Client: Dan FieldsBackground:
When Dan Fields contemplated his new Volvo dealership building, he knew that being “green” is important to Volvo customers, and that a USGBC LEED certification would have marketing appeal to those customers who care about safety and the environment. So he set off to build what would become the “World’s Greenest Volvo Dealership”. That meant that he needed to construct a building using sustainable practices that included recycled materials, energy efficiency and sustainable energy and water sustainability. Wahaso joined the team early on to make the building nearly 100% water sustainable.
System Type: Rooftop Rainwater to Flush Toilets and Irrigate Landscaping
Commissioning Date: 02/10/2011
Challenge: To earn LEED Silver certification, the building would have to reduce its use of municipal water by 20%. Stormwater runoff would need to be reduced, and the landscaping would need to be drought tolerant and use little to know municipal water for irrigation.
Solution: Wahaso worked with JDR Engineering out of Madison, Wisconsin to design a single source, multi-use system that would capture rooftop rainwater into two different cisterns to provide 100% of the toilet flushing requirements throughout the year and nearly all the requirements for landscape irrigation during summer months. We used two 2,200 gallon CorGal cisterns above-grade that provided the "show" that Dan Fields wanted, while storing the majority of water (10,000 gallons) below-grade in an Atlantis D-Raintank structure. The above grade tanks are used during the summer months when more storage is needed to meet irrigation demands, and supplement the below-grade storage. We used the Wahaso WCS-100 chlorination system to automatically add liquid chlorine as needed to keep the harvested water safe for public exposure. One filtration and pumping system serves both end uses. An ET Water irrigation controller uses local weather data to apply only as much water to the landscaping as needed to make up moisture lost through plant evaporation and transpiration.
Results: The water harvesting system should save over a quarter of a million gallons per year of municipal water while supporting the effort to prevent any stormwater runoff from the property. And by irrigating with harvested water, the landscaping requires almost no municipal water for irrigation.