VIRUS REMOVAL

In 1995, the Commonwealth of Massachusetts made significant changes to its regulations governing onsite septic systems to reflect advancements in the knowledge base of onsite wastewater treatment. While these changes reflect many of the advances in our understanding of the treatment for certain constituents, much was still not understood about the role of standard septic tank-leach fields in the treatment for pathogens, notably viruses. The need for this type of understanding was amplified when the state allowed the use of innovative/alternative (I/A) septic systems, which under certain approvals were allowed to compensate for certain deficiencies that an applicant might present (i.e. less distance to groundwater or less available soil absorption system area). While the efficacy of I/A for treatment of certain constituents was widely accepted, questions arose as to whether the “credits” granted to I/A technology were appropriate in light of the present knowledge base regarding pathogens. The purpose of this study was to determine the efficiency of standard septic systems for the removal of viruses and compare this performance with selected I/A technology. The study further endeavored to place the findings in context of recent literature and make recommendations for maximizing virus removal from onsite septic systems.