Thunder Creek mercury control

1992 ◽  
Vol 19 (3) ◽  
pp. 478-491
Author(s):  
M. D. Haug ◽  
D. J. L. Forgie ◽  
R. Zitta ◽  
B. E. Bews
Keyword(s):  
Contaminated Sediments ◽  
Control Measures ◽  
Mercury Contamination ◽  
Cutoff Wall ◽  
Control Plan ◽  
The North ◽  
North Bank ◽  
Slurry Trench ◽  
Mercury Control ◽  
Floodplain Sediments

In 1978, mercury contamination was discovered in sediments near the confluence of Thunder Creek and the Moose Jaw River, in the City of Moose Jaw, Saskatchewan, Canada. A detailed investigation revealed up to 95 mg/kg of mercury in the floodplain sediments. This contamination was primarily concentrated along the north bank of Thunder Creek and in the adjacent creek sediments. The extent of the contamination indicated that it had not occurred recently, and that total removal of the mercury would be difficult and costly. Thus, a mercury control plan was initiated to remove or effectively contain 95% of the contamination. Contaminated sediments were excavated by dragline from the floodplain and placed on top of mercury contaminated surface sediment along the north bank of Thunder Creek. A soil backfill slurry trench cutoff wall was constructed along the creek through permeable soils and keyed into a low permeability clay shale to isolate the contaminated sediments. The contaminated sediments were also isolated by the construction of an interceptor ditch to direct water around the containment area past the cutoff wall. The contaminated sediments were compacted and covered with lime-modified clay and a topsoil cover which was seeded with grass. Monitoring of water and sediments along Thunder Creek and the Moose Jaw River since implementation of these control measures has shown a significant reduction in mercury levels, indicating that the control system is meeting its objectives. Key words: mercury, environment, contamination, mitigative measures, slurry trench cutoff, interceptor drains, monitoring.

Construction de la digue nord de l'aménagement La Grande

1995 ◽  
Vol 22 (4) ◽  
pp. 723-735 ◽  
Author(s):  
Michel Massiéra ◽  
Jerry Levay
Keyword(s):  
Special Design ◽  
Marine Clay ◽  
River Sand ◽  
Hydroelectric Project ◽  
The North ◽  
Foundation Treatment ◽  
Construction Techniques ◽  
North Bank ◽  
Slurry Trench ◽  
Sensitive Marine Clay

LG-1 hydroelectric project, part of La Grande Complex in northern Quebec, required the construction of a 2444 m long dyke on the north bank. The presence of sensitive marine clay, with deltaic and river sand and silt deposits on top of the clay in the central terrace, called for special design features. These included the construction of a dyke with side berms in a depression to ensure stability and the construction of a cement–bentonite cutoff through the sand and silt deposits of the terrace. This paper describes the different phases of dyke construction with emphasis on foundation treatment and construction techniques. Key words: bentonite, cement, clay, construction, cutoff, dyke, excavation, foundation, slurry, trench.

Implementation of Hamilton-Wentworth Region’s Pollution Control Plan

1996 ◽  
Vol 31 (3) ◽  
pp. 453-472 ◽  
Author(s):  
M. Stirrup
Keyword(s):  
Wastewater Treatment ◽  
Pollution Control ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Control Measures ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Control Plan ◽  
Combined Sewer ◽  
Sewer Overflows

Abstract The Regional Municipality of Hamilton-Wentworth operates a large combined sewer system which diverts excess combined sewage to local receiving waters at over 20 locations. On average, there are approximately 23 combined sewer overflows per year, per outfall. The region’s Pollution Control Plan, adopted by Regional Council in 1992, concluded that the only reasonable means of dealing with large volumes of combined sewer overflow in Hamilton was to intercept it at the outlets, detain it and convey it to the wastewater treatment plant after the storm events. The recommended control strategy relies heavily on off-line storage, with an associated expansion of the Woodward Avenue wastewater treatment plant to achieve target reductions of combined sewer overflows to 1–4 per year on average. The region has begun to implement this Pollution Control Plan in earnest. Three off-line detention storage tanks are already in operation, construction of a fourth facility is well underway, and conceptual design of a number of other proposed facilities has commenced. To make the best possible use of these facilities and existing in-line storage, the region is implementing a microcomputer-based real-time control system. A number of proposed Woodward Avenue wastewater treatment plant process upgrades and expansions have also been undertaken. This paper reviews the region's progress in implementing these control measures.

scholarly journals Effectiveness of SOx, NOx, and Primary Particulate Matter Control Strategies in the Improvement of Ambient PM Concentration in Taiwan

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 460
Author(s):  
Jiun-Horng Tsai ◽  
Ming-Ye Lee ◽  
Hung-Lung Chiang
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Model Simulation ◽  
Control Strategies ◽  
Ambient Air ◽  
Clean Air Act ◽  
Control Measures ◽  
Control Plan ◽  
Clean Air ◽  
Pm2.5 Concentration

The Community Multiscale Air Quality (CMAQ) measurement was employed for evaluating the effectiveness of fine particulate matter control strategies in Taiwan. There are three scenarios as follows: (I) the 2014 baseline year emission, (II) 2020 emissions reduced via the Clean Air Act (CAA), and (III) other emissions reduced stringently via the Clean Air Act. Based on the Taiwan Emission Data System (TEDs) 8.1, established in 2014, the emission of particulate matter 2.5 (PM2.5) was 73.5 thousand tons y−1, that of SOx was 121.3 thousand tons y−1, and that of NOx was 404.4 thousand tons y−1 in Taiwan. The CMAQ model simulation indicated that the PM2.5 concentration was 21.9 μg m−3. This could be underestimated by 24% in comparison with data from the ambient air quality monitoring stations of the Taiwan Environmental Protection Administration (TEPA). The results of the simulation of the PM2.5 concentration showed high PM2.5 concentrations in central and southwestern Taiwan, especially in Taichung and Kaohsiung. Compared to scenario I, the average annual concentrations of PM2.5 for scenario II and scenario III showed reductions of 20.1% and 28.8%, respectively. From the results derived from the simulation, it can be seen that control of NOx emissions may improve daily airborne PM2.5 concentrations in Taiwan significantly and control of directly emitted PM2.5 emissions may improve airborne PM2.5 concentrations each month. Nevertheless, the results reveal that the preliminary control plan could not achievethe air quality standard. Therefore, the efficacy and effectiveness of the control measures must be considered to better reduce emissions in the future.

scholarly journals Sedimentation processes and sedimentary characteristics of tidal bores along the north bank of the Qiantang Estuary

2012 ◽  
Vol 57 (13) ◽  
pp. 1578-1589 ◽  
Author(s):  
DaiDu Fan ◽  
GuoFu Cai ◽  
Shuai Shang ◽  
YiJing Wu ◽  
YanWei Zhang ◽  
...  
Keyword(s):  
Sedimentary Characteristics ◽  
The North ◽  
Tidal Bores ◽  
North Bank ◽  
Sedimentation Processes

A Carved Stone from D'Arcy, Saskatchewan

1940 ◽  
Vol 5 (4) ◽  
pp. 334-335
Author(s):  
Vladimar Alfred Vigfusson
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Glacial Lake ◽  
Bering Strait ◽  
The North ◽  
Gravel Pit ◽  
North Bank ◽  
The Town

In recent years, the attention of some archaeologists has been directed to the Canadian Northwest with the expectation of finding some evidence or indication of the early migrations of man on this continent. That man reached North America by Bering Strait from Asia, is generally accepted, but the theory that the migrations took place in late Pleistocene times and by way of an open corridor between the Keewatin ice and the Rockies, requires confirmation. It is significant that Folsom and Yuma points from Saskatchewan, described by E. B. Howard, were found mainly in areas bordering the ancient glacial Lake Regina.As a further contribution to this problem, it seems desirable to present a brief description of a carved stone relic found in gravel in central Saskatchewan about three years ago.The stone was found about seven miles southeast of the town of D'Arcy in a gravel pit located on Sec. 9, Tp. 28, Rge. 18, W. 3rd Meridian, on the north bank of a ravine running east into Bad Lake.

The Social Structure of Modern Bamako

Africa ◽  
1965 ◽  
Vol 35 (2) ◽  
pp. 125-142 ◽  
Author(s):  
Claude Meillassoux
Keyword(s):  
Social Structure ◽  
The North ◽  
The Social ◽  
North Bank ◽  
Niger River ◽  
Opening Paragraph ◽  
The Town

Opening ParagraphAccording to a partial census taken in 1960, Bamako city has about 130,000 inhabitants. Small by Western standards, it is still by far the largest city in Mali. At the time of the French conquest Bamako had only between 800 and 1,000 inhabitants; it was the capital of a Bambara chiefdom, grouping about thirty villages on the north bank of the Niger river, with a total of about 5,000 people. The ruling dynasty was that of the Niaré, who, according to their traditions, came from the Kingi eleven generations ago (between 1640 and 1700). For defence against the neighbours and armed slave-raiders fortifications were built around the town and a permanent army of so-fa (horsemen) was raised. Soon after its foundation Bamako attracted Moslem Moors from Twat who settled as marabouts and merchants under the protection of the Niaré's warriors. Among them, the Twati (later to be called Touré) and the Dravé became, alongside and sometimes in competition with the Niaré, the leading families.

A GIS planning model for urban oil spill management

2001 ◽  
Vol 43 (5) ◽  
pp. 239-244 ◽  
Author(s):  
J. Li
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Pollution Prevention ◽  
Control Measures ◽  
Planning Model ◽  
Local Conservation ◽  
Control Plan ◽  
Environmental Features ◽  
And Control ◽  
The City

Oil spills in industrialized cities pose a significant threat to their urban water environment. The largest city in Canada, the city of Toronto, has an average 300–500 oil spills per year with an average total volume of about 160,000 L/year. About 45% of the spills was eventually cleaned up. Given the enormous amount of remaining oil entering into the fragile urban ecosystem, it is important to develop an effective pollution prevention and control plan for the city. A Geographic Information System (GIS) planning model has been developed to characterize oil spills and determine preventive and control measures available in the city. A database of oil spill records from 1988 to 1997 was compiled and geo-referenced. Attributes to each record such as spill volume, oil type, location, road type, sector, source, cleanup percentage, and environmental impacts were created. GIS layers of woodlots, wetlands, watercourses, Environmental Sensitive Areas, and Areas of Natural and Scientific Interest were obtained from the local Conservation Authority. By overlaying the spill characteristics with the GIS layers, evaluation of preventive and control solutions close to these environmental features was conducted. It was found that employee training and preventive maintenance should be improved as the principal cause of spills was attributed to human errors and equipment failure. Additionally, the cost of using oil separators at strategic spill locations was found to be $1.4 million. The GIS model provides an efficient planning tool for urban oil spill management. Additionally, the graphical capability of GIS allows users to integrate environmental features and spill characteristics in the management analysis.

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