Evaluation of Effects of Wastewater Treatment Discharge on Estuarine Water Quality

This report marks the completion of a two-year project focused on observed and estimated effects of wastewater treatment facilities (WWTFs) on estuarine water quality within the New Hampshire (NH) Seacoast region. This study was designed and carried out in an effort to help the NH Department of Environmental Services (NHDES) and NH Estuaries Project (NHEP) evaluate the effects of WWTF effluent quality on bacterial and nutrient concentrations in New Hampshire’s estuarine waters, as well as to help NHDES/NHEP identify related WWTF infrastructure problems. An extensive database of bacterial and nutrient concentrations in effluent collected post-disinfection from 9 NH WWTFs and 2 Maine WWTFs that discharge into the Great Bay and Hampton/Seabrook estuaries was developed. The data were used to determine ratios between different bacterial indicators in WWTF effluent, estimates of in-stream bacterial concentrations following effluent discharge to receiving waters and estimates of nutrient loading from selected WWTFs

Use of Annual Phosphorus Loss Estimator (APLE) Model to Evaluate a Phosphorus Index

The Phosphorus (P) Index was developed to provide a relative ranking of agricultural fields according to their potential for P loss to surface water. Recent efforts have focused on updating and evaluating P Indices against measured or modeled P loss data to ensure agreement in magnitude and direction. Following a recently published method, we modified the Maryland P Site Index (MD-PSI) from a multiplicative to a component index structure and evaluated the MD-PSI outputs against P loss data estimated by the Annual P Loss Estimator (APLE) model, a validated, field-scale, annual P loss model. We created a theoretical dataset of fields to represent Maryland conditions and scenarios and created an empirical dataset of soil samples and management characteristics from across the state. Through the evaluation process, we modified a number of variables within the MD-PSI and calculated weighting coefficients for each P loss component. We have demonstrated that our methods can be used to modify a P Index and increase correlation between P Index output and modeled P loss data. The methods presented here can be easily applied in other states where there is motivation to update an existing P Index

Future agriculture with minimized phosphorus losses to waters: research needs and direction

The series of papers in this issue of AMBIO represent technical presentations made at the 7th International Phosphorus Workshop (IPW7), held in September, 2013 in Uppsala, Sweden. At that meeting, the 150 delegates were involved in round table discussions on major, predetermined themes facing the management of agricultural phosphorus (P) for optimum production goals with minimal water quality impairment. The six themes were (1) P management in a changing world; (2) transport pathways of P from soil to water; (3) monitoring, modeling, and communication; (4) importance of manure and agricultural production systems for P management; (5) identification of appropriate mitigation measures for reduction of P loss; and (6) implementation of mitigation strategies to reduce P loss. This paper details the major challenges and research needs that were identified for each theme and identifies a future roadmap for catchment management that cost-effectively minimizes P loss from agricultural activities

Sorption of Phosphorus from Swine, Dairy, and Poultry Manures

In most phosphorus (P) sorption studies, P is added as an inorganic salt to a predefined background solution such as calcium chloride (CaCl2) or potassium chloride (KCl); however, in many regions, the application of P to agricultural fields is in the form of animal manure. The purpose of this study, therefore, was to compare the sorption behavior of dissolved reactive P (DRP) in monopotassium phosphate (KH2PO4)–amended CaCl2 and KCl solutions with sorption behavior of DRP in three different animal manure extracts. Phosphorus single-point isotherms (PSI) were conducted on eight soils with the following solutions: KH2PO4-amended 0.01M CaCl2 solution, KH2PO4-amended 0.03M KCl solution, water-extracted dairy manure, water-extracted poultry litter, and swine lagoon effluent. The PSI values for the dairy manure extract were significantly lower than the CaCl2 solution for all eight soils and lower than the KCl solution for six soils. The PSI values were significantly higher, on the other hand, for poultry litter extract and swine effluent than the inorganic solutions in four and five of the soils, respectively. Our observations that the sorption of DRP in manure solutions differs significantly from that of KH2PO4-amended CaCl2 and KCl solutions indicates that manure application rates based on sorption data collected from inorganic P salt experiments may be inaccurate

Recovery of chlorine-exposed Escherichia coli in estuarine microcosms

Laboratory microcosm experiments were performed to determine whether chlorine-exposed Escherichia coli are capable of recovery (i.e., increase in numbers of culturable cells) in estuarine waters and if so what water-quality parameters are responsible for this recovery. Suspensions of E. coli were exposed to 0.5 mg L-1 of chlorine for 5 min followed by dechlorination with sodium thiosulfate. The chlorine-exposed bacteria were introduced into 2-L microcosms containing estuarine water collected from the Seacoast region of New Hampshire. Culturable cells in the microcosms were enumerated at 0, 10, 24, 48, and 74 h. In all estuarine microcosms the number of culturable cells increased by factors ranging from 2.8 to 50 over the 74-h incubation period. Multiple linear regression analyses indicated that ammonium and salinity were most significantly correlated with the recovery of E. coli over the 74-h incubation period; however, ammonium concentrations were strongly correlated with dissolved organic carbon and total dissolved nitrogen, making it impossible to determine with any degree of certainty the unique effect nitrogen or carbon had on recovery. The extensive recovery observed in our study indicates that following exposure to concentrations of chlorine that cause cell injury rather than death, numbers of culturable E. coli may increase significantly when discharged into estuarine waters. Thus, depending on the effectiveness of the chlorination process, the regular monitoring of chlorinated wastewater treatment effluent may underestimate the true impact on water-quality and public health risks

GOES Solar Radiation for Evapotranspiration Estimation and Streamflow Prediction

This study explores the value of incoming solar radiation estimates derived from geostationary operational environmental satellites (GOES) as an alternative solar radiation data source to historical solar radiation estimates for use in rainfall–runoff simulations. At 26 sites in the United States, the GOES-based solar radiation (R2=0.79) and ETp(R2=0.94) estimates agreed well with the ground-based estimates. There was a slight positive bias for the GOES-based solar radiation (5.4%) and potential evapotranspiration (8.7%) estimates compared to the ground-based estimates, with the strong and significant biases noted during the warm seasons. However, individual stations biases ranged from −12 to 27%. Daily streamflow predictions made using National Weather Service River Forecast System’s Sacramento Soil Moisture Accounting rainfall–runoff model for four NOAA Distributed Model Intercomparison Project watersheds show that although notable peak storm flow differences occurred occasionally during extended drying periods, on average, the GOES-based potential evapotranspiration estimates slightly outperformed the simulations using ground-based data on an annual basis and were relatively insensitive to biases. However, on seasonal time scales, differences in soil water storage are evident and can result in numerous moderate differences in streamflow predictions

Escola catalana

Resumen basado en el de la publicaciónDespués de un período de debate curricular -que pasó abajo con una gran indiferencia tanto por parte de la mayoría del profesorado como de los estamentos universitarios- se publicó provisionalmente, entre los de las otras áreas, los nuevos currículos correspondientes a las áreas de conocimiento del medio para la primaria y de ciencias sociales, geografía e historia para la secundaria obligatoria. Una vez leídos y analizados, se comentan que el resultado general es confuso y decepcionante.Universitat de Barcelona. Biblioteca del Campus de Mundet ; Passeig de la Vall d'Hebron 171; 08035 Barcelona; Tel. +34934021035; Fax +34934021034ES