The Nevada Test Site (NTS) was the location for at least 100 above ground
Nuclear Weapons tests during the 1950's and early 1960's. Radioactive fallout
from these tests spread to many areas north and west of the NTS. According to
estimates from the NCI and DOE, Washington County, Utah was...
Chromium, an element of widespread use, is toxic in some
forms. Improper disposal of waste chromium products has
resulted in contamination of many sites throughout the United
States, including the United Chrome Products Superfund site
in Corvallis, Oregon. A better understanding of chromium
chemistry is needed to facilitate the remediation...
Nitrification and denitrification are major biological processes transforming nitrogen (N) in soils to plant available N, highly leachable nitrate (NO₃⁻) and gaseous N oxides. Although many studies in the past have studied N cycling communities, the effect of increased N inputs on ammonia-oxidizer and denitrifier population dynamics is still under...
The Oregon Water Quality Decision Aid (OWQDA) is
a first-tier screening tool that allows you to make a broad
determination of the likelihood that a specific chemical,
when applied to a specific Oregon soil, will move through
the soil and contaminate groundwater. This determination
is called the groundwater vulnerability rating.
Radioecology observes the movement of radioactive isotopes throughout the environment. For radioecology, locations of study are limited to areas accidentally contaminated from a number of sources. The Chalk River Laboratories of Atomic Energy of Canada Limited have stored low level waste since the mid 1940s. In certain instances, the wastes...
Produced water is a highly saline waste product of oil and gas production, which is generated in larger volumes than the hydrocarbons themselves in the United States. Spillage of produced water is of concern because its high salinity can contaminate soil, surface water and groundwater resources, and kill vegetation, including...
Volatile hydrophobic compounds (HOCs) brought into soil and sediment
systems represent a serious threat to the environment. Dissolved
organic carbon (DOC) may exert an important influence over the total
aqueous solubility and mobility of organic pollutants through their
incorporation into micelles or the formation of soluble complexes.
To date, however,...
Chromium spills on soils are causing severe groundwater contamination
problems. To increase the performance of cleanup methods, the chemical behavior
of chromium in soils and its transport through soils have to be understood. The
objectives of this research were to investigate the sorption characteristics of
chromium(VI) in soil and to...
One of the basic questions facing transportation planners and road managers is how to provide and maintain a road system that provides efficient access to the forest while limiting adverse effects roads can have on water and soil resources. The purpose of this study is to develop decision support models...
Soils of 49 agricultural and 2 "native condition" sites in the Lower Umatilla Basin,
Oregon were sampled for nitrate-nitrogen, ammonium-nitrogen, chloride, and pH
beginning in Fall of 1992. Several sites were sampled in Spring and Fall 1993 in order to
indicate movement or loss of residual soil nitrogen over time....
Ground-based skidding may cause unacceptable damage to woodland soils when owners make no attempt to minimize the area covered with skid trails. As much as 40 percent of the area may be covered with skid trails during a single entry if you do not plan and mark them in advance.
The Oregon Long-Term Soil Quality Project was initiated to identify soil
properties that respond rapidly to alternative management practices. Such practices
included winter cover cropping, which was implemented at two experimental research
stations and several grower fields throughout the Willamette Valley. The goal of this
thesis was to identify the...
Soil effects from mountain beaver (Aplodontia rufa ) burrowing were
investigated in Oregon Coast Range soils formed from Tyee sandstone. The potential
for observed changes in soil to affect productivity was assessed. Soil horizons from
mountain beaver mound soil and adjacent unmounded profiles were collected with a
monolith-type quantitative sampler....
China has experienced rapid economic growth in the last twenty years, accompanied by large-scale land conversion, severe environmental degradation, and rising carbon dioxide (CO₂) emissions. Designing policies for sustainable development requires a comprehensive understanding of the relationship between economic growth, land-use change, carbon sequestration and emissions in China. This dissertation...
According to the United States Geological Survey, 9 percent of wells in the Willamette Valley exceed the EPA’s 10 ppm drinking water standard for nitrogen in the NO3– compound, or NO3–-N. A study of 281 domestic drinking water wells in Lane County showed that 22 percent of the wells exceeded...
Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare.
Consequently, long-term effects of fire on soils are often hypothesized from
short-term effects. In a chronosequence study, I studied 24 western Cascades
(Oregon) forest stands thought to...
Four factors govern the potential for groundwater
contamination by pesticides passing through the soil:
• Properties of the soil
• Properties of the pesticide
• Hydraulic loading on the soil
• Crop management practices