Conveyance and End-of-Pipe Measures for Stormwater - FCM
Conveyance and End-of-Pipe Measures for Stormwater - FCM
Conveyance and End-of-Pipe Measures for Stormwater - FCM
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4. Applications <strong>and</strong><br />
Limitations<br />
4.4 Management<br />
Practices<br />
Table 4–1b<br />
Application <strong>of</strong> <strong>End</strong>-<strong>of</strong>-<strong>Pipe</strong><br />
Control Best Management<br />
Practices (continued)<br />
Table 4–1b: Application <strong>of</strong> <strong>End</strong>-<strong>of</strong>-<strong>Pipe</strong> Control Best Management Practices (continued)<br />
Tank/Tunnel<br />
Application<br />
Requirements<br />
Opportunities <strong>and</strong><br />
Limitations<br />
Proven Effectiveness<br />
The primary application <strong>of</strong> tanks/tunnels is in retr<strong>of</strong>it conditions where opportunities<br />
<strong>for</strong> the application <strong>of</strong> source <strong>and</strong> conveyance controls are limited due to the fully<br />
developed condition <strong>of</strong> the area. These facilities are well suited <strong>for</strong> urbanized areas,<br />
since they can be buried <strong>and</strong> will not restrict the use <strong>of</strong> parkl<strong>and</strong>, beach areas, etc.<br />
Opportunities identified based on l<strong>and</strong> availability, tributary area, <strong>and</strong> outfall locations.<br />
Recent monitoring conducted <strong>for</strong> the Eastern Beaches tank (in Toronto) indicates<br />
the removal efficiency is 67% <strong>for</strong> total suspended solids, 43% <strong>for</strong> total phosphorus,<br />
47% <strong>for</strong> oil <strong>and</strong> grease, <strong>and</strong> 21% to 70% <strong>for</strong> metals. Similar results can be expected <strong>for</strong><br />
tunnels. Tunnels/tanks are effective in the control/treatment <strong>of</strong> overflows due to<br />
stormwater.<br />
Cost Capital cost: high. Operation <strong>and</strong> maintenance costs: medium.<br />
Infiltration Basins<br />
Application<br />
Requirements<br />
Opportunities <strong>and</strong><br />
Limitations<br />
Proven Effectiveness<br />
Infiltration basins are generally considered <strong>for</strong> drainage areas < 5 ha that have<br />
permeable soils. They should be used in residential areas only, <strong>and</strong> are ideal <strong>for</strong> soils<br />
with high infiltration potential <strong>and</strong> where the groundwater table is > 1 m.<br />
Opportunities identified based on l<strong>and</strong> availability, tributary area, <strong>and</strong> outfall location.<br />
Experienced high rate <strong>of</strong> failure, which can be attributed to poor site selection, poor<br />
design, poor construction techniques, large drainage area, <strong>and</strong> lack <strong>of</strong> maintenance.<br />
Cost Capital cost: low. Operation <strong>and</strong> maintenance costs: low.<br />
S<strong>and</strong> Filters<br />
Application<br />
Requirements<br />
Opportunities <strong>and</strong><br />
Limitations<br />
Proven Effectiveness<br />
S<strong>and</strong> filters can be constructed either above or below ground, <strong>and</strong> are generally only<br />
appropriate <strong>for</strong> relatively small drainage areas (< 5 ha). Very little is known <strong>of</strong> their<br />
per<strong>for</strong>mance <strong>and</strong> cold-climate operation <strong>and</strong> maintenance.<br />
Opportunity identified based on the presence <strong>of</strong> certain surface features, such as the<br />
type <strong>of</strong> l<strong>and</strong> use, the type <strong>of</strong> soil, <strong>and</strong> ground topography.<br />
S<strong>and</strong> filters are not widely used in Canada, <strong>and</strong> should be generally applied after a<br />
detailed feasibility assessment.<br />
Cost Capital cost: low. Operation <strong>and</strong> maintenance costs: low.<br />
38 <strong>Conveyance</strong> <strong>and</strong> <strong>End</strong>-<strong>of</strong>-<strong>Pipe</strong> <strong>Measures</strong> <strong>for</strong> <strong>Stormwater</strong> Control — July 2005