Changes

The roof membrane installed on the SBR is a polymethyl methacrylate (PMMA) membrane, which was liquid-applied and rolled on like paint. By using a liquid-applied membrane, the roof surface has no seams that could lend themselves to leaks on the roof. The SBR has four (4) roof drains and two (2) overflow pipes that direct rainwater to the basement cistern. The roof surface also has two (2) redundant overflow mechanisms called scuppers that can direct rainwater to the foot of the building in the extremely unlikely event that both overflow pipes fail. The SBR is not expected to overflow for over 100 years…

The roof membrane installed on the SBR is a polymethyl methacrylate (PMMA) membrane, which was liquid-applied and rolled on like paint. By using a liquid-applied membrane, the roof surface has no seams that could lend themselves to leaks on the roof. The SBR has four (4) roof drains and two (2) overflow pipes that direct rainwater to the basement cistern. The roof surface also has two (2) redundant overflow mechanisms called scuppers that can direct rainwater to the foot of the building in the extremely unlikely event that both overflow pipes fail. The SBR is not expected to overflow for over 100 years…

=='''Station 2 – Modulating Control Valves'''==

=='''Station 2 – Modulating Control Valves'''==

The key mechanisms for the SBR’s ability to hold water are the modulating control valves installed on the third floor. Whereas typical flat roof buildings allow rainwater to passively drain from their roofs without rainwater retention, the SBR roof drains are configured with valves that stop drainage from occurring. These valves allow water to pond on the roof up to a safe maximum depth, determined by the height of the overflow pipes, which is an average of 130 mm in the case of the SBR. Water that is held back by these valves is passed through the SBR’s first CSA-compliant treatment system via a suction line that is installed immediately upstream of the east modulating control valve.

The key mechanisms for the SBR’s ability to hold water are the modulating control valves installed on the third floor. Whereas typical flat roof buildings allow rainwater to passively drain from their roofs without rainwater retention, the SBR roof drains are configured with valves that stop drainage from occurring. These valves allow water to pond on the roof up to a safe maximum depth, determined by the height of the overflow pipes, which is an average of 130 mm in the case of the SBR. Water that is held back by these valves is passed through the SBR’s first CSA-compliant treatment system via a suction line that is installed immediately upstream of the east modulating control valve.

=='''Station 3 – Third-Floor Treatment System'''==

=='''Station 3 – Third-Floor Treatment System'''==

It is important to note that chlorination only occurs when the roof water’s chlorine residual drops below 0.5 mg/L, at which water is passed through a chlorination unit and directed back to the filters. This recirculation system was not included in the original SBR design, but its inclusion will ensure that the ponding of water on the roof does not present any water quality and human health concerns. CVC has engaged Toronto Metropolitan University (TMU) to research the water quality of the SBR (among other research areas). Hopefully, this research will demonstrate that rooftop treatment is not required and that treatment before final distribution is sufficient.

It is important to note that chlorination only occurs when the roof water’s chlorine residual drops below 0.5 mg/L, at which water is passed through a chlorination unit and directed back to the filters. This recirculation system was not included in the original SBR design, but its inclusion will ensure that the ponding of water on the roof does not present any water quality and human health concerns. CVC has engaged Toronto Metropolitan University (TMU) to research the water quality of the SBR (among other research areas). Hopefully, this research will demonstrate that rooftop treatment is not required and that treatment before final distribution is sufficient.

=='''Station 4 – Base Cistern and Treatment System'''==

=='''Station 4 – Base Cistern and Treatment System'''==

Once treatment is complete, the rainwater is added to Building A’s greywater line for use in the building’s toilets. Currently, rainwater is only planned for use in toilets, but greywater use could be expanded to irrigation applications at a later phase. Although CVC would have no need for it, there is potential for rainwater to be reused for industrial uses, like vehicle washing and industrial processes. Upgrading the treatment systems could also make rainwater reusable as potable water.

Once treatment is complete, the rainwater is added to Building A’s greywater line for use in the building’s toilets. Currently, rainwater is only planned for use in toilets, but greywater use could be expanded to irrigation applications at a later phase. Although CVC would have no need for it, there is potential for rainwater to be reused for industrial uses, like vehicle washing and industrial processes. Upgrading the treatment systems could also make rainwater reusable as potable water.

=='''Station 5 – Programmable Logic Controller'''==

=='''Station 5 – Programmable Logic Controller'''==