Alaska to Everglades National Park in Florida, and from Acadia National Park in the Northeast to park lands in Hawaii and Pacific Island territories in the West. Project goals range from periodic stream monitoring, to determining the occurrence and concentrations of contaminants and the potential for them to exceed human health or aquatic life criteria, to conducting interpretive studies to evaluate the effect(s) on or vulnerability of national park resources to visitor usage and other natural and anthropogenic activities.

Fact Sheet↗

USGS2007

Sediment storage and severity of contamination in a shallow reservoir affected by historical lead and zinc mining

A combination of sediment-thickness measurement and bottom-sediment coring was used to investigate sediment storage and severity of contamination in Empire Lake (Kansas), a shallow reservoir affected by historical Pb and Zn mining. Cd, Pb, and Zn concentrations in the contaminated bottom sediment typically exceeded baseline concentrations by at least an order of magnitude. Moreover, the concentrations of Cd, Pb, and Zn typically far exceeded probable-effects guidelines, which represent the concentrations above which toxic biological effects usually or frequently occur. Despite a pre-1954 decrease in sediment concentrations likely related to the end of major mining activity upstream by about 1920, concentrations have remained relatively stable and persistently greater than the probable-effects guidelines for at least the last 50 years. Cesium-137 evidence from sediment cores indicated that most of the bottom sediment in the reservoir was deposited prior to 1954. Thus, the ability of the reservoir to store the contaminated sediment has declined over time. Because of the limited storage capacity, Empire Lake likely is a net source of contaminated sediment during high-inflow periods. The contaminated sediment that passes through, or originates from, Empire Lake will be deposited in downstream environments likely as far as Grand Lake O' the Cherokees (Oklahoma). ?? 2007 Springer-Verlag.

Environmental Geology↗

USGS1983

Fish abundance and population stability in a reservoir tailwater and an unregulated headwater stream

Fish abundance and population stability were compared in the tailwater and in an unregulated tributary of Barren River Lake, a flood control reservoir in south central Kentucky. Fish abundance was greater in the tailwater near the dam and was dominated by three species common in the reservoir: gizzard shad ( Dorosoma cepedianum ), bluegills ( Lepomis macrochirus ), and white crappies ( Pomoxis annularis ). Three riverine suckers were less abundant in the tailwater than in the unregulated stream: northern hog suckers ( Hypentelium nigricans ), black redhorse ( Moxostoma duquesnei ), and golden redhorse ( Moxostoma erythrurum ). The fish populations in the tailwater, particularly common carp ( Cyprinus carpio ), northern hog suckers, black redhorse, and golden redhorse, were less stable than those in the unregulated stream. Population stability is defined as the extent to which fish remain in a stream section. This study suggests that the occurrence of reservoir species in the tailwater was the result of fish passage from the reservoir during high discharges in fall and winter. Reservoir operations (altered flow, low summer water temperature, and poor summer water quality) probably were responsible for the unstable populations of common carp and riverine suckers in the tailwater.

Kentucky↗

USGS2023

The Colorado River water crisis: Its origin and the future

During much of the 21st century, natural runoff in the Colorado River basin has declined, while consumption has remained relatively constant, leading to historically low reservoir storage. Between January 2000 and April 2023, the amount of water stored in Lake Mead and Lake Powell, the two largest reservoirs in the United States, declined by 33.5 million acre feet (41.3 billion cubic meters). As of April 2023, total basin-wide storage was sufficient to support the 21st century average rate of basin-wide consumption for only 15 months. Runoff in spring 2023 is predicted to be large, providing a short-term reprieve. However, it will take four to five additional unusually wet years in succession to refill Lake Powell and Lake Mead if basin-wide water use remains unchanged. Increasing evapotranspiration and dry soils associated with global climate change makes such a scenario unlikely. To stabilize reservoir storage, basin-wide use needs to equal modern runoff. To recover reservoir storage, basin-wide use needs to decline even more. Based on 21st century average runoff, a 13%–20% decline in basin-wide use would allow for stabilization and some reservoir storage recovery. Future policy debate about reservoir operations will inevitably concern whether most, or all, reservoir storage should be in Lake Mead or in Lake Powell. The choice of one or the other will result in significantly different environmental and recreational outcomes for Glen Canyon and the Grand Canyon.

Arizona, Baja California, California, Colorado, Ne↗

USGS2008

Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling

Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and sediments in the reservoir. The purpose of this study was to assess if release of DOC from reservoir sediments containing ferric chloride coagulant was a significant source of DOC to the reservoir. We examined the source-specific contributions of DOC using a profiling system to measure the in situ distribution of optical properties of absorption and fluorescence at various locations in the reservoir. Vertical optical profiles were coupled with discrete water samples measured in the laboratory for DOC concentration and optical properties: absorption spectra and excitation emission matrix spectra (EEMs). Modeling the in situ optical data permitted estimation of the bulk DOC profile in the reservoir as well as separation into source-specific contributions. Analysis of the source-specific profiles and their associated optical characteristics indicated that the sedimentary source of DOC to the reservoir is significant and that this DOC is labile in the reservoir. We conclude that optical profiling is a useful technique for understanding complex biogeochemical processes in a reservoir.

Lake and Reservoir Management↗

USGS2013

Water levels shape fishing participation in flood-control reservoirs

We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

Mississippi↗

USGS1993

Hydrologic data collected in Maumelle and Winona reservoir systems, central Arkansas, May 1989 through October 1992

Physical, chemical, and biological water-quality data were collected and compiled for sites located in the Lakes Maumelle and Winona reservoir systems May 5, 1989, to October 30, 1992. Data were collected in order to establish a comprehensive water-quality data base for the two systems and will be used in water-quality interpretive chemical variables (temperature, pH, specific conductance, dissolved oxygen, light transparency, and penetration); solids, and major cations and anions); trace metals; organics (pesticides and industrial organic chemicals); and biological components (bacteria and chlorophyll-a); and nutrients, trace metals, and organic contaminants in bed material. Reservoir sedimentation was measured by comparing fathometry measurements taken during the study to pre-impoundment tophographic maps.

Open-File Report↗

USGS2001

River and Reservoir Operations Model, Truckee River basin, California and Nevada, 1998

The demand for all uses of water in the Truckee River Basin, California and Nevada, commonly is greater than can be supplied. Storage reservoirs in the system have a maximum effective total capacity equivalent to less than two years of average river flows, so longer-term droughts can result in substantial water-supply shortages for irrigation and municipal users and may stress fish and wildlife ecosystems. Title II of Public Law (P.L.) 101-618, the Truckee?Carson?Pyramid Lake Water Rights Settlement Act of 1990, provides a foundation for negotiating and developing operating criteria, known as the Truckee River Operating Agreement (TROA), to balance interstate and interbasin allocation of water rights among the many interests competing for water from the Truckee River. In addition to TROA, the Truckee River Water Quality Settlement Agreement (WQSA), signed in 1996, provides for acquisition of water rights to resolve water-quality problems during low flows along the Truckee River in Nevada. Efficient execution of many of the planning, management, or environmental assessment requirements of TROA and WQSA will require detailed water-resources data coupled with sound analytical tools. Analytical modeling tools constructed and evaluated with such data could help assess effects of alternative operational scenarios related to reservoir and river operations, water-rights transfers, and changes in irrigation practices. The Truckee?Carson Program of the U.S. Geological Survey, to support U.S. Department of the Interior implementation of P.L. 101-618, is developing a modeling system to support efficient water-resources planning, management, and allocation. The daily operations model documented herein is a part of the modeling system that includes a database management program, a graphical user interface program, and a program with modules that simulate river/reservoir operations and a variety of hydrologic processes. The operations module is capable of simulating lake/ reservoir and river operations including diversion of Truckee River water to the Truckee Canal for transport to the Carson River Basin. In addition to the operations and streamflow-routing modules, the modeling system is structured to allow integration of other modules, such as water-quality and precipitation-runoff modules. The USGS Truckee River Basin operations model was designed to provide simulations that allow comparison of the effects of alternative management practices or allocations on streamflow or reservoir storages in the Truckee River Basin over long periods of time. Because the model was not intended to reproduce historical streamflow or reservoir storage values, a traditional calibration that includes statistical comparisons of observed and simulated values would be problematic with this model and database. This report describes a chronology and background of decrees, agreements, and laws that affect Truckee River operational practices; the construction of the Truckee River daily operations model; the simulation of Truckee River Basin operations, both current and proposed under the draft TROA and WQSA; and suggested model improvements and limitations. The daily operations model uses Hydrological Simulation Program?FORTRAN (HSPF) to simulate flow-routing and reservoir and river operations. The operations model simulates reservoir and river operations that govern streamflow in the Truckee River from Lake Tahoe to Pyramid Lake, including diversions through the Truckee Canal to Lahontan Reservoir in the Carson River Basin. A general overview is provided of daily operations and their simulation. Supplemental information that documents the extremely complex operating rules simulated by the model is available.

Water-Resources Investigations Report↗

USGS1992

Lake acidity and mercury content of fish in Darwin National Reserve, Russia

Darwin National Reserve is a protected natural area on the north-west shore of the Rybinsk Reservoir, 350 km north of Moscow. In June 1989, six lakes in the Reserve and the reservoir were surveyed to assess lake acidity and the mercury content of perch, Perca fluviatilis . Five were seepage lakes with no permanent inlets or outlets and one was a drainage lake with both an inlet and an outlet. The seepage lakes were acidic (mean pH 4·6–4·8) and varied in colour from 20 to 200 Hazen units. The drainage lake and reservoir were alkaline (mean pH 8·0–8·1) and colour spanned a similar range. The mean mercury content of perch dorsal epaxial muscle ranged from 0·5 to 1·1 μg g −1 wet weight in the five acidic lakes and from 0·1 to 0·2 μg g −1 in the alkaline lakes. Fish mercury contentwas negatively correlated with lake pH ( r = −0·93, P = 0·002)if all waters were considered together, and positively correlated with apparent colour ( r = 0·91, P = 0·03) in the seepage lakes.

Environmental Pollution↗

USGS2010

Importance of benthic production to fish populations in Lake Mead prior to the establishment of quagga mussels

Limnologists recently have developed an interest in quantifying benthic resource contributions to higher-level consumers. Much of this research focuses on natural lakes with very little research in reservoirs. In this study, we provide a contemporary snapshot of the food web structure of Lake Mead to evaluate the contribution of benthic resources to fish consumers. In addition, we document the available food to fishes on soft sediments and changes to the invertebrate community over 2 time periods. Benthic invertebrate food availability for fishes is greater in Las Vegas Bay than Overton Arm. Las Vegas Bay is dominated by oligochaetes, whose biomass increased with depth, while Overton Arm is dominated by chironomids, whose biomass did not change with depth. Diet and isotopic measurements indicate the fish community largely relies on benthic resources regardless of basin (Las Vegas Bay >80%; Overton Arm >92%); however, the threadfin shad likely contribute more to largemouth and striped bass production in Overton Arm versus Las Vegas Bay. A 2-time period analysis, pre and post quagga mussel establishment and during lake level declines, suggests there is no change in the density of benthic invertebrates in Boulder Basin, but there were greater abundances of select taxa in this basin by season and depth than in other basins. Given the potential of alterations as a result of the expansion of quagga mussel and the reliance of the fishery on benthic resources, future investigation of basin specific, benthic processes is recommended.

Nevada↗

USGS2025

Geochemical assessment of the suitability of converting a coal-fired power plant reservoir to a drinking-water reservoir

There is an increasing need for additional water storage in the United States, especially in arid regions. Alternatives like decommissioned power plant raw-water reservoirs would be cheaper to use than creating new reservoirs; however, the biogeochemical pollution risk of these reservoirs is not well understood. The San Juan Generating Station power plant and the associated reservoir will be used as a sediment-settling basin to store drinking water. To evaluate whether the reservoir is appropriate for this use, inorganic and organic constituents of concern were measured in reservoir sediment cores, pore water, and reservoir water in 2020. Forty-six percent of sediment arsenic concentrations measured in core subsamples (8 to 12 mg/kg) were slightly above the New Mexico residential cancer threshold for soil of 7.07 mg/kg. One sediment sample contained elevated total barium concentrations (6020 mg/kg). The organic compounds analyzed were either below detection limits or below regulatory thresholds. Reservoir water had one sample with arsenic greater than the drinking water standard (10 µg/L). Overall, the reservoir sediment inorganic and organic analyte concentrations are within acceptable ranges. The few samples that have elevated concentrations are not of a sufficient magnitude that dilution and/or treatment processes would preclude the use of the reservoir for water storage. Our findings show potential for use of former coal power station raw-water reservoirs as drinking-water reservoirs after plant closure.

New Mexico↗