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WATER

CASE STUDY

BADGER METER Milwaukee, Wisc. Since 2003, the Milwaukee Metropolitan Sewerage District (MMSD) has been awarding green roof incentive funding to building owners to help reduce the volume and number of sewer overflows to waterways. Badger Meter was awarded $48,135 through MMSD’s Regional Green Roof initiative program to pay for part of its green roof project. Installed July 2012 and completed in November 2012, the new green roof is expected to reduce the annual runoff into the storm water system—an estimated 249,000 gallons—by as much as 90% and delay the remaining 10% to a time past peak flows. For every 1 in. of rainfall, the green roof collects just under 6,000 gallons of water if it is dry. If it is saturated or frozen, some of the water will run off. By keeping excess water from roofs, parking lots and impervious surfaces out of the sewer system, the company is helping reduce the risk of basement backups and sewer overflows. Badger Meter installed two of its 2-in. M-Series Electromagnetic (mag) Flow Meters and a controller, so it can measure the outflow from each of two roof drains. It also mounted a weather station on the rooftop to measure rainfall.

26 | 06.14 | NET ZERO BUILDINGS

Vegin' Out Vegetation is sedum, which is selected, developed and tested for rooftop cultivation.

Green Roof Benefits A key benefit of a green roof is water retention. During a rainstorm, green rooftops collect and store water that would otherwise run off into the sewer.

MILWAUKEE, WI.

Roof Materials The roof consists of a 3-in. layer of insulation, hard board and sealing membrane.

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ARCSA contends that regulations that either require disinfection or approvals, were perceived to be obtained easier if disinfection is included in the design. Pre-green Langer Roofing and Sheet Metal, Inc. handled the design, tear-off of the old roof, and installation of portions of the new roof.

Wahaso’s Bauer suggests owners need to identify and quantify all potential sources and uses of onsite water for reuse. Next, look at the total supply and demand but also the seasonality to balance the two. Also, when looking for an efficient system, design a system for the most contaminated water source, optimize the cistern size and identify options and the relative cost and benefit, and create metrics and goals for the system.

www.nzbmagazine.com

Net Zero Buildings - June 2014  

Highlighting the Path Toward Net Zero Building Design.

Net Zero Buildings - June 2014  

Highlighting the Path Toward Net Zero Building Design.