May, 2014: Large commercial installation for research biology department of Washington University. Design and materials provided by Rainwater Harvesting Supply Company, LLC. System installed by Green Turf Irrigation Company.
Specifications: 20,000 gallons of storage (via (8) 2,500 gallon Poly-Mart storage tanks in dark green); (2) Mini-Cascade inlet filters with knife valves; (4) Vortex 150 medium flow vortex filters with 6” butterfly valves; (2) surface mounted demand pumps with automatic controllers; multiple interconnecting piping and valves for tank storage level control; outflow spin down filters; mechanical level indicators on two primary tanks.
This system is part of the overall construction of a controlled plant grow facility for the Biology Department of Washington University, located at the Tyson Research Facility in Eureka, MO. The system draws from 15,000 square feet of roof surface via two 4” downspouts and two 6” downspout leader pipes. Water from the 4” downspouts is filtered through the Mini-Cascade filters. 4” Knife valves control water diversion and facilitate winterization. The 6” leader pipes (originally cast iron – converted to PVC) filter water through paired vortex filters, utilizing 6” butterfly valves for diversion control and winterization. The vortex filters were paired in parallel because the potential rain fall rate of the local area could have exceeded the flow capacity of single filters. All overflow water is piped back through the 6” floor-penetrated existing drains.
The systems also employ the use of two “demand” pressure pumps. These surface mounted pumps utilize controllers that sense downstream water demand and cycle them accordingly. The pumps are connected to a common pipe system employing five yard hydrants. Water is fed through two spin down, transparent canister filters.
The system is actually comprised of two independent, 10,000 gallon, four tank systems that feed the common string of yard hydrants. The four tanks of each sub-system are connected at the tops and bottoms. Multiple 2” knife valves are used to help control tank volumes. The systems can be alternated from day to day which will result in increased pump life and reduced energy consumption. Each system acts as a “back-up” system in the event maintenance requirements force one system to be deactivated.