Estimating Remediation Costs at Contaminated Sites With Varying Amounts of Available Information

Environmental professionals are often tasked with projecting the cost to bring a contaminated site or portfolio of sites to regulatory closure. Fortunately, there are a number of useful guidance documents and industry publications available to assist in such cost projections. However, the usefulness of such tools is limited when adequate costing information is lacking, such as (a) the nature and extent of contamination; (b) regulatory requirements; (c) the remedial approach to be implemented; and/or (d) the duration of operation, maintenance, and monitoring activities. Despite the lack of such information, cost‐to‐closure estimates are nevertheless routinely needed and generated for internal assessments or audits, regulatory disclosures, property acquisitions, insurance claims, litigation, and other business transactions. Cost estimates are also often needed in bankruptcy proceedings where the trier of fact must estimate the total future costs associated with an environmental legacy portfolio to determine the overall value (or solvency in the case of evaluating the potential bankruptcy) of a company. This article presents a solution for developing cleanup costs for single sites or a portfolio of sites using a comprehensive, three‐tiered method that is effective over a wide range of site information. Real‐world examples of the successful application of this method are then provided, based on detailed environmental analyses that were completed for a recent bankruptcy proceeding and a case in which an estimated cleanup cost was needed in a legal proceeding. © 2013 Wiley Periodicals, Inc.     

Toxic effects of oral 2-amino-4,6-dinitrotoluene in the Western fence lizard (Sceloporus occidentalis)

The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD₅₀ values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at ≥15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis.     

Personal care product use and urinary levels of phthalate metabolites in Mexican women

Sources of phthalates other than Polyvinyl chloride (PVC) related products are scarcely documented in Mexico. The objective of our study was to explore the association between urinary levels of nine phthalate metabolites and the use of personal care products. Subjects included 108 women who participated as controls in an ongoing population-based case-control study of environmental factors and genetic susceptibility to breast cancer in northern Mexico. Direct interviews were performed to inquire about sociodemographic characteristics, reproductive history, use of personal care products, and diet. Phthalate metabolites measured in urine by high performance liquid chromatography-isotope dilution tandem mass spectrometry were monoethyl phthalate (MEP), monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), mono-3-carboxypropyl phthalate (MCPP) as well as mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP) that are metabolites of di-ethylhexyl phthalate (DEHP). Detectable urinary concentrations of phthalate metabolites varied from 75% (MEHP) to 100% (MEP, MBP, MEOHP, MEHHP and MECPP). Medians of urinary concentrations of some phthalate metabolites were significantly higher among users of the following personal care products compared to nonusers: body lotion (MEHHP, MECPP and sum of DEHP metabolites (ΣDEHP)), deodorant (MEHP and ΣDEHP), perfume (MiBP), anti-aging facial cream (MEP, MBP and MCPP) and bottled water (MCPP, MEHHP and MEOHP). Urinary concentrations of MEP showed a positive relationship with the number of personal care products used. Our results suggest that the use of some personal care products contributes to phthalate body burden that deserves attention due to its potential health impact.     

Four Decades of Plant Community Change in the Alpine Tundra of Southwest Yukon,Canada

Repeat measurements from long-term plots provide precise data for studying plant community change. In 2010, we visited a remote location in Yukon, Canada, where a detailed survey of alpine tundra communities was conducted in 1968. Plant community composition was resurveyed on the same four slopes using the same methods as the original study. Species richness and diversity increased significantly over the 42 years and non-metric multidimensional scaling indicated that community composition had also changed significantly. However, the direction and magnitude of change varied with aspect. Dominant species were not replaced or eliminated but, instead, declined in relative importance. Fine-scale changes in vegetation were evident from repeat photography and dendro-ecological analysis of erect shrubs, supporting the community-level analysis. The period of study corresponds to a mean annual temperature increase of 2°C, suggesting that climate warming has influenced these changes.     

Comparative distribution, sourcing, and chemical behavior of PCDD/Fs and PCBs in an estuary environment

PCDD/F and PCB field data (1041 samples) in five media (dissolved, suspended sediment, bed sediment, catfish, and blue crab) were studied to explore dual contaminant patterns in the Houston Ship Channel, Texas, USA. PCDD/Fs showed greater concentration than PCBs in suspended sediments while PCBs were higher in apparent dissolved (truly dissolved + DOC-associated), fish, and crab. PCDD/Fs at nearly all locations contributed more strongly to dioxin-like toxicity. The fraction of PCB TEQ was, however, enriched in biotic over abiotic media due in large part to the presence of PCB 126, which was mostly undetected in water and sediment and yet exhibited a BAF three times greater than 2,3,7,8-TCDD. Dissolved-suspended sediment and suspended-bed sediment relationships showed that (1) observed apparent dissolved concentration differences (as fraction of total water were mean 10% PCDD/Fs and 63% PCBs) can reasonably be explained by a four-phase partition model (truly dissolved, DOC-associated, suspended OC, and suspended BC) for PCBs but not for PCDD/Fs and (2) the contaminants behaved similarly in bed to suspended sediment concentration ratios (C_bed/C_susp) upstream of a major confluence but not downstream. PCA-cluster analysis pointed to the possibility that suspended sediment PCB contamination originates from resuspended bed sediment while PCDD/Fs in suspended sediment originates more probably from other sediment sources such as upstream wash load or air deposition. Finally, examinations of a congener marker ratio (PCB 209/206) seemed to indicate that a source of pure PCB 209 may exist in bed sediment near Patrick Bayou though the source was not completely localized.     

Transport and fate of nitrate at the ground-water/surface-water interface

Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemical, dissolved gas, and isotopic data were used to determine the processes controlling transport and fate of NO(3)(-) in streambeds at five sites across the USA. Water samples were collected from streambeds at depths ranging from 0.3 to 3 m at three to five points across the stream and in two to five separate transects. Residence times of water ranging from 0.28 to 34.7 d m(-1) in the streambeds of N-rich watersheds played an important role in allowing denitrification to decrease NO(3)(-) concentrations. Where potential electron donors were limited and residence times were short, denitrification was limited. Consequently, in spite of reducing conditions at some sites, NO(3)(-) was transported into the stream. At two of the five study sites, NO(3)(-) in surface water infiltrated the streambeds and concentrations decreased, supporting current models that NO(3)(-) would be retained in N-rich streams. At the other three study sites, hydrogeologic controls limited or prevented infiltration of surface water into the streambed, and ground-water discharge contributed to NO(3)(-) loads. Our results also show that in these low hydrologic-gradient systems, storm and other high-flow events can be important factors for increasing surface-water movement into streambeds.     

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) in the serum of US Air Force veterans in 2002

We measured levels of PCDDs, PCDFs, non-ortho, and mono-ortho substituted PCBs in 106 US Air Force Vietnam veterans, participants of the Air Force Health Study (AFHS) who attended the final medical examination in 2002. Twelve veterans were Ranch Hands involved in aerial spraying of herbicides in Vietnam (1962-1971), and 94 were Comparisons who flew transport missions in Southeast Asia (SEA) during the same time period. These veterans had no previous 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) measurement because they had not attended any of the previous AFHS examinations, or their previous measurements were missing or not valid. The mean TCDD levels in 2002 were 1.7 pg/g lipid in Comparisons and 5.5 pg/g lipid in Ranch Hands. The mean PCDD toxic equivalent - TEQ (1997) in Comparisons was 12.6 pg/g lipid, 5.4 pg/g lipid for PCDFs, 5.2 pg/g lipid for non-ortho PCBs, and 9.4 pg/g lipid for mono-ortho PCBs, with a total mean TEQ (1997) of 32.6 pg/g lipid. Corresponding mean TEQs in Ranch Hands were 15.5 pg/g lipid for PCDDs, 4.6 pg/g lipid for PCDFs, 2.2 pg/g lipid for non-ortho PCBs, and 9.3 pg/g lipid for mono-ortho PCBs, yielding the total mean TEQ (1997) of 31.6pg/g lipid. Using the re-evaluated 2005 WHO TEFs, the total mean TEQs (2005) decreased by about 28% in both Comparisons and Ranch Hands, to 23.6 pg/g lipid and 22.8 pg/g lipid, respectively. This was mainly due to changes of TEFs for the group of mono-ortho PCBs, which decreased the mono-ortho PCBs TEQs by almost 90% in both Ranch Hands and Comparisons.     

Household youth on minority operated farms in the United States, 2000: exposures to and injuries from work, horses, ATVs and tractors

INTRODUCTION: It is likely that youth living on minority operated farms (<3% of U.S. farms) face hazards similar to the general farm population; however, since minority youth are not well represented by general farm surveys, this information hasn't been confirmed. METHOD: Nonfatal injury and exposure data were obtained from the 2000 Minority Farm Operator Childhood Agricultural Injury Survey (M-CAIS). RESULTS: On racial minority farms, there were an estimated 28,600 household youth. Of these, about 41% worked, 26% rode a horse, 23% drove an ATV, and 23% operated a tractor. On Hispanic farms, there were an estimated 17,998 household youth. Of these, 44% worked, 30% rode a horse, 27% drove an ATV, and 25% operated a tractor. CONCLUSIONS: These results show the value of conducting a survey of minorities to identify high risk groups and target issues that may be unique to the minority farm population.     

Mine capacity and mineral price

The loss of foreign mineral supplies may affect domestic supply and price. To investigate the assumption that prices, a simple mine investment model that relates mine capacity to deposit attributes is used. A test of the model to see how well it approximates industry investment practice illustrates its accuracy. The model suggests that price changes can substantially affect the optimal capacity of planned or existing mines as well as the mineral supply in the USA.