vvEPA
United States
Environmental Protection
Agency
Off ice of Water
Program Operations (WH-547)
Washington DC 20460
September 1982
430/9-82-007
Sludge and the Land:
The Role of Soil and
Water Conservation Districts
in Land Application
of Sewage Sludge
Final Report
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Sludge and the Land:
The Role of Soil and
Water Conservation Districts
in Land Application
of Sewage Sludge
Final Report
September, 1982
Prepared by the National Association of
Conservation Districts
Suite 730,1025 Vermont Avenue, N.W.,
Washington, D.C. 20005
202/347-5995
Disclaimer Statement
This report has been reviewed by the
Environmental Protection Agency and
approved for publication. Approval
does not signify that the contents neces-
sarily reflect the views and policies of
the Environmental Protection Agency,
nor does mention of trade names or
commercial products constitute en-
dorsement or recommendation of use.
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Contents
1 Introduction
2 Bonoficial Uses of Sludge
Land Spreading on Cropland, Pasture or Range
Forest land Application
Reclamation of Surface Mined Land
Marketing Sludge Products
Recycling Wastes in Natural Biological Systems
4 Conservation Districts and Land Application of Sludge
Objectives of Agricultural Involvement in Land Application
How to Seek Involvement
Specific Aspects of District Involvement
6 "Good" Sludge for Land Application
Organic Matter and Nutrients
Heavy Metals and Toxic Materials
Pathogenic Bacteria, Viruses and Parasites
8 Factors to be Considered in Land Application
Addressing Public Concerns
Assessment of the Sludge
Land Availability
Site Characteristics
Soils and Other Physiographic Conditions
Determining Application Rates
Selecting the Crop
Conservation Plans
Liquid or Dewatered Sludge
Techniques for Applying Sludge
Monitoring
12 Case Studies
Monroe County, New York
Ohio Farm Bureau Program
Lewis County, Washington
Somerset County, Pennsylvania
Racine, Wisconsin
Florence, Alabama
16 Appendices
Suggestions for Further Reading
State Guidelines for Land Application
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Foreword
This paper has been prepared by the staff
' of the National Association of Conserva-
tion Districts as a contribution toward
clarifying the potential role of conservation
districts in land application of sewage
sludge. We are indebted to the many peo-
ple who assisted in its writing and review.
The initial data and materials for the
study were assembled and the paper was
written by W. Wendell Fletcher.
Review and comments on the first draft
were contributed by Jamon Baker, Monroe
County CD (NY); Robert Bastian, U.S. EPA;
Joseph C. Horvath of EKo-Kompost, Inc.;
Philip L. Mummert, Tennessee Valley
Authority; M. L. Goldhammer, Charles Mix
CD (SD); Terry W. Miller, Somerset CD
(PA); and, John Snider, Jr., Selah, WA.
Contributors on the NACD staff included
Robert E. Williams, Director of Special
Projects; James E. Lake, Program Spe-
cialist; Charles L. Boothby, Executive Sec-
retary. Word Processing was done by
Donna K. Smith.
These people all contributed to the
amount and the quality of the material in
the paper, but NACD is responsible for the
conclusions reached and for any errors
that may become evident.
Neil Sampson
Executive Vice President
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Introduction
As part of the country's commitment to re-
'^ducing water pollution, many communi-
ties either are building municipal wastewater
treatment plants for the first time, or are
upgrading existing treatment facilities.
While the new facilities reduce quantities of
pollutants entering lakes and streams, they
also produce large amounts of residue
(called sewage sludge) which is left behind
after the wastewater is processed and
reused or discharged into the waterbody.
The sludge consists of organic matter, nu-
trients, and other materials (such as heavy
metal contaminants) that are removed from
the wastewater during treatment.
In the past, disposal of sludge received
relatively little attention on the part of water
pollution control officials. But, as more and
more sewage treatment plants come into
operation, the sheer volume of sludge is in-
creasing more rapidly. By 1990, according
to one projection, as much as 16 million
tons of dry sewage sludge will be produced
each year—nearly three times the amount
of sludge produced annually in the 1970s.
Further complicating the situation is the
fact that many of the traditional methods of
sludge disposal—such as ocean dumping,
placement of sludge in sanitary landfills, or
incineration—have become environmen-
tally or politically unacceptable, or are sim-
ply too expensive for many communities to
afford.
As a consequence, there is an upsurge of
interest in land application of sludge. Em-
ployed for decades by many communites in
the mid-West, the technique makes an
asset out of what otherwise is a problem: it
turns a waste into a valuable resource by
using the land to recyle the organic matter
and nutrients that the sludge contains.
When properly applied to the land, the
sludge conditions the soil and serves as a
fertilizer supplement that can be put to
beneficial use in agriculture, forestry, land
reclamation, and other land management
activities.
Examples of land application opportuni-
ties include:
— spreading sludge on cropland, pasture or
grassland;
— using the sludge to help reclaim surface
mined land, mine spoils, and other drastic-
ally disturbed lands.
— application of sludge products on gar-
dens, nurseries, golf courses, etc.
— application of sludge on forestland, park-
land or highway median strips.
A key advantage of land application is
that it usually takes place on privately
owned land. Thus, the municipality can
avoid the high costs of acquiring land for
disposal sites, or of constructing expensive
sludge processing facilities. Private land
owners who accept the sludge not only help
to solve a municipal problem, but also may
improve the condition of the soil, reduce
fertilizer costs and increase crop yields.
Sludge application to land is not problem
free, however. A number of factors can limit
its use. For the farmer, the most important
of these is the quality of the sludge itself. All
sludge contains at least small concentra-
tions of heavy metals and other potentially
toxic contaminants that may enter munici-
pal wastewater treatment systems from
households, industries or storm drains. In
so-called "good" or "clean" sludges, con-
taminants are present at such low concen-
trations that they do not pose an appreci-
able hazard for contamination of the soil,
vegetation, or surface and underground
water supplies. Sludges that contain higher
concentrations of heavy metals or other
contaminants are usually not appropriate
for most land application techniques unless
special management procedures are fol-
lowed that carefully limit the locations
where and amount of these materials that
are applied to the land.
As increasing numbers of communities
around the country upgrade wastewater
treatment facilities, the issue of sludge
management will be increasingly visible.
Recycling sewage sludge on private land
will not always be a viable option for a given
community, but where it is, the active
involvement of farmers and other land-
owners from the earliest stages will be
essential. All too often, land application
proposals have failed because good
channels of communication between
municipal officials, landowners and nearby
residents were not established.
Moreover, in many cases, a land applica-
tion program will not be carried out in the
urban area where most of the sludge is pro-
duced, but in neighboring rural jurisdic-
tions. If the land application program is to
succeed the urban jurisdiction needs to be
especially sensitive to the special problems
and concerns of the rural area residents.
This booklet is aimed at facilitating com-
munication between rural and urban areas
in assessing sewage sludge management
options involving land application. The
booklet briefly describes alternative bene-
ficial uses for sludge; alternative roles for
soil and water conservation districts in land
application of sludge; the difference
between a "good" and "bad" sludge for
land application; factors involved in design-
ing a sludge application program for
agricultural land; and case histories of
involvement of agricultural agencies in land
application.
Because the actual design of a land appli-
cation program is a highly technical site
specific matter, the booklet is not intended
to provide specific technical guidance to
individual communities to their potential
land application projects. A variety of
information sources and state and local
agencies can provide such technical
assistance.
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Beneficial Uses
of Sludge
/Currently, about one-fourth of all sewage
^-'sludge is applied to the land through a va-
riety of recycling approaches. About one fifth
of all municipal sewage plants "dispose" of
at least part of their sludge through land
application.
Although expected to increase rapidly in
the years to come, land application is not
always a viable disposal option for an
individual community even when the
quality of the sludge is appropriate for land
application. Some communities may not
have suitable land available close enough to
the treatment plant to make transporting of
sludge to farmland practical. Still other
communities may encounter resistance on
the part of residents located near land appli-
cation sites. Yet for many communities,
recycling sludge on the land may be the
most cost-effective and environmentally
sound way to dispose of their sludge.
Many of the advanced engineering tech-
nologies for disposing of sludge are expen-
sive to build and both labor and energy in-
tensive—and are thus subject to increasing
operation costs as energy and labor prices
continue to rise. The costs to the municipal-
ity of land application vary from place to
place, depending primarily on such factors
as the distance of the application site from
the treatment plant, and the quantity of
sludge that is produced. But, for many small
communities and even some large cities,
land application has proven to be less costly
than other sludge disposal systems.
Environmental concerns have already re-
sulted in the phasing out of many coastal
cities' use of ocean dumping as a sludge
disposal alternative. In other areas, air qual-
ity limitations along with increasing energy
costs have precluded incineration. Another
disposal option—the sanitary landfill—
generally prompts more vehement political
opposition from nearby residents than does
land application. Because landfills involve
disposal of large quantities of wastes on a
small land area, there are often major con-
cerns about odors, groundwater contami-
nation and runoff of pollutants to nearby
streams. (Improper land application can
also result in similar problems, but because
smaller quantities of sludge are applied per
acre, the potential for such problems is sel-
dom so great.)
Thus, where economics and the quality of
the sludge permits, land application may be
the most suitable disposal technique—
especially since it affords the opportunity to
recyle resources which would be otherwise
wasted. This is an important philosophical
concept jn a society that has only recently
discovered that its natural resources are
limited. But it also has tangible results—as
many farmers, mine owners, and land man-
aging agencies are discovering—in terms of
improved productivity of the soil. As a
result, many communities do not have to
acquire land to dispose of their sludge;
many private landowners are more than
willing to accept it.
Briefly discussed below are the major re-
cycling alternatives: '
Land Spreading on Cropland,
Range or Pasture
Spreading of sludge on cropland or other
farmland is the most common method of
land application. This approach has been
used for decades by some communities—
especially in the mid-Western part of the
country where suitable cropland is widely
available and population densities are rela-
tively low. An estimated 400 towns in Illi-
nois and 250 towns in Ohio alone apply
sludge to the land. As understanding has
grown that a properly managed land appli-
cation program will bring benefits to
farmers, the interest on the part of the
farmers in sludge application is growing in
other areas of the country.
One of the key benefits to the farmer is
economics. As an incentive for land applica-
tion, most municipalities will provide sludge
to farmers at little or no cost. Thus, land
spreading of good quality sludge can reduce
the fertilizer costs of participating farmers.
According to the Council on Agricultural
Science and Technology, a dry metric ton of
sewage sludge contains $15 to $30 worth
of nutrients, based on 1976 fertilizer prices.
It is estimated that the fertilizer replace-
ment value of N,P, and K nutrients in all do-
mestically produced sewage sludge is
nearly $200 million per year.
Ongoing research designed to test crop
yields on sludge-amended land is being
conducted in several areas of the country.
Researchers in Ohio, for example, found
that, over a three year period, corn and
wheat yields on test plots amended with
three to six tons of sludge per acre were
roughly comparable to yields on test plots
where commercial fertilizer was utilized at
recommended application rates, and sub-
stantially above the control plots where no
fertilizer or sludge was applied. Similar
research in Oregon, Wisconsin, Maryland,
Alabama, and elsewhere shows that sludge
increases crop yields when properly
applied.
Farmers participating in landspreading
should be certain that the sludge provided
by the municipality is of good quality for
agricultural use. Application rates for high
quality sludges are normally determined on
the basis of nitrogen or in some cases phos-
phorus levels in the sludge. Where lesser
quality sludge with higher levels of heavy
metals or toxic organic compounds are in-
volved, smaller or less frequent applications
may be necessary to adequately limit the
amounts of contaminants applied with the
sludge.
Special management criteria—both fed-
eral and state—may affect farm manage-
ment practices on crop or pasture land for
some time after sludge application. These
can include: limitations on the kinds of
crops grown, restrictions on the quantity
and timing of sludge application in order to
reduce levels of pathogens or heavy metal
contaminants in crops or animals subse-
quently consumed by humans, and periodic
liming of the soil in order to reduce the solu-
bility of heavy metals.
Although some special managment prac-
tices are needed, a well designed land
spreading operation generally can be
undertaken in such a way as to provide
minimal interference with normal farm
activities. Agricultural agencies, such as
local conservation districts and agricultural
extension services, can play a key role in
helping to mesh municipal and landowner
objectives in land application of sewage
sludge.
Forest Land Application
Although not yet widely utilized in this
country, application of sewage sludge to
forest land may avoid some of the potential
hazards and public concerns that some-
times arise in the landspreading of sludge
on cropland. While there may be some
biomagnification of contaminants in wild-
life, concern about build-up of heavy metals
in the human food chain is largely avoided.
(Nonetheless, some regulatory agencies
recommend that the same criteria be used
in determining acceptable levels of heavy
metals in sludge applied to forest land that
are used in agricultural land spreading.
Reasons for this include limited data about
impacts of heavy metals on the forest
ecosystem; possible future clearing of
sludge-amended forest land for subsequent
use in agricultural production; and the
prevalent acidity of forest soils, which
encourages solubility of metals.)
Because forest land is generally located
at some distance from thickly settled areas.
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concern about excessive odors from
improper sludge disposal practices is
unlikely. Moreover, much of the forest
acreage in the United States—especially in
the West—is deficient in nitrogen. Sludge
application can be a cheap and convenient
way to improve forest production. On inten-
sively managed stands, forest land applica-
tion of sludge is Ijkely to result in fewer
interruptions in management practices
than is the case with row crop production.
In areas with cold weather, however,
sludge application is generally avoided in
the late summer and early fall in order to
prevent rapid twig growth and possible
subsequent damage from freezing weather.
Reclamation of Surface Mined Land
and Other Disturbed Lands
In several areas around the country, sew-
age sludge is being applied to surface
mined land and other drastically disturbed
land areas as an aid to reclamation. Ex-
periments in the eastern United States and
elsewhere have shown that use of sludge
can assist in the revegetation of such
disturbed areas by conditioning the soil and
promoting plant growth. Because of the
acidic nature of surface mine spoils, careful
management and monitoring is needed to
help minimize solubility of heavy metals in
the soil or in runoff.
Other Sewage Sludge Disposal Processes
In addition to recycling of sludge,
several other major sludge disposal prac-
tices are employed, including:
Landfilling—about 25 percent of all
sludge is disposed of in sanitary landfills.
Such facilities—where large volumes of
sludge are disposed of on relatively small
land areas—generally produce vehe-
ment political opposition. This may delay
or complicate municipal sludge disposal
plans. Public concerns about odors, pos-
sible health hazards and contamination
of groundwater or surface waters due to
leaching are more prevalent in the case
of landfilling than land application be-
cause of the far greater volume of
sludges and other wastes that are dis-
posed of in one location.
Good management of sanitary landfills
generally requires stabilization of the
sludge, covering of the sludge each day
with soil and other precautionary meas-
ures to prevent odors and control over
other nuisance problems—depending on
the extent of public access to the site.
The selection of the site itself should
take into account the need to prevent
groundwater contamination, and runoff
of materials into surface waters, as well
as nearby and abutting land uses which
might be affected by the landfill.
Careful monitoring of groundwater
(through observation wells) and surface
water quality is essential in landfill
operations.
Incineration—in instances where land
availability is limited, and the volume of
sludge is large, incineration is some-
times used to reduce the volume of
sludge to more manageable proportions.
It is not an ultimate disposal method,
however, since the ash remaining after
incineration must be disposed of eventu-
ally. Air quality concerns can limit the
circumstances in which incineration can
be used. Because incineration is an
energy intensive process, recovery and
reuse of energy from the incineration
process itself is often essential to keep
down costs. A number of different pro-
cesses and technologies have been
developed to help reduce energy costs
associated with incineration.
Ocean Disposal—although long used
by many large coastal cities, disposal of
sludge in the ocean has been phased out
by many cities in recent years, mostly
because of environmental concerns.
Since the mid-1970s, ocean dumping
has been permitted only through the
issuance of temporary permits. Most
communities utilizing this method of dis-
posal have been actively devising other
means of sludge disposal.
Lagoons and Storage Basins—many
communities simply dispose of their
sludge in lagoons. Sometimes lagoons
are used to stabilize sludge prior to land
application or to store sludge during
those periods when land application is
inappropriate. Key problems with
lagoons include: odors associated with
inadequate management, public opposi-
tion from nearby landowners, and site
limitations associated with possible
groundwater contamination. Nonethe-
less, lagoons and storage basins are
often a cheap and convenient method for
treating sludge.
Surface mine reclamation has become a
key sludge disposal alternative for some
large cities which produce large volumes of
sludge. Such sludges often contain higher
levels of heavy metals or other wastes from
industry than would be appropriate for land
application at higher application rates to
agricultural land. Less stringent application
rate restrictions are usually imposed on
sludge used in mine reclamation. Moreover,
because the volume of sludge from large
cities is so great, and because repeated
application on the surface mined land may
be permitted, economics of scale may
permit transportation of the sludge to dis-
tant surface mine sites.
For over 10 years, Chicago has been
barging much of its sludge over 200 miles
down the Illinois River to Fulton County,
Illinois, where the city has acquired several
thousand acres of previously mined land for
land application. More recently, the City of
Philadelphia has begun a land application
program involving shipment of sludge (by
backhaul in coal trucks) some 250 miles for
use in reclaiming surface mined land in
Somerset County, PA. Research and moni-
toring is now being conducted to determine
any potential problems associated with
using sludge-reclaimed land for agriculture
once reclamation is achieved.
Marketing Sludge Products
Although liquid sludge is often preferred by
farmers because it is easy to apply, a num-
ber of communities around the country (as
well as several private firms) now market
sludge products for use by commercial nur-
series and horticulturalists, turf farmers,
gardeners, golf courses, and other users.
Several commercially available products—
ranging from products wholly comprised of
processed sludge, to sludge based com-
posts augmented by other materials—are
now available.
The City of Milwaukee's sludge product,
Milorganite, has been marketed for
decades. The sludge is heat dried to reduce
moisture, destroy pathogens, and granu-
lated. The sludge is then packaged and sold
for use as a fertilizer on golf courses, and
other uses where nonedible plants are
involved.
More recently, composting of sludge
(which maintains the soil conditioning
capabilities of the organic matter in the
sludge) has become the subject of wide-
spread interest. Although a number of
different composting methods have been
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Conservation Districts
and Land Application
of Sludge
developed, all composting techniques
stabilize the sludge through microbial
decomposition. While the decomposition
process may reduce nitrogen concentra-
tions in the sludge, the end product is
useful as a soil conditioner and low analysis
fertilizer.
The "aerated pile" method of composting,
developed by researchers from the U.S.
Department of Agriculture and the Mary-
land Environmental Service Corp., is receiv-
ing especially widespread attention, since it
can be used to compost both small and
large quantities of either digested or undi-
gested sludges in a relatively short period of
time. The process involves mixing the
sludge with a bulking agent (such as wood-
chips) to increase aeration. The mixture is
then placed in carefully constructed piles
for several weeks time, during which stabil-
ization and curing takes place.
Some private firms add extra ingredients
to composted sludge, and market the prod-
uct commercially. One of these sludge
based products, for example, includes ani-
mal blood, bone meal, sawdust, shredded
bark and granite dust in addition to the
sludge. According to one firm, use of their
product results in improvements in crop
yields, and better soil conditions than com-
mercial fertilizer. Heavy metal concentra-
tions are reported to be well within the
guidelines established for food chain crops.
Generally speaking, composted sludge
has a minimal potential for causing odor
problems, and is easy to store. Composting
reduces levels of persistent organic com-
pounds and pathogens. Composting of sew-
age sludge is also considered an alternative
technology under the Clean Water Act, and
is eligible for up to 85 percent federal con-
struction grants for land, equipment and
related construction costs.
Recycling Wastes in Natural
Biological Systems
Currently, considerable research is being
conducted on the potential of other natural
biological systems (such as wetlands,
ponds, and other aquatic systems) in treat-
ment of municipal wastewater. Utilization
of sludge in such processes is more limited,
due to concerns about biomagnification of
contaminants. However, as more research
is conducted, some sludge disposal proces-
ses may come to involve these other natural
biological systems. Any such approach will
require careful management to prevent
damage to natural ecosystems.
Ooil and water conservation districts are lo-
^cal units of state government, which work
with federal, state and local agencies, and
individual landowners to implement appro-
priate conservation programs. Since the
mid-1930s, nearly 3,000 conservation dis-
tricts have been established. They cover
more than 99 percent of the nation, and are
generally (but not always) contiguous with
county boundaries.
Districts are directed by local citizens rep-
resenting a variety of occupations associ-
ated with resource management. Nation-
wide, over 17,000 local citizens serve as
district directors. From an initial focus on
soil and water conservation, district activi-
ties have expanded over the years to
include such additional areas of concern as
nonpoint water pollution, coastal zone
management, surface mine reclamation,
wetlands protection, and a variety of other
resource management concerns and
objectives.
A major component of every conservation
district's program is the assistance it pro-
vides to individual landowners. At the re-
quest of the owner, the conservation district
undertakes a cooperative effort with the
landowner to develop conservation plans
intended to achieve resource conservation
objectives as well as the individual owner's
objectives. Responsibility for implementing
the conservation plan rests with the land-
owner, but additional technical assistance
on a continuing basis will be provided by the
district when requested. A variety of federal
and state cost-sharing programs also have
been established to help landowners imple-
ment such plans.
Because the conservation district works
closely with both individual landowners and
other units of government, it is often able to
facilitate interaction and to remedy prob-
lems that might arise when different objec-
tives are apparent. This is an especially im-
portant consideration in the land applica-
tion of sewage sludge, which, in many
instances, is applied to privately owned
land. Many of the successful sludge appli-
cation programs conducted in this country
have involved the intensive participation of
the local conservation district.
Discussed below are some alternative
roles that conservation districts and other
agricultural organizations can play in help-
ing to assure that land application of sludge
is conducted in the most beneficial way.
Objectives of Agricultural
Involvement in Land Application:
When done properly, land application proj-
ects have multiple benefits to the public at
large, to individuals landowners, and to the
objectives of resource conservation. Al-
though the circumstances in each commu-
National Association of Conservation Districts' Policy Position on Sludge
As more communities assess land
application options, making sure that a
program is sensibile not only for the
community but also for the landowner is
a pressing priority. In 1980 and 1981,
the conservation districts—through their
national association—voted to adopt pol-
icies encouraging research and imple-
mentation of safe and effective methods
for recycling sewage sludge. In addition,
several state associations of conserva-
tion districts have adopted policies on
sewage sludge and land application.
The 1981 policy statement follows:
1. With increasingly strict restrictions
on the dumping of sewage sludge in the
oceans, increased attention needs to be
given to its safe disposal on land. In addi-
tion to organic matter and plant nutri^
ents, sludge can contain both beneficial
and harmful microorganisms, heavy
metals and organic chemicals from both
industrial and urban runoff.
2. NACD urges both USDA and EPA to
improve their capability to help local
communities deal with appropriate dis-
posal of sewage sludge. In addition to
accelerated research into the problems
of sludge disposal on agricultural land,
there needs to be a way to assist com-
munities in locating disposal sites and
developing management plans.
3. State Associations of districts should
work with state governments to assure
that state policies and guidelines for
sludge application on agricultural land
consider sound agricultural and conser-
vation practices. State monitoring pro-
grams should be established to assure
that all sludge applied to farmland has
been properly tested and its safety to
crops and soils assured.
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nity will differ, the objectives of conserva-
tion districts in land application projects
may include such items as the following:
— Helping to assure that the quality of the
sludge is appropriate for land application,
and that proper management techniques
are utilized in applying the sludge to the
land.
— Helping to safeguard the interests of the
farmer or other landowner in land
application.
— Furthering conservation objectives such
as rehabilitation of drastically disturbed
land, recycling of resources, and improving
crop yields and soil conditions.
— Improving relations between urban and
rural communities, and increasing public
understanding of the role that the land can
play in helping to solve urban problems.
— Reducing, in may cases, the economic
costs and/or environmental problems asso-
ciated with some other sludge disposal
methods.
— Furthering the national policy goal of
conservation districts to achieve safe and
effective ways of disposing of sludge.
How to Seek Involvement
In many past instances, municipalities have
presented land application strategies to the
public with little forewarning. The result
can lead to the end of a project before it
begins. In other instances, landowners and
farmers have approached local wastewater
treatment officials to inquire about land
application, only to receive a deaf ear.
Conservation districts—representing as
they do both local land users and govern-
ment—often are in an ideal position to get
the ball rolling in assessing land application
options. Steps that could betaken include:
— Letting local government officials know
that land application of sludge, when man-
aged properly, is often less costly and less
environmentally objectionable than many
other treatment options.
— Informing state and local wastewater
officials about district capabilities, re-
sources and interests in land application
techniques.
— Offering to coordinate the effort to deter-
mine whether land application of sludge is
an advisable treatment option on private
land for the community.
— Canvassing local farmers and other land
users to determine their interest in land
application of sludge.
— Beginning to assemble information
about land application projects conducted
under similar conditions in other
communities.
— Being alert and responsible to the con-
cerns of farmers and other local residents
about the possible adverse effects of land
application projects.
— Initiating or coordinating demonstration
tours or educational programs about land
application projects in the vicinity.
Specific Aspects of
District Involvement
a) Determining whether land application
is appropriate:
— Making sure that proper testing has
been done of any sludge proposed to be
used for land application.
— Identifying and assessing possible alter-
native uses for the sludge, i.e., agricultural
use, reclamation uses, use on forest land,
parkland or other public lands.
— Determining landowner interest in land
application.
— Providing information on soils, erosion
and water resources which would permit
initial screening of potentially suitable land
for sludge application.
— Working With municipal wastewater
treatment officials to determine possible
constraints on land application.
— Identifying appropriate crops or other
vegetation for sludge application.
b) In designing a land application project:
— Coordinating efforts by resource special-
ists to determine the acceptability of indivi-
dual sites for land application.
— Providing information and analysis
about the timing of sludge application and
the rate of application that is consistent
with the capabilities of the land, current
cropping patterns, or other uses of the land.
— Identifying any special management
procedures (including changes in normal
cropping patterns, conservation practices,
pH management, and pollution minimizing
measures) which might be needed.
— Informing landowners of any necessary
restrictions on normal farming practices
which would occur if sludge application
takes place.
c) In applying sludge to the land:
— Making sure that the project meets fed-
eral and state criteria for the specific sludge"
application technique that is used, and that
the application rate is appropriate.
— Helping landowners develop conserve- .
tion plan incorporating desirable measures
to control erosion or runoff from sludge-
augmented lands.
— Making sure that any agreement
between a landowner and a municipality
serves the interest of both parties. Land- !
owners in particular should be assured that
the sludge is suitable for agricultural use,
and should understand any limitations
(such as temporary restrictions on growing
crops for direct human consumption) that
may be associated with their acceptance of:
the sludge.
— Making sure that the sludge delivery
system (i.e. tank truck equipment, injection,
or surface spreading equipment) is appro-
priate, and that modifications (such as
floatation tires) are used as needed in order,
to adequately protect the land during sludge
application.
— Working with landowner to insure that
they successfully carry out any special
management practices that maybe needed,
and that sludge application is done in such
a way as to minimize disruption of normal
farming operations. '
d) In monitoring and follow up
Even when sludge is applied only once to a
parcel of land, monitoring and follow up
procedures are an excellent idea. This per-
mits identification of any problems (such as
water pollution) that could arise, and, more-
over, reporting procedures that are used
further the state of knowledge about land
application of sludge. Conservation districts
can assist in this process by:
— Making sure that landowners participat-
ing in projects understand from the outset
the need for and agree to post-application
monitoring by technicians.
-------
Good Sludges for
Land Application
— Coordinating or conducting monitoring
of groundwater, surface water, soil quality,
and vegetation on project sites in order to
determine if any problems with heavy
metals or other contaminants exist, report-
Ing results on the monitoring process in
order to further the state-of-knowledge.
— Recommending any changes in man-
agement practices (either by the municipal-
ity or the landowner) that would resolve
problems, or improve the land application
project.
— Monitoring yields of crops or other vege-
tation on land application sites.
— Establishing, when possible, control or
test plots in order to compare conditions on
sludge-augmented land with other land that
has not been subject to sludge application.
I Inless very low application rates are used,
'"'all sludges applied to agricultural land
should be "good" or "clean" sludges: that
is, their application to cropland as a source
of nitrogen or phosphorus should not
present an appreciable risk of contaminat-
ing soil, water, or food chain crops, or other-
wise damage crops and other vegetation.
Thus, in every community, careful
assessment of the sludge itself is the key
first step in determining whether land
application should be used. Under current
federal regulations, the responsibility for
such assessment rests with the operators
of individual wastewater treatment
facilities. Any farmer or other landowner
who is considering land application should
be certain that proper testing of the sludge
quality has been conducted, and the sludge
is acceptable for agricultural use.
In most instances, the most suitable
sludge for land application in agriculture
will come from municipal treatment plants
which primarily serve residential communi-
ties. Such sludges are less likely to have
unacceptable high levels of contaminants,
and may have higher levels of organic
matter and nutrients, than sludge from
municipal plants which also process
industrial wastes and storm drain runoff.
Briefly described below are the beneficial
and potentially detrimental c istituents of
sludge.
Organic Matter and Nutrients
The amount of organic matter in sewage
sludge varies, but can be quite high—up to
50 percent by dry weight. Because the or-
ganic matter serves as a soil conditioner,
application to the land may improve the tilth
and the texture of the soil. Generally, the
higher the degree of sewage treatment or
sludge processing employed, the less the
organic matter will be contained in the
sludge. One benefit of land application of
"good" sludges is that high levels of treat-
ment to reduce organic matter content are
not generally required since these substan-
ces will be recycled, although special atten-
tion to assure adequate pathogen kill may
be necessary. Hence, overall community
treatment costs may be reduced.
Sewage sludge also contains variable
amounts of nitrogen and phosphorus, as
well as very small quantities of potassium
and many micronutrients. Because all of
these materials are essential for plant
growth, sludge can be used to supplement
fertilizer regimes. Although concentrations
of nutrients in sludge are relatively low,
sludge application rates can be adjusted so
that most of the nitrogen and phosphorus
requirements of many crops can be met—
provided that heavy metals or other con-
taminants do not restrict application rates.
Potassium concentrations in sludge are
generally too low to meet the needs of most
crops, and supplemental fertilizer usually is
required.
Research on crop yields and vegetation
response to "good sludge" is being con-
ducted. Most of the research results to date
indicate that crop yields on sludge-amended
land compare favorably with the use of
commercial fertilizer. An added benefit for
farmers is that most municipalities provide
the sludge to farmers at little or no cost.
Heavy Metals and Toxic Materials
Concern about heavy metals and other
potentially toxic materials in sewage sludge
remains a constraint to greater use of
sludge in agriculture. While scientific
knowledge about these substances—and
how to manage them has evolved rapidly,
there are still areas of disagreement about
what levels of contaminants are acceptable
for sludges applied to agricultural land.
, The presence of small concentrations of
some heavy metals in the sludge—"trace
elements" such as zinc, copper, and sele-
nium—need not be considered a liability. In
fact, very small concentrations of such trace
elements are essential for plant and animal
metabolism, and are often present in defi-
cient amounts in the soil. Thus, when
sludge contains proper concentrations of
these elements, it may help to make up
nutrient deficiencies in soils and crops.
At higher concentrations, however, such
trace elements are potentially toxic. Two
contaminants frequently found in sludge—a
heavy metal, cadmium, and a group of per-
sistent organic compounds, polychlorinated
biphenyls (PCBs)—have no known beneficial
metabolic effects, and can be extremely
toxic. Thus, concern about possible soil,
water, or crop contamination, and potential
impacts of such toxic substances to animals
or man has arisen.
As has been mentioned, heavy metals or
other contaminants may be a problem in
communities where industries discharge
wastes into municipal systems, or where
combined stormwater and wastewater
treatment systems are employed. Sludges
from such treatment facilities may not be
appropriate for land application unless pre-
treatment of industrial wastes or other
measures are employed to reduce
contaminants to acceptable levels. While
such measures may make previously
unsuitable sludges acceptable for land
application, careful monitoring and periodic
-------
testing of the sludge is needed to assure
that the improved quality is maintained.
Landowners should not accept such
sludges unless they have assurance that
proper quality controls are in place.
The federal government and some state
governments have established criteria for
determining the suitability of sludge and
sludge application rates for land applica-
tion. At the federal level (see box below),
interim criteria have been established
for cadmium, and polychlorinated biphenyls
(PCBs)—two substances thought to be of
major concern. Additional guidance also
exists for determining threshold levels for
other contaminants in sludge. Unless their
use is very carefully managed, sludges with
relatively high concentrations of such heavy
metals as zinc, nickel, lead, mercury and
chromium should not be used for land appli-
cation, even though formal regulatory crite-
ria have not yet been issued by federal
agencies. In some instances, the state cri-
teria are more restrictive than the federal
criteria and guidance.
Pathogenic Bacteria, Viruses
and Parasites
Since raw sewage contains pathogenic bac-
teria, viruses and certain parasites, any
sludge disposal method can involve poten-
Federal Criteria on Heavy Metals and Toxic Materials
Sludge was defined by Congress as a
solid waste in the provisions of the
Resource Conservation and Recovery
Act of 1976 (acronymed RCRA), which
regulates the disposal of hazardous and
nonhazardous solid wastes. EPA regula-
tions under RCRA do not list sewage
sludge as hazardous waste unless tests
show on a case-by-case basis that an
individual sludge is hazardous. Initial
responsibility for such determination
rests with the owner or operator of a
publicly owned treatment plant. Any
farmer or other land operator receiving
sludge for land application should be
sure that an assessment of the sludge
has been conducted and that testing
shows that the sludge falls within
acceptable quality parameters for land
application.
An ongoing federal interagency effort
(involving the Environmental Protection
Agency, the Department of Agriculture,
and the Food and Drug Administration) is
underway to establish criteria or toler-
ance levels for sludge-borne contami-
nants in food chain crops.
At the present time, "threshold" cri-
teria and associated management prac-
tices for land application of sludge have
been established for cadmium and poly-
chlorinated biphenyls (PCBs). These cri-
teria are enforceable, though interim in
nature, and subject to change.
PCBs (as well as certain other persist-
ent organic compounds) tend to concen-
trate in fatty tissues of animals, and
could be biomagnified in the food chain.
Research conducted on plant uptake of
PCBs or related compounds suggest
minimal uptake by forage and grain
plants. However, direct indigestion of
PCBs by grazing animals is a potential
problem where surface application of
sludge containing these compounds has
been used.
The present federal criteria for land
application of sludge containing cad-
mium and PCBs are increasingly more
restrictive as the probability of human
food chain involvement increases. The
least restrictive category is for land appli-
cation in which no human food chain
involvement is likely, followed by the use
in feed grain and forage crop production.
The most restrictive category includes
sludge use in the production of crops
grown for direct human consumption.
Additional guidance exists about
acceptable levels of other heavy metals
(e.g., zinc, copper, and nickel) in land
application of sludge. High levels of
these materials in a sludge may preclude
its use in land application. Several states
have established their own regulatory
criteria for contaminants in sludge which
may be more stringent than federal
requirements and guidance.
Although there remain scientific dis-
agreements about acceptable levels of
potentially toxic materials in sludge, the
use of "clean" sludge in land application
Is the best way to minimize potential
hazards. According to a joint policy state-
ment on the use of sewage sludge in the
production of fruits and vegetables
issued by EPA, USDA and FDA in 1981,
"the use of high quality sludges, coupled
with proper management precautions,
should safeguard the consumer from
contaminated crops and minimize any
potential adverse effect on the
environment."
tial risks of transmitting diseases to
humans. Most of these organisms are
destroyed during sludge processing at a
sewage treatment plant, but some patho-
gens survive most treatment processes. In
the case of land application, transmission of
disease could theoretically occur through
direct exposure of farm and sanitation
workers to the pathogens, contamination of
surface water, groundwater, or crops, or by
vectors (carriers of disease organisms, such
as rodents or insects).
To minimize the potential for public expo-
sure to pathogens, EPA has established
special criteria to be used in processing the
sludge prior to land application, timing the
application of sludge, and managing the
land after sludge application. All sludge
applied to cropland must undergo a process
which significantly reduces pathogen levels
(such as aerobic and anaerobic digestion,
air-drying, heat-drying, irradiation, corn-
posting and lime stabilization). Public
access to land application areas is to be
limited for one year after land spreading,
and grazing by animals that produce
products consumed by humans is pro-
hibited for at least one month.
Processes which reduce pathogens to
very low levels must be utilized in those
instances where crops are grown for direct
human consumption within 18 months of
land spreading. This further requirement
does not apply if the sludge does not
actually come into direct contact with the
edible portion of the plant.
Care should be taken to assure that farm
workers and operators who are directly
exposed to sewage sludge receive proper
immunizations against disease, and are
aware of the need to follow proper sanita-
tion when exposed to areas where sludge
has been recently applied.
Resistant parasites in the sludge are also
a potential concern. For example, the ova of
Ascaris lumbricodes, a parasitic intestinal
worm in humans, can be excreted by
affected humans into sewage. Since the
ova are relatively resistant to most waste-
water treatment and sludge stabilization
processes, they may be present in the
sludge when it is applied to the land.
While there is always a potential for
transmission of disease from sludge to
humans, the experience to date with land
application has been a good one. Studies
made at actual land application projects
investigating potential public health con-
cerns to date have recorded no instances of
disease transmission attributable to land
application of sludge where proper
management practices were followed.
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Factors to be
Considered in Land
Application
Although land application is simple in con-
*"* cept, the actual design of a good program
is quite complex. Communities seeking to
implement a land application approach
need to draw upon the expertise of many
different specialist in the technical design
of a program, and in implementing and
monitoring a sludge application program.
Experience with land application of
sludge is growing rapidly, and there now
exists a fairly well defined government and
private support structure which can assist
communities in the design of an appropriate
land application program. In many in-
stances, the community will be able to draw
upon the technical expertise of local con-
servation districts, forest and agriculture
extension agents, university professors,
and consultants to design program options,
and work with individual landowners partic-
ipating in the program. Federal agencies,
including the U.S. Environmental Protection
Agency, several agencies within the U.S.
Department of Agriculture, and the Food
and Drug Administration, also provide tech-
nical information and other assistance or
guidance.
On the following pages, many of the
issues associated with land application are
discussed. The discussion is intended to be
general in nature, and should not be con-
strued as providing specific guidance to a
community that is assessing land applica-
tion alternatives.
Addressing Public Concerns
Even the best designed land application
program can falter if it does not gain public
acceptance. Although land application proj-
ects generally are not resisted as strongly
by nearby residents as are sanitary landfills,
public acceptance problems can arise—
especially when land application sites are
located near residential development or
when little effort is made by public officials
to deal with the legitimate concerns of
nearby residents about odors, health
effects, and property values, as well as the
more generalized public concern about pos-
sible contamination of food chain crops.
These concerns are not frivolous. Impro-
per land disposal of sludge can indeed pro-
duce odors, or contaminate the surface
water, groundwater, soil or vegetation with
pathogens, heavy metals or other toxic ma-
terials. Were such problems to arise,
property values could be affected as well.
Moreover, in some situations it has been
proposed that notations be made on the
deeds of private land used for land applica-
tion, This is intended to permit long term
monitoring of the land effects of land appli-
cation, and to guard against changes to
incompatible future land uses. While there
are advantages to such proposals—in terms
of monitoring longterm effects and potential
problems associated with land applica-
tion—landowners will be wary of accepting
sludge under such conditions.
Another problem is psychological. Al-
though land recycling of human wastes has
been used in Europe, Asia, and other areas
of the world for centuries, the use of such
practices has been much more limited in
the United States. Most Americans have
always had a preference for engineering
approaches to sewage disposal. From an
environmental and economic perspective,
the engineering approaches in many in-
stances may be less cost-effective than land
application techniques, but psychological
opposition on the part of the public tends to
be high.
Thus, dealing with public concerns is an
essential component of many land applica-
tion programs. Fortunately, land application
usually does not present as many risks as
some other methods of sludge disposal. An
improperly selected and operated landfill
site, for example, presents a far greater risk
of groundwater contamination or produc-
tion of odors because much larger volumes
of wastes are disposed of on a site.
In land application, the sludge is spread
infrequently and in relatively small volumes
on many sites; thus the potential for local-
ized problems is reduced. Moreover,
because land application can improve the
physical properties of the soil and boost
crop yields, the value of the land for agricul-
tural use may actually rise. Thus, farmers
and other landowners who are participating
in a land application program are likely to
take up the case of land application with
other farmers in a far more persuasive
manner than government officials. (By con-
trast, no one wants to live next to a landfill
site—no matter how necessary suqh facil-
ities may be.)
Because resistance to sludge land appli-
cation projects is greatest from nearby land-
owners and residents, selection of sites that
are relatively isolated from residential or
commercial development and other non-
farm activities can help reduce public oppo-
sition. One comparison of 16 land applica-
tion sites and their abutting land uses found
that there was no public opposition to the
five projects in which low intensity land
uses (defined as forests, abandoned strip
mines and sand dunes) were adjacent to the
site. Medium intensity abutting land uses—
active strip mining, and grazing or ranch-
ing—brought more intense public opposi-
tion. (Only one of the eight projects in this
category encountered no opposition; the
others encountered lawsuits or individual
opposition by abutting landowners.) In the
case of high intensity abutting land uses—
residential development and intensive agri-
culture —all three of the proposed projects
become the subject of legal actions which
eventually prevented these projects from
being implemented.
Assessment of the Sludge
As has been mentioned, the first step in any
land application system must be analysis of
the sludge itself in order to determine its
suitability for various land application tech-
niques. Because analysis of the sludge is
the responsibility of the operator of the
municipal treatment plant, landowners or
other communities considering acceptance
of sludge should insist that sufficient test-
ing has been conducted to assure that the
sludge is suitable for the intended benefi-
cial use. (Agricultural uses of sludge, for
example, generally involve more restric-
tions on heavy metals than when the sludge
is used in surface mine reclamation.) The
U.S. Environmental Protection Agency rec-
ommends that a minimum of 3 to 6 samples
of sludge should be analyzed over a one
year period to determine its suitability for
land application. More frequent sampling
may be needed in many situations.
Key components of sludge analysis
should include, among other things, analy-
sis of heavy metal concentrations (espe-
cially cadmium, copper, nickel, lead and
zinc); specific persistent organic com-
pounds (such as PCBs); and pathogens, in
order to determine limitations on land appli-
cation. Other important information which
should be determined include:
— Current and future levels of sludge pro-
duction, in order to determine the likely
range of land requirements and estimated
costs.
— Nitrogen, phosphorus and potassium
content, to determine value of the sludge as
fertilizer, and proper application rates for
farm use.
— Testing for volatile solids to determine
likely odor problems.
Various measures can be taken to reduce
levels of heavy metal concentration in
-------
sludge prior to land application. These
include pretreatment by metal using indus-
trial sources discharging into municipal
systems, and changes in the wastewater
and sludge treatment processes utilized by
the sewage treatment plant.
As has been mentioned, EPA, USDA, and
FDA are surveying available information in
order to help establish final land application
criteria and tolerance levels for heavy
metals, pathogens and other sludge con-
taminants for various beneficial uses.
Land Availability
On a national basis, the physical availability
of land for sludge application is not a prob-
lem. In fact, according to one estimate, only
two percent of all cropland in the United
States would be needed for land application
of all Sewage sludge likely to be produced by
1985."Forest land, surface-mined land,
range and pasture, are also potential sites
for sludge application.
At the local level, however, a variety of
constraints affect land availability. In some
heavily urbanized states with relatively little
cropland per capita, widespread adoption of
land application by communities could
require a fairly high proportion of existing
cropland. In Florida, for example, it is esti-
mated that about 20 percent of the state's
cropland would be required if all sludge
produced in the state by 1985 were applied
to cropland. Similarly, in New Jersey, 55
percent of the cropland would be required.
While land application of all sludge is not
likely, some localities that have high levels
of urbanization (either concentrated or ,
dispersed) may experience difficulties in
locating suitable cropland for land applica-
tion in the future.
As a result, some land application proj-
ects involve transport of the sludge to a
neighboring or more distant jurisdiction.
Transportation costs are a key factor here,
since transporting sludge long distances
usually involves very high costs. Moreover,
sludge is applied infrequently when it is
used on farmland; in many cases, it is
- applied only once in several years oh a
specific field because of regulatory limita-
tions, or possible interference with cropping
practices. Therefore, in some instances,
cities have used publicly owned land where
frequent repetition of sludge application is
possible.Jn such cases, production of agri-
cultural crops is not the primary purpose of
the program.
While transportation distance is centrally
important, shipment of sludge well over one
hundred miles for land application has
proven feasible for some large cities. Phila-
delphia and Chicago transport large vol-
umes of sludge to distant sites for use in
surface mine reclamation; in both instan-
ces, land application has been cost-effec-
tive. A key factor in these two cases is that
the sludge is shipped in large volumes to a
centralized area which will have sites avail-
able for land application of sludge over a
number of years. In these cases transporta-
tion arrangements such as longterm
barging contracts, use of pipelines, and
special back haul arrangements in which
sludge is hauled to reclamation sites in the
same trucks which haul coal to the city
were developed. v
Site Characteristics
For many smaller communities, finding
farmers or other landowners willing to
apply sludge to their land has not been a
major problem. In fact, in some instances,
municipal land application programs have
been established because of interest
expressed by local farmers. However, other
communities may have greater difficulties
in locating private landowners who are will-
ing to accept sludge. In such instances, uti-
lization of publicly owned land (such as
highway median strips, parkland, or spe-
cially dedicated land) may be an alternative
worthy of consideration.
Whether private or public land is to be
used, however, it is essential that the site
be carefully assessed to determine whether
land application is appropriate, and,
whether special soil conservation or other
management practices will be needed.
Most communities that are considering
landspreading can tap the professional
expertise of local conservation districts, and
extension agents in order to assess site
conditions on specific farms or other private
lands. Prior to any sludge application, all
potential sites should be visited by resource
specialists in orderto determine limitations
of the land, or the need for compensating
management practices.
In communities where limited land is
available, initial screening of (and within an
economically affordable distance of the
treatment plant (usually within a 30 mile
radius or less) is an advisable first step in
determining whether land application is
feasible. Often, considerable information
about land use patterns, soil conditions, site
geology and hydrology, and climatic limita-
tions already will be available. In general,
land near residential, commercial or other
intensive development should be excluded
because of possible health concerns, odor
problems and likely political opposition.
When feasible, land within the same local
jurisdiction which produces the sludge
should be considered first. Even though
some communities transport their sludge to
neighboring or more distant jurisdictions,
such jurisdictions often resist receiving
another community's sludge. While agricul-
tural land application is the most common
means of land application, other potential
uses (such as use on forestland, surface
mined land, highway median strips, and so
forth) should be kept in mind. To the extent
possible, attitudes of residents about land
application should also be taken into
account in order to avoid political "hot
spots." Very often, local conservation
district personnel can provide information
about the expected attitude of farmers on
this subject.
Soils and Other Physiographic
Conditions
Once a general understanding of the feasi-
bility of land application in an area is
gained, more specific analysis of topo-
graphic and geologic conditions, soil char-
acteristics, and other physiographic factors
is needed to determine whether a specific
site is appropriate.
In order to minimize the potential for run-
off and erosion, relatively flat land generally
is preferred. Land that has a slope of more
than 4 to 6 percent generally should not be
used without special management or con-
servation practices which reduce runoff.
Sites subject to flooding should also be
avoided, since this will substantially
increase the risk of water pollution. An
understanding of subsurface geology is also
essential in those instances where contam-
ination of groundwater could occur with
improper sludge application.
With proper management, soils with a
wide range of physical, biological and
chemical properties can be used for land
application. While few soils are completely
unsuited for sludge application, some are
far better than others.
Since all sewage sludges contain at least
small concentrations of heavy metals, the
pH of the soil is an especially important
management factor. The solubility of most
heavy metals tends to increase as soils
become increasingly acidic. This means
that uptake of metals by plants and down-
ward leaching of metals towards the
groundwater will tend to be greater with
-------
acidic soils. Therefore, a soil pH of 6.5 or
above is generally required when sludge is
applied to the land. Moreover, a pH of 6.5
may need to be maintained for several years
after application, since heavy metals may
continue to be present in the soil in an
insoluble form. Lime is usually applied to
raise the pH of acidic soils. Annual monitor-
ing (with lime additions where necessary)
should be continued after sludge
applications.
When sludge is used in commercial farm-
ing, both the constraints on sludge and the
possible need for liming should be under-
stood by the landowner prior to any sludge
application. Considerable evidence now
exists that proper use of high quality sludge
can safely improve crop yields. Moreover,
lime additions are often beneficial to crop
growth on many soils, and are frequently
used anyway by farmers. However, in some
instances where proper sludge use prac-
tices are not followed, an excessive buildup
of plant available heavy metals in the soil
could occur and result in reductions of crop
yields. While yields may rebound subse-
quently, farmers need assurance that the
sludge they receive is of good agricultural
quality and that appropriate sludge applica-
tion rates and liming procedures are fol-
lowed to adequately manage any metal
additions to the soil in a manner that will
not reduce expected crop yields or quality.
Where sludge application is not compatible
with commercial farming, other alternatives
(such as land application on noncommercial
grassland owned by the municipality or on
publicly or privately owned forest land) may
still be possible.
Determining Application Rates
Where metals or other contaminants are
not a potential problem, the determination
of how much sludge to apply to crops is
based on the nutrients needed to achieve
the intended yield, just as is the case with
commercial fertilizer. Crop uptake of nitro-
gen (which is the most concentrated nutri-
ent) generally is the primary consideration.
Usually, phosphorus needs will also be met.
Even when nitrogen is applied at rates
equivalent to those recommended for com-
mercial fertilizer, however, supplemental
potassium fertilizer additions may be
needed for some crops.
Sludge application rates may be limited
by the presence of heavy metals in the
sludge, soil response to such metals, and
uptake of such metals by the individual crop
grown. As has been discussed, cadmium is
the heavy metal which is most likely to
reduce application rates below levels
needed to supply crop nitrogen needs.
Depending upon the individual characteris-
tics of the sludge, however, other metals,
such as zinc, copper, lead and nickel may
affect application rates in some instances.
Because of the number of variables
involved, technical expertise is needed in
order to determine appropriate application
rates (both in quantity and in frequency) for
individual sites. This usually requires a
coordinated effort on the part of agronomic
professionals and water quality specialists.
Researchers have developed a number of
different equations which can be used to
determine proper sludge application rates.
Selecting the Crops
From the perspective of the farmer, land
application should be conducted in such a
way as to require minimal disruption of nor-
mal farm operations and cropping patterns.
Thus, timing of sludge applications in order
to meet cropping needs is essential.
For example, where row crops such as
corn are grown, sludge application is not
possible except before plowing or after har-
vesting in most instances. (A possible ex-
ception is where ridge and furrow applica-
tion is utilized.) Similarly, requirements and
restrictions on the timing of sludge applica-
tions when crops are grown for either direct
human consumption or as feed for animals
whose products are consumed by humans
must be taken into account. In some areas,
fruit and vegetable processors may be
reluctant to purchase products from
growers that have applied sludge on their
land, even when proven precautions have
been taken. Thus, growers should be cogni-
zant of the attitudes of their clients prior to
land application.
Different crops vary in their uptake of
heavy metals and other contaminants.
' Moreover, there is a variation noted within
individual plant tissues: seed, fruits and
vegetables, for example, may absorb heavy
metals at rates different than stems and
leaves.
Conservation Plans
Although seldom required by state or local
regulations, farmers seeking to have sludge
applied to their land may wish to develop a
soil and water conservation plan in order to
assure that farm management and sludge
application objectives are mutually re-
enforcing. The plans can help to identify
possible problems—erosion, water contam-
ination, and so forth—that could arise from
improper land application, and any post
application measures that are needed to
accommodate sludge application. They can
also identify appropriate farm management
practices, timing of sludge applications, and
other factors that may limit sludge use.
Liquid, Dewatered or Composted
Sludge?
Some large communities partially dewater
sludge in order to make it easier to store or
transport, and to minimize odor problems.
For the smaller communities, however, de-
livery of liquid sludge is usually a less costly
alternative. Farmers often prefer liquid
sludge because it easier to apply evenly on
fields, and because the sludge delivery
truck's driver will usually spread the sludge
on the field.
Because of the energy costs involved, it
can be costly for the community to dewater
sludge. But transporting liquid sludge long
distances can be much more expensive
than transporting dewatered sludge due to
the difference in water content. Unlike
liquid sludge, the dewatered sludge can
easily be deposited at an on-farm storage
area allowing the farmers to apply the
sludge at their own convenience. However,
at times when immediate application is not
appropriate (such as in the winter or during
the growing season), storing of the sludge
can be a problem.
High quality composted sludge can be an
important option for many communities.
Composted sludge is easy to store and pack-
age, and presents minimal potential for
odor problems. Often, local farmers and
gardeners will transport compost provided
by the municipality. Some municipalities
market sludge composts, and thus partially
defray treatment costs.
Techniques for Applying Sludge
Sludge can be applied to either the surface
or the subsurface of the ground. Some
states require that all sludge be incorpo-
rated into the ground during or immediately
after application. This is designed to control
odor problems, reduce potential pathogen
problems, and minimize the potential for
sludge runoff to surface waters. Different
.incorporation methods include plowing to
create a furrow in which the sludge is
10
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deposited and covered, discing, and direct
subsurface injection. In some instances, the
municipality provides the equipment
needed to apply and incorporate the sludge;
in other instances, the farmer is responsible
for sludge incorporation into the soil.
Even where not required by regulation,
soil incorporation of sludge is not uncom-
mon. Since less organic matter and nutri-
ents are lost through volatilization or runoff,
it can have beneficial effects for the soil and
plant growth. However, incorporation
generally cannot be done during the
growing season, and is more difficult to
accomplish during wet weather or when
the ground is frozen.
a) Tank Truck Application
Although pipelines, barges, trains and other
conveyances are often used to transport
sludge from large cities to disposal sites,
smaller communities using land application
will most likely truck the sludge to nearby
farms. In most instances where liquid
sludge is involved, the tank truck will apply
the sludge on the land by driving across the
field. Where incorporation into the ground
Federal Laws Relevant to Sludge Disposal
Several federal laws and agencies are
actively involved in assisting states and
localities in the management of sewage
sludge. In addition, many states have
established their own criteria and stand-
ards for sludge disposal which, in some
instances, may be more stringent than
federal requirements. The major federal
laws include:
The Clean Water Act of 1977: This act
amended the 1972 Federal Pollution
Control Act Amendments, by tying
sludge disposal to the National Pollutant
Discharge Elimination System (which
requires permits for regulated point
sources discharging into navigable water
bodies), by authorizing minimum federal
standards for sludge disposal and utiliza-
tion, by authorizing the development of
pretreatment standards for industries
which discharge their wastes into muni-
cipal wastewater treatment systems,
and by encouraging beneficial use of
sludges that conform to federal stand-
ards. Increased levels of federal con-
struction grant funding were authorized
for innovative and alternative waste-
water treatment and sludge manage-
ment technologies that include benefi-
cial use of such sludges.
Resource Conservation and Recovery
Act of 1976 (RCRA): RCRA gives the
EPA broad statutory authority to regulate
the disposal of an array of hazardous and
nonhazardous waste materials. Sludge,
within the definition of the act, is defined
as solid waste. Also, the Act authorizes
the EPA to identify sludge as a potentially
hazardous waste material when an indi-
vidual sludge contains unacceptably high
levels of metals or other contaminants.
Responsibility for informing EPA of the
characteristics of an individual sludge
which makes it potentially hazardous
rests with the individual operator of the
treatment plant.
The Act also authorizes financial
assistance to states and localities for
preparation of solid waste management
plans and technical assistance on devel-
opment of appropriate solid waste dis-
posal processes. Research and develop-
ment provisions are intended to encour-
age better technologies for disposal of
solid wastes and for resource
conservation.
Other Relevant Federal Statutes
The Marine Protection Research and
Sanctuaries Act of 1977: Provides for
phasing out of ocean dumping of sludges
which may irreparably degrade the
marine environment. The Act also gives
EPA authority to establish compliance
schedules for land based alternatives to
ocean dumping.
The Clean Air Act: Provides the basic
structure for regulating of air pollutants,
including air pollutants emanating from
sewage sludge incineration.
Safe Drinking Water Act: Specifies a
coordinated approach with RCRA to pre-
vent contamination of drinking water.
Toxic Substances Control Act of 1976:
Provides for a coordinated approach for
disposal of toxic wastes.
is desirable, equipment following immedi-
ately behind the truck or attached to it can
be used.
The principal advantages of a tank truck
system are low capital investment for the
community and ease of operation. The sys-
tem is also flexible in that a variety of appli-
cation sites can be served, such as pas-
tures, cropland and even tree plantations.
Disadvantages of tank truck spreading
include inability of trucks to cross fields in
wet weather, possible compaction of the
soil due to repeated truck trips across fields,
and a limited ability to apply sludge during
the growing season. Flotation tires can help
reduce problems associated with wetness.
Improper application of liquid sludge by
inexperience drivers or through use of inap-
propriate distribution devices can be a prob-
lem. The simplest form of tank truck distri-
butes liquid sludge from a conduit at the
back or side of the vehicle. Uneven applica-
tion on the field can result, since distribu-
tion depends on the speed of the truck and
the slope of the ground. Because such tank
trucks need to make repeated trips across
the field, compaction problems are more
pronounced with this equipment.
Splash plates and perforated T pipes can
provide more even distribution, but these
systems still operate on gravity flow. Higher
rates of application will occur at the begin-
ning of a trip across the field, or when the
truck is moving up a grade, unless proper
compensating adjustments are made to the
speed at which the truck is driven. One
modification of the basic process is to
mount a spray apparatus on a truck so that
a wider, more even area can be covered by
each pass.
b) Irrigation
Spray irrigation equipment that is capable
of handling solid material without clogging
is sometimes used for sludge application to
agricultural and forested lands where
immediate incorporation is not required.
Because of concerns about pathogens and
odors, it is not recommended for use on
fields that produce crops consumed raw by
humans, or in areas where wind is likely to
carry aerosols to nearby residences. Care
must be taken to avoid excessive applica-
tions of liquid sludge since sludge covered
foliage will receive less sunlight and may
result in damage to sensitive plants. In
some circumstances, spray irrigation is
advantageous, however. It can be used
throughout the growing season, as well as
on land that is too wet or too rough for tank
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Case
Studies
trucks. One of its most promising uses is on
forest land (provided spraying is not con-
ducted near public recreation areas).
Application of sludge by ridge and furrow
irrigation is similar to normal ridge and
furrow irrigation practices used in agricul-
ture. However, because of the solids in the
sludge, the slope of the furrow is of greater
importance. When the slope is not appropri-
ate, solids may collect at the beginning of
the furrow, and cause ponding.
Monitoring
Unless only very limited applications of
sludge are involved, careful monitoring and
follow up procedures are usually required in
land application of sludge. The sludge itself
should be re-assessed periodically in order
to determine whether changes have
occurred in its composition which could
affect land application rates. Analysis of the
soil and vegetation to determine levels of
heavy metals and persistent organic com-
pounds should also be conducted, along
with monitoring of soil pH, and surface and
groundwater conditions. As has been men-
tioned, maintenance of a pH of 6.5 or higher
through lime application or other tech-
niques generally is required on cropland in
order to minimize the potential for plant
uptake or leaching of excess heavy metals.
Such a pH is within the optimal range for
production of most crops, although there
are exceptions.
Landowners that are participating in a
sludge application project should be in-
formed at the outset that monitoring of con-
ditions on their land may be needed. Very
often, monitoring activities are undertaken
by conservation district and extension
service personnel who are familiar with and
sensitive to the concerns of landowners. In
general, the monitoring requirements for
use of high quality sludge at appropriate
application rates should not be much more
involved than normal agricultural soil test
ing.
The following case studies briefly discuss
' several examples of involvement by agri -
cultural agencies in land application. The
specifics vary in each instance, but all involve
a concerted effort to assure that land appli-
cation is done in a way that safeguards the
best interests of landowners and the land
itself.
Monroe County, New York
Since 1975, Monroe County—the home of
the city of Rochester—has been applying
part of its municipal sludge to farmland. The
program has the active support of area far-
mers, who are assisted in all stages of the
land application program by the Monroe
County Soil and Water Conservation Dis-
trict. Other agricultural agencies—includ-
ing the Extension Service, and Cornell Uni-
versity agronomy specialists—also are
actively participating in the program.
As often happens in land application pro-
grams, the genesis of Monroe County's
project was public dissatisfaction with a tra-
ditional means of sludge disposal. In 1974,
the county manager (who was formerly a
director of the conservation district)
received complaints about odors arising -
from an incinerator used to dispose of
sludge from one of the county's treatment
plants. The plant, located near Lake
Ontario, collected waste from nearby resi-
dential subdivisions but no industrial facili-
ties, and was therefore found to be a
"clean" sludge.
Following initial meetings between the
county manager, Monroe County Conser-
vation District Officials, and the Pure Water
Board (the municipal sewage treatment
authority), the county decided to test a land
application program on a 175 acre parcel of
publicly owned land. The district, along with
several other local agenices, conducted
extensive tests at the site. Monitoring wells,
retention ponds and other facilities were
established. Actual sludge application
began on the publicly owned site in the fall
of 1975.
In 1977, the County expanded its pro-
gram in order to make sludge available to
nearby farmers. Prior to initiating the pro-
gram, the Monroe conservation district
identified farmers interested in the pro-
grams, evaluted site conditions on local
farms, and worked with farmers to upgrade
conservation plans to take into account pos-
sible changes needed to accommodate
sludge application. The district is continuing
to work with interested farmers, and over-
see the process of securing requisite gov-
ernmental approvals.
Farmers who participate in the program
receive the sludge free of charge. In return,
they sign an agreement with the county
under which they are hot permitted to grow
root crops on their land for three years. In
addition, they agree to provide access to the
land to government officials responsible for
monitoring crops, soil and water conditions
after land application.
Currently, about 12 farmers have
received the sludge on a one time applica-
tion basis from one of the County's three
main sewage treatment plants. The sludge
is lime stabilized prior to application, in
order to reduce pathogen levels, and is
dewatered to a 20% solids content. But it is
not otherwise treated, and therefore
contains valuable organic matter and
nutrients. Available nitrogen content is
about 4 percent, which is typical of many
sewage sludges. Because the sludge comes
from residential neighborhoods, it has low
concentrations of heavy metals, and other
contaminants that might otherwise be a
problem. These low levels of contaminants
have been verified by more than 45 sepa-
rate analyses of the sludge.
Truck drivers employed by the Pure Water
Board haul the sludge to the application
sites. It is immediately incorporated into the
soil with a moldboard plow, disc, and culti-
packer provided by the county. The operator
then checks the land to make sure that full
incorporation has been accomplished and
completes any additional coverage by hand
if necessary. Thus, the application process
requires minimal labor on the part of the
farmer.
Staff of the Monroe conservation district
estimate that the entire cost of the land
application program—including transporta-
tion and personnel expenses associated
with applying and incorporating the
sludge—are about 80% of the previous
operating costs of incinerating the sludge.
Protection of the land is built into the
program, through state and local require-
ments, and monitoring. Permits from the
New York State Department of Environmen-
tal Conservation are required prior to land
application at each site. In addition, special
conditions—such as prohibiting land appli-
cation within 200 feet of a streambank, or
near grassed waterways—are required. The
Monroe Conservation District assists with
monitoring of groundwater, runoff, and
heavy metals (which are analyzed by the
county), and has established some test sites
on nearby farmland in order to compare
conditions. Soil samples are tested at
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Cornell University. In the early days of the
project, district officials found that a need
arose for relatively intensive observation of
application procedures by the county. As
county drivers have become more experi-
enced with sludge application, however, the
need for supervision has been less
pronounced.
Currently, none of the privately owned
farmland enrolled in the program has been
treated with more than one application of
sludge. Because of the low heavy metal
content, the one time sludge application
rate is rather high—averaging 20 dry tons
per acre. The program is very popular with
nearby farmers; as a result, far more private
land had been evaluated and approved for
sludge volume. District personnel have
found that the sludge has helped to quickly
reestablish orchards on land in which old
trees have been cleared, and has had bene-
ficial effects on corn and wheat yields.
Another sludge application activity being
investigated by the district involves planting
of hybrid poplars as a biomass energy
source. This experimental project began in
1979, with the establishment of a district
energy committee. The committee is inves-
tigating the effects of different levels of
sludge application on poplar growth.
Eventually, the poplars will be harvested
and processed for ethanol and butanol pro-
duction. (Some research on hybrid poplars
suggests that they can be planted and har-
vested on two year rotations to produce
1,500 gallons of ethanol and butanol per
acre per year.) Lignin byproducts of this
process can be reformulated into pressed
lumber, and other products can be pellet-
ized into livestock feed. If the experimental
project succeeds, it is possible that sludge
from other Monroe County sewage plants
will be utilized.
Ohio Farm Bureau Program
Since 1978, the Ohio Farm Bureau has
been coordinating an experimental field
investigation program of land application in
five Ohio counties. The project involves
comparison of land application under con-
trolled conditions in which some farmers
receive municipal sludge, while others do
not. The project, funded through an EPA
research and development grant, involves
extensive cooperation with Ohio State Uni-
versity researchers who are conducting
much of the technical analyses and
assessment.
The requirements of the program specify
that participating counties provide sludge of
. acceptable quality for agricultural use, as
defined by State criteria. This led to the
deletion of one county from the program,
when it was discovered that the municipal
sludge from one city contained relatively
high levels of heavy metals.
In all, some 100 farms have been
involved in the project, with about half of
the farms receiving the sludge, which is
delivered in a thick slurry, and the other half
with similar soil conditions receiving no
sludge. An extensive monitoring program,
undertaken by Ohio State specialists and
extension personnel, is utilized in order to
test soil and water conditions, livestock
health, and human health on both the
sludge-augmented farms and the control
farms. To date, there is no evidence of signi-
ficant differences between the two.
The program also involves yield-compari-
sons conducted on sludge augmented land,
land treated with commercial fertilizer at
prescribed rates, and control plots (provided
by the agricultural extension service at Ohio
State) where neither sludge nor fertilizer is
applied. Preliminary results show sludge-
augmented land outperformed the control
plots in all cases, and performed nearly as
well as commercially fertilized land. The key
difference, of course, is the cost. Participat-
ing farmers do not pay for the sludge—and,
in fact, are given a small fee ($150) at the
end of the project. Ohio Farm Bureau per-
sonnel estimate that even if municipalities
charged farmers half the cost of an equiva-
lent amount of commercial fertilizer,
farmers would come out ahead. It has been
reported that some farmers who are part of
the control group are eagerly awaiting the
end of the project so that land application
may begin on their land.
The success of the Ohio Farm Bureau
Program has spurred interest in land appli-
cation throughout the rest of the state. For
example, in the Toledo area, farmers have
been willing to pay a private contractor for
sludge applications as a phospherous fertil-
izer source. The Ohio Farm Bureau has also
worked with other states (including Arkan-
sas and New York) to help institute well
managed land application programs.
Lewis County, Washington
Although not often required by regulatory
agencies, a good conservation plan can
identify and address potential problems in
land application of sludge. Although most
farmers are aware that conservation
districts provide assistance in preparing
such plans, many private companies and
some local governments that are involved in
sludge application projects may not be.
Two Lewis County, Washington projects
involve conservation plans to demonstrate
the advantages of utilizing the capabilities
of soil and water conservation districts in
the design of a land application program.
One of the projects being conducted invol-
ves reclamation of surfacemined land
owned by the Washington Irrigation and
Development Company (WIDCOJ, a subsidi-
ary of a Spokane power company. The other
is a county owned and operated sludge
management facility. The Lewis District was
a very active participant in site selection and
in preparation of conservation plans for both
of these projects, which are now
operational.
The WIDCO project began in 1977, with
an informal research effort designed to test
the suitability of using sludge from Seattle
(located about 50 miles from Lewis County)
in reclaiming surface-mined land. Early in
the project, WIDCO contacted the Lewis
Conservation District, in order to identify
appropriate sites for conducting the land
application program, and for assistance in
preparing a conservation plan. The district
assembled a team of specialists—a forester,
soil scientist, wildlife biologist, and engi-
neer—to determine basic site conditions,
and to recommend appropriate conserva-
tion actions. Factors such as what plant ma-
terials to use, and sediment and runoff
problems were addressed by the conserva-
tion plan. Vegetation field trials were begun
on some sites; research to date suggests
that the sludge outperforms commercial
fertilizer in stimulating plant growth.
Now that the project is operational. Dis-
trict involvement is less intense. WIDCO
anticipates that, by the end of 1982, all of
the sludge from Olympia, Centralia and
Chehalis, as well as 35 percent of the
sludge from Seattle may be used in its
reclamation project.
District involvement in the County owned
and operated project consisted of recom-
mending an appropriate site for the facility
which is used to manage sludge, and in
preparing a conservation plan which the
County follows in management of the
facility.
Somerset County, Pennsylvania
Located 200 miles from Philadelphia,
Somerset County is helping one of the
country's major cities—Philadelphia—
dispose of its sludge. In the process Somer-
set County is helping to solve one of its own
13
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problems—reclaiming surface mined land.
Since the beginning of the project in 1978,
the Somerset County Conservation District,
together with other agricultural and natural
resource officials, have been actively
involved in helping to oversee and carry out
the project.
Philadelphia's sludge disposal problem
began in 1975, when it was told that it
would need to phase out ocean dumping of
sewage sludge. The City then began a major
effort to assess alternative means of sludge
disposal. A central alternative was thought
to be application of sludge for use in recla-
mation of surface mined land. Initial
screening by the City identified several
counties with areas of unreclaimed surface
mined land that were thought to be promis-
ing candidates to receive the sludge, but
political problems arose in most of them
once serious discussions began about initi-
ating actual projects.
Philadelphia's plan received its best
reception {albeit not a warm one) in Somer-
set County—a county with many sites
scarred by surface mining. After a some-
what hesitant approval by the county com-
missioners in 1978, the initial project began
on a ten acre demonstration site. This gen-
erated immediate opposition on the part of
many people in the county; when subse-
quent plans were announced to expand the
sludge application program, even greater
opposition arose. In order to help it deter-
mine whether continued sludge application
was appropriate, the county commis-
sioners, working through the Somerset
Conservation District, formed a Stripmine
Reclamation Advisory Board, consisting of
district officials, Soil Conservation and
extension service personnel, representa-
tives of the state fish and game commis-
sions, and a private landowner.
The Board was charged with responsibil-
ity for overseeing the monitoring of soils,
water, vegetation and other conditions
pertinent to the land application project in
order to provide the county commissioner—
and local citizens—with impartial advice
about future projects. Through the use of
RCA funds provided by the Pennsylvania
Bureau of Soil and Water Conservation, an
extensive, two year monitoring program
was begun. Assistance in monitoring and
evaluation has also been provided by
researchers from the Pennsylvania State
University, the Cooperative Extension
Service, and the State Fish Commission.
Initially, sludge was applied at the land
reclamation rate on a one time basis to four
surface mined sites. Prior to application,
these sites were either not reclaimed, or
inadequately reclaimed. Indications to date
are that the sludge has greatly improved
soil conditions and plant growth. The recla-
mation process involves grading, liming,
sludge addition and incorporation, then
seeding of the plots with grasses and
legumes. Extensive monitoring of the vege-
tation, soil, and groundwater has been
undertaken to determine what positive or
negative impacts of the sludge addition
occur and whether future agricultural use
of the land is desirable.
Actual transportation and application of
the sludge is managed by a private com-
pany. To keep transportation costs down,
the company transports treated and com-
posted sludge from Philadelphia in the
same large trucks that are used to haul coal
from Somerset County to Philadelphia.
In 1981, the Somerset County Conserva-
tion District prepared a report which
provides an extensive analysis of the first
two years of monitoring data gathered from
the project. In general, the report concluded
that heavy metal loadings and contami-
nants were well within the conservative
state guidelines that Pennsylvania pre-
scribed for use of sludge in surface mine
land reclamation. Most of the samples were
within the even more stringent guidelines
prescribed for sludge use in agriculture, as
well, but tended towards the higher range
The Role of Entrepreneurs in Sludge Processing
Land application of sludge—almost by
necessity—requires the active involve-
ment of the private sector to succeed. Is
there also a role for the private sector in
processing and marketing sludge
products? Joseph C. Horvath, a Hungar-
ian born resource economist now living
in Missoula, Montana, has staked his
future that there is—and in the process
is educating the public about the advan-
tages of recyling composted sludge.
Horvath came to the United States
following the Russian invasion of Hun-
gary in 1956. After 20 years of working
on a variety of environmental and eco-
nomic problems, Horvath established
Eko-Kompost, Inc., in 1977; the company
now markets a sludge based compost—
also called Eko-Kompost—to garden
stores, greenhouses, nurseries and
others in 12 states.
Situated on a 35 acre site adjacent to
Missoula's municipal sewage treatment
plant, the City's sludge forms the basis of
Eko-Kompost. But the product also is
augmented by a variety of other ingredi-
ents, which according to the company's
promotional materials, make it a biologi-
cally rich rooting medium, soil condi-
tioner, and organic fertilizer. First, the
municipal sludge is mixed with animal
blood, bone meal, sawdust, shredded
bark and granite dust. Then it is com-
posted for several weeks in a forced aer-
ation system. Finally, it is screened and
cured for an additional four weeks prior
to packaging (it is also available in bulk)
and marketing. According to company
figures, heavy metal concentration in
Eko-Kompost fall far below the levels for
heavy metals recommended by EPA,
USDA, and FDA.
Before marketing his product, Horvath
had to seek and secure no less than 17
federal, state and local government per-
mits. Eko-Kompost apparently cleared in
flying colors; unlike some sludge derived
products, its very low levels of heavy
metals makes it safe for agricultural and
home gardening use.
Eko-Kompost is catching on, and the
company proudly provides a long list of
testimonials to substantiate this point.
But, as both a vehement proponent of a
cause and as a businessman, Horvath
would like to see a little more interest on
the part of state officials and western
mine operators in using his product in
surface mine reclamation.
He has taken his case to everyone in
the state government from the Governor
on down, and has even taken the extra-
ordinary step—for a businessman—of
donating 120 tons of Eko-Kompost to a
coal company for use in reclamation.
"That"particular acreage is so much
better in vegetation that the others look
sick in comparison," Horvath writes in
the Missoulian, but adds, ruefully, "I
could not sell one pound to them."
Horvath admits that his personal crusade
for recycling can be tiring, but he is not
giving up. "I know my product, and now
many thousands know that it works.I"
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of acceptability. In order to protect unknow-
ing people from purchasing a sludge treated
property for possible incompatible land
uses, the County is considering placing
special notational information on the tax
rolls which would permit individuals to
obtain information about sludge loading
rates, acres reclaimed and so forth. The
monitoring program also found that water
pollution resulting from runoff from stock-
piled sludge could be a problem unless
dikes are constructed around the stockpiles.
The report provides a variety of recommen-
dations to mine owners and operators on
better practices for reclaiming mined land,
and minimizing soil erosion and possible
water pollution problems.
A centrally important recommendation—
one that could help remedy concerns about
future use of reclaimed land for agricultural
use—deals with the wastewater and sludge
treatment processes utilized by urban areas
that are seeking rural land for sludge dis-
posal sites. The report calls for more exten-
sive pretreatment of industrial wastes, or
for segregated treatment and disposal of
industrial and residential wastes in order to
avoid concerns about heavy metals and
other contaminants.
Although opposition to the program still
exists, the monitoring program, together
with public meetings where the data has
been discussed, have helped to relieve con-
cerns about the project. To date, no sub-
stantial pollution or contamination prob-
lems have been identified, but the advisory
board has identified and made public the
potential problems associated with the
project, and appropriate remedies and
adjustments which would help alleviate
these problems. As part of its continuing
involvement in the land application pro-
gram, the Somerset Conservation District is
preparing an informational slide show
which will portray the program and the
results to date.
Racine, Wisconsin
Racine County, Wisconsin, located adjacent
to Milwaukee, provides another example of
how land application of sludge can help
solve municipal treatment problems and at
the same time further soil and water con-
servation objectives. Since 1977, when the
county began its land application program,
it has received sludge from the Milwaukee
Metropolitan Area Sanitation Commission.
More recently, two towns within the
county—the City of Racine and Rochester—
have initiated land application programs.
The County land application program is
administered by the Planning and Zoning
Office, with the close cooperation of the
Racine Soil and Water Conservation
District. In Wisconsin, soil and water con-
servation districts are part of the county
government.
The sludge is shipped to the county for
land application in trucks owned by private
corporations or by the municipal sewage
treatment plant operator. These entities are
responsible for providing analyses of the
sludge to the Planning and Zone Office.
Under the Racine program, no sludge
may be applied to the land unless a conser-
vation plan for the farm is in effect. Trans-
porters seeking to apply sludge to the land
first query area farmers about their interest
in receiving sludge. The transporter then
submits a list of farms to the Planning and
Zoning Office, which in turn provides the
list to the Racine Conservation District.
The Conservation District then contacts
the farm owner and prepares a conserva-
tion plan for the land. So far, roughly 50
such plans have been prepared. Prior to
land application, appropriate conservation
practices to prevent erosion, and reduce
runoff or possible contamination of water
sources are put into effect as needed.
Once a plan has been approved, the Plan-
ning and Zoning Office determines an
appropriate sludge application rate for the
farm. This takes into account heavy metals
in the sludge in order to minimize possible
buildup in the soil. A staff specialist has
been hired to undertake this analysis.
The sludge is generally provided and
applied for the farmers at no cost. In most
instances, the transporter will apply and
incorporate the sludge into the ground.
(Incorporation is a county requirement and
is encouraged by the state). In instances
where farmers receive liquid sludge, the
transport companies often apply the sludge
to the land, and also incorporate it into the
soil through discing and knifing equipment
shipped to the site along with the sludge
truck. Some semi-dried sludge is also
applied to the land—sometimes by farmers
with their own manure spreaders. This has
caused some complications in the winter
months, when the sludge must be stored
since the state generally does not permit
sludge applications on frozen ground.
Monitoring of the land application sites is
conducted by the Wisconsin Department of
Natural Resources.
Florence, Alabama
In many areas of the country, a "show me"
attitude exists among public officials and
the public at large about land application. In
such cases, a demonstration project may be
needed in order to identify the benefits and
possible problems of land application.
That was the situation that confronted
the water and sewer commission of Flor-
ence, Alabama, in 1973. Florence was con-
fronted with what has now become a com-
mon problem for many communities:
increasing volumes of sludge produced by
its upgraded sewage treatment facilities.
The commissioners believed at the time
that land application of liquid sludge might
be a feasible solution to their problem. In
1973, the city was using 8 drying beds to
Crop Yields and Land Application:
the Florence Results
The Florence—TVA project is still on-
going. Initial test results, presented at a
1981 meeting of the American Society of
Agronomy, showed the following:
— A single application of sludge in 1978
resulted in higher soybean yields for
three consecutive years than did annual
conventional fertilization.
— In two of the three years, two levels of
sludge application (11 and 78 metric
tons per hectare) promoted higher yields
of corn than did conventional fertilizer.
(In the third year, conventional fertilizers
outperformed the sludge, except in the
case of the highest sludge application
level of 78 metric tons).
— Production of seed cotton was initi-
ally lower on the sludge-amended land
than on land treated with conventional
fertilizer. However, in 1981, the cotton
yields on both test plots were
comparable.
Heavy metal concentrations were not
found to be appreciably different in the
vegetative tissues, grain or seeds of the
crops grown on sludge-augmented land
when compared with the crops grown
with conventional fertilizer. There was a
slight increase in zinc and cadmium con-
centrations in the sludge-amended
lands, but the variation was found to be
greater than would be attributable to the
sludge itself.
15
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Appendix I
dewater the sludge. If the use of drying beds
was to be continued, an additional 12
beds—costing $200,000, and $10,000 a
year in maintenance costs—would be
needed. Moreover, drying the sludge didn't
really solve the problem; it still had to be
disposed of—by incineration, landfilling or
through distribution to landowners. If land
application of liquid sludge was feasible,
processing costs could be reduced, and the
problem of ultimate disposal overcome.
However, there were several impedi-
ments to implementing land application of
liquid sludge. At the time, no guidelines
existed at the state level for land application
of sludge. Moreover, concerns existed
about the environmental impact of land
application, and possible effects on crops or
other agricultural products. Florence has
favorable soils for land application, but is
underlined by limestone bedrock which dis-
solves easily. Thus movement of heavy
metals and other contaminants in the
sludge through the groundwater was
thought to be a possibility. Therefore, prior
to adopting a full scale land application
program, a demonstration project seemed
to be in order.
Fortunately, Florence's interest in land
application was shared by the Tennessee
Valley Authority (TVA), which provides
waste management assistance to commu-
nities in the area, and has a major agricul-
ture and chemical fertilizer development
program. Moreover, WA was especially
interested in the limestone geology of the
Florence area, since the same underlying
geologic conditions existed in many local-
ities in the WA region. If land application
could be accomplished on the Florence site
without contamination of the groundwater,
the same technique might be transferable
to other areas in the Tennessee Valley with
similar geologic conditions.
In mid-1978, Florence and TVA entered
into a five year cooperative project to test
land application on a 173 acre site owned
by the city. On a f ive-and-one-half acre
demonstration plot, liquid sludge is being
applied under carefully controlled circum-
stances that are monitored by WA special-
ists. Several smaller research plots have
been established by WA agricultural and
fertilizer development specialists in order to
compare the respective effects of sludge,
farm manure and chemical fertilizer on
plant growth. Sludge application rates on
the test sites vary from 25 dry tons per acre
per year, to no sludge whatsoever. Monitor-
ing of nutrient and heavy metal uptake is
being evaluated for such crops as Bermuda
grass, hay, corn, soybeans and cotton. On
all of the sites, groundwater and surface
water conditions are being carefully
assessed.
The test program won't be completed
until 1983, but the early results are prom-
ising—something that has not gone unno-
ticed by area farmers. Says the manager of
the Florence municipal sewage commis-
sion: "The local agricultural agent and I
have farmers calling every day to try sludge
on their fields as soon as it is available. If it
were approved today, I'd have 10,000
acres for land disposal sites."
Suggestions for
Further Reading
Many of the following reports were prepared by
or for the U.S. Environmental Protection Agency
and can be purchased from:
U.S. Department of Commerce
National Technical Information Science
5282 Port Royal Road
Springfield, Virginia 22151
Telephone: 703/487-4650
In ordering, refer to the title andthe report number.
Reports not prepared by or for EPA can be obtained
from the addresses noted.
Less Technical
Knezek, Bernard D. and Robert H. Miller, (eds),
Application of Sludges and Wastewaters on
Agricultural Land: A Planning and Educational
Guide, Report #MCD-35, March, 1978, (Pre-
pared for the U.S. Environmental Protection
Agency, Office of Water Program Operations,
March, 1978), 93 pp. (NTIS Order No.
PB 2848247 AS)
Sludge Recycling for Agricultural Use, (Illus-
trated Brochure). 1982, 20 pp. SIMPAC, 203 W.
Main Street, Collinsville, IL 62234.
More Technical
Council for Agricultural Science and Technology,
Application of Sewage Sludge to Cropland:
Appraisal of Potential Hazards of the Heavy
Metals to Plants and Animals, Report #MCD-33,
EPA 430/9-76-013. (Prepared for the U.S.
Environmental Protection Agency, Office of
Water Program Operations, November, 1976),
63 pp. (NTIS Order No. 264015/AS)
Environmental Research Information Center,
Sludge Treatment and Disposal, Volume 2,
Sludge Disposal, EPA-625/4-78-012b, October,
1978,155 pp. (NTIS Order No. 299594/2BE)
U.S. Environmental Protection Agency, U.S. Food
and Drug Administration and U.S. Department of
Agriculture, Land Application of Municipal
Sewage Sludge for the Production of Fruits
and Vegetables: A Statement of Federal Policy
and Guidance, 1981,21 pp. (Available free from:
U.S. EPA, Publications (WH-562), 401 M Street,
SW, Washington, DC 20460)
16
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Appendix 2
State Guidelines on
Land Application
U.S. Environmental Protection Agency, Office of
Water Program Operations, A Guide to Regula-
tions and Guidance for the Utilization and '
Disposal of Municipal Sewage Sludge, Report
#MCD-72, EPA 430/9-80-015. September,
1980,48 pp. (NTIS Order No. PB 81108508)
U.S. Environmental Protection Agency, Office of
Water Program Operations, Municipal Sludge
Management: Environmental Factors, Report
#MCD-28, EPA430/9-77-004. October, 1977,
130 pp.
Sopper, W. £., E. M. Seaker, and R. K. Bastian.
(eds), Land Reclamation and Biomass Produc-
tion with Municipal Wastewater and Sludge.
1982,535 pp. The Pennsylvania State University
Press, 215 Wagner Building, University Park, PA
16802.
Robson, C. M. and L. E. Sommers, Spreading
Lagooned Sewage Sludge on Farmland: A Case
History. EPA 600/52-82-019. May, 1982. (NTIS
Order No. PB 82-181 082).
Miller, R. The Ohio Farm Bureau Demonstration
and Research Project on Land Application of
Municipal Sewage Sludges. IN: Proceedings of
the 1979 Annual Conference of Applied Re-
search and Practices on Municipal and Industrial
Waste. September, 1979. University of Wiscon-
sin, Madison, Wl 53706.
Several states have established their own
guidelines on land application of sludge. The
following references provide citations to such
guidelines in selected states. Although the listing
is not comprehensive, it should be useful to
conservation districts and others, even in states
that are not identified.
Colorado
Department of Health, Water Quality Control
Commission
Guidelines for Sludge Utilization on Land
1978
Illinois
Environmental Protection Agency
Technical Policy WPC-3
Design for Criteria for Municipal Sludge Utilization
on Agricultural Land
April, 1977
Maryland
Department of Health and Mental Hygiene
Code of Maryland Regulations 10.03.48
Uses and Methods of Collecting, Handling,
Burning, Storage or Transportation of Sewage
Sludge
1980
Michigan
Department of Natural Resources
Water Resources Commission
General Rules R 323.2201 to R 323.2211
May, 1 978
Minnesota
Minnesota Pollution Control Agency
Recommendations for Application of Municipal
Wasterwater Sludges on Land
August, 1978
New Jersey
Department of Environmental Protection
Division of Water Resources
Guidelines for the Preparation of Sludge Manage-
ment Plans (Draft, 1979)
Ohio
Cooperative Extension Service
Ohio State University
Ohio Guide for Land Application of Sewage
Sludge, Bulletin 598(revised)
June, 1979
Oregon
Department of Environmental Quality
Guidelines for Land Application of Wastewater
and Sludge
May, 1981
Pennsylvania
Department of Environmental Resources
Interim Guidelines for Sewage Sludge Use for
Land Reclamation
Solid Waste Rules and Regulations, Chapter 75,
Subchapter C, Section 75.32
1978
Wisconsin
Department of Natural Resources
Guidelines for the Application of Wastewater
Sludge to Agricultural Land
Technical Bulletin #88
1975
»U.S. Government Printing Office : 1982 -388-462/265
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