Agriculture, Livestock, and Aquaculture

Adverse effects of selenium (Se) on fish and waterfowl in wetlands receiving agricultural drainage occurred in the 1980s in the San Joaquin Valley of California. The identified mechanisms of Se enrichment helped resolve Se toxicity problems associated with irrigated agriculture in the arid West. Bioaccumulation of Se in ancient marine sediments is postulated as a primary pathway in source rocks.

The San Francisco Bay-Delta receives selenium (Se) internally from oil refineries and externally through riverine agricultural discharges. Predator species considered at risk from Se consume the estuary’s dominant bivalve, C. amurensis, an efficient bioaccumulator of Se. Modeling predicts site-specific ecological risk and derives a range of protective Se concentrations for use by decision-makers.

In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. This page discusses the first two decadal cycles of NAWQA research from 1991 through 2012.

All water naturally contains dissolved solids that can make it "brackish" or distastefully salty. The amount of freshwater for drinking-water, agricultural, industrial, and environmental needs has declined in many areas and has led to concerns about future availability. The USGS conducted a national assessment of brackish aquifers that could supplement or replace freshwater sources.

Reconnecting people and water is an increasingly important goal in many urban areas. Parks, urban trails, boat ramps, and urban agriculture all are ways that an urban population can interact with nature and improve quality of life. USGS is participating in gathering the information that will make these projects possible.

A solar distillation loop apparatus includes a first pipe section disposed on a ground surface, the first pipe section including a substantially straight portion and elevated portions on each end of the substantially straight portion, an impure water inflow coupling and an impure water outflow coupling. (Full details provided by the U.S. Patent and Trademark Office website.)

Methyl halide contaminants are oxidized in a reaction chamber containing a methylotrophic bacterium through direct oxidation of the methyl halide contaminant. (Full details provided by the U.S. Patent and Trademark Office website.)

A method for treating nitrate-contaminated water comprising treating said water with hydrogen-oxidizing denitrifying bacteria in the presence of hydrogen. (Full details provided by the U.S. Patent and Trademark Office website.)

A method is provided for enhancing oxidation of methyl bromide during agricultural fumigations of fields using a fumigant containing methyl bromide. The method comprises adding a methylotrophic bacterium to the soil in an amount effective to provide bacterial oxidation of the methyl bromide. (Full details provided by the U.S. Patent and Trademark Office website.)

A method and apparatus for removing selenate from waste water through the use of selenate respiring microorganisms under substantially anoxic conditions is described. The method includes a first zone for removing nitrate by assimilation into biomass. (Full details available at the U.S. Patent and Trademark Office website for patents 5,271,831 and 5,009,786.)

As one of several Focus Area Studies within the USGS National Water Census (NWC), the USGS has completed a 3-year study of water availability and use in the Colorado River Basin.