Use of Natural 35S to Trace Sulphate Cycling in Small Lakes,Flattops Wilderness Area,Colorado, U.S.A.

Measurements of the cosmogenically-produced ³⁵S, a radioisotope of sulphur (t_1/2 = 87 days), are reported for the Ned Wilson Lake watershed in Colorado. The watershed contains two small lakes and a flowing spring presumed to be representative of local ground water. The watershed is located in the Flattops Wilderness Area and the waters in the system have low alkalinity, making them sensitive to increases in acid and sulphate deposition. Time series of ³⁵S measurements were made during the summers of 1995 and 1996 (July–September) at all three sites. The system is dominated by melting snow and an initial concentration of 16–20 mBq L^-1 was estimated for snowmelt based on a series of snow samples collected in the Rocky Mountains. The two lakes had large initial ³⁵S concentrations in July, indicating that a large fraction of the lake water and sulphate was introduced by meltwater from that year's snowpack. In 1995 and 1996, ³⁵S concentrations decreased more rapidly than could be accounted for by decay, indicating that other processes were affecting ³⁵S concentrations. The most likely explanation is that exchange with sediments or the biota was removing ³⁵S from the lake and replacing it with older sulphate devoid of ³⁵S. In September of 1995 and 1996, ³⁵S concentrations increased, suggesting that atmospheric deposition is important in the sulphate flux of these lakes in late summer. Sulphur-35 concentrations in the spring water were highly variable but never higher than 3.6 mBq L^-1 and averaged 2 mBq L^-1. Using a simple mixing model, it was estimated that 75% of the spring water was derived from precipitation of previous years.     

Yields of Dissolved Organic C,N, and P. from Three High-Elevation Catchments,Colorado Front Range,U.S.A.

Ecosystem dynamics in high-elevation watersheds are extremely sensitive to changes in chemical, energy, and water fluxes. Here we report information on yields of dissolved organic C, N, and P for the 1999 snowmelt runoff season from three high-elevation catchments in the Colorado Front Range, U.S.A.: Green Lake 4 (GL4) and Albion townsite (ALB) on North Boulder Creek and the Saddle Stream (SS), a tributary catchment dominated by alpine tundra. Dissolved organic carbon (DOC) concentrations in stream waters ranged from <1 to 10 mg C L^-1, with the highest values occurring at the SS site. Dissolved organic nitrogen (DON) concentrations ranged from below detection limits to 0.28 mg N L^-1 and were again highest at the tundra-dominatedsite. Dissolved organic phosphorus (DOP) concentrations were at or near detection limits throughout the season in all three catchments indicating a strong terrestrial retention of P. OnlyDOC showed a significant relationship to discharge. Yields of DOC in the three catchments ranged from 10.6 to 11.8 kg C ha^-1 while yields of DON and DOP ranged from 0.32 to 0.41 and 0.02 to 0.08 kg ha^-1, respectively. The relatively highyield of organic N and P relative to C from the highest elevationsite (GL4) was somewhat surprising and points to either: (1) a source of dissolved organic material (DOM) in the upper reaches of the catchment that is enriched in these nutrients or (2) theselective uptake and processing of organic N and P downstream ofthe sampling site. Additionally, seasonal changes in the relativeimportance of DOM precursor materials appear to result in changesin the N content of DOM at both the GL4 and ALB sites.     

The future course of solid waste management in the U.S.

It is postulated that the current “garbage crisis” is due to a shortage of disposal capacity, not to burgeoning amounts of municipal solid waste (MSW). In support of this, trends in the quantity and composition of MSW, methods of waste reduction, recycling and growth of waste-to-energy capacity are examined to gain insight as to the future course of MSW management in the U.S. over about the next 15 plus years. This is the likely time to install new disposal capacity if pending legislative proposals are passed, that would enable states that provide their own disposal to ban wastes from other states.A new term, the “intensity of waste generation”, is proposed and illustrated, analogous to the intensity of mineral usage. The intensity is decreasing, implying that it is unlikely that waste generation will grow at rates projected by extrapolation or simple macroeconomic assumptions. Some other conclusions are: per capita MSW generation was nearly statistically constant from 1970 to 1984; the content of most forms of packaging in MSW are decreasing; packaging decreases the amount of food residues in MSW; and proposed national recycling targets of about 25% or more are not likely to be achieved, in part because of changes in the composition of MSW. Coupled with likely shortages of labor to process separated waste, it is forecast that there will be some future time when people will not think source separation is worth the bother and recycling will decrease. The future growth of waste-to-energy capacity is projected by assuming that a city will install capacity when others have done so, which leads to a simple quantitative model. The likely effects of impending landfill and incineration regulations are addressed.     

Nuclear waste disposition and site remediation: U.S. department of energy,state governments,and other stakeholders dialogue

Remediation responsibilities of the U.S. Department of Energy (DOE) encompass a vast national complex of highly contaminated former weapons facilities. During the mid‐1990s, DOE announced its intentions to consolidate some waste types at specific sites. At about the same time, organizations and public officials around DOE sites urged a National Dialogue, designed to develop comprehensive solutions to the Department's needs for waste disposition ( transportation, treatment, and storage). Recent opposition from citizens and elected officials in Nevada and Washington State has presented obstacles to DOE's plans. Additionally, chairs of nine site‐specific advisory boards recommended that DOE support a National Stakeholder Forum, similarly designed to develop solutions to disposition needs. This article reviews the chronology of DOE's disposition efforts, along with public and state reactions and recommendations. © 2006 Wiley Periodicals, Inc.     

Curbside Recycling In The U.S.A.: Convenience And Mandatory Participation

This research examines the relationship between the success of a residential curbside recycling program (RCRP), measured as material recovery rate (MRR), and two program factors: (1) whether or not participation is mandated; and (2) convenience, measured by container provision, collection frequency and collection day relative to municipal solid waste collection day. Residential curbside recycling programs, with correct strategies and program design, can be an important part of solid waste management plans world-wide. While residential curbside recycling programs are growing in popularity, many basic design questions lie unanswered and successful program strategies are not always obvious. Data from 357 residential curbside recycling programs in the United States are used to test the hypotheses. Mandatory participation residential curbside recycling programs are seen to collect more material than voluntary participation residential curbside recycling programs. Container provision appears effective for voluntary, but not mandatory, residential curbside recycling programs. Increasing collection frequency appears to have a small positive effect on residential curbside recycling program success, while collection day has little effect on material recovery rate.     

Lessons learned outfitting the U.S. Coast Guard with oil pollution equipment

Lessons learned procuring U.S.$30 500 000 of oil pollution recovery equipment for the United States Coast Guard (USCG) in response to requirements of the Oil Pollution Act of 1990 (OPA-90) are presented. A generic requirements analysis and a selection process useful for making equipment acquisitions and staging site selections are described. Response mission, oil spill threat, response area peculiarities, available resources, equipment capabilities, training requirements and life cycle costs are all factors which must be carefully considered in outfitting a response organization. A method to ensure you obtain quality equipment which meets your functional requirements is outlined. Long range concerns about logistics support, training and maintenance are also important considerations.Leveraging existing resources such as existing USCG vessels, commercial vessels available on short notice for lease and the original oil response equipment inventory of the two USCG Strike Teams proved to be extremely cost effective. Selection of a vessel of opportunity skimming system (VOSS) and outfitting replacement offshore buoy tenders with an on-board spilled oil recovery system (SORS) eliminated the costly option of procuring dedicated pollution response vessels which are generally underutilized as a single mission platform. A first article field and factory acceptance testing program ensured all equipment functioned as specified, eliminating costly errors. This process also provided valuable customer input and significant equipment improvements before production started. Quality assurance testing and Government oversight ensured production units were fabricated properly with specified materials identical to the approved first articles adding reliability to the entire delivered system. Staging equipment at three Strike Teams and 19 sites near existing Coast Guard buoy tenders best used the available personnel and vessel resources adjacent to primary oil spill threat areas.     

Dynamics of P, Al, and Fe during High Discharge Episodic Acidification at the Bear Brook Watershed in Maine, U.S.A.

Phosphorus (P), aluminum (Al), and iron (Fe) stream chemistry were assessed for high discharge snowmelt events at the Bear Brook Watershed, Maine (BBWM) during December 2001 and February 2002 and compared with results from a January 1995 study of the same streams. The West Bear catchment has been subjected to artificial acidification since 1989. The East Bear catchment is the untreated reference. Total (acid soluble) Al, Fe, and P were positively correlated with discharge during the 2001–2002 events. However, dissolved P concentrations remained low (≤0.1 μmol L^-1) during high discharge events as pH decreased in both streams.For example, in 2001, total P concentration increased to 1.7 μmol L^-1 during the rising limb of the hydrograph in West Bear, approximately five times the value in East Bear. During the same event, in West Bear and East Bear dissolved Al concentrations increased to 21 and 6.3 μmol L^-1, respectively, while total Al concentrations increased to 166 and 30 μmol L^-1, respectively. Dissolved Fe concentrations remained ≤0.9 μmol L^-1 in both streams during all study events. However, total Fe concentrations in 2001 increased to 239 and 4.1 μmol L^-1 for West Bear and East Bear, respectively. Total Al and Fe declined parallel to total P after peaking during all study periods. Nearly all of the base cations were in dissolved form during the three events, indicating that total Al in West and East Bear Brooks is not associated with primary minerals such as feldspars. We conclude that particulate Al, Fe, and P are chemically linked during transport at high discharge in these episodically and chronically acidified streams.     

Residential solid waste generation and recycling in the U.S.A. and Japan

The generation rates of each residential solid waste component was determined for test areas in the U.S.A. and Japan. To keep the results consistent; single family dwelling areas in Madison (U.S.A.) and Sapporo (Japan), which have similar characteristics, were selected as test areas; the same survey methods were employed in both cities; all waste material from households, including recycled material, was estimated. The average person in Madison was found to produce twice the amount of paper waste, half the amount of food waste but approximately the same quantity of total residential waste (other than yard waste) as in Sapporo.     

Citizen board issues and local newspaper coverage of risk,remediation, and environmental management: Six U.S. nuclear weapons facilities

We examined site‐specific advisory board (SSAB) minutes and local newspaper coverage of the Fernald, Hanford, Idaho, Oak Ridge, Rocky Flats, and Savannah River sites of the U.S. Department of Energy (US DOE) in order to determine the importance of risk‐related issues related to remediation and other forms of environmental management. About one‐third of SSAB issues were risk‐related, and these were disproportionately major issues at meetings. The media focused on risks associated with remediation and other forms of waste management. The analysis implies that contractors and government officials need to establish and maintain communications with advisory panels and accentuate these contacts well in advance of contemplated new actions. © 2008 Wiley Periodicals, Inc.