Agenda - Council - 07/28/2015 - Laserfiche WebLink

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Community Highlights Rainwater Harvesting at CHS Field CHS Field is a regional ballpark in the heart of the Lowertown neighborhood of Saint Paul, Minnesota just a few hundred feet from America's greatest river. CHS Field is home to the Saint Paul Saints minor league baseball team. The ballpark has a capacity of 7,000 spectators, will host approximately 400,000 visitors annually and will be used for a both sporting and non -sporting events. With population on the rise, Minnesota's groundwater supplies continue to decline and stormwater runoff pollutes local lakes and the Mississippi River. Ballparks require large amounts of water for irrigation, drinking and other operational activities. To reduce consumption of potable water as well as the amount of polluted runoff flowing to the Mississippi River, the City of Saint Paul, Saint Paul Saints, Metropolitan Council and Capitol Region Watershed District collaborated to collect and store rainwater and use it for irrigation and other uses at CHS Field. Why do this? Because even in the Land of 10,000 Lakes, water is a resource we can't afford to take for granted. Project Implementation Source Rooftops provide a great opportunity to collect rainwater because the water flowing off roofs is relatively clean compared to streets or parking lots. CHS Field doesn't have a lot of roof cover, but the Metropolitan Council offered the roof area of the Green Line light rail Operations and Maintenance Facility (OMF) located next door. A pipe installed between the properties allows rainwater to flow from roughly 3/4 -acre portion of the OMF roof to a 27,000- gallon steel cistern tank below the ballpark concourse near center field. Treatment Harvested rainwater at CHS Field is used to irrigate the ball field and flush toilets. Before it can be used for those purposes, water is treated to ensure it is safe. A vortex filter removes large particles such as leaves and sediment (or baseballs!) from the water before it goes to the cistern. From there, a pump pulls water from the cistern and sends it through two filters that remove smaller particles. Finally, UV light is used to disinfect the water before it is sent to the irrigation system or toilets. Irrigation The harvested rainwater is used to irrigate the main playing field, which includes two acres of sod. The area is watered by 115 irrigation heads and 7,000 feet of irrigation pipe. Toilet flushing The public toilets located behind center field include nine water closets and four urinals which are serviced by water from the cistern. The remaining 127 public toilets are located too far away to be served by the cistern, but all toilets in the park include water -saving fixtures. Plumbing Code The rainwater harvesting design was reviewed and approved locally under Minnesota Plumbing Code Rule 4715.0330 "Alternative Fixtures, Appurtenances, Materials, and Methods." Criteria within Uniform Plumbing Code Chapter 17 ("Non -Potable Rainwater Catchment Systems") were used to support the review and approval. Water quality treatment standards were derived from NSF/ANSI 350 for onsite residential and commercial water reuse treatment systems. Challenges • Obtaining approval from the plumbing inspector for rainwater reuse inside the building (toilets) • Constructing the rainwater conveyance piping inside an active rail facility COMMUNITY HIGHLIGHTS WATER SUPPLY MASTER PLAN- Draft June 2015