Review
A short history of methods used to measure bathing beach water quality

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Highlights

  • Methods for measuring fecal indicator bacteria (FIB) first developed in late 1800's.

  • Relationship between health effects and FIB densities in water first shown in 1940's.

  • Recreational water quality now determined by E. coli or Enterococci FIB densities.

  • Culture methods for E. coli and enterococci have improved throughout 20th century.

  • Molecular methods developed starting in 21st century now provide more rapid results.

Abstract

The enumeration of fecal indicators of bathing beach water to determine quality have been used since the mid-20th century. In the 1930s and as late the 1970s, the Most Probable Number procedure for estimating microbial densities in water was in general use. The most probable number procedure was replaced as a method of choice by the membrane filter procedure. The membrane filter had been developed in the early 1950s but did not find widespread use until the 1970s. Another development during the 1970s was the quanti -tray method, a proprietary multi-well tray, which was introduced as an innovative form of the Most Probable Number procedure. In 2005 molecular methods were introduced as a rapid 3-hourh procedure for measuring bathing beach water quality. Several variations of this approach are currently in use or in development.

Introduction

The history of the methods used for measuring the quality of recreational water is a relatively short history by any standard. In the United States the question of whether there was a need to monitor the quality of recreational beach waters had been discussed for decades by public health authorities. However, according to the US Public Health Service it was deemed to be unnecessary because there was little evidence in the way of health effects to support initiating health standards and water quality monitoring for bathing beach waters (APHA, 1933). Subsequently the US Public Health Service conducted a series of epidemiological studies in the late 1940s that indicated a relationship between water quality and health effects (Stevenson 1953). This relationship was based on the amount of feces in the water, which were measured by the density of fecal bacteria in the water and illness in swimmers. At that time, the coliform group of microorganisms was used to measure drinking water quality and that methodology was easily transferred to the measurement of bathing beach waters (Standard Methods, 1946). Coliform bacteria occur in the feces of warm-blooded animals including humans and are generally believed to be harmless. They were first discovered in 1885 by a biologist named Escherich who found them in the feces of infants (Escherich 1885). He named the microorganism Bacillus coli, which much later was re-named Escherichia coli or E. coli (Castellani and Chalmers 1919). Not much later in 1892, another biologist named Schardinger, found Bacillus coli in human and animal feces, and in water. He suggested they might be used to measure the degree of fecal contamination in the water (Schardinger, 1892). His reasoning was simple: the greater the numbers, the greater the risk. Since no one has found a target microbe or chemical that is more effective at quantifying feces or pathogens in the water environment, the approach has held up to this day. Many years later the Bacillus coli and some related microbes were given the general name coliforms (Breed and Norton 1937).

Two researchers who made valuable contributions to the measurement of fecal contamination of water in the late nineteenth century are mentioned here because of the significance of their research. They each devised procedures that allowed coliforms in water samples to be quantified. The first advance in the quantification of coliform bacteria was suggested by Durham (1898). This technique involved the capture of gas produced by coliforms by introducing a small inverted tube into the liquid growth media, which collected the gas as it was produced. Another valuable tool which aided in the quantification of coliforms was the development of a probability-based system by McCrady (1915) who estimated the number of organisms in a water sample based on the number of positive and negative gas producing tubes in a series of tubes from a water sample. A table was prepared for this system from which the number of positive and negative tubes could be converted to an estimate of the most probable number (MPN) of microbes in the sample. These two significant developments provided the tools that later allowed for the quantification of coliform and other fecal indicator bacteria in a water sample by a system referred to as the multiple-tube fermentation technique.

This historical review of methods for the measurement of recreational water quality covers only methods developed in the United States that have been approved by the United States Environmental Protection Agency (USEPA) or accepted by the Standard Methods for the Examination of Water and Wastewater Organization.

Section snippets

The coliform era 1900–1976

Coliforms are a diverse group of microbes, generally made up of the species E coli, Klebsiella, Citrobacter and Enterobacter spp. They have in common these characteristics: all are Gram-negative, non-spore forming, rod-shaped bacilli that ferment lactose, producing acid and gas. They are oxidase negative and grow at temperatures from 35 °C to 37 °C. (At some point in the early 1960s coliforms were re-named total coliforms in the United States. In this review, coliforms and total coliforms will

The fecal coliforms 1965–present

Fecal coliforms, a subset of the coliform group, have the ability to grow at much higher temperatures, 44 °C to 46 °C. Fecal coliforms are measured using EC medium. The EC medium for fecal coliforms is a modification of an earlier medium formulation developed by Eijkman (Eijkman, 1904) and modified by Perry and Hajna to measure thermotolerant coliforms (Perry and Hajna 1933). EC medium selects mainly for E. coli, but also allows the growth of Klebsiella spp and some Citrobacter spp. The

Fecal streptococci and enterococci 1957–1968

These Gram-positive, coccoid-shaped, catalase negative, non-spore forming organisms that today we call Enterococcus species or more commonly enterococci, have gone through many name changes since their discovery in the late 19th century. The enterococci that are used today to measure water quality have the main distinguishing characteristics that they are able to grow in a medium containing 6.5% sodium chloride and they can grow at 10 °C as well as 45 °C. The name Enterococcus was first used by

E. coli 1962–present

The measurement of coliforms and fecal coliforms with the MPN and membrane filter methods for beach water quality was carried out well into the late 1980s. There were, however, many microbiologists and water authorities who recognized faults in these two methods (Edberg et al. 2000). It was pointed out that the indicator bacteria, total coliforms and fecal coliforms, contained bacteria that were not associated with feces, sometimes indicating gross overestimates of the level of fecal

Background

In 2000, the Congress of the United States passed the Beaches Environmental Assessment and Coastal Health Act of 2000 (BEACH Act, 2000)) which mandated the USEPA to “find appropriate and effective indicators for improving detection in a timely manner in coastal recreational waters of the presence of pathogens that are harmful to human health”. Furthermore to “develop appropriate accurate, expeditious and cost-effective methods (including predictive models) for detecting in a timely manner in

Methods for the future

Future of methods will strive to be faster, cheaper and better than what are available today. What those methods might be are unknown, although there are hints of things to come. One of the potential indicators that is being considered today is the measurement of coliphages, both somatic and male specific (USEPA 2015). These microbes are being investigated because they are believed to be more similar to human viruses which, at this point in time, have been shown to be the main cause of health

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (55)

  • R.S. Breed et al.

    Nomenclature for the colon group

    Am. J. Public Health

    (1937)
  • G.E. Budnick et al.

    American Society for Microbiology evaluation of Enterolert for enumeration of enterococci in recreational waters, American Society for Microbiology evaluation of Enterolert for enumeration of enterococci in recreational waters

    Appl. Environ. Microbiol.

    (1996)
  • V. Cabelli

    Health Effects Criteria for Marine Recreational Waters

    (1983)
  • A. Castellani et al.

    Manual of Tropical Medicine

    (1919)
  • H.A. Clark et al.

    The membrane filter in sanitary bacteriology

    Public Health Rep.

    (1951)
  • J.E. Delaney et al.

    Measurement of E. coli Type I by the Membrane Filter, Water and Sewage Works, Vol. 109

    (1962)
  • A.P. Dufour

    Health for Effects Criteria Fresh Recreational Waters

    (1984)
  • A.P. Dufour et al.

    Membrane filter method for enumerating Escherichia coli

    Appl. Environ. Microbiol.

    (1981)
  • H.E. Durham

    A simple method for demonstrating the production of gas by bacteria

    Brit. J. Med.

    (1898)
  • S.C. Edberg et al.

    Enumeration of total coliforms and Escherichia coli from source water by the defined substrate technology

    Appl. Environ. Microbiol.

    (1990)
  • S.C. Edberg et al.

    Escherichia coli, the best biological drinking water indicator for public health protection

    J. Appl. Microbiol.

    (2000)
  • C. Eijkman

    Die Garungsprobe bei 460 als Hilfsmittel bei der Trinkwasseruntersuchung

    Zbl. Bakt.

    (1904)
  • S. Endo

    Über ein Verfahren zum Nachweis der Typhusbacillen

    Centr. f. Bakt.

    (1904)
  • T. Escherich

    Die Darmbakterien des Neugeborenen und Säuglings

    Fortschritte der Med.

    (1885)
  • Federal Register

    Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking ater Act; Analysis and Sampling Procedures, Federal Register/Vol. 82, No. 143/Thursday, July 27, 2017/Rules and Regulations

    (2017)
  • E.E. Geldreich et al.

    A fecal-coliform-organism medium for the membrane filter technique

    J. Am. Water Works Assoc.

    (1965)
  • A. Goetz et al.

    Application of molecular filter membranes to the bacteriological analysis of water

    J. Am. Water Works Assoc.

    (1951)
  • View full text