About Us | Help Videos | Contact Us | Subscriptions

Journal of Environmental Quality Abstract - Ground Water Quality

A Field Study of Virus Removal in Septic Tank Drainfields


This article in JEQ

  1. Vol. 30 No. 6, p. 1933-1939
    Received: Feb 21, 2000

    * Corresponding author(s): lncartaya@earthlink.net
Request Permissions

  1. L.A. Nicosia *a,
  2. J.B. Rosea,
  3. L. Starkb and
  4. M.T. Stewartc
  1. a Dep. of Marine Science, Univ. of South Florida, 140 7th Ave. S., St. Petersburg, FL 33701
    b Tampa Dep. of Health, 3952 W. Dr. Martin Luther King Jr. Blvd., Tampa, FL 33614
    c Dep. of Geology, Univ. of South Florida, Fowler Avenue, Tampa, FL 33602


Two field studies were conducted at a research station in Tampa, Florida to assess the removal of bacteriophage PRD1 from wastewater in septic tank drainfields. Infiltration cells were seeded with PRD1 and bromide and the effects of effluent hydraulic loading rate and rainfall on virus removal were monitored. Septic tank effluent samples were collected after passage through 0.6 m of unsaturated fine sand and PRD1 was detected over an average of 67 d. Bacteriophage PRD1 breakthrough was detected at approximately the same time as bromide in all three cells except for the low-load cell (Study 1), where bromide was never detected. Log10 removals of PRD1 were 1.43 and 1.91 for the high-load cells (hydraulic loading rate = 0.063 m/d) and 2.21 for the low-load cell (hydraulic loading rate = 0.032 m/d). Virus attenuation is attributed to dispersion, dilution, and inactivation. Significant increases in PRD1 elution with rainfall were observed in the first 10 d of the study. Approximately 125 mm of rainfall caused a 1.2 log10 increase of PRD1 detected at the 0.6-m depth. Current Florida on-site wastewater disposal standards, which specify a 0.6-m distance from the drainfield to the water table, may not provide sufficient removal of viruses, particularly during the wet season.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2001. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyPublished in J. Environ. Qual.30:1933–1939.