[en] This study attempted to measure the effect of a shallow biobarrier of gravel and cobble on water flow patterns during spring snow melt and recharge. The design consisted of 30 metal culverts 3 m in diameter and 1.6 m long, positioned on end. Test culverts contained 50-cm biobarrier of gravel or cobble and then an additional 50 cm of soil placed above the barrier layer. A neutron probe was used to measure soil moisture above and below the barrier. Measurements were made in the fall and again immediately after snow melt in the spring. During recharge, the biobarriers provided a capillary break which resulted in a pooling of water above the barrier layer. With sufficient snowmelt, the water can penetrate the break and possibly penetrate deeper than in the absence of the barrier layer

[en] Tests were performed to evaluate the behaviour of silicate grout with different reagents (ethylacetate - formamide SA and calcium chloride SC) in pure silica sand and natural soils from coastal areas containing organic matter, clayey soil and silica sand. The grouted specimens were tested with simulated fresh and salt water. The setting process during chemical grouting in the soil and sand was studied. The grouting of soil and sand with SA caused a transfer to the environment of some compounds: sodium formate, sodium acetate, ammonia and part of the initial ethylacetate and formamide. This process had a tendency to decrease for approximately 4 months. The stability of specimens was low. The grouting of soil and sand with SC caused no significant contamination of the environment. The increase of pH of environmental water was even less than with SA grouting. Also, the stability of specimens is higher in comparison with SA grouting. Salt water protected the specimens grouted with SA and SC from destruction and prevented contamination

[en] A chromic acid release was discovered at a former electroplating shop at the U.S. Coast Guard Support Center in Elizabeth City, North Carolina. Initial investigative activities indicated that chromic acid had migrated into the subsurface soils and groundwater. In addition, trichloroethylene (TCE) was also discovered in groundwater during subsequent investigations of the hexavalent chromium (Cr VI) plume. Corrective measures were required under the Resource Conservation and Recovery Act (RCRA). The in-situ remediation method, proposed under RCRA Interim Measures to passively treat the groundwater contaminants, uses reactive zero-valent iron to reductively dechlorinate the chlorinated compounds and to mineralize the hexavalent chromium. A 47 meter by 0.6 meter subsurface permeable iron wall was installed downgradient of the source area to a depth of 7 meters using a direct trenching machine. The iron filings were placed in the ground as the soils were excavated from the subsurface. This is the first time that direct trenching was used to install reactive zero-valent iron filings. Over 250 metric tons of iron filings were used as the reactive material in the barrier wall. Installation of the iron filings took one full day. Extensive negotiations with regulatory agencies were required to use this technology under the current facility Hazardous Waste Management Permit. All waste soils generated during the excavation activities were contained and treated on site. Once contaminant concentrations were reduced the waste soils were used as fill material

[en] The purpose of this source unit Statement of Basis/Proposed Plan is to describe the preferred alternative for addressing the F-Area Burning/Rubble Pits (231-F and 231-1F) and Rubble Pit (231-2F) (FBRP) source unit located at SRS, in southwestern Aiken County, South Carolina and to provide an opportunity for public input into the remedial action selection process

[en] This memorandum addresses whether there is a technical basis for discontinuing the tracking of sites where isolated spills of particular chemicals onto Savannah River Site soils occurred

[en] Turnaround time for this project was 60 days, as required in Reference 2. The analyses were to be performed using SW-846 procedures whenever possible to meet analytical requirements as a Resource Conservation Recovery Act (RCRA) protocol project. Except for the preparation and analyses of polychlorinated biphenyl hydrocarbons (PCB) and Nickel-63, which the program deleted as a required analyte for 222-S Laboratory, all preparative and analytical work was performed at the 222-S Laboratory. Quanterra Environmental Services of Earth City, Missouri, performed the PCB analyses. During work on this project, two events occurred nearly simultaneously, which negatively impacted the 60 day deliverable schedule: an analytical hold due to waste handling issues at the 222-S Laboratory, and the discovery of PCBs at concentrations of regulatory significance in the 105-N Basin samples. Due to findings of regulatory non-compliance by the Washington State, Department of Ecology, the 222-S Laboratory placed a temporary administrative hold on its analytical work until all waste handling, designation and segregation issues were resolved. During the hold of approximately three weeks, all analytical and waste.handling procedures were rewritten to comply with the legal regulations, and all staff were retrained in the designation, segregation and disposal of RCRA liquid and solid wastes

[en] For decades, large quantities of organic and inorganic pollutants have been brought into the soil as a result of the industrial operations of smelting and coking plants. This paper reports on the prospects of separating heavy metals from soil contaminated by smelting and coking plants by means of a physical/chemical washing procedure. Besides the description of virgin soil characteristics, cleaning results and process parameters of calssification, density separation and flotation processes are presented. It is shown that heavy metal pollution of virgin soil can be reduced by the classical process stages of soil washing. The metal content of virgin soil are critically assessed whereby the limits of the physical-chimical washing process will also be entered into. Emphasis is placed on the significance of the determination of limiting values for inorganic contamination, especially for soil contaminated with both organic and inorganic pollution. (orig.)

[en] Forest damage and decline are the consequence of several stress factors acting upon forest ecosystems in various combinations and degrees. Impact of atmospheric pollutants is certainly one of the most prominent of these factors. Regional comparion is facilitated by considering groups of atmospheric substances. We distinguish: 1. Acids and acidifying substances, 2. Heavy metals and 3. Nutrients: N, P, K, Ca, Mg, S. Forest decline has to be recognized as an expression of changes within the forest ecosystem, changes which must be accompanied by a non-steady state of the material balance. The best way to investigate changes in the material balance is to look at input and output of matter to the ecosystems. A positive balance (input > output) over a period of more than one year means accumulation, negative balance (input < output) means depletion of a substance. Based upon several case studies (Subjects I, K), we come to a typification of the material balance at any individual site which is defined by the immission/deposition situation on the one hand, by the geological-pedological site characteristics on the other hand. (orig.VT)

[en] The comparative field results demonstrated important interregional differences in the concentrations of labile Al and strong acid anions in soil drainage and surface waters at the study catchments. Results also showed that for those watersheds containing soils with < 10% base saturation, increased concentrations of SO₄^2- plus NO₃- in soil drainage waters were accompanied by increased concentrations of labile Al. Nutritional effects from Al exposure generally occured at lower labile Al concentrations than those associated with growth reductions. (orig.)

[en] As a comparison of the 1983 and 1988 needle-analysis inventories showed, Mg and K deficiency situations, in particular, and conditions of inadequate calcium supply tend to persist and were clearly to be distinguished from fluctuations due to weather during the five-year observation period. Obviously, therefore, a complete, lasting recovery of the nutrition situation in such regions without aimed interventions is rather unlikely. Restoring stable nutritive element cycles will also in the future require application of nutritive elements and buffer substances as part of site-specific melioration measures. Sulfur contents show for the greater part a decreasing tend, which indicates a generally reduced deposition of this element. (orig./EF)