Client: Pioneer Hi-Bred InternationalBackground:
Pioneer Hi-Bred, a DuPont business headquartered in Johnston, Iowa, is the world’s leading developer and supplier of advanced plant genetics, agronomic support and service to farmers (Pioneer). Innovative and customer focused, Pioneer seeks to increase farmer productivity and profitability, and to develop sustainable agricultural systems for people everywhere. The company had six new greenhouses slated for construction in 2011 that would use over 13 million gallons of municipal water annually for irrigation. The company’s sustainability team met with Wahaso late in 2010 to evaluated ways to replace a significant amount of the municipal water with harvested rainwater.
System Type: Stormwater for Greenhouse Irrigation
Commissioning Date: 05/10/2013
Challenge: Pioneer needed a large amount of storage - 100,000 gallons, with a cistern located beside a stormwater detention area. Water quality in storage was an issue - with long storage periods when the water could turn stagnate. Additionally, a high CFS flow rate needed to be filtered properly to keep the cistern clean of sediment. The rainwater was to be used in Pioneer's research greenhouses - where consistent water quality is a critical issue.
Solution: Wahaso worked with the Pioneer sustainability team to put together a plan to capture rainwater and stormwater to feed their new greenhouses. Phase I of the project called for constructing a 100,000 gallon Atlantis Modular Rainwater harvesting system. The 50'x200' basin consisted of 1,079 triple Atlantis tanks which were wrapped in a geotextile and encased in a 45 mil. Firestone EPDM impermeable liner. The tank was designed to capture the rainwater from rooftops and stormwater from parking lots, channeled through a CDS system (continuous deflection separation) and captured within the tanks. Atlantis was a perfect solution for the cistern because of the cistern location within a stormwater retention area. In addition to water entering the tank directly from the CDS unit, additional stormwater can filter through plant medium and sand directly into the top of the tank. A unique pressure-regulating valve allows water pressure outside the tank to equalize tank levels during high-capacity storms. The Atlantis system passively manages water quality in the tank during long storage periods. Wahaso designed and supplied a custom R/O system to bring both rainwater and municipal make-up water to a high quality standard to supply the greenhouses. The R/O discharge is captured and used to supply toilet flushing and general cleaning in the facility. A 15,000 HDPE tank in the equipment area holds treated R/O water and a second 5,000 gallon tank stores discharge for reuse. A UV loop in both tanks maintains water quality by preventing any growth of algae or pathogens.
Results: The design of the Atlantis system maintains the water quality in the tank without the need for additional treatment or circulation. The water quality, without chlorine and with low dissolved solids, is a superior source of water to the municipally supplied source. The system is expected to save over 3 million gallons of municipal water per year while also reducing the company's fees for stormwater runoff.