Deadly Deceit   
                                     CHAPTER 7

                        Deadly Microbes

There are many different kinds of victims of sludge.

Although we never suffered as much physical harm as the Zanders

from land application of sludge, we nevertheless were victims

because our property was contaminated with Salmonella and E.

coli! We are trustees for a farm surrounded on three sides by

Kansas City, Missouri's 1200 acre sewage sludge application

site.  For ten years we have suspected there might be a

problem with toxic contaminated surface water run-off from

the site which collects on the property.

On May 6, 1998, James Macy, Regional Director of the

Missouri Department of Natural Resources, called a meeting

with Kansas City's Sludge Manager, John Bozarth, and EPA's

Regional Sludge Coordinator, John Dunn, to evaluate our

concerns over the potential contamination of the farm, since

there was documented ground water contamination at the

property line.  The ground water contamination under the

sludge disposal site included fecal coliform, aluminum and

nitrogen.  Arsenic had also been a ground water contaminate

in one area of the sludge disposal site. Both the City and

EPA agreed to do comparison ground water testing on the Trust

property as well as soil testing for the nine toxic

"regulated" metals, aluminum, thallium and pathogenic disease

organisms.  Two months after the meeting, the City and EPA

backed out of the testing agreement and Kansas City fired

its Sludge Manager.  As an honorable man, Macy, who had given

his word that the tests would be done, committed the State to

do the soil test for toxic metals, since the State could not

force either the City or EPA to comply with the agreement

made in May.  When the City and EPA refused to do the testing

they had committed too, we decided since the State was only

going to do the metals test, we would do the soil testing for


The first immediate problem we had to overcome was to

find a laboratory to do the tests.  There was no laboratory

in Kansas City that could or would do the actual testing for

us because of conflicts of interest. The only laboratory we

could find within 150 miles of Kansas City that would do the

testing only had the capability of testing for fecal coliform

and the pathogenic disease organisms Salmonella, E. coli and

fecal streptococci. If the laboratory had known the purpose

of the tests, there would have also been a conflict of

interest, since the laboratory does sludge testing for a

number of small community sewage treatment plants.

On the evening of August 16, 1998 the ALICE MINTER TRUST

collected four soil samples from its farm and an access right

of way where toxic comtamination was suspected. The times,

date and location were documented by photographs. The

following morning the samples were delivered to the


No sludge or manure has ever been applied on our farm

and no sludge had been applied to the City of Kansas City's

sludge disposal drainage area for almost a year, so we were

shocked by two of the test reports which revealed both

Salmonella and E. coli at a little less than 800,000 COL/100

ML. That is 800,000 colony forming units of each bacteria per

100 grams of soil!  EPA claims it will allow no more than 75

Salmonella bacteria per 100 GRAMS in Class A sludge

fertilizer. There is no standard for E. coli in sludge or


What was more amazing was that the tests revealed fecal

coliform bacteria at a level of 650,000 per 100 ML of soil on

our farm roadway where the City claimed it has not applied

any sludge since 1991. According to EPA, the safe level of

fecal coliform in sludge for public contact sites is 1000 per

gram of sludge.

A fourth test comparing fecal coliform at 50,000 colony

forming units to fecal streptococci at 10,000 colony forming

units (4.4 to 1 ratio) revealed that the toxic contamination

in the soil was from human waste.

We were astounded by the Salomella and E.  coli numbers

because for the past 10 years EPA and USDA have claimed

infectious pathogenic disease organisms were destroyed either

in the sewage treatment process for Class A sludge or within

30 days after application for Class B sludge. EPA claims

there are no pathogenic disease organisms in unregulated

Class A sludge for use on home lawns and gardens when the

fecal coliform level is less than 1000 per gram in sludge. In

this case the fecal coliform levels was 30 and 90 per gram of

soil vs 8000 units of Salmonella and E.  coli per gram of


When the laboratory report was sent to one of the major

sludge product producers, J.  Patrick Nicholson, CEO of N-

Viro International, his reaction was that the Trust must be

using chicken manure as a fertilizer on the farm. According

to Mr. Nicholson, the use of chicken manure was the only

thing which would account for the high Salmonella numbers.

Although manure is being blamed for the rise in both

foodborne and waterborne diseases, the results from these

pathogen tests clearly indicate that sludge could be the

culprit instead of animal manure.

The 1998 Certified laboratory's test reports show that

not only will bacteria survive the treatment process, but it

will survive for long periods of time in the soil.  Bacteria

will also leave the sludge disposal site in surface water

run-off and it will regrow in the soil.  This is not some

startling new evidence. In a letter dated April 6, 1998, Rob

Atwill, a professor with the School of Veterinary Medicine,

University of California-Davis writes of the danger of

pathogens in sludge:

We veterinarians are all too aware of the ability of

trucks and our own boots to move pathogens between

locations. Large numbers of wildlife, particularly

birds, such as flocks of blackbirds or cowbirds, can

quickly transmit pathogens between a nearby field and a

dairy. Application of biosolids [sludge] to animal

forage crops such as alfalfa can likewise expose our

food animals to human pathogens. Animal consumption of

water contaminated with sewage discharges has been

associated with Salmonella being transmitted from humans

to poultry in Southern California. The incident resulted

in a large outbreak investigation by the California

Department of Health Services, California Veterinary

Diagnostic Laboratory System, and the California

Department of Food and Agriculture.

Professor Atwill warns, "In addition, many of these

pathogens can be transmitted to livestock, such as dairy and

beef cattle. These pathogens can replicate in our livestock

populations and become a meat-borne or milk-borne human

health risk."

D. Strauch in his 1991 paper, "Survial of pathogenic

micro-organisms and parasite in extreta, manure and sewage

sludge" reported that two groups of researchers had found

that pathogenic disease organisms will be taken up inside the

food crops.  In other words, it will do little good to wash

the outside of fresh vegetables and fruit when the pathogenic

bacteria, viruses and worms from the sludge can be inside the

plant.  Strauch concluded in his report that, "In any case,

the agricultural utilization of hygienically dubious sewage

sludge poses a risk for the whole national economy."

The Trust's laboratory test results revealed that EPA

and USDA lied to us when they claimed all the pathogenic

disease organisms would be destroyed in the soil within 30

days. According to  D. Strauch, who is with the Institute of

Animal Medicine and Hygiene, University of Hohenhiem, this is

not the case. Salmonella has survived in forest stands

between 424 and 820 days. It appears that in spite of EPA

claims to the contrary not only is it not safe to harvest any

food or feed crops 30 days after sludge has been used, it's

not safe to grow crops on pollutant contaminated soil a year

after sludge has been applied.

Both animal manure from confined animal feeding

operations (CAFO's) and sewage sludge used as a fertilizer

can cause serious damage to human health and the environment

and can cause foodborne and waterborne diseases if not

properly managed.  Could it be a mere coincidence that after

the final Part 503 sludge rule was released promoting the

widespread land application of sludge in 1993, that there was

a dramatic increase of bacterial food poisoning by Salmonella

and E.  coli, from 6.5 MILLION INCIDENTS in 1994 TO 80


In May  1996, Ralph J. Touch, Chief Sanitarian for the

U.S Public Health Service reported in his "Emerging

Infectious Diseases" Paper that the Centers for Disease

Control said that bacterial food posioning affects as many as


Yet, in May 1997, the six federal agencies responsibile

for food safety which includes the FDA, CDC, USDA and EPA

reported to the President in "FOOD SAFETY FROM FARM TO TABLE,


between 6.5 and 33 million food related illnesses in the

United States each year. It would appear that the CDC forgot

to use its current data in the report, since the numbers

quoted by these government enforcement agencies, who are all

promoting the use of sludge as a fertilizer, were from 1994


EPA now wants Congress to create a separate law

controlling manure which appears to be aimed at dairy farmers

opposed to sludge use. EPA has even funded a lobbying

campaign through the WEF.  They claim the pathogenic

organisms in animal manure are causing people to become ill

when exposed to it, especially in contaminated water. At the

same time, the agency has removed its sludge disposal

marketing program from all safety provisons of the

environmental laws.

Pathogenic disease organisms in sludge can pose a public

health risk when humans come in contact with them through

breathing contaminated air, drinking contaminated water,

eating contaminated food, and playing or working in

contaminated soil. Although EPA recognizes the danger from

exposure to pathogens in sludge, it claims both its

unrestricted Class A (used on home lawn and gardens), and

semi-restricted Class B sludge products (used on food crop

production land) are completely safe when they comply with

the pathogen reduction requirements of the Part 503 Sludge

Use and Disposal Standard.

The first requirement for heat dried, sanitized or

composted Class A pathogen reduction is that the sludge must

meet either the density requirements for the indicator

organism, fecal coliform, which must be less than 1,000 most

probable number (MPN) per gram total solids (dry-weight

basis) or Salmonella sp. which must be less that 3 MPN per 4

grams of total solids (dry-weight basis) when the sludge is

used or disposed or prepared for sale or give-away.  EPA

concluded that fecal coliform bacteria could be used to

indicate the presence of other pathogenic organisms in the

sewage sludge.  The fecal coliform was selected because an

analytical method existed for it, it was cheap and because

POTWs routinely conduct fecal coliform analyses. Class B

sludge products must meet the requirements for fecal coliform

density of less than 2 million MPNs per gram per total


Fecal Coliform Test

Pathogen reduction does not mean pathogen elimination.

It only takes a very few of some of the deadly bacteria and

emerging viruses to cause disease and death.  Although the

EPA asserts that the fecal coliform tests or Salmonella sp.

tests for pathogens and the pathogen reduction alternatives

ensure that pathogen levels in sludge products either Class A

or Class B are reduced to levels considered safe to be

applied to land, some microbiologists have questioned this


Gerba and Rose cite a study by Clarke and Kabler (1964)

where "as early as 1960 there was concern that coliform

bacterial standards used to detect domestic pollution were

not adequate in regard to viruses" (p.394).  According to

these researchers, viruses are more resistant to inactivation

and removal by treatment processes than the coliform bacteria

and can survive in the environment for longer periods of time

than the bacteria. They give examples from reports in the

literature of where viruses have even been isolated from

drinking water meeting U.S. bacteriological standards.  They


These reports have initiated concerns in regards to the

adequacy of the standards and guidelines governing the

hygienic quality of potable waters.  Water which was

presumed to be safe based on currently used coliform

standards should not be assumed to be free of viruses."

Dr. Aaron Margolin, a microbiologist, certified in virus

and protozoa, from the University of New Hampshire is

critical of the fecal coliform tests. He says:

Throughout the literature--it is permeated with many

examples--my own labs being one--time and time again

where bacteria are inadequate indicators or predictors

of the presence and/or absence of these other infectious

organisms, viruses and intestinal parasites...while

someone may be able to tell you what the fecal coliform

levels are of the sludges--that is well and good and I

don't doubt that the levels are what they are saying

they are--but that does not necessarily or adequately

predict what the other pathogens in the sludge are.

(p. 2)

Twenty-three years before, in 1974, Gerald Berg, Chief,

Biological Methods Branch of the EPA's National Environmental

Research Center in Cincinnati, Ohio warned of the inadequacy

of the fecal coliform test. He stated:

For some time we have been aware that fecal coliforms

are not always reliable indicators for viruses and that

neither fecal coliforms nor other bacteria are inviolate

indicators of fecal pollution. To be sure, fecal

coliforms indicate a sanitary hazard, but certain other

bacteria may seem to be fecal coliforms in the standard

membrane filter test. Moreover, fecal coliform may

multiply in waters where pathogenic bacteria and

certainly viruses cannot. And fecal coliforms may be

destroyed in waters polluted with certain industrial

wastes--wastes that do not seem to affect fecal

streptococci and may not affect viruses either. Clearly,

it is a matter of some importance to develop a bacterial

indicator system that can definitively differentiate

fecal organisms from free-living forms. (p. xii)

Salmonella Test

The effectiveness of the Salmonella sp. test has also

been questioned by microbiologists. In 1995,

when William Yanko, Laboratory Supervisor,  Alan Walker,

James Jackson, Leticia Libao, and April Garcia, staff

scientists in the CSDLAC Microbiology Laboratory, conducted a

study to evaluate the Part 503 Salmonella methods and two

other Salmonella methods previously developed to test sludge

and composts, they found the other methods were superior to

the 503 methods. They undertook the study because as they

stated in the report "the designation of specific Salmonella

methods in the 503 regulations has essentially established

standard testing protocols without documenting the validity

or suitability of the cited methods for the intended

purpose". (p. 369)

In their study, these scientists analyzed ten samples

each of activated sludge, anaerobically digested sludge, and

compost using the different Salmonella methods.  Statistical

analysis indicated that there was a significant difference

between the methods, with the two methods that had been

developed for testing sludge recovering significantly more

Salmonella than the 503 methods. One 503 method failed to

detect Salmonella in 43% of the samples containing

Salmonella. Based on their findings the scientists suggest

"that a thorough evaluation of methods using a

multilaboratory round-robin format should be conducted to

establish appropriate methods for Salmonella compliance

testing." (p. 389)

The National Research Council also criticizes the 503

Salmonella methods. They state that because of the small

sample size and interference by a large number of

nonsalmonella bacteria the Part 503 Salmonella method is "apt

to underestimate the number present in any given sludge

sample" (p. 122)

The density of fecal coliform or Salmonella in the

sludge must be met for all six of the Class A pathogen

alternatives. The reason for these requirements is stated by

Walker, Knight, Stein, (1994), "Perhaps the most significant

of the requirements is to avoid regrowth of bacteria as

indicated by the results of a fecal coliform or Salmonella

test." (p. 111)

As the reliability of these tests in detecting pathogens

in both Class A and Class B sludge has been called into

question by some scientists, there is a real danger of

undetected regrowth of Salmonella. Although the EPA claims

that any one of the six alternatives for Class A pathogen

reduction will prevent regrowth of Salmonella, an EPA-

sponsored survey of distribution and marketed sludges in the

U. S. (Yanko 1987) found that Salmonella was often present in

PFRP-treated sludges and sludge products (13) (high-

temperature composting, heat-drying, heat treatment, and

thermophilic aerobic digestion). The conclusion of the author

was that the occurrence of pathogenic bacteria in distributed

and marketed sludge products represented a potential health

hazard, but the extent of the health risk was unknown.

In 1994, Constantine Skanavis and William Yanko

conducted a study of composted sewage sludge based soil

amendments for potential risks of salmonellosis. They

analyzed samples of composted sewage sludge, amendment

materials added to the compost (bulking agents such as aged

redwood, fir bark, redwood chips, rice hulls, and sawdust)

and four bagged commercial sludge soil conditioner products

representing different blends of materials for home garden

use. These bagged products were designated Product A

(recycled compost), Product B (made with rice hulls), Product

C (made with wood chips) and Product D (made by modifying

sludge with the addition of the company's proprietary


All samples were tested for total and fecal coliforms

and the presence of Salmonella. The average total and fecal

coliform concentrations were significantly lower in the

composted sludge compared to the four compost-based products.

Although there were no significant differences in total and

fecal coliform concentrations among products A, B, and C, the

average total and fecal concentrations in Product D were

significantly higher than in A,B,C products and the bulking

agents. Laboratory tests detected salmonella in the compost-

based products but not in the compost material used to make

the products. Thirty-six percent of Product D samples were

positive for Salmonella. Product D also contained the highest

average concentration of Salmonella. Product A was second

with 27 percent and Products B and C were tied with 22

percents of the samples positive for Salmonella. Because

Salmonella was detected in the sludge products but not in the

compost, the authors retested (using another testing

procedure) four samples that had been negative for

Salmonella. Retesting resulted in detection of Salmonella in

2 of the 4 compost samples. The authors conclude that

"compost-based products could, in specific situations,

represent a source of Salmonella infection. This study,

therefore, points to the need for intensive study of the

factors associated with Salmonella spp. regrowth." (p.  9)

Enteric Viruses

Salmonella is not the only threat to public health.

According to Dr. Margolin, enteric viruses also pose a

danger.  He says:

Enteric viruses are so small and have characteristics

that are very unique to only themselves. One of these

characteristics is that when complexed with organic

material and/or particulate material--given the right

temperature...conditions are extremely ripe for the long

survivability of viruses in sludges...and because of

their characteristics--the way they act as particles--

that with the high water table, it makes a perfect

situation for the transport of these infectious agents

from the sludge into the underground aquifers, (p. 2)

In a meeting of Milton, New Hampshire Board of Selectmen

on September 29, 1997, Dr. Margolin told Dr. Bolton

concerning land application of sludge that if the sludge

application was allowed he would put in a proposal to come

back and study their town again. "Because I think it would be

a neat little experiment--especially to actually see what the

end results are--because in the lab--the lab data would tell

us you would wind up being exposed to pathogens." (p. 11)

EPA's Part 503 pathogen reduction requirements for Class

A sludge products have been met if pathogens are below

detectable limits. Just because they are undetectable does

not make them safe. Gerba and Rose in their report on enteric

viruses in drinking water state:

Thus, viruses may be present in numbers below the

detection limits of the methods. The significance of low

levels of contamination can be exemplified by the low

infectious dose of viruses. Studies on minimum

infectious dose (i.e., that dose which causes infection

in 1% of the exposed population) indicates that as few

as 1 to 2 tissue-culture plaque-forming-units of enteric

viruses are capable of causing infection (Ward and Akin,

1984; Ward et al., 1986)

Risks from Pathogens

When Straub, Pepper and Gerba (1993) reviewed the

literature to assess the microbial (bacteria, viruses and

parasites) risks associated with application of sludge to

agricultural land, they found that "despite a 1-2 log 10

decrease in bacterial and viral number, significant

concentrations of these pathogens persist after sludge

treatment (Pepper and Gerba 1989; Soares 1990)." (p. 70)

Furthermore, most methods used in the detection of pathogens

were not 100% efficient and concentrations were always

underestimated. They also discovered that methods did not

exist for the detection of all pathogens that the sludges

could contain.  They stated that "It would not be

unreasonable to suggest that the actual concentrations of

enteric viruses are 10-100 times the number observed

experimentally". (p. 81)

In their summary of the review of the literature,

Straub, Pepper, and Gerba state the various risks found to

public health from the microorganisms in the sludge applied

to the land:

This becomes a public health concern because the

infectious dose for some of these pathogens may be as

low as 1 particle (virus) to 50 organisms (Giardia).

When sludge is applied to land for agricultural use and

landfill compost, these pathogens can survive from days

(bacteria) to months (viruses) to years (helminth eggs),

depending on environmental conditions. Shallow aquifers

can become contaminated with pathogens from sludge and

depending on groundwater flow, these organisms may

travel significant distances from the disposal site.

Communities that rely on groundwater for domestic use

can become exposed to these pathogens, leading to a

potential disease outbreak. Currently, methods to

determine the risk of disease from pathogens in land-

disposed sludge are inadequate because the sensitivity

of pathogen detection is poor. (p. 85)

Emerging New Pathogens

Of particular worry to microbiologists are the emerging

new pathogens. The Institute of Medicine published a report

in 1992 entitled Emerging Infections: Microbial Threats to

Health in the United States in which they defined emerging

infections as "new", reemerging or drug-resistant infections

whose incidence in humans threatens to increase in the near

future." The report describes the urgency of addressing the

problem of emerging infectious pathogens. "It is time to

mount an organized collaborative national and global counter

offensive against these potentially deadly microorganism."

(Quote from 1992 National Institute of Medicine report.)

According to Ralph Touch, Chief Sanitarian of the Public

Health Service, "emerging infectious diseases in the United

States include a wide variety of parasitic, bacterial and

viral diseases." (p. 3)

Bernard LeGuenno, a virologist who leads the national

reference center for hemorrhagic fever at the Pasteur

Institute in Paris, in an article "Emerging Viruses" in

Scientific American of October of 1995, writes about the

emerging hemorrhagic fever viruses which he says are "among

the most dangerous biological agents known."

According to his article, one of these viruses, the

hantavirus, has shown up in several places in the United

States. LeGuenno reports "Hantavirus Sin Nombre, {Spanish for

"no name"} strikes 114 and kills 58 in New Mexico, Colorado

and Nevada in 1993; in 1994 a researcher at Yale University

is accidentally infected with Sabia but survives" (p, 58)

LeGuenno vividly describes what happens when one is infected

by these dangerous viruses:

Sabia and Sin Nombre both cause illnesses classified as

hemorrhagic fevers. Patients initially develop a fever,

followed by a general deterioration in health during

which bleeding often occurs. Superficial bleeding

reveals itself through skin signs, such as petechiae

(tiny releases of blood from vessels under the skin

surface), bruises or purpura (characteristic purplish

discolorations). Other cardiovascular, digestive, renal

and neurological complications can follow. In the most

serious cases, the patient dies of massive hemorrhages

or sometimes multiple organ failure. (pp. 56-7)

An article by Peter Jaret (medical writer) entitled

"Viruses" in National Geographic for July 1994 also reports

the latest pathogen threat from emerging viruses--the "hot

agents--viruses that spread easily, kill swiftly, and have no

cures or vaccines." (p. 64) These viruses are so deadly that

extreme precautions must be observed by scientists who study

them.  According to the article, scientists at CDC "must wear

suits hooked to outside air supplies and enter a lab via

airtight hatches that seal behind them. All materials

entering the lab must be sterilized or burned to ensure that

nothing hazardous escapes." (p. 64)

Jaret began his article with a firsthand graphic

description of the effects of one of these deadly hot

viruses, Lassa fever, on its young victim:

First came fever. Then Hamid Mansaray, a young nurse's

aide at a remote African hospital, began to hemorrage.

Blood erupted from his nose and mouth. It burst out of

capillaries beneath his skin and eyes. By the time I

reached the village of Panguma in Sierra Leone, Mansaray

lay isolated in a special ward. Doctors had diagnosed an

obscure illness called Lassa Fever. Its cause was a

virus, an infective agent so small that 100,000 all

clumpted together would still scarcely be visible.

(p.  64)

He also describes his trepidation upon entering the

Lassa fever ward where Mansaray lay:

It is also what made my chest tighten as we entered the

Lassa fever ward. I knew that in neighboring Liberia a

medical team had unsuspectingly treated a pregnant woman

who was infected with the Lassa virus. Within four weeks

two patients from the ward and two of the hospital staff

were dead.

According to Jaret, although the Lassa fever virus is

frightening, a more frightening hot virus is the one that

causes Ebola fever. He reports that the Ebola virus, which

was first documented in 1976 when it killed half the people

in a small village in the Sudan, affects its victims much

like the Lassa virus causing fever and bleeding. He wrote

that by the time it had later struck Zaire, it was "seemingly

more virulent than before." (p.  64) It killed 90% of its

victims in over 50 villages.

Although these hot viruses have mostly been found in

Africa, the rest of the world is not safe from infection--

including the United States. Jaret reports on what could have

been a disastrous outbreak of Lassa fever in Chicago.

According to his account, in 1989, a 43-year-old mechanical

engineer, who had recently returned from attending his

parents' funerals in Nigeria, came to a suburban Chicago

clinic with a fever and sore throat. He was sent home with a

prescription for antibiotics. More than a hundred people had

come into contact with him before he died. Jaret reports the

concerned reaction of the CDC to this incident: "We had all

the makings of a catastrophe," said C.J. Peters, who directs

the CDC's Special Pathogens Branch. The disaster may have

been prevented because threat of the AIDS virus had led to

stringent standard sanitary procedures.  According to Jaret,

"Next time," says Peters, "we may not be so lucky."

(pp.65., 67).

We may not be so lucky because as Jaret says in his

article "When a rare virus does emerge from its seclusion,

modern air travel may offer it a free ride anywhere in the

world. "(p. 65) This was brought home to us in 1996 when a

research laboratory outside of Alice, Texas, which our fire

and safety company serviced, averted a near catastrophe when

during the quarantine period they discovered a monkey brought

over from Africa was carrying the Ebola virus.  Fortunately,

the monkey was destroyed before it could spread the virus.

Detection of Pathogens

It has been recognized in Germany, at least since D.

Strauch published his paper in 1991, that" most pathogenic

agents can survive the treatment process" and the sewage

treatment process causes some of the pathogenic disease

organisms to be absorbed or enclosed in faecal particles

during the treatment process. "Therefore," according to

Strauch, "sewage sludge is rightly described as a

concentration of pathogens."

In a personal interview with scientist David Lewis of

the EPA, who is a whistleblower, more disturbing facts about

pathogens and their detection came to light including the

information about the AIDs virus. According to Lewis,

standard test methods underestimate the number of water

repellant contaminates. In looking at the aids virus found on

medical and dental tools, Lewis discovered that the HIV

virus, when it was covered with a water repellant lubricant

such as silicone, was still infectious after several days.

The water repellant lubricants such as silicon and petroleum

products cover the pathogens and prevent them from being

found by standard test methods. It was only when he dissolved

the lubricants with acetone or other solvents, that the

pathogens showed up in tests. "Body fluids also break down

the lubricants surrounding the contaminates," he said. Lewis

has brought these facts to the attention of the Food and Drug

Administration who is supposed to be setting up a committee

to study the problem.

"The problem of pathogen detection in sludge, according

to Lewis, "is that the sewage treatment process changes the

outside crust of the aggregates in sludge and only the

pathogens on the outside of the aggregates are measured by

standard tests." He says that most of the microbes are

trapped inside the aggregates.  When ultrasound was used to

break open the aggregates of sludge the trapped microbes were

revealed. In effect, it appears that the treatment processes

hide most of the pathogens rather than destroying them.

Straub, Pepper and Gerba say that the list of pathogens

are not constant but keep changing:

As advances in analytical techniques and changes in

society have occurred, new pathogens are recognized and

the significance of well-known ones change.

Microorganisms are subject to mutation and evolution,

allowing for adaptation to changes in the environment.

In addition, many pathogens are viable but nonculturable

by current techniques (Rozak and Colwell 1987), and

actual concentrations in sludge are probably

underestimated.(p. 58)

They add further:

Thus, no assessment of the risks associated with the

land application of sewage sludge can ever be considered

complete when dealing with microorganisms. As new agents

are discovered and a greater understanding of their

ecology is developed, we must be willing to reevaluate

previous assumptions. (p.  58)

Some pathogens have even developed resistance to time-

tested controls such as heat and refrigeration. Several of

the alternatives to reduce pathogens in sludge products use

heat at temperatures of 55 C and above to achieve Class A

status. However, according to the article "Pathogen

Destruction and Biosolids Composting" in Biocycle of June of

1996, "There is some evidence that coliforms and Salmonella

sp. can survive prolonged exposure to temperatures of 55 C."

They cite a study done by Droffner and Brinton (1995) using

DNA gene probes, where they detected E. coli and Salmonella

sp. in samples collected from an in-vessel composting

facility after the first 15 days of active composting at a

temperature above 55 C. In Table 5-4 Processes to Further

Reduce Pathogens in A Plain English Guide to the EPA Part 503

Biosolids Rule, composting time and temperature requirements

for within-vessel composting method was 55 C or higher for

three days!  Droffner and Brinton found that it took 56 days

and 90 days for the densities of Salmonella sp. and E. Coli,

respectively, to decline below the detection limit...These

investigators also "cite evidence of mutant strains of E.

coli and Salmonella sp. resistant to thermal environments in

composting." (p. 68)

According to microbiologists, some bacteria form an

endospore, a cell type developed from the vegetative

bacterial cell through a sequence of morphological changes.

Although the vegetative cell of bacteria is usually killed by

heat and disinfectant, the endospore is resistant to agents

that kill the vegetative cell (heating, drying, freezing,

chemicals, and radiation).  Nester, Roberts, Pearsall and

McCarthy (1978) in their text Microbiology point out the

threat that endospores present.  They say:

Endospores represent the most resistant form of life

known; they tolerate extremes of heat and dryness, the

presence of disinfectants, and radiation. Some members

of Bacillus and Clostridium play a role in fixing

atmospheric nitrogen and others cause serious infectious

diseases. Thermophilic strains of Bacillus can grow at

temperatures above 70 C (158 F) (p. 260)

Linne and Ringsrud (1979) in their text Basic Techniques

for the Medical Laboratory also point out how spores, as

highly resistant forms of bacteria, pose a great problem in

sterilization. They state that certain spores have been known

to survive 16 hours of boiling. (p. 452)

One of the methods for treating sludge for pathogen

reduction is adding lime to a pH of 12. According to a study

done by John Walker, when he was with the USDA in Beltsville,

liming doesn't prevent regrowth of Salmonella. When John

Walker (USDA) and a colleague conducted experiments to

determine what would happen to disease organisms in limed

soil, they found Salmonella organisms even at the highest

lime levels which indicated that Salmonella had regrown when

the pH dropped. (p. 46)  According to Dean of the EPA, "We

know that a limed sludge if stored too long will putrefy,"

(p. 46).

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Draft copy of some data to up date
Chapter  7: Deadly Microbes, Deadly

Jim Bynum and Gail Bynum, Ph.D