Grantee Research Project Results
2018 Progress Report: Gray Water Treatment System: For Sustainable Home Irrigation
EPA Grant Number: SU839265Title: Gray Water Treatment System: For Sustainable Home Irrigation
Investigators: McCreanor, Philip , Rexhausen, Victoria , Kim, Jin Young , Khoja, Simran , Murphy, Griffin , Werner, Deryl Hart
Current Investigators: McCreanor, Philip , Rexhausen, Victoria , Kim, Jin Young , Murphy, Griffin , Hart Jr., Deryl
Institution: Mercer University
EPA Project Officer: Page, Angela
Phase: I
Project Period: January 1, 2018 through December 31, 2018 (Extended to August 31, 2019)
Project Period Covered by this Report: 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: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources , Sustainable and Healthy Communities
Objective:
A gray water landscape irrigation system was installed in 2016 at a Macon Area Habitat for Humanity (MAHfH) home with funding from the Mercer University Quality Enhancement Office. This system treats the gray water via gravity flow through a detention tank, coarse filter, and an intermittent sand filter consisting of one layer of Eljen® GSF modules and 16-inches of #20 filter sand. Atlantis D-Raintank™ modules were used to create a sump beneath the intermittent sand filter. The effluent from the sump is discharged to a buried drip irrigation system via a bottomsuction high-head submersible pump. The treatment system and sump were housed in a 1500 gallon concrete septic which weighs approximately 6 tons. The weight of the concrete septic tank limits installation to septic contractors that are equipped to modify and maneuver concrete septic tanks.
The goal of P3 Phase I funding was to install a gray water landscape irrigation system that used the same treatment technologies but incorporated lighter weight and/or lower-cost materials for the containment vessels. Above ground, detention only gray water irrigation systems were installed at two MAHfH prior to installation of the in-ground system described above. The P3 Phase I system would be installed at one of these homes which already have a sub-surface drip irrigation system.
Progress Summary:
Due to the timing of the funding announcement (mid-spring 2018), the project team has yet to install the lighter-weight, lower-cost gray water treatment system described above. The project team is currently working on obtaining materials and is planning to install the new system in either July or September of 2018. Efforts are being made to arrange donations of some of the larger cost items (500-gallon plastic septic tank, membrane liner, Eljen® GSF modules, bottom-suction high head submersible pump, and Atlantis D-Raintank™ modules). If donations or sufficient discounts can be negotiated, both of the above-ground detention only treatment systems will be upgraded to the new in-ground intermittent sand filter system.
The project team has continued to monitor the installed gray water treatment system which has been successful at treating residential gray water to the effluent for irrigation treatment standards of 25 mg/l 5-day biochemical oxygen demand (BOD5) and 30 mg/l suspended solids (SS). This home consumed potable water at an average rate of 254 gpd. Fifty-seven percent of this water has been treated via the gray water irrigation system. The average loading rate to the intermittent sand filter was 6 gpd/ft2.
Future Activities:
Detention followed by an intermittent sand filter is an effective treatment methodology for reducing the BOD5 and SS of residential gray water. This type of system can be successful at producing a NSF/ANSI 40 Class I effluent when operated in either a partial recirculation or single-pass mode. The information developed from the installation and monitoring of the system funded in Phase I will aid in reducing the capital costs associated with these systems and provide additional information on how the intermittent sand filter component should be sized.
Journal Articles:
No journal articles submitted with this report: View all 6 publications for this projectSupplemental Keywords:
Gray water, intermittent sand filter, irrigationProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.