Virus occurrence and transport in a school septic system and unconfined aquifer

• Published in: Ground water Vol. 36; no. 5; pp. 825 - 834
• Main Authors: DeBorde, D.C. (University of Montana, Missoula, MT.), Woessner, W.W, Lauerman, B, Ball, P.N
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.1998; Ground Water Publishing Company
• Subjects: AGUAS FECALES; BACTERIOFAGOS; BACTERIOPHAGE; BACTERIOPHAGES; CAPA FREATICA; COLIPHAGES; EAU USEE DOMESTIQUE; EDUCATIONAL INSTITUTIONS; Effluent treatment; ENTEROVIRUS; Environmental impact; ETABLISSEMENT D'ENSEIGNEMENT; Groundwater; GROUNDWATER POLLUTION; GROUNDWATER TABLE; HIGH SCHOOLS; HUMAN ENTEROVIRUS; Hydraulic conductivity; INSTITUCIONES DE EDUCACION; Mass transfer; MONTANA; NAPPE SOUTERRAINE; POLLUTION DE L'EAU SOUTERRAINE; POLUCION DE AGUAS SUBTERRANEAS; Sanitation; Schools; SEPTIC TANK EFFLUENT; Septic tanks; SEWAGE; TRANSPORT PROCESSES; Viruses
• ISSN: 0017-467X; 1745-6584
• DOI: 10.1111/j.1745-6584.1998.tb02201.x

Federal efforts to establish reliable natural disinfection criteria for ground water supplies require the identification of appropriate indicator viruses to represent pathogenic viruses and an understanding of parameters affecting virus survival and transport in a variety of hydrogeologic settings. A high school septic system and the associated fecal waste impacted unconfined sand and gravel aquifer were instrumented to: (1) evaluate if the concentrations of enterovirus and coliphage in this system were sufficient to allow their use as indicator viruses; (2) establish viral transport rates, transport distances, and concentrations in a highly conductive cold water aquifer. Enteroviruses were found in only two of eight assays of the septic tank effluent (0.26 and 4.4 virus/L) and were below detection in eight ground water samples. Male-specific and somatic coliphage were detectable in both the septic tank effluent (averaging 674,000 and 466,000 coliphage/L, respectively) and in the impacted underlying ground water, decreasing to detection limits beyond 38 m of the drainfield. Virus transport parameters in this aquifer were measured by seeding high numbers of MS2 and theta X174 coliphage into the ground water and documenting their transport over 17.4 m. A portion of the seeded virus traveled at least as fast as the bromide tracer (1 to 2.9 m/d). Proposed natural disinfection criteria would not be met in this aquifer using standard 30.5 m setback distances. In addition, the virus sorption processes and long survival times resulted in presence of viable seed virus for more than nine months