Gray Water Treatment System: For Sustainable Home Irrigation

EPA Grant Number: SU839265
Title: Gray Water Treatment System: For Sustainable Home Irrigation
Investigators: McCreanor, Philip
Institution: Mercer University
EPA Project Officer: Page, Angela
Phase: I
Project Period: January 1, 2018 through December 31, 2018
Project Amount: $14,986
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2017) RFA Text |  Recipients Lists
Research Category: Sustainability , P3 Awards , P3 Challenge Area - Water


On average, United States citizens individually use approximately 50 gallons of water per day–100 times the required volume of water for living. Water, for many in North America, is seen as a copious resource in our country, but what is the price for our seemingly endless supply of clean water? Greenhouse gas emissions from water treatment and the energy production needed for the process is a significant contribution to climate change, and the Colorado River is beginning to run dry in several places. It is obvious that this exploitation of resources needs change, but humans are resistant to change. Americans are not willing to sacrifice the lifestyle we have been manifesting the past several hundred years, so our challenge as conservationists is to make water conservation a piece of the habits already adopted.



Approximately 30% of all treated, potable water used in the average American household is used for irrigation of private property. Methods of decreasing financial burdens of land irrigation and protecting against potential droughts such as rainwater harvesting are both unreliable and often inconsistent with important civil engineering regulations. Designing a gray water treatment system that utilizes the gray water already produced in daily household activities for the use of irrigation has the capability of decreasing the demand for treated water, without requiring a change in lifestyle. This system, if adopted by the community, has the capability of decreasing climate change inducing energy production, and becoming a step on the path to a mindset of community sustainability.


The system described utilizes biofiltration technology and an in ground detention tank to treat gray water produced in a household’s shower/bath/laundry to be used for outdoor application, namely irrigation. Implementing this system gives households a way to significantly decrease their overall domestic water consumption, and requires no change to their current routines. Water conservation can be observed on a municipal level, reserving water and energy resources, and ultimately decreasing demand of water from natural reservoirs and contribution to climate change. Water conservation must begin with education, and this project creates a tangible medium for homeowners across the country.

Expected Results:

The system design has been built and tested, and the challenge now resides in optimizing resources to create a cost-effective model to bring to the public, as well as providing suitable evidence that the system meets National Sanitation Foundation regulatory standards. Continued suspended solids analysis and measurement of biological oxygen demand of existing laboratory models of treatment system as well as new and existing field systems will support the system’s cooperation with existing regulations. As soon as the system receives approval, the product will be prepared for the marketplace. Bringing the system to the public will require strategic education, and could benefit from the cooperation of local government.

Supplemental Keywords:

Water, treatment technologies, emission control technologies, land use, sustainable urban planning, sustainable infrastructure design, anaerobic processes, biofiltration technology, environmental policy, conservation, sustainable urban redevelopment, water conservation, sustainable water management, urban water planning, water treatment, water filtration, sustainable irrigation, greywater treatment, wastewater, rainwater harvesting

Progress and Final Reports:

  • Final