ROCK OUTCROPS IN THE CANADIAN SHIELD: AN INVESTIGATION OF CONTAMINANT TRANSPORT FROM SURFACE SOURCES IN FRACTURED ROCK AQUIFERS

Flow, recharge and transport dynamics in fractured rock aquifers with low lying rock outcrops is a largely unexplored area of study in hydrogeology. The purpose of this thesis is to examine these topics in an agricultural area in Eastern Ontario. The study consists of a regional scale groundwater quality study, an infiltration experiment that considers bacteria transport from the ground surface to a well, and a numerical modelling study that tests the parameters that affect surface infiltration of a tracer from a rock outcrop to a deeper horizontal fracture. In the water quality study, approximately 65% of the samples contained total coliform, 16% contained E. coli, and 1% contained nitrate-N at greater than 5 mg/L. Occurrence of E. coli increased when considering seasonality, where wells were drilled on rock outcrops, and for shallow well intervals. Nitrate-N did not occur above the Guidelines for Canadian Drinking Water Quality (Health Canada, 2012) of 10 mg/L. Rapid arrival times were observed in the infiltration study for both the microspheres (30 minutes) and a dye tracer (45 minutes) in a well approximately 6.0 m in horizontal and 2.8 m in vertical distance from the tracer source. Transport velocities were approximately 38.9 m/day for the dye tracer and 115.2 m/day for the colloidal tracer. Results of the model runs indicate that overburden can provide an effective protective layer to transport in fractures, that high groundwater velocities occur in larger fracture apertures and higher gradients dilute tracer concentrations, and that lower groundwater velocities occur with smaller fracture apertures and lower gradients result in elevated tracer concentrations. Lower rainfall rates, larger fracture apertures, early tracer time, larger gradients, and lower water levels maintained unsaturated conditions for longer time periods such that tracer transport was delayed until saturated conditions were attained. The overall heterogeneity of this aquifer environment creates a source water protection conundrum where the water quality is generally good, while transport can occur very quickly in proximity to rock outcrops and in areas with limited overburden.

Uso sustentável de pesticidas : análise comparativa entre a União Europeia e o Brasil

Tese de doutoramento, Ciências do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2016

Recursos hídricos superficiais vs subterrâneos na Várzea da Nazaré : implicações na qualidade da água

Tese de doutoramento, Geologia (Hidrogeologia), Universidade de Lisboa, Faculdade de Ciências, 2016

Minor element geochemistry of Lake Michigan ferromanganese nodules

Samples of ferromanganese nodules from several localities in Lake Michigan have been analyzed for their minor element content utilizing neutron activation techniques. The thorium and uranium levels in Lake Michigan nodules exhibit marked dissimilarities with marine nodules. The radium content of these freshwater nodules is substantially higher than the reported marine values. The concentrations of barium in the Lake Michigan nodules appear to be abnormally high. Although barium could be present as minute segregations of the mineral barite, patterns obtained using the electron microprobe suggest it is evently dispersed throughout the nodules. The average arsenic content of these freshwater nodules is at least twice as great as that reported for highly oxidized marine sediments. If all this arsenic is dissolved and released into Green Bay as a result of changing environmental conditions (eutrophication), the concentration in the water of Green Bay would be several times the maximum permissible level for drinking water.

Contaminants associated with direct and indirect reuse of municipal wastewater /

Contract 68-02-2257.

Proposed system for determining NPDES and NIPDWR method equivalency.

Mode of access: Internet.

Packed column air stripping.

Mode of access: Internet.

Treatment of combined sewer overflows by high gradient magnetic separation : on-site testing with mobile pilot plant trailer /

Mode of access: Internet.

More about leaking underground storage tanks : a background booklet for the chemical advisory /

Mode of access: Internet.

Análisis hidrotimétrica de las aguas potables de Bilbao y grados hidrotimétricos de las de sus cercanías /

Mode of access: Internet.

Memoria sobre el modo directo de surtir a la villa de Madrid de aguas potables de que carece, y medios de aumentarlas con abundancia para fertilizar los jardines ... /

Mode of access: Internet.

Guidance for the issuance of variances and exemptions.

Title from cover.

Acta de la sesión pública inaugural que en 2 de enero de 1865 celebró la Academia de Medicina y Cirugía de Barcelona : o ensayo analítico de las aguas potables de Tarragona : opúsculo ; Pedro Roqué y Pagani] ; [De las funestas consecuencias físicas y morales de la inobservancia de los preceptos higiénicos en la actual sociedad /

Incluye la lista de las obras que recibió la Academia durante el año 1864; la lista de los Señores Académicos de Número; el escalafón de los Señores Socios corresponsales extranjeros; y el escalafón de los Señores Socios corresponsales españoles.

Acta de la sesión pública inaugural que en 2 de enero de 1866 celebró la Academia de Medicina y Cirugía de Barcelona : Opúsculo... ; Pedro Roqué y Pagani] ; [Reseña Histórica de los asuntos que han ocupado a la Academia de Medicina y Cirugía de Barcelona en el año 1865... /

Incluye la lista de las obras que recibió la Academia durante el año 1865;la lista de los Señores Académicos de Número; el escalafón de los Señores Socios corresponsales extranjeros; y el escalafón de los Señores Socios corresponsales españoles.

Acta de la sesión pública inaugural que la Academia de Medicina y Cirugía de Barcelona celebró el día 16 de enero de 1864 : Opúsculo... ; Pedro Roqué y Pagani] ; [Reseña Histórica de los asuntos que han ocupado a la Academia de Medicina y Cirugía de Barcelona en el año 1863... /

Incluye la lista de las obras que recibió la Academia durante el año 1863;el escalafón de los Señores Académicos de Número; el escalafón de los Señores Socios corresponsales extranjeros; y el escalafón de los Señores Socios corresponsales españoles.