Toxicity of surface waters in a part of Shubenacadie drainage system, Nova Scotia

1961 ◽  
Author(s):  
J S Scott
Keyword(s):  
Nova Scotia ◽  
Surface Waters ◽  
Drainage System

Chemical recovery and browning of Nova Scotia surface waters in response to declining acid deposition

2021 ◽  
Author(s):  
D. Redden ◽  
B. F. Trueman ◽  
D. W. Dunnington ◽  
L. E. Anderson ◽  
G. A. Gagnon
Keyword(s):  
Nova Scotia ◽  
Acid Deposition ◽  
Surface Waters ◽  
Chemical Recovery ◽  
Size Distributions ◽  
Iron Aluminum

Colour, pH, iron, and aluminum are increasing in NS surface waters; iron/aluminum size distributions include at least two colloidal fractions.

The Effect of a Storm on an Inshore Area with Markedly Stratified Waters

1935 ◽  
Vol 1 (4) ◽  
pp. 227-237 ◽  
Author(s):  
H. B. Hachey
Keyword(s):  
Nova Scotia ◽  
North Atlantic ◽  
Surface Waters ◽  
South Coast ◽  
The South ◽  
Wind Action ◽  
Bottom Waters ◽  
Mixed Water

Coincident with the formation and subsequent movement of a North Atlantic cyclone following the characteristic track, offshore surface waters are forced to the south coast of Nova Scotia with consequent removal of intermediate and bottom waters. Wind action, as the storm approaches, intensifies the mixing of the waters. Markedly stratified waters are thus temporarily replaced by a body of thoroughly mixed water.

scholarly journals Modelling acidification, recovery and target loads for headwater catchments in Nova Scotia, Canada

2007 ◽  
Vol 11 (2) ◽  
pp. 951-963 ◽  
Author(s):  
C. J. Whitfield ◽  
J. Aherne ◽  
P. J. Dillon ◽  
S. A. Watmough
Keyword(s):  
Nova Scotia ◽  
Surface Waters ◽  
Dynamic Models ◽  
Model Simulation ◽  
Aquatic Organisms ◽  
Good Prognosis ◽  
Emissions Reductions ◽  
Critical Limit ◽  
Headwater Catchments ◽  
Magic Model

Abstract. The response of twenty acid-sensitive headwater catchments in Nova Scotia to acidic deposition was investigated for the period 1850–2100 using a dynamic hydrochemical model (MAGIC: Model of Acidification of Groundwater in Catchments). To ensure robust model simulation, MAGIC was calibrated to the long-term chemical trend in annual lake observations (13–20 years). Model simulations indicated that the surface waters of all twenty catchments acidified to the 1970s but showed subsequent recovery (increases in acid neutralising capacity (ANC) and pH) as sulphate deposition decreased. However, under proposed future emissions reductions (approximately 50% of current deposition) simulated ANC and pH will not return to estimated pre-industrial levels by 2100. An ANC of 20 μmolc L−1 and pH of 5.4 were defined as acceptable chemical thresholds (or critical chemical limits) for aquatic organisms in the current study. Under the proposed emissions reductions only one catchment is predicted to remain below the critical limit for ANC by 2100; three additional catchments are predicted to remain below the critical limit for pH. Dynamic models may be used to estimate target loads, i.e., the required deposition reductions to achieve recovery within a given time. Setting target loads at approximately 30% of current depositions would allow three of the four lakes to reach the chemical criteria by 2030. In contrast to the generally good prognosis for surface waters, soils lost an average of 32% of estimated initial base saturation and recovery is estimated to be very slow, averaging 23% lower than pre-acidification levels in 2100.

Cretaceous Deposits in the Musquodoboit River Valley Nova Scotia

1971 ◽  
Vol 8 (9) ◽  
pp. 1152-1154 ◽  
Author(s):  
Chang L. Lin
Keyword(s):  
Nova Scotia ◽  
Early Cretaceous ◽  
Drainage System ◽  
River Valley ◽  
Tributary Stream ◽  
Available Information ◽  
Cretaceous Deposits

Two carbonaceous samples recovered from pre-Pleistocene unconsolidated deposits in a borehole at Elmsvale, Musquodoboit River Valley, Nova Scotia, were dated as Early Cretaceous in age. The thickness of the deposit encountered was 551 ft (168 m). Available information suggests that the upper segment of the present Musquodoboit River was a tributary-stream of the Shubenacadie drainage system.

scholarly journals Impact of historical gold mining activities on marine sediments in Wine Harbour, Nova Scotia, Canada

2015 ◽  
Vol 51 (1) ◽  
pp. 344 ◽  
Author(s):  
Megan E Little ◽  
Michael B Parsons ◽  
Brent A Law ◽  
Timothy G. Milligan ◽  
John N Smith
Keyword(s):  
Nova Scotia ◽  
Marine Sediments ◽  
Surface Waters ◽  
Mine Tailings ◽  
Crushed Rock ◽  
Mine Wastes ◽  
Wide Range ◽  
High Concentrations ◽  
Early Operations ◽  
Harbour Area

Past investigations at historical gold (Au) districts in Nova Scotia, Canada have identified elevated concentrations of arsenic (As) and mercury (Hg) in nearby sediments and waters. These metal(loid)s are derived from erosion of mineralized bedrock, and the disposal of mine tailings into the environment during early operations. The Wine Harbour gold district is located along the eastern shore of Nova Scotia, and produced 1329 kg of Au from 75 581 tonnes of crushed rock from 1862 to 1939.The gold occurs in arsenopyrite-bearing quartz-carbonate veins and was extracted using stamp milling and Hg amalgamation. Historical maps document tailings deposits near former stamp mill sites; however, the extent to which these mine wastes influence environmental quality in the adjacent marine environment is uncertain. In this study, we measured metal(loid) concentrations in tailings, marine sediments, and surface waters to assess the lateral and vertical extent of mining-related impacts on Wine Harbour. Chemical analyses of terrestrial and intertidal tailings reveal high concentrations of both As (86–196 000 mg/kg) and Hg (444–320 000 µg/kg). Analyses of marine sediments show a wide range in both As (4–568 mg/kg) and Hg (<5–7430 µg/kg) concentrations. In general, the highest metal(loid) concentrations in sediments were recorded down-gradient of stamp mill sites. Elevated concentrations were also detected in sediments underlying an active mussel aquaculture operation at the western end of the harbour. Results from this study have been used to help assess potential ecosystem and human health risks associated with historical gold mine wastes in the Wine Harbour area.

Influence and modelling of urban runoff on the peak flows in rivers

2009 ◽  
Vol 60 (7) ◽  
pp. 1919-1927 ◽  
Author(s):  
G. Vaes ◽  
T. Feyaerts ◽  
P. Swartenbroekx
Keyword(s):  
Surface Waters ◽  
Drainage System ◽  
High Water ◽  
Water Levels ◽  
Urban Drainage ◽  
Combined Sewer Overflows ◽  
Drainage Systems ◽  
Simplified Approach ◽  
Urban Drainage Systems ◽  
Urban Catchments

Surface waters and urban drainage systems are usually studied separately. However there are important interactions between both systems. Urban drainage systems can have an important impact on the surface waters, mainly at combined sewer overflows. On the other hand during periods of high water levels in a river, the runoff from the urban drainage system can be significantly influenced by backwater, which increases the probability of flooding in is not obvious, because the modelling tools for both systems are often hard to combine properly. To properly assess the probability of flooding for this kind of integrated water systems, different submodels are needed for both subsystems. In practice often one single model is used to describe the runoff to rivers despite the presence of urban catchments. The main objective of this study is to show the limits of this simplified approach. Furthermore, it is necessary to use continuous long term simulations, because of the differences in runoff behaviour. Detailed hydrodynamic models do not really fit for this purpose because of long simulation times and high demands in memory and disk space. Therefore simplified conceptual models are more useful.

scholarly journals A Direct Method to Measure14CO2Lost by Evasion from Surface Waters

Radiocarbon ◽  
2006 ◽  
Vol 48 (1) ◽  
pp. 61-68 ◽  
Author(s):  
M F Billett ◽  
M H Garnett ◽  
S M L Hardie
Keyword(s):  
Surface Waters ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Direct Method ◽  
Initial Period ◽  
Drainage System ◽  
Isotopic Signature ◽  
Direct Measurements ◽  
Floating Chamber ◽  
A Direct Method

Recent methodological advances in the use of zeolite molecular sieves for measuring the isotopic signature of CO2have provided the opportunity to make direct measurements of14CO2 in various field situations. We linked a portable molecular sieve/pump/IRGA system to a floating chamber to demonstrate the potential of the method to quantify the isotopic signature (δ13C and14C) of CO2lost by evasion (outgassing) from surface waters. The system, which was tested on a peatland stream in Scotland, involved 1) an initial period of scrubbing ambient CO2from the chamber, 2) a period of CO2build-up caused by surface water evasion, and 3) a final period of CO2collection by the molecular sieve cartridge. The field test at 2 different sites on the same drainage system suggested that the results were reproducible in terms of δ13C and14C values. These represent the first direct measurements of the isotopic signature of CO2lost by evasion from water surfaces.

scholarly journals Distribution, Drivers, and Threats of Aluminum in Groundwater in Nova Scotia, Canada

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1578
Author(s):  
Kristin A. Hart ◽  
Gavin W. Kennedy ◽  
Shannon M. Sterling
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Surface Waters ◽  
Fossil Fuels ◽  
Salmon River ◽  
Risk Areas ◽  
High Concentrations ◽  
Health Canada ◽  
Al Treatment ◽  
Carbon Concentrations

Increased rates of acid deposition derived from the burning of fossil fuels over the last century have resulted in the acidification and increase in aluminum (Al) levels in freshwaters and soils in sensitive areas. While the acidification of surface waters such as lakes and rivers has been extensively studied, the acidification status and resulting Al concentrations in groundwater are poorly understood. Here we aim to describe the distribution of Al in groundwater across the province of Nova Scotia, Canada. We investigate the hydrogeological conditions that influence Al concentrations in groundwater and compare Al concentrations to legislated threshold levels for human and aquatic health. We found groundwater Al concentrations to be highest in areas underlain by plutonic and metamorphic bedrock types as well as surficial aquifers, with pH and organic carbon concentrations having the strongest correlation with groundwater Al concentrations. Few samples exceed the maximum acceptable concentration of 2900 µg/L released by Health Canada (2021), but these exceedances are important to highlight given the challenges with respect to Al treatment in private domestic wells and our evolving understanding of Al impacts to human health. High concentrations of Al in groundwater may also be exported to surface waters such as rivers and lakes, where they can be harmful to aquatic populations such as Atlantic salmon (Salmo salar). We recommend that private well owners test their water supplies for Al, and that further studies on Al export from groundwater to surface water be carried out in the most high-risk areas coincident with important Atlantic salmon river watersheds.

scholarly journals Modelling acidification, recovery and target loads for headwater catchments in Nova Scotia, Canada

2006 ◽  
Vol 3 (6) ◽  
pp. 3595-3627 ◽  
Author(s):  
C. J. Whitfield ◽  
J. Aherne ◽  
P. J. Dillon ◽  
S. A. Watmough
Keyword(s):  
Nova Scotia ◽  
Surface Waters ◽  
Dynamic Models ◽  
Model Simulation ◽  
Aquatic Organisms ◽  
Good Prognosis ◽  
Emissions Reductions ◽  
Critical Limit ◽  
Headwater Catchments ◽  
Magic Model

Abstract. The response of twenty acid-sensitive headwater catchments in Nova Scotia to acidic deposition was investigated for the period 1850–2100 using a dynamic hydrochemical model (MAGIC: Model of Acidification of Groundwater in Catchments). To ensure robust model simulation, MAGIC was calibrated to the long-term chemical trend in annual lake observations (13–20 years). Model simulations indicated that the surface waters of all twenty catchments acidified to the 1970s but showed subsequent recovery (increases in acid neutralising capacity (ANC) and pH) as sulphate deposition decreased. However, under proposed future emissions reductions (approximately 50% of current deposition) simulated ANC and pH will not return to estimated pre-industrial levels by 2100. An ANC of 20 μmolc L−1 and pH of 5.4 were defined as acceptable chemical thresholds (or critical chemical limits) for aquatic organisms in the current study. Under the proposed emissions reductions only one catchment is predicted to remain below the critical limit for ANC by 2100; three additional catchments are predicted to remain below the critical limit for pH. Dynamic models may be used to estimate target loads, i.e., the required deposition reductions to achieve recovery within a given time. Setting target loads at approximately 30% of current depositions would allow three of the four lakes to reach the chemical criteria by 2030. In contrast to the generally good prognosis for surface waters, soils lost an average of 32% of estimated initial base saturation and recovery is estimated to be very slow, averaging 23% lower than pre-acidification levels in 2100.

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