Water Conservation

Water Reuse Case Studies

Case studies can accelerate progress in water reuse. They share lessons learned, both Do's and Don'ts, transfer technology, foster people-to-people networking and enable rapid research that can lead to a creative "Ah-Ha!" moment. Case studies also honor the good work of trail blazers, thereby encouraging more of the same.

The following water reuse case study resources are organized by topic; however, in some cases the distinctions are not clear and there is overlap among topics.

Centralized Non-potable Reuse

  • Raw Food Crop Irrigation - The classic Monterey Study: The five-year study, published in 1987, investigated agronomic issues (crop yield and quality, metals in soils, metals in plant tissue, soil salinity, sodicity and permeability), health issues (viruses, bacteria, parasites, organic compounds, aerosols and worker safety), and groundwater issues and benefits associated with saltwater intrusion. The conclusions addressed the effectiveness and reliability of the wastewater treatment, consumer and worker safety, agronomic practices, market attitudes, feasibility, and full scale implementation. 1997 Follow-on Study More information on the Monterey County Reclamation Projects.

On-Site Non-Potable Reuse

  • Stormwater Reuse at Baltimore Montgomery Park Office Building: Montgomery Park is an adaptive re-use of the 1.3 million square feet Baltimore, Maryland Montgomery Wards Building built between 1925 and 1927. Home of the Maryland Department of Environment (MDE), one of the many green building features, adopted in 2002, is stormwater used to flush its toilets. A drain field at the bottom of Monroe Street is used to collect stormwater from drains running along Monroe Street and from runoff of the Montgomery Park property. It is cleaned via a sand filtration system and the treated stormwater is then pumped to a cistern on the roof, where it is held and then distributed for use in the toilets. More of the Green Building Features.

  • Graywater Reuse for toilet flushing in a College Residence Hall: Implementation of graywater system at Aspen Residence Hall on Colorado State University’s campus reveals for toilet flushing reveals many practical issues. These include water balance factors, technical details, regulatory interactions (State, plumbing codes, local health department and university authorities), water conservation, water quality, costs and benefits, implications for local city ordinance, user acceptance. Summary Presentation.

Potable Reuse

Centralized Indirect Potable Reuse of Wastewater Effluent (IPR)

  • EPA's 2017 Compendium on Potable Reuse - Case Studies (A1 - A3, A7): This compendium includes the following four case studies of indirect potable reuse:

    • A1. Los Alamitos Barrier Water Replenishment District of So. CA/Leo J. Vander Lans Advanced Water Treatment Facility

    • A2. Orange County Groundwater Replenishment System Advanced Water Treatment Facility

    • A3. Gwinnett F. Wayne Hill Water Resources Center, Chattahoochee River and Lake Lanier Discharge

    • A7. Potable Water Reuse in the Occoquan Watershed

Centralized Direct Potable Reuse of Wastewater Effluent (DPR)

  • EPA's 2017 Compendium on Potable Reuse - Case Studies (A4 - A6): This compendium includes the following four case studies of indirect potable reuse:

    • A4. Village of Cloudcroft PURe Water Project

    • A5. Colorado River Municipal Water District Raw Water Production Facility Big Spring Plant

    • A6. Wichita Falls River Road WWTP and Cypress WTP Permanent IPR and Emergency DPR Project

On-site Potable Reuse of Graywater

  • Direct Potable Reuse (DPR) in Rural Office fewer than 25 Consumers: Ohio passed legislation (Senate Bill 179) in 2014 that added ‘recycled water’ to the list of sources for private drinking water systems (serving fewer than 15 service connections or 25 consumers on average), which falls under the regulatory authority of the Ohio Department of Health. A pilot building-scale direct potable reuse system began operation at a rural office building in 2013 under supervision by the Ohio Department of Health and Cuyahoga County Board of Health, with review by a panel of international water experts. Following a start-up phase with purified water discharged to the septic system, the purified water was allowed to be plumbed into the building’s premise plumbing in 2014. An alternative supply was initially provided for drinking and cooking with notifications posted throughout the building. Since late 2015, the building-scale DPR system has been the primary source of water for all indoor uses including drinking and cooking. The pilot process was concluded in 2016 with approval for continued operation subject to ongoing monitoring, maintenance, notification, and reporting requirements. Tangent Company (of Chagrin Falls, Ohio) designed and continues to operate the building-scale DPR system described above.



Contact Information

Please direct questions or comments to Jim George.​