WATER QUALITY: Technical Information -- Briefing paper on "Microorganisms in Stormwater -- A summary of recent investigations,"

In Reply Refer To:                                July 14, 1980
EGS-Mail Stop 412


QUALITY OF WATER BRANCH TECHNICAL MEMORANDUM NO. 80.20

Subject: WATER QUALITY: Technical Information -- Briefing paper on 
         "Microorganisms in Stormwater -- A summary of recent 
         investigations," by Gail E. Mallard, WRD, Syosset, 
         New York

In 1974, at the suggestion of the Task Group on Biology and 
Microbiology, the Quality of Water Branch initiated the briefing 
paper series. Since then, 13 briefing papers related to aquatic 
biology have been prepared and distributed under Quality of Water 
Branch Technical Memoranda. In addition, three briefing papers on 
organic substances in water have been prepared and distributed. 
The enclosed general discussion of microorganisms in stormwater is 
a continuation of the series of briefing papers.

The briefing papers have been extremely successful in increasing 
the awareness and understanding in the Division of the role and 
significance of various aspects of water quality. Because of their 
success, and the fact that they are written in a non-technical, 
easy-to-understand manner, it has been suggested on several 
occasions that the briefing papers be given wider distribution, 
for example, outside of the Geological Survey. We have accepted 
these suggestions and are preparing the papers for formal 
publication in the USGS Circular series.

The 17 briefing papers, including the one enclosed herein and two 
that are in final preparation, will be published as compilations 
of briefing papers in five USGS Circulars. Other Circulars will be 
prepared as the need arises. It is hoped that a wide range of 
persons, including those interested in the quality of our Nation's 
water resources but who have little or no technical training, will 
find value in reading these papers. Furthermore, it is hoped that 
the papers will be suitable for supplemental reading in secondary 
education programs and in beginning college-level courses.

Please circulate the enclosed briefing paper as widely as possible 
in all District and Project offices.



                              R. J. Pickering 
                              Chief, Quality of Water Branch

Enclosure

Distribution: A, B, FO-L, PO

Key Words: Water quality, information, publications, bacteria, 
           stormwater, viruses 

Superseded memoranda: None



MICROORGANISMS IN STORMWATER

A Summary of Recent Investigations

By Gail E. Mallard

ABSTRACT

The major concepts and considerations in microbiological analysis 
of storm runoff are summarized and documented to provide a basis 
for use by community planners, water managers, and others 
interested in studies of stormwater.  Twenty-five published 
reports dating since 1964 are cited.

All storm runoff contains a variety of bacteria, including total 
coliforms, fecal coliforms, and fecal streptococci, that are 
derived from the land over which the water flows.  Most of the 
total coliforms are native soil organisms, whereas the fecal 
coliforms and fecal streptococci originate from the feces of wild 
and domestic animals.  Urban runoff has been reported to contain 
pathogenic organisms, but this probably presents little direct 
threat to human health because the runoff is not ingested.  Runoff 
water, however, can have other negative effects such as 
contamination of surface waters which may result in beach 
closures, or contamination of shellfish.  This type of 
contamination is generally of short duration because indicator 
bacteria and pathogens die rapidly in the aquatic environment.  
Similarly, bacteria and viruses deposited on soil by stormwater 
are inactivated by drying, competition from soil microflora, and a 
variety of other processes.

Every storm producing runoff is unique in terms of the number and 
type of microorganisms, for they vary from site to site, from 
storm to storm, and over time during any one storm event.  
Stormwater to be examined for microorganisms must be collected in 
sterile containers and processed immediately.