Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Abstract.

Texas A&M University‘s On-Site Sewage Facility (OSSF) Research Team (AgriLife) was awarded three contracts to address topics requested by the Texas Commission on Environmental Quality 2019 OSSF research grant program. Proposals addressing black water non-potable reuse (BWR), low-pressure dosing systems (LPD), and aerobic treatment unit adequacy with higher strength wastewater and alternative dosing schemes (ATU) were funded.

BWR has been recognized as a partial solution for bridging the gap between water supply and demand in Texas, particularly for residential and commercial dwellings. AgriLife is conducting field scale research and testing of on-site reuse technology to evaluate BWR system performances under varying flow, maintenance, and monitoring conditions.

LPD offers an alternative to a standard gravity or pumped drain field system for disposal and treatment of septic tank effluent to overcome soil and site limitations. Common problems reported by regulators/owners/designers of LPD in Texas were identified by AgriLife and a field research design was conceived to determine if effluent distribution lines using spray emitters with downward orientation can be improved through reorientation.

Use of ATUs for treating domestic wastewater in Texas has increased sharply since the late 1990s. In addition, both organic strength and hydraulic flows of residential ATU‘s have changed due to water conservation devices and graywater reuse. AgriLife is evaluating performance of a most commonly used ATU for its adequacy over a range of experimental high organic strengths and two different dosing operations, timed- and demand dosing. A manufactured high-strength waste is added to raw sewage influent to produce the experimental organic load concentrations. ATU performance adequacy is being evaluated by comparing the five-day biological oxygen demand and total suspended solids concentrations of the ATU influent and effluent streams.

This paper reports the three projects‘ description, work plan, the field experiments design and monitoring schedule that are planned to be implemented at the Texas A&M AgriLife Wastewater Research Facility Center.