New horizons for commercial vermiculture

States and Cinada have seriously
begun sampling institutional and
municipal organics a s feedstocks
for earthworms. The techniques
and terminology differ somewhat
from placet o place, but in Florida,
vermicomposting or vermiculture projects
are in progress. This represents a resurgence for an industry that has
experienced
its share of ups and downs. There are stories of municipalities investing in worms
t o convert problematic organic wastes t o
topsoil, only t o find that the worms had
been killed by a toxic contaminant or had
all moved overnight to other, more palatable, pastures. In the 1970s, a pyramid
scheme of fish bait franchisesquickly saturated the market in California and ultimately collapsed, leaving growers with
more wormson their hands than they
knew
what to do with.
“Actually, this was probably the beginning of large-scale vermicomposting,” says
Clive Edwards, aprofessor of entomology at
Ohio State University who recently organized an international symposiumon earthworm ecology (see accompanying article).
“People were stuck with all these worms
they couldn’t sell but theydid have thisnice
end product and began
t o wonder who might
be interested in it.”
As the demandfor effectivemethods of diverting organics fromNorth American landfills grew, earthworms began receiving renewed attention. Consequently, an industry
centered around producing worms and utilizing their unquestionable skill at digesting organic material and excreting a top
quality soil amendment known as castings,
has begun to mature.
COMMERCIAL
VERMICULTURE
Technologies based on earthworms ofier
effective methodsto compostlarger
portions of organics in the residentialand
commercial waste streams.
INSTITUTIONAL INTEREST
For Original Vermitech Systems, Ltd.
(OVS) in Toronto, expanding into larger
quantities of worms andorganics wasa natural outgrowth of earlier work. The compa- .
ny, founded in 1990, initially
developed a
worm bin for household use called “The
Canadian Original Vermicomposter.” In
1992, after some success with the small
David Riggle and Hannah Holmes
bins, OVS began marketing larger unitsdesigned to process between 50 and 100 lbs.of
organics per day from restaurants, schools
and the like. Since earthworms can
conHospital in Ontario.“It’s the largest vermisume and excrete their body weight in 24
composter in Canada right now,” says Lori
hours, roughly 50 to 100 lbs. of worms are
Halcrow of Ontario’s Green WorkplaceProrequired for each bin. According
t o A1
gram, which oversees recycling in ProvinEggen, presidentof Original Vermitech,five
cially owned institutions (see “Creating the
such units currently are installed and
operMaximum Green Workplace,” BioCycle,
ating in Ontario. The company recently
June, 1994). The system requires preshredsigned a contract withthe Universityof Otding feedstock,and manual loading and untawa to install up to ten medium.sized bins
loading, but Eggen equipped it with heat
across its sizeable campus, each initiallydipanels and temperature sensorsto monitor
gesting 50 lbs. per day offood scraps, paper
and maintain a tolerable environment for
and animal manures.
the worms.
OVS has continued to scale up for still A layer of organic materials is
“We’vebeen very happy with it,” says Hallarger facilities. In 1993, a unit with a ca- spread on top of the worm
crow. “Last winter was very cold, but the
pacity of up to 600 lbs. of organics per day digester at Oregon Soil
worms survived. The
staff at Brockville also
was installed at the Brockville Psychiatric Corporation.
seems to be pleased. All of their food scraps
58
BIOCYCLE
OCTOBER
1994
LONGEVITY OF SOIL IMPROVEMENTS
Perhaps the greatest benefits
derived from
compost additions to soils with high
clay content areimprovements in soil structure and
water infiltration.All compost treatments in
this study increasedsoil organic mattercontent, reduced bulk density, and increased
water infiltrationrates when comDared with
soils to applications of different compost
products. Questions that still need to
be addressed are: How quickly does the organic
portion of certain composts break down, how
long will soil improvements last, and will
compost additions have lasting
effects under
high-traffic conditions? More work also is
needed on the effects of soluble salts on
seedling turf and on the impacts of surface
applications of composts onestablished turf:'
We are in theprocess of examining some'of
these issues and plan todo more tesiing in
the
,,
future.
near
Peter Landschoot and Andy McNik are
in the
Department of Agronomy at , ? e m State Univerisity in University Park./'
f a s t e rt h a np e a t ,
thereby providing only short-term soil improvement. Although it is true that theorganic fraction of most peats is more stable
than freshcomposts, this does not necessarily mean that the effects of compost additions on soil physical properties are shortterm. When applied properly, good quality
composts produce dense and actively growinn turf stands
which generate organic mat-
The plot amended with
biosolids compost from the
Philadelphia Water
Department (topleft) showed
no additional benefit from a
starter fertilizer application on
its left half, compared to the
control plot (middle left)which
received no compost but a
similar application of fertilizer.
The plot amended with a
papermill by-product compost
has improved turf color and
density
a dramatic
difference from the yellow,
thin growth in the border
areas.
-
T h e V,~f"&onversion"" Solution
bidkolids, food, manure, wood, and paper
jkto premium products
/
and other premium soils, fuels and
r e c o n s t i t u t e d wood
market and seasonal fluctuations
of t,Ke goals of o u r
study is to determine changes in the levels
of soil organic matterf$r the compost treatments over the next &vera1 years. Hopefully, we will be able p'determine when (or
if,
additional compoyt applications are needed.
Water infiltrahion is defined as the rateat
which water enters thesoil and is one of the
best measures of soil physical conditions in
the field. "the
compost treatments in this
test incrdsed water infiltration rates in
new r e v e n u e s t r e a m s
Reso'urce Conversion Corporation
. theGlobahLeaderindesigning,installing,
a n d operating V e r m i c o n v e r s i o n S M S y s t e m s
\ .\ /
..',-
-...,,,
\-
I.n- S
t evgsrE
taeqtm
iuoinp m z n t
"
Earthworms
Microbial Innoculants
Management
TM
properties, we plan to
monitor water infiltrationover the nextseveral years.
Although mostof the products usedin our
study significantlyimproved turf establishment, the quality
of established turf,as well
as soil chemical and physical properties,
much more information is needed on predicting the long-term response of turf and
BIOCYCLE
C
O
R
P
O
R
System Sales & Licensing
Equipment Sales
VermigroTM Sales
7 8 2 5 Fav A v e n u e
S u i t e3 8 0
A
T
I
O
N
61 9.551.4800
619.551.4818
61 9.551.4820
L a J o l l a C A9 2 0 3 7
USA
OCTOBER
1994
57
expressed interest in additional vermicomposting projects, but thus far has not funded further development.
Currently, OregonSoil accepts yard trimmings deliveries fromlocal landscapers and
picks up food scraps and paper from 15 Fred
Meyers one-stop shopping stores around
Portland. “We process around five or six
tons of food scraps, over two tons
of supplementals like yard trimmings or compost,
and around half a ofton
paper per day,” says
Holcombe. He points out that it takes 21
days to make earthworm castings using this
method.
His operation currently is located on an
organic vegetable farm with65,000 square
feet of raised beds. “Thefarm owner likes to
experiment,” he says, noting that other vermiculture methods can be utilized in an
agricultural setting. When acrop has been
harvested, the beds can be filled with
worms, paper, yard trimmings and food
scraps. The next crop is planted when the
w o r m sa r ef i n i s h e d .I nt h ew i n t e r ,
windrows keep the worms warm enough t o
function - and again,crops can be planted
in the castings.
Holcombe, who has been raising worms
since 1988,sees real potential in using them
to handle a wide rangeof biodegradable organics. “I’ve never seen any mechanical
technology do a better job than the earthworms themselves,” he says.
”I’ve neverseen any
mechanical
technology do a
better job than the
earthworms
themselves.”
are going into the
worm bin, whichhas lowered their residuals from 33cubic yards to
around eightcubic yards perday. Brockville
also has acresof grounds on which to use the TACKLING MUNICIPAL ORGANICS
vermicompost.”
“It’s only in recent years that the notion
of
Eggen, who subcontracts the manufactur- harnessing earthworms for commercial
con- At Brockville Psychiatric
ing for all sizes of the units, says the bulk
of waste management has been seriously
his company’s sales still come from t h e s i d e r e d i n t h i s c o u n t r y , ” s a y s J o s e p h
Hospital in Ontario, food
smaller, household bins. Nevertheless, he isRoberts, president of Resource Conversion scraps (top), cardboard and
Corporation in La Jolla, California, who
considering starting a farm to raise more
milk cartons (boitom) are
worms in windrows as sales of the larger hopes to develop a series of earthworm pro- shredded before being fed to
worms.
iects on a m u n i c i ~ a lscale. In February,
systems increase.
1993, his companysigned 50150
a
CONTINUOUS FLOW
joint venture agreement with
Residuals Processing, Inc., a subOutside of Portland, Oregon, Dan Holcombe’s Oregon Soil Corporation has devel- sidiary of Sanifill, a national
oped a technology to reduce the space re- landfill company. “Sanifill has
agreed to install25 of our vermiquirements for a vermiculture operation.
conversion systems at their sites
The “continuous flow system’’ was pioneered in the United
Kingdom in the1970s. o v e r t h e n e x t d e c a d e , ” s a y s
Roberts.
Clive Edwards was instrumental in the
This past July, Resource Contechnology’s development, and is working
v e r s i o na n dS a n i f i l lo p e n e d
with Holcombe to improve it. It utilizes a
raised, 120-foot trough that is2.5 feet deep Canyon Recycling outside of San
a n d 8 feet wide, with a mesh floor.
An Diego - a six acre facility currently processing around 100 tons
adapted manure spreader makes a daily
per day of brush, green material,
pass over the trough, laying down about
three inches of prepared organic materials wood from construction and de(roughly six tons per day).
As the worms eat molition operations and manure
up throughit, their castings sink down, andfrom the San Diego Zoo. Not all
are mechanically scraped off the bottom of feedstocks are fed to worms. After
the screen and collected. Under the protec- grinding and screening, some
tion of a greenhouse like structure, the re- woody materials are marketed as
actor can handle about2,500 tons of resid- is. However, leafy greens, wood
finesandmanuresproceed
uals a year.
In 1993, METRO, the solid waste man- through a blending plant, then
agement agency for Portland, Oregon, sent “cured via thermophiliccompost1,450 tons of organic material toHolcombe’s i n g t o n e u t r a l i z e p a t h o g e n s .
operation as partof a pilot project, with en- Roberts adds that Canyon Recycouraging results. Reportedly,METRO has cling could also use lime stabilizaBIOCYCLE
1994
OCTOBER
59
Heat panelsand temperature sensors
maintain a tolerable environment for worms
at Brockville Psychiatric Hospital.
WORM RESOURCES
Enviro-Ganics
P.O. Box 20241
Grantham Postal Station
St. Catharines, Ontario L2M7W7
Sandra Kandracs
(905) 646-8690
Environmental Earthworm
Projects, Inc.
81 14 Port Said St.
Orlando, FL 3281 3
Frank Stevenson
(407) 678-6454
Oregon Soil Corporation
17810 SSW Bunker Oak Rd
Aloha, OR 97006
Dan Holcombe
(503) 629-5933
Original Vermitech Systems, Ltd.
2328 Queen Street East
Toronto, OntarioM4E 1G9
Albert Eggen
(416) 693-1 027
Resource Conversion Corp.
7825 Fay Ave., Suite 380
La Jolla, CA 92037
Joseph Roberts
(61 9)551 -4800
The Worm Concern
1450 Tierra Rejada
Simi Valley, CA 93065
Jay Escover
(805) 496-2872
Worm Digest
Box 544
Eugene, OR 97440-9998
Stephen White
(593) 896-9058
60
BIOCYCLE
California’s draft
regulations exclude
vermicomposting
operations from the
notification and
permitting that
would be required
of most larger
facilities using
thermophilic
composting.
tion or other heatprocesses in the future.
After curing, material is applied to short
vermiculture windrows in thin layers. The
rows are carefully segregated and checked
for biological reactions to new feedstock.
“We apply two tofour inchesof material every other day, continuously,” Roberts says.
“The rows are compartmentalized to prevent contamination of the entire facility if
there should be a problem with any incoming material.”Windrows never exceed three
feet in height, and earthworms
periodically
a speare separatedfrom the castings using
cialized method.
Resource Conversion’s windrow system
did not develop overnight. In 1989, Roberts
purchased a 12 acre facility with a 41,000
square foot building that previously was
used to grow mushrooms and started the
S o i lM a s t e rE a r t h w o r mF a r mn e a r
Olympia, Washingtonto raise earthworms.
“From the outset, our aim was to also use
the facility for R&D,” Roberts says. “We
wanted to explore the
technology of raising
earthworms from a microbiological point
of view, test various physical processing
systems, and determine the most
cost-effective methods.”
Subsequently, the company developed a
proprietary “Vermiconversion System,”
which modified traditional vermiculture
windrow methods. Variations include a
sloped plastic liner beneath the windrows to
reclaim water, aeration piping and a micro
emitter sprinkler to maintain propermoisture levels.
“With thermophiliccomposting alone, it’s
difficult to get an outstanding product in
under six months,” Roberts says. “With
vermiconversion, we can create a marketable
end product in one-sixth the time. On the
other hand, thermophilic composting does
actually achieve PFRP (pathogen reduction)
standards and is simpler to manage.
We’ve
combined the two and employ thermophilic
composting for three to 15 days. When
pathogens and weed seed have been neutralized, materialis placed in vermiprocessing beds. In 30 days, it’s converted to humus.Wewantedtobeabletomove
significant quantities of product through
quickly to compete for
municipal contracts.”
At present, CanyonRecycling is negotiating with the City
of San Diego for a portion
or allof the city’s 60,000 annual tonsof yard
trimmings. The companyalso has proposed
building a 100-acre facility to manage San
Diego’s biosolids under a 20-year contract.
Even without the municipal contracts,
Roberts maintains Canyon Recycling will
scale up to handle 200 tons per day in the
near future. The company makes 15 different products that are sold to six different
markets. In the San
Diego area, “Vermigro,”
its brandof worm castings, sellsfor around
$33 per tonon the bulk market and
$120 per
ton bagged for consumers.“Sales have been
OCTOBER
1994
I
. .
...
good,” says Roberts. “The
proof is in the pur-that. However, as Jeff Huntsof the CIWMB
chase orders, some of which we will be un- notes, these are still draft regulations and
presently are “open for discussion.”
able tofill until production increases.”
“The state isworking on a tiered approach
WORM FARM PROCESSING
to regulate composting operations,” he says,
In Simi Valley, California, The Worm
pointing out that itsometimes is difficult to
Concern has grown to a 22-acre spread dur-tell where certain kinds of facilities fit. “If
the
ing its 18 years in business. Around 100 part of a vermiculture operation falls into
tons per day of brush, leaves, tree limbs, state’s final definitionof a compostingfaciligrass clippings and horse manure delivare
ty, then it could be regulated as such.” Folered to the site, mostly from municipal or
lowing the endof a 45-day comment period in
commercial sources in Simi Valley, Thou- mid-October, a testimony forum
will be held.
sand Oaks, Santa
Rosa Valleyand evenLos Hunts adds that thefinal regulations could
Angeles. However, co-owner J a y Escover be in place as early as March, 1995.
makes it clear that he does not see The
At The Worm Concern, incoming materiWorm Concern as a waste processingfacili- al first passes through a Willibald grinder
ty. “This is an agricultural operation,” he
and a Powerscreen trommel before being
says. “Vermiculture uses organics
as a feed- placed in windrows by a front-end loader.
stock forraising worms.”
After 60 to 90 days in<he windrow, the feedPart of Escover’s insistence on terminolo- stock is moved
to
100 foot long
windrows
gy can be more clearly understood in the
where around afoot or so of new material is
context of the current debate taking
place in added each week.“Windrowpreprocessing
California regarding the classification and is a fairly anaerobic process,” says Escover.
potential regulationof composting facilities. “The piles aren’t turned a t all until materiA draftof regulations released in August
by al is moved to the worm
rows.”
the California Integrated Waste ManageAt harvest, worm rows are scooped up
ment Board (CIWMB) excludes vermicom- with a front-end loader and placed in
a
posting operationsfrom the notification and small trommel screen. “Castings come out
permitting that would be required of most one end and the worms come out the other,
larger facilities using thermophilic comunharmed,” Escover explains.
posting to process yard trimmings, manure, Vermicastings are sold in bulk, blended
biosolids and other materials. Worm farms on site with mulch or other landscape
prodtraditionally have been exempted and the
ucts, bagged for retail sale, or sold in
current version essentially doesn’t change popular, refillable two-gallon buckets.
I
HIGH MOISTURE MATERIALS SCREENING IS NOW
AVAILABLE WITH THE MULTISCREENTMSYSTEM!
BIOCYCLE
”Worms derive
their nutrients from
the microbes and
fungi thatgrow on
organic matter, not
the organic matter
itself. As they ingest
material, it is
reduced in size and
what
out
the other endis
much more
microbiologically
active than what
rr
went in-
Reclaimandprocess up to 150 yards
per hour.
I Adjustablehydraulicspeed
controls.
I Extremelydurable,mobile, low labor
operation.
Electricstationaryunits.
Some of the
composted
materials
you
can economically screen include:
Sludge, Agricultural residues,
OCTOBER
1994
61
In California,
interest in
vermiculture has
escalated overthe
past two years. One
operator added a
demonstration area
for school tours.
62
BIOCYCLE
Worm casting tea, worms, worm
books and operate the composter, with EEP servicing
bins, and “worm soil” - a premium soil
it periodically and harvesting the castings.
with worms and cocoons mixed in - also
Stevenson is hoping to relocate the company’s vermicomposting operations to a perare available.
Some customers have expressed concerns mitted site in the near future. If the move
comes through, he’ll also be negotiating to
about possible contaminants in the end
product, but “there seems be
to enough heat handle biosolids, he says.
in the windrow to control pathogens and
weed seeds,” according to Escover. He has PATHOGEN QUESTIONS
been promoting use of the castings to the
The digestive processes of earthworms
a
agricultural sector and so far hasn’t heard are still imperfectly understood, but body
of knowledge is growing. “Worms derive
of any problems.
Education is important to Escover, who their nutrientsfrom the microbes and fungi
says he’s seen an escalation of interest in that grow on organic matter, not the organvermiculture over the past two years, espe- ic matter itself,” saysClive Edwards of Ohio
cially since passage of California’s AB 939 State University. “As they ingest material,
it isreduced in size and whatcomes out the
has generators examining diversion options. He addeda demonstration area to his other end is much more microbially active
site andoffers tours of the facility to school than what went in.”
One issue that arises regarding vermiculchildren and municipalities.
ture as a n organics management technoloINTEREST IN FLORIDA
gy centers around pathogen reduction in the
In Orlando, Florida, Environmental
end product. “There is good evidence that
Earthworm Projects, Inc. (EEP) is preparpathogens areknocked out toa considerable
ing to take on the institutional waste
extent by vermicomposting,” says Edwards,
stream. Four years
ago, Frank Stevenson- who headed up an extensive research proa long time organic gardener - bought a ject on earthworms in England during the
stock of earthworms toproduce soil and be- 1980s. “A fair amountof work has beendone
gan experimenting with different growing
with E. coli for instance.” For the most part,
techniques. While developing an apprecia- results of those studies apparently remain
tion for the prodigious production capacity
unpublished.
of worms, he met Barnell Logue, a pioneer
Dan Holcombe of Oregon Soil - and othin the field who had developed a windrow er vermiculturists - report that plant or
vermicomposting system to handle munici- human pathogens have never been a probpal solid waste during the 1970s. Stevenson lem in their operations. Others, including a
discovered a growing interest in vermicom- microbiologist who has worked with the full
posting from waste managers and formed
range of organics management technoloEEP with his son, George, and Logue in
gies, suggest that some of the more resisSeptember, 1993.
tant pathogens, especially those in spore
Currently, the company operates two
form, have been know to survive passage
sites handling a combined total of 30 tons through earthworms’ digestive tracts.
per month of composted yard trimmings
In vermicomposting, temperatures are
from the Orange County landfill and
20 generally keptbelow 30”C, according to Edtons per month of shredded cardboard. w a r d s . “ W o r m s c a n b e f o u n d i n t h e r They also have conducted earthworm trials mophilic composting windrows, but they
with RDF fines from Palm Beach County
tend to stick to the edgesof the pile. Temperatures above 35°C will kill them,” he
and other orgaoics.
Two projects being discussedare of partic- says. For practical comparison, meeting the
ular interest. The first, in cooperation with requirements of the EPA’s Process to Furfor in-vessel
the PalmBeach CountySolid Waste Author- ther Reduce Pathogens (PFRP)
ity, would require 600 tons of worms tohan- or aerated static
pile compostingof biosolids
of 55°C
dle commercial organics fromsupermarkets requires maintaining a temperature
windrow
and institutions. “This past year,
we made it or higherfor three days. Using the
through all the budget cuts but theone,”
last method, a temperatureof 55°C orhigher for
says Stevenson,who still has hopes that the15 days or longer with
a t least five turnings
project eventuallywill be funded.
of the windrow in that timeperiod.
Noting the federal requirements, EdIn another development, the University
of
Florida Energy Extension Service in Palm wards says that, just
to be on the safe side,
Bay has been talking with large businesses “it’s not a bad idea to precompost material
in Orange County, encouraging them to
before adding worms. Otherwise, it may
dedicate their organics to EEP’s worms.
need to be treated afterwards.”
Clients will be provided with clean containOn the positive side, people love worm
ers to collect food, soiled paper and card- castings, and consumers
will pay up to three
board. (The glue in cardboardboxes is usu- times more for them than they’d pay for
ally animal-derived, a fact in which worms most “normal” compost. Among the blessings of castings, vermiphiles count a smalltake much delight, Stevenson says.) The paper products and food will be shredded and er particle size than thermophilic compost,
fed to the windrows.
lower odor, enhanced microbial activity,
The biggest accounts would be outfitted and asa bonus, the vermicompost oftenconwith an Original Vermitech system on the tains worm cocoons, meaning a free work
premises. Hotel or restaurant staff would force
future.
for the
OCTOBER
1994