7 ways to make our project water usage efficient & sustainable
_____________________________________________________________________________________________________
BY JOSEPH AZAR
The three things to think about first are Indoor water usage, outdoor water usage and water metering
1.Outdoor water usage:
Starting with the outdoor water usage the perfect scenario would be to implement a design where no irrigation is needed at all after two years from planting Landscape.
2.Plant species choice
To mention few examples how this can be achieved, Implement the Xeriscaping strategy, that uses a little to no water at all, this could be achieved by choosing native and adaptive plants and by avoiding the usage of Turf Grass.
3.Irrigation
To implement this strategy, you need to a study including a description of the plants and an indication obtained from calculations and data collection on why the average rainfall will be sufficient and that no water budget would be used in your project.
If this cannot be accomplished then at least go for a design that can reduce irrigation if avoiding irrigation altogether is impossible, to mention the calculation results could be obtained using the EPA water sense budget tool, and this reduction should be 50 % at least from the baseline, again this reduction must be achieved through plant species selection and through irrigation efficiency strategies and not by using alternative water sources.
4.Alternative water usage
Alternative water sources such as gray water, rainwater, etc … are not part of this reduction, but if course it is important to use them in our strategies but the first step is to make reductions by not using alternative water.
So always remember to address your irrigation installed in the fundamental commissioning.
5.Indoor water usage:
The reduction should be at least 20 % from the baseline, to meet this a prescriptive path can be applied just by using specially fabricated high performance fixtures and fitting like the water sense labeled for newly installed toilets, urinals, private and public lavatory faucets, shower heads, … and each fixtures shouldn’t exceed the maximum level required in order for your project to comply with the baselines extracted from the Energy policy act of 1992 as a standard.
If this prescriptive path is not applied a calculations method can be made in order to achieve at least this 20 % reduction from the baseline.
To mention ENERGY STAR appliances can help you achieve this and remember for each strategy try to implement as soon as possible during the integrative design phase.
You can use a special calculators to get your results like the calculator on the USGBC website , to have a glimpse of what are this about in the calculator usually the team will need to enter the type of fixtures , the flush and the flow rates the manufacturer and model, the percentage of the occupants using the fixture….
6.Install water metering:
A prerequisite is to install building – level water metering in order to measure and track water efficiency , and to enable facility manager a better comprehension of what is happening this a better management for the water building consumption, at least do this installation for each ground and provide the building with monthly and yearly water usage date , the meters can be either manual or automated.
Implement metering by identifying all the sources of potable water used in the building and the grounds from plumbing , to irrigation , to Cooling towers, etc …
Once the building is occupied you will need this start of tracking of water usage, always remember to figure out the meters early in the integrative design with the MEP also with the facility manager.
If you want optimize the performance and develop metering to get into numbers a bit permanent installation should be a least for two subsystems like tracking at least 80 % of your irrigation, also at least track 80 % of your indoor fixtures and fittings, a third subsystem could be domestic hot water also at least track 80 % , also you can track 100 % of boilers if usage is more than 100.000 gallons and more than 500000 BtuH, also track 100 % of reclaimed water for other process water at least 80 % of expected daily consumption.
Remember ony potable water end uses must be metered for example an on-site potable water treatment or a public supply, an onsite well…
Cooling towers are not included and another example of things that does not need to be metered is a rainwater collection system.
7.Cooling towers:
Cooling Towers have thein own special approach , I won’t get into technical way of doing things but it is related to achieving a maximum number of cycles without exceeding filtration levels or affecting the operation of condenser water system, drift, blowdown or bleed off overflows should also be in mind, so again this is technical a bit but just what you need to know is the cooling towers should be taken into consideration to have a better performance.
THE CONCLUSION:
In conclusion, achieving LEED credits for indoor and outdoor water usage is a critical component of sustainable building design. By implementing efficient plumbing fixtures and water-saving technologies, buildings can significantly reduce their water usage and contribute to conservation efforts. Furthermore, incorporating green spaces, such as rain gardens and vegetative roofs, can help manage stormwater and reduce the impact of development on local water resources. Achieving LEED credits for water usage is not only environmentally responsible but can also result in cost savings for building owners and occupants. As water scarcity becomes an increasingly pressing issue, sustainable water practices will become even more important in building design and operations.