of Fisheries and Aquatic Chemistry, for Ontario surface water sites, only increasing or stable SO/" trends were observed, and these had both concomitant increasing and decreasing trends for pH. Despite a con siderable number of lakes showing decreas 4
'
ing SO/" trends in Quebec, pH also de creased. The opposite situation was ob served in Atlantic Canada lakes were, de
spite increasing SO/", the dominant trend observed for pH was increasing. Herbicide Loss in Drain Water The dissipation and loss of atrazine and metolachor from field plots and an agricul tural watershed were compared for scale factors related to dissipation and loss. The watershed and field plots, located in south western Ontario, were planted with com and cash crops associated in the watershed. National Water Research Institute scientist
H.Y.F. Ng,and colleagues from Agriculture and Agri-Food Canada, found that factors affecting the dissipation rates in the surface runoff and tile drainage included soil organic carbon, water table depth,soil moisture con tent, soil textures, antecedent days, and time after application. As described in Water Research, such dissipation from the field plots was faster than that from the agricul tural watershed.
Modelling Hydrological Processes INRS-Eau scientists J.P. Fortin and J.P.
Villeneuve, together with colleagues in France, have developed a distributed hydrological model which is able to use data from remote sensing and geographic information systems. The model, Hydrotel, is capable of estimating daily variation and metamorphism of the snowpack, potential evapora tion and the vertical water budget on a wa tershed basis. As described in Revue des
DAVID ELLER, MWI PRESIDENT/CEO WITNESSING TEST OF 60" SUBMERSIBLE PUMP IN MWI'S 10,000 SQUARE FOOT HYDRAULIC TESTING LABORATOF
MWI Submersible Storm Water Pumps!
Earthquakes and hur icanes may be unavoidable,but you prevent flooding in your community.
HOW?
By installing a properly designed storm drainage system using large pumps that remove water rapidly. And since 1926, the premier designer and manufacturer of large storm water pumps has been MWI.
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sciences de I'eau, the model has been ap
plied to watersheds located in Quebec, On tario and British Columbia and to one in
southem France. Hydrotel appears to be a useful tool for understanding and manag
ing phenomena related to hydrogeological processes.
RBC Biofilm Performance
In a paper presented at the 30th Central Canadian Symposium on Water Pollution Research, University of Toronto scientists W.M. Zahid and J.J. Ganczarczyk showed
that the presence of organic particles in the feed to an RBC unit adversely influenced the physical and attachment properties of the RBC biofilms as well as the unit per formance. Biofilms, especially those in the initial compartments of the RBC module, exhibited a fluffy, loose filamentous struc ture which was continually eroding. It is believed that the entrapment of the particulate organics by the biofilm matrix causes a subsequent development ofoxygen-depleted zones and structural flaws within the biofilm.
For more Information,
Circle reply card No. 111 (See page 17)
MWI has thousands of successful pump station designs stored in its computers, ready to help solve your particular flood problem. These successful engineering solutions all utilize MWI's unique submersible pumps. They are available in sizes from 10 hp to 2,000 hp,and feature: Large slow speed propellers that allow the water to be pumped down to the lowest levels in the shortest time and avoid cavitation.
^ Simple, cost effective, and easily maintained installations.
^ Stainless steel construction for longer life and lower maintenance costs.
^ USA-sourced replacement parts that are non-exclusive and reasonably priced. To learn more, call MWI's International Sales/
Engineering Department at(305)426-1500. We'll show you that the best way to prevent flooding is with the three-letter solution: MWI.
APS Atlantic Purification Systems Exclusive Representative for the Atlantic Provinces
(902) 469-2806 - Fax (902)463-3529 SASS Manufacturing Chatham, Ontario
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