Stormwater Reuse in Urban Settings Case Study: Minneapolis Edison High School

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1 Stormwater Reuse in Urban Settings Case Study: Minneapolis Edison High School CEAM 2015 Annual Conference January 28, 2015 Photo Courtesy of Mississippi WMO

2 Agenda 1 Project Background and Overview 2 Supply vs. Demand 3 Storage Sizing 4 Regulatory Hurdles

3 MWMO Who we are Joint Powers Organization; 7 member cities and MPRB MWMO Offices Edison HS Mission and Goals Protect & improve urban ecosystem by managing water and associated land resources Program areas: CIP Education/outreach Planning Monitoring Watershed Assessment

4 Joined the Initiative in 2009/10 Main Motivators Partnerships Connects to multiple components of our work: Innovative stormwater practice(s) Education/outreach Monitoring

5 NE GREEN CAMPUS

6 EDISON PHASE I

7 EDISON PHASE II

8 1 Background/Overview Northeast Green Campus Site Improvements Modernized Football Field and Track Community Plaza Concessions/Bathroom Building Additional Parking

9 1 Background/Overview Northeast Green Campus Green Elements Engineered Soil Amendments for Football Field Storm Water Re-use Irrigation Future use in Toilets/Urinals Storm Water Monitoring/Education Community Gardens Solar Canopy

10 EDISON PHASE II

11 1 Background/Overview Northeast Green Campus Project Partners Mississippi Watershed Management Organization Minneapolis Public Schools Holland Neighborhood Improvement Association National Football League thru the Local Initiatives Support Corporation

12 PROJECT SCHEMATIC

13 2 Supply vs. Demand Northeast Green Campus Gray vs. Green 3:1 Rule of thumb Supply Impervious Surfaces Roofs Sidewalks/Plazas Parking Lots Turf areas Demand Irrigation Turf (1 per week) Gardens

14 Impervious and Irrigation Areas

15 3 Storage Sizing Northeast Green Campus Design parameters Size of storm/impervious Area? Can store a X rain event Irrigation Area/Duration w/o Supplement? Can irrigate XX acres for XX days w/o supplement Reliability? Met Council Worksheet Diminishing Returns

16 Metropolitan Council Stormwater Reuse Guide Water Balance Tool - 31 year Precipitation Data September, 2011 Prepared by CDM SOURCE Site Data Impervious Area 115,870 square feet Impervious Area 2.66 acres USE Demand Data Irrigation Area 89,298 square feet Irrigation Area 2.05 acres Irrigation Rate 1 inches per week Irrigation Rate 1 inches / week during hot season Irrigation Season week number Hot Irrigation Season week number Storage Data Storage Provided 200,000 gallons Total Storage Required 674,407 gallons % Weeks that Flows Must be Augmented 234 weeks 28.0% Weeks that Reuse System will Meet Demand 603 weeks 72.0% Common Questions on Storage: 1. How much storage do we need? 2. How often will we need to use potable water? 3. Will we drain it in the winter? 4. How deep does it need to be?

17 4 Regulatory Hurdles Requirements for stormwater reuse systems in Minnesota Currently, the State of Minnesota does not have a state-specific code applicable to stormwater harvesting and reuse. The MPCA has developed guidelines for the use of reclaimed wastewater. In 2011, the Metropolitan Council developed the Stormwater Reuse Guide, which was developed based on review of water reuse programs and guidance from other states.

18 4 Regulatory Hurdles City of Minneapolis Requirements Meet 2-, 10-, 100-year pre/post conditions Need to oversize storage? Is the glass half full or half empty? Meet water quality requirements (70% TSS removal for a 1.25 rainfall) Is the underground storage the same as a NURP pond?

19 4 Regulatory Hurdles Plumbing Code Uniform Plumbing Code allows for use of storm water in toilets, urinals, but leaves regulation up to local agency. Not currently allowed by State plumbing code. U of M and St. Paul Saints ballpark trials

20 Questions? Stephanie Johnson, PhD, PE - Mississippi Watershed Management Organization SJohnson@mwmo.org Dan Edgerton, PE - Stantec DEdgerton@stantec.com Mark Statz, PE - Stantec MStatz@stantec.com