Survival of Cryptosporidium parvum oocysts in calf housing facilities in the New York City watersheds

Pathogen contamination of the public drinking water supply in the New York City watersheds is a serious concern. New York City's Watershed Agriculture Program is working with dairy farms in the watersheds to implement management practices that will reduce the risk of pathogens contaminating the water supply. Solar calf housing (SCH) was suggested as a best management practice (BMP) to control Cryptosporidium parvum, a common protozoan parasite that causes disease in humans. This BMP targets young calves because they are the primary source of C. parvum in dairy herds. The objective of this project was to assess and compare the survivability of C. parvum in SCH and in conventional calf housing (CCH), usually located in the main barn. C. parvum oocysts were secured in sentinel chambers and placed in SCH and CCH bedding on four farms. The chambers were in thermal, chemical, and moisture equilibrium with their microenvironments. An oocyst-filled control chamber, sealed from its surroundings, was placed near each chamber. Chambers and controls were sampled after 4, 6, and 8 wk. Oocyst viability in the chambers decreased to less than 10% in warm months and between 15 and 30% in the winter months. The viability of the control oocysts was similar to the chambers during warm months and generally higher during winter months. There was no significant (P > 0.05) difference in the viability decrease between SCH and CCH. Although oocyst viability was similar in both types of calf housing, SCH allow contaminated calf manure to be isolated from the main barn manure and potentially managed differently and in a way to decrease the number of viable oocysts entering the environment during field spreading.     

Laboratory and field evaluation of a pretreatment system for removing organics from produced water

Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. This "produced water" is characterized by saline water containing a variety of pollutants, including water soluble and immiscible organics and many inorganic species. To reuse produced water, removal of both the inorganic dissolved solids and organic compounds is necessary. In this research, the effectiveness of a pretreatment system consisting of surfactant modified zeolite (SMZ) adsorption followed by a membrane bioreactor (MBR) was evaluated for simultaneous removal of carboxylates and hazardous substances, such as benzene, toluene, ethylbenzene, and xylenes (BTEX) from saline-produced water. A laboratory-scale MBR, operated at a 9.6-hour hydraulic residence time, degraded 92% of the carboxylates present in synthetic produced water. When BTEX was introduced simultaneously to the MBR system with the carboxylates, the system achieved 80 to 95% removal of BTEX via biodegradation. These results suggest that simultaneous biodegradation of both BTEX and carboxylate constituents found in produced water is possible. A field test conducted at a produced water disposal facility in Farmington, New Mexico confirmed the laboratory-scale results for the MBR and demonstrated enhanced removal of BTEX using a treatment train consisting of SMZ columns followed by the MBR. While most of the BTEX constituents of the produced water adsorbed onto the SMZ adsorption system, approximately 95% of the BTEX that penetrated the SMZ and entered the MBR was biodegraded in the MBR. Removal rates of acetate (influent concentrations of 120 to 170 mg/L) ranged from 91 to 100%, and total organic carbon (influent concentrations as high as 580 mg/L) ranged from 74 to 92%, respectively. Organic removal in the MBR was accomplished at a low biomass concentration of 1 g/L throughout the field trial. While the transmembrane pressure during the laboratory-scale tests was well-controlled, it rose substantially during the field test, where no pH control was implemented. The results suggest that pretreatment with an SMZ/MBR system can provide substantial removal of organic compounds present in produced water, a necessary first step for many water-reuse applications.     

Valuation of open space and conservation features in residential subdivisions

Conservation subdivision design has been promoted as a way to protect ecologically sensitive areas while maintaining housing densities comparable to standard subdivisions, but many developers and planners question the appeal of conservation design to consumers. This study was conducted to compare economic aspects of conservation subdivision design to standard subdivision design in the midwestern United States. Three methods were used to determine the value homebuyers have for embedded conservation features in residential areas: transactional analyses (to indicate the value homebuyers have expressed for such features in the past); hedonic analyses (to determine the proportion of present value of homes attributable to such features); and contingent valuation (to examine willingness to pay according to homebuyers' preferred features, an indicator of potential future investment). Transactional analyses were based on assessment and transaction data for homes in three conservation-oriented subdivisions and three standard subdivisions in Cedar Rapids, Iowa, United States. Hedonic price models were also derived from assessment and transaction data. Contingent valuation analyses were based on a survey of residents in the same six subdivisions. Transactional data indicated higher 5-year appreciation rates for conservation versus standard subdivision design. Hedonic price models revealed that well-integrated conservation features (e.g. protected stream corridors) within subdivisions have a positive effect on home prices. Sixty-six percent of all respondents indicated willingness to pay for more embedded open space. Maximum willingness to pay was related to several factors including income, gender, desired level of open space, and concern about urban development. Overall, these results indicate that consumer demand and willingness to pay for conservation subdivision design are positive and should not be considered a barrier to implementation.     

Further water solubility determinations of insecticidal compounds

Abstract

The aqueous solubility of 39 insecticidal and related compounds was determined at 20±1.5°C, using a previously described shaking and centrifugation method. Fenamiphos, fenthion and methi‐dathion produced values substantially less than those reported in the literature whereas, aminocarb, diazinon, dicapthon, pirimiphos‐ethyl and pirimiphos‐methyl gave solubilities substantially greater than reported literature values.     

Fishers,Farms, and Forests in Eastern North America

The fisher (Martes pennanti) has recently recovered from historic extirpations across much of its geographic range. There are at least five explanations for the recovery of the fisher, including changes in the amount of habitat, the suitability of habitat, trapping pressure, societal attitudes toward predators, and climate. We evaluated a recovering fisher population in Ontario to test two conditions we viewed as necessary to support the hypothesis that fisher populations have increased due to an increase in the amount of forested land. First, we tested whether the amount of forested land has increased. Second, we tested whether contemporary fisher abundance (and therefore habitat quality) was related to the amount of forest. Topographic maps showed that the proportion of forested land in the study area had increased by 1.9% per decade since 1934 and 3.3% per decade since 1959, likely as a result of land conversion from agricultural uses. Overall the proportion of the study area that was forested increased from 29% to 40% during 1934 to 1995. Census data from the region indicated that there had been a decline in the amount of land area being farmed during the last 50 years. Recent livetrapping data showed that fisher abundance was positively related to the proportion of landscapes that were forested. Based on our results, we could not reject the hypothesis that an increase in the amount of forested land has contributed to the recovery of fisher populations.     

Land clearance not dieback continues to drive tree loss in a Tasmanian rural landscape

Tree cover has declined markedly since European settlement in the agricultural areas of Australia due to land clearing and natural and stress-induced senescence of remnant trees combined with widespread regeneration failure. These decreases in tree cover have seldom been quantified on a landscape scale, but are important in understanding losses in carbon storage and biodiversity across large areas of the continent. We used historical aerial photography and satellite imagery to study changes in tree canopy cover in the southern Tasmanian Midlands, one of the oldest agricultural regions in Australia. Tree cover at 1,000 random sites was assessed from imagery captured on four occasions between 1947 and 2010. Tree cover was stable between 1947 and the 1970s, but decreased from 33 % in the 1970s to 21 % in 2010. The decrease appeared driven by transition from some cover to no cover, rather than from more cover to less cover, because sites with tree cover in 2010 showed little net change during the study period. Statistical modelling showed soils derived from igneous rocks lost more cover than did the less fertile sedimentary soils, and contrary to the expectations, if drought was the cause of cover loss, sun-exposed north-facing sites did not lose more cover than south-facing ones. We argue that these temporal and spatial patterns of tree cover change are consistent with tree clearing rather than loss of remnant isolated trees due to drought-induced dieback.     

Adsorption,desorption, soil mobility,aqueous persistence and octanol‐water partitioning coefficients of terbufos,terbufos sulfoxide and terbufos sulfone

Abstract

Terbufos, t. sulfoxide and t. sulfone (5 μg ml^‐1) were incubated in natural, sterilized natural and distilled water, with initial pH values of 8.8, 8.8 and 6.0, respectively, at 20°C. First‐order disappearance was observed for the three compounds. Rates in natural and sterilized water were similar indicating chemical degradation predominated. Terbufos disappeared rapidly (t½>=3 days) in all systems. T. sulfoxide and t. sulfone were more persistent in the natural (t½>=18–40 days) and distilled water (t½>=280–350 days). Adsorption data for the three compounds in four soil‐water systems showed the decreasing order of adsorption to be terbufos>>t. sulfoxide=t. sulfone. Desorption from soils fortified at 5 μg g^‐1 with water was examined for 4 successive 18‐hr cycles. T. sulfoxide and t. sulfone were totally desorbed; terbufos was too unstable to study. The mobility of the compound in soil eluted with water was in the order, t. sulfoxide=t. sulfone>> terbufos, in agreement with adsorption‐desorption results. The octanol‐water partitioning coefficients for terbufos, t. sulfoxide and t. sulfone, at 23°C, were 3:30 x 10 , 164, and 302, respectively.     

Inactivation of Ascaris suum in a biodrying compost system

Pathogen contamination of waterways is a serious concern in dairy farming areas where livestock waste is applied to agricultural fields. As an alternative, a biodrying composting system dries collected livestock waste, reduces the strong odors, and has been proposed as a means of reducing, and even eliminating pathogens present in the waste. Therefore, the survival of pathogens in a biodrying composting system was investigated. Dairy farm livestock waste was piled in a biodrying storage shed where forced aeration and natural decomposition processes heated a major portion of the waste pile to temperatures exceeding 55 degrees C. Ascaris suum eggs were used as the surrogate species and inoculated into special chambers and placed at three different elevations at different intervals along the length of the pile. Control chambers were stored in water at 4 degrees C in the laboratory. Both compost and control chambers were removed at Day 4, 8, 12, 16, and 20. The eggs were extracted from the chamber medium and analyzed for viability. No viable eggs were recovered from any of the chambers removed from the compost pile, while >or=90% viability was observed in the control chambers. High temperatures and continued drying were the major contributing factors to the inactivation of the helminth eggs. The complete inactivation of A. suum eggs by the biodrying process encourages the storage and treatment of manure to high temperatures and reduced moisture conditions before field spreading to reduce the risk of harmful pathogens contaminating waterways and potential drinking water supplies.