v>EPA
United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-81-074 May 1981
Project Summary
Safe Disposal Methods for
Agricultural Pesticide Wastes
Charles V. Hall, James Baker, Paul Dahm, Loras Freiburger, Greg Gorder,
Layne Johnson, Gregor Junk, Fred Williams, and Charles J. Rogers
During the 3-year period from
October 1976 to 1979, comprehen-
sive chemical, biological, climatolog-
ical, and engineering studies were
conducted at Iowa State University,
Ames, Iowa, to determine effective-
ness of pesticide disposal facilities
being used at the school and to com-
pare controlled systems that might
provide a basis for improvement.
Evaluation of the pit disposal systems
included detailed chemical sampling
of the systems and their surrounding
environments, identification and
counts of bacterial populations, ento-
mological studies, estimation of
pesticide volatilization rates, and
evaluation of pit design for efficiency,
effectiveness, and convenience of
operation.
This Project Summary was develop-
ed by EPA's Municipal Environmental
Research Laboratory. Cincinnati. OH.
to announce key findings of the
research project that is fully docu-
mented in a separate report of the
same title (see Project Report ordering
information at bach).
Introduction
A polyethylene-lined open pit at the
Agronomy-Agricultural Engineering
Research Center had been used for
dumping surplus dilute pesticides,
primarily herbicides, for about 14 years.
In 1978, a new pit was built; it was lined
with two layers of 6-ml-thick polyethyl-
ene plastic; filled with sand, soil, and
gravel, and covered by a metal building.
Sampling wells were installed for moni-
toring purposes.
To test pit disposal methods under
controlled conditions, 56 polyethylene
mmipits, each with a capacity of 115
liters and equipped with a cover, were
installed partially underground. Com-
binations of four herbicides (alachlor,
atrazine, trifluralin, and 2,4-D) and two
insecticides (carbaryl and parathion)
were studied in mixtures and individ-
ually at two concentrations after being
incorporated with 15 kg of soil and 55
liters of water per container. One half of
the containers were aerated. For each
combination of pesticide, chemical
dissipation, bacterial activity, and bio-
assays were conducted.
A concrete pesticide disposal pit at
the Horticulture Station, in operation
since 1970, was systematically
monitored, and the chemical disposal,
accumulation, bacterial activity, and
evaporation were evaluated. The inside
pit dimensions are 3.35 m (width) x8.84
m (length) x 1 m (depth). It is filled with
soil and gravel layers each approxi-
mately 30 cm thick. A motorized cover
triggered by rainfall closes to prevent
flooding. Climatological data were col-
lected on the site and correlated with
pan and pit evaporation. Programs were
developed to predict pit evaporation
rates from local evaporation data. Leak-
age from the pit was monitored as well
as pollution of a lake and well located on
the station.
; US GOVERNMENT PRINTING OFFICE 1981-757-012/7U3
-------
Results
After 14 years of dumping dilute
pesticides (primarily herbicides) in the
open, polyethylene-lined pit at the
Agronomy-Agricultural Engineering
Research Center, the surrounding area
obviously had been affected The pit was
ineffective because it had overflowed,
rainfall had not been excluded, and the
plastic had deteriorated. A large area,
free of all vegetation, was cultivated,
planted with corn, soybeans, and selec-
ted weed species. Only corn grew,
which indicated a high concentration of
triazine compounds.
The newly constructed polyethylene-
lined pit covered with a metal building
appears to have a seepage problem
since the water level fluctuates. Obvi-
ously two 6-ml-thick layers of plastic are
inadequate regardless of the care taken
in installation. In areas where the water
table is high or where seepage will
occur, similar systems for disposal are
unsatisfactory. In colder climates,
where freezing and thawing of soil
occurs to a considerabledepth, pit liners
must be selected with extreme care.
The reinforced concrete disposal pit at
the Horticulture Station appears to be
completely environmentally safe and
effective for pesticide waste disposal.
Following 10 years' use and the dispos-
al of over 40 different pesticides (insec-
ticides, fungicides, herbicides, etc.), the
system continues to function efficiently
and no leakage has occurred Aerobic
bacterial activity in the soil is highly
effective in biodegradmg many of the
compounds. Liquids continue to evapo-
rate with no detectable atmospheric
pollution. The rainfall-activated cover
functions to prevent overflowing and
excludes all outside water
Evaporation and climatological data
collected on the site were used to
develop models for predicting evapora-
tion at other geographic locations.
During a normal season, over 6,000
gallons of water are evaporated from
this pit.
A new cover design was developed to
reduce initial cost and restrict access to
the disposal area. All pesticide sprayers
being used have been modified to
permit excess liquids to be dumped into
the pit without the equipment entering
the pit.
After 68 weeks, of which only about
30 were conducive to active pesticide
decay, data collected from residues in
the micropits containing the six select*
pesticides were evaluated. The effect i
aeration and nutrient supplements c
decay rate and bacterial and insecticid
activity were measured. Those con
pounds most resistant to decay wei
atrazme, alachlor, and trifluralin; the
were, however, contained and did n<
contaminate surrounding areas.
Complete methodology for all phase
of research were developed and ar
described m the final report.
The full report was submitted m fu
fillment of Grant No. R-804533 by low
State University under the sponsorshi
of the U.S. Environmental Protectio
Agency.
Charles V. Hall, James Baker, PaulDahm, Loras Freiburger, Greg Gorder, Layne
Johnson, Gregor Junk, and Fred Williams are with the Iowa State University,
Ames, I A 50011.
Charles J. Rogers is the EPA Project Officer (see below).
The complete report, entitled "Safe Disposal Methods for Agricultural Pesticide
Wastes," (Order No. PB 81-197 584; Cost: $18.50, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Municipal Environmental Research Laboratory
U. S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
RETURN POSTAGE GUARANTEED
Third-Class
Bulk Rate.
------- |