environmental
                                                                                            action
                                                                                         foundarion
                                                                                                solid
                                                                                                waste
                                                                                                project
Sewage    Sludge
   Back  To  Th6   Land?
Bloomington, Indiana,  1976. When farmer Ron Nehrig discover-
ed the sewage sludge he'd used as a soil conditioner was heavily
contaminated with cancer-causing  PCBs, he became concerned
about his  family's health.  Upon  his insistence city  officials
tested the milk from  a family cow that had grazed on the
sludge-treated pasture.  They found the milk fat contained twice
the amount of PCBs allowed by the Federal government.

   Farmer Nehrig's pliaht is part of a sludge crisis that threatens
to engulf many communities, bringing with it a possible environ-
msntal nightmare. As  municipal wastewater  treatment plants
spuw out over 25 billion gallons of sludge daily, cities  are hard
pressed  to find  disposal  methods that are both economically
acceptable and environmentally sound.
   Ironically, the onslaught of sludge is a direct result of the
battle against water pollution: the cleaner we get our waters, the
more .sludge we produce. The disposal dilemma is becoming in-
creasingly acute as communities upgrade their sewage treatment
processes (as required by the 1972 Federal Water Pollution Con-
trol Act).  The  Environmental  Protection  Agency  (EPA) esti-
mates that by 1985 we -yill have to contend with at least twice
as much sludge as we face today.
   Every time anyone  flushes the toilet, does  their laundry, or
uses the garbage disposal they create sludge. Largely due to the
contribution  of local  industries that use the public sewage
system,  municipal sludge often contains detectable  amounts of
heavy metals and  toxic chemicals that may  endanger human
health and pollute the environment.
   Currently about 15  percent of the nation's sludge is dumped
into the ocean, 35 percent  is burned (incinerated), 25 percent
is buried (landfilled), and 25 percent  is spread on the land as a
soil conditioner  (landspread). However, this pattern is rapidly
changing as the result of environmental legislation and the rising
costs  of' traditional disposal methods. Because of mounting
evidence of serious damage to the marine ecosystem,'  EPA has
ruled  that all ocean dumping of  sludge  must cease by  1981.
Simultaneously,  incineration is being priced out of range for
most communities; only the largest cities can pay for expensive
fuel and adequate air pollution control equipment.
  With more and  more sludge and fewer places to put it, cities
are  looking to the land  as the answer to their sludge disposal
woes. Because urban landfill space is rapidly disappearing, com-
munities are  trying to  keep as much out of the landfill as
possible. This means that wherever it.is practical, cities are likely
to find landspreading the most attractive disposal alternative.
   At first glance, landspreading urban sludge appears to be the
ideal solution to a compiicated problem: an otherwise wasted
resource, loaded with soil-enriching organics, can be used to
build the soil and close the ecological circle. This sounds like the
perfect environmental answer, and both city officials and much
of the environmental  community tout it as such.
   But there's a catch. If  sludge contaminants  have caused
enough  concern  to ban  sludge from the ocean, there is good
reason to fear the same  contaminants will wreak havoc on the
land, particularly if they  enter  the food chain. Scientists,
environmentalists, and offices within EPA sharply disagree as to
just how much of a hazard is posed by applying sludge to farm
land. These experts heatedly debate what levels of heavy metals,
toxic chemicals, and  pathogens (disease-causing organisms) are
"safe;" some  believe  that even sludges low in heavy metals are
dangerous  on food  chain  crops, while others claim that
vegetables can be safely grown on  highly contaminated sludges.
The unfortunate result of this numbers  squabble is that the
public may be misled  about the seriousness of the problem.
   Close  examination of the evidence  indicates that there is
cause for grave concern.
 He
   Leavy metals, including cadmium, chromium, lead, mercury,
nickel, and  zinc,  can accumulate  in food chain  plants and
animals in sufficient concentrations to endanger human health.
The U.S. Food and Druq Administration (FDA) has singled out
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cadmium as the greatest threat to human health through the
food supply.
   Cadmium is a persistent, pervasive metal that has entered our
environment primarily as a result of the mining and refining of
zinc ores. It is mainly used by the electroplating industry, the
pigments  and  compounds  industries,   and  the  metallurgy
industry, and it ends up in products ranging from motor oil to
television tubes.
   Even present  levels of cadmium in our air, drinking water,
cigarette tobacco and food cause some scientists concern. Cad-
mium is a cumulative poison that is retained mostly in the liver
and kidneys. In high concentrations it is known to cause acute
kidney disease, and  it has been linked with cancer in tin smelter
workers; in much lower concentrations it has been associated
with  hypertension  and  heart  disease.  Scientists worry most
about  the  lower exposure chronic  diseases, for we already
absorb  more   cadmium  than  prescribed  by  international
standards. Both the Food and Agricultural Organization and the
                 WHAT IS IN SLUDGE?

    Sludge,  a watery substance typically composed of 90 to
 95 percent water  and 5 to  10 percent solids,  is the  end
 product  of the  wastewater  cleanup  process. When sewage
 from homes  and industries  enters a wastewater treatment
 plant it  undergoes primary  treatment to  strain out  large
 solids and  grit.  In  70 percent of our  communities it then
 undergoes further processing — secondary treatment — which
 removes  up to 90 percent of the organic material present in
 the  effluent.  If there is no  other processing,  raw sludge
 results;  it  is  very  smelly in  this form, and contains  large
 numbers'of disease-causing organisms (pathogens).
    In most cases,  the sludge is further treated and is con-
 verted into a less toxic, less chemically active form. This pro-
 cess, known  as  stabilization, eliminates most of the  odor
 and  pathogen problems. The basic ways of stabilizing sludge
 are digestion, composting, and chemical treatment; digestion
 is most common.
    •  Digestion  is  a   biological process in which micro-
 organisms  interact  with  the  sludge either  in  the presence
 of air (aerobically)  or in the absence of air  (anaerobically).
 Digested sludge may  be left  in liquid form  or may  be
 dewatered.
    •  Composting is familiar to many.  In this process wood
 chips, bark, organic refuse or some  other  bulking agent  is
 a.ded to dewatered  sludge.  Over time the sludge decom-
 poses, producing temperatures as high  as 140° F. The end
 product  is an  earthy, humus-like product that is almost
 odorless  and pathogen-free.
    •  Chemical  treatment  involves adding  large  amounts
 of lime.
    About three-quarters of sludge soiids are bio-degradable,
 organic   materials that give  sludge its  soil-enriching reputa-
 tion. The  remaining  portion is  composed  largely of  silica
 (sand),  potassium,  iron, and can contain trace amounts of
 heavy metals such as  cadmium, lead, and mercury, and per-
 sistent toxic chemicals such DDT, aldrin, dieldrin, and poly-
 chlorinated biphenyls '(PCBs).  It  is this small  portion of
 sewage sludge that is cause for serious concern.
World Health Organization of the United Nations recommend a
maximum cadmium intake of  57 to  71  micrograms per day
from all sources; a recent FDA study concludes that the average
American consumes 72 micrograms of cadmium daily from food
and drink alone.
   Landspreading  sludge  on food crops  causes  such concern
because sludges consistently have cadmium concentrations high
above the average  soil  level of .15 parts per million (ppm); the
sludge in over half of our communities has  more than 16 ppm
cadmium, and urban sludges have been found with  more than
3600 ppm cadmium. Since food is our major source of cadmium
intake, the large scale application of urban sludges to cadmium-
absorbing leafy green vegetables and grains could significantly
increase our intake. Salad lovers and cereal eaters beware!
   Dr.  Charles Jelineck, FDA's Deputy Associate Director for
Technology,  warns  that  "new developments  should not  be
established on a large scale that could cause a significant and
possibly  irreversible  increase of cadmium in the food supply.
The  uncontrolled, widespread application of sewage  sludge on
land should be considered in this category."

  ' loxic organic compounds in sludge may also threaten human
health  and the environment.  These very persistent chemicals
include pesticides such as DDT, aldrin, dieldrin, and chlordane,
as well as the polychlorinated biphenyls (PCBs) that ended up
in farmer Nehrig's milk. What little we know about the fate of
these substances  in  the ecosystem and tolerance levels in hu-
mans is not reassuring.
   Toxic  chemicals  are  potent,  cancer-causing  agents  that
already have embedded themselves  in food chain plants and
animals; any increased exposure should be avoided.
   Numerous  pathogens, .or disease-causing  organisms,  are
always present  in municipal sludge. These include bacteria  and
viruses, such  as  salmonella and  tuberculosis,  and parasites.
According  to  FDA's Dr. Jelineck, the main concern  is that
grazing animals or  people may  come  into contact with these
infectious agents.
UNDER CONTROL?
   There are ways to minimize sludge's adverse impacts through
careful site management and crop selection. Perhaps the most
important of these measures is to maintain the soil in a neutral
or slightly alkaline state (pH 6.5 or above) by applying lime.
"Maintaining soil  pH at 6.5 or above minimizes the migration of
heavy metals," according to U.S. Department of Agriculture
(USDA)  heavy metal specialist  Rufus Chaney.  "The  manage-

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ment of a sludge disposal  site is crucial in determining  how
much  of  a hazard  the  sludge will be.  Even a good  sludge
can  cause  heavy  metals  problems  if  there isn't proper  pH
management."
   Unfortunately,  little  control  currently  exists  over  either
sludge quality or its management. Despite enthusiasts' claims,
there is no guarantee that safe sludge will be put on the land,
or that there will  be proper site management.  This creates an
opportunity for a wealth of abuses both on farms and home
gardens.
   EPA case  studies confirm  that actual  application practices
seldom follow recommended controls.  One  survey found  that
only  5 out  of  15 communities  met  USDA  interim  land-
spreading  criteria;  4 of  the  violators grossly  exceeded the
recommended cadmium  limits. Another  study of 25  sludge
spreading  sites  found that  none of the farmers sampled the
content of the sludge before putting it on  crops, and only a
handful monitored the soil pH.
   The story  is even worse for home gardeners who unwittingly
are spreading "natural" fertilizers loaded with heavy metals on
their vegetable plots. Treated urban sludges such as Milwaukee's
"Milorganite" and Chicago's "Nu-Earth," for example, contain
inordinately  high  amounts  of cadmium.  Milorganite  averages
around 112 ppm cadmium, and yet it is widely sold for garden
application.  Ironically,  home  farmers  who grow  their  own
"organic" vegetables are likely to suffer the most.
WHAT WE CAN DO ABOUT IT
   Why are heavy metals and toxic organics in sludge in the first
place? One  important reason is  that industries often are  big
users of  municipal  wastewater  treatment  systems.  On the
average, they contribute about 40 percent of what flows into an
urban sewage  plant.  Since industrial chemicals  and metals  are
largely responsible for the major environmental complications
caused by sludge, it makes sense to attack the problem head on
— at the source. Such  an  approach  is  called pretreatment.
Extracting contaminants   before  they  mix with  residential
sewage  should significantly purify many sludges, and  conse-
quently should  decrease  the environmental risks  of  all dis-
posal methods.
   A vigorous pretreatment program, while not the complete
answer, is the only way to make more sludges acceptable  for
land application. EPA currently  is writing pretreatment stan-
dards for seven types of industries that discharge toxins and
heavy metals into the municipal sewage system. By 1981 such
standards  will  cover 21 major types of industries and will affect
over 50,000 companies. The first seven standards were to have
been issued by  the  beginning  of July, 1977,  but are several
months behind schedule.
   It also  is imperative to develop ways to control  sludge land-
spreadifig  to ensure sites  are properly maintained and applica-
tion rates are adequately  limited. Such  management controls
can  be  achieved  both by state and federal  regulations. Long-
awaited federal  guidance  is on the horizon as  a result  of the
Resource Conservation and Recovery Act of 1976. EPA's Office
of Solid Waste currently is developing minimum criteria for the
landspreading of  sludge that will define acceptable practices.
These criteria, due in by October, 1977,  must be met by  all
state solid waste disposal programs. If a state refuses to comply
with them, citizen suits can force it into action.
CITIZENS AND SLUDGE
   We  all  have  a  large stake in sludge from start to finish: we
create  it and at the other end  we pay for its disposal with our
health, our tax dollars, and the integrity,of our environment.
Given that many states and communities will be making impor-
tant sludge decisions  in the coming  years, it is important for
citizens to familiarize themselves with the problems and actively
participate in the debate and its solutions.
   There are a number of things you can do:

At  home. Inform yourself about sludge and spread the word.
For more information write to:  Systems Management Division
(AW-464), Office of Solid Waste, U.S.<  Environmental  Protec-
tion Agency, Washington, D.C.  20460. j
— If you use sludge fertilizer (other than your own home com-
posted type) on your  home vegetable' garden, make sure you
know what's in it. It  probably would ;be best not to grow any
food in the  sludge-treated garden, but  at  least stop growing
the worst metal  absorbers — leafy vegetables  (i.e.  spinach,
lettuce, swiss chard),  and root crops. Make certain  your soil  is
above pH  6.5; lime it if necessary.

In your community. Organize a group of concerned citizens and
put sludge on the agenda at your next city council meeting.
— Find out where your sewage sludjge goes, and which local in-
dustries  use the municipal  wastewater  treatment  system.
Common  high  polluters include the  viscose  rayon,  vulcanized
rubber, and  paper industries (which discharge excess zinc) and
the metal plating industry (which contributes copper, nickel,
cadmium, and chromium).
— If local produce  is  grown on  sludge-fertilized soil, find out
what is in the sludge and what, if any, management procedures
are followed. If your city officials do  not know the answers,
prod them to find out.
— If your community  will be making sludge-related decisions.

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ask hard questions  about the safety  of  the  proposed  pro-
gram. Try to make certain all of the risks and merits are taken
into  account.
—  Your  community  has  the  tools for making informed de-
cisions; use them. EPA offers communities  general assistance in
assessing sludge disposal options, as well as guidance on proper
sludge management  and control.  Have your city  or county
officials contact your regional  EPA office for information. For
specific advice, turn to USDA. For a nominal fee, USDA's  Agri-
cultural Extension Service often will analyze soil/sludge samples
and give site-specific assistance to  communities that landspread
sludge. Your local  government  people  should contact the
county extension agent for assistance.
   * establishes  adequate  management controls if food-chain
application is allowed. This includes setting specific low limits
on  how much heavy metals and nitrogen can be  applied, pH
control of 6.5 or above, and a conservative ceiling  on the total
amount of heavy metals that can accumulate in the soil. Provi-
sions for adequate monitoring should be included.
—  Push for a strong pretreatment program both with state
planners and your state officials.

On the national  scene.    Write ^to your congressman and/or
senator  expressing your support of  a vigorous pretreatment
program, and ask them to  inquire on  your behalf what EPA is
doing in this area.
At  the  state level.  Become actively involved  in  the sludge
debate and  voice your concerns to responsible  state officials.
States must develop  a comprehensive sludge policy as part ot an
overall solid waste management plan required  under the Re-
source Conservation and  Recovery Act of 1976.  You have a
legal right to be part of that planning process, so take advantage
of it.
— Insist that state planners address the sludge issue thoroughly
and responsibly. Tell them you want a policy that:
   •  puts primary emphasis on applying sludge to devastated
areas  such as stripmines and gravel pits and provides that the
land will not be used for food chain crops if large quantities of
sludge are applied.
   •  encourages the use of sludge on ornamental lands such
as golf courses, rights of way,  flower gardens and parks.  Even
here there should be limits on the amount of sludge applied so
as to avoid water contamination.
   •  encourages establishing  "sludge farms" for careful dis-
posal of the maximum amount of sludge the environment can
safely tolerate.  This  land  would have to be "dedicated," or
legally restricted for sludge disposal, to ensure that food chain
crops are not grown.
   •  discourages landspreading sludge on food-chain crops, and
forbids  putting  it on leafy green vegetables,  tobacco, and root
crops.
   It is time that government and citizens alike focus our atten-
tion on this obscure — but important — issue and find better
ways  of dealing witn  sludge  berore  it poisons  us  and our
environment. Let's make certain  we  are making the  best
possible  decisions  about  sludge,  the  much-ignored effluent
of affluence.

For further reading: "Municipal Sludge: What Shall We Do With
It?" by the League of Women Voters (pub. no. 627, 50 cents).
Contact  LWV Education Fund, 1730 M Street, N.W., Washing-
ton, D.C.20036.
   EAF  has detailed fact  sheets on  specific  sludge problems
and promises.             	
   The Environmental Action Foundation is a non-profit, tax-exempt
citizens' organization devoted to research and education on a variety
of environmental issues.
   The Solid Waste Project is an information clearinghouse and
citizens'.communication network. The Garbage Guide is produced by
the project staff:  Kay Pitcher. Elizabeth  Tennant, and Merchant
Wentworth.

   This project has been financed in part with federal funds from the
Environmental Protection Agency under the grant number T90551-
01-0. The contents do not necessarily reflect the views and policies of
the Environmental Protection  Agency  nor does mention of trade
names or commercial products constitute endorsement or recommen-
dation for use.
                                                                           Reprinted  with permission of the
                                                                           Environmental  Action Foundation.
                                                                           U.S.  EPA,  1979.

                                                                           SW-805
                                                 environmental  action   foundation

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