Properly planned and operated, land
treatment is an effective method of water
purification and a safe and beneficial method
of irrigation. The land treatment of municipal
wastewater already enjoys a long and
successful history in this country.
Careful Planning and Operation Are Necessary
IF YOU WOULD LIKE FURTHER INFORMA-
TION OR ASSISTANCE IN LAND TREAT-
MENT. CONTACT:
Chief, Land Treatment Task Force
U. S Environmental Protection Agency
Robert S. Kerr Environmental Research
Laboratory
P. O. Box 1198
Ada, Oklahoma 74820
Phone: 405-332-8800
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United States
Environmental Protection
Agency
March 1980
wEPA
HEALTH EFFECTS
OF LAND TREATMENT -
IS IT REALLY SAFE?
Land Treatment Can Be Safe and Beneficial

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It is well known that land application of
municipal wastewater has many economic
benefits, but there is also the widespread
fear that land treatment endangers public
health.
1. IS LAND TREATMENT
REALLY A SAFE WAY
TO CLEAN
WASTEWATER?
A well-planned, well-run land treatment
system poses no significant health
problems, and it is as safe or safer than
traditional methods which discharge into
lakes or streams.
2. WHAT ABOUT ITS
TRACK RECORD?
At present there are more than 700 land
treatment systems operating in the United
States. More than 500 of these have been in
operation for more than 10 years. Studies
have shown no increase in harmful con-
taminants, no increased health risks and
there have been no reported disease
outbreaks from any of these facilities.
3. ARE LAND TREATMENT
SYSTEMS REGULATED?
The Clean Water Act requires that land
treatment systems meet certain standards
just like traditional systems. In fact, even
more is required of land treatment systems.
Both must ensure the safety of discharges
into surface waters, but because land
treatment can impact groundwater supplies,
such systems must also ensure that all
discharges into underground aquifers will
not contaminate the drinking water.
4. DOES IT REALLY
CLEAN WASTEWATER?
Land treatment has the benefit of helping to
recharge groundwater supplies. The right types of
soil can reduce heavy metals and toxic organisms
to safe levels. Preapplication treatment can supple-
ment where particularly high concentrations are
present. Careful management of water application
relative to soil absorption and filtering capacity is
important. Land treatment has been shown to be an
even better method of removing viruses from
wastewater than traditional systems. Actual techni-
ques for the control of toxics and pathogens depend
largely on the particular land treatment system
used.
Land Treatment Is Safe For Grazing Animals
5. CAN LAND TREATMENT
CONTAMINATE CROPS?
Organisms that cause disease in man have been
found in food crops irrigated with municipal
wastewater, but illness occurred only when foods
were eaten raw. It is recommended that irrigation be
used for non-food crops or food crops such as
wheat that must be processed before consumption.
The health hazard from heavy metals and toxic
chemicals is not great because those substances
usually appear in sewage in extremely small
quantities. Moreover, land treatment design
guidelines restrict the presence of metals to safe
levels.
6. CAN ANIMALS
SPREAD DISEASE
FROM LAND
TREATMENT
SYSTEMS?
Studies have shown that fish, birds and
rodents on land treatment systems are as
healthy or healthier than offsite control
animals. The mosquito is of more concern
because of the potential for increasing its
breeding habitat. But this is easy to control
with a conventional mosquito control
program.
7. CAN HUMANS
BE CONTAMINATED
BY COMING IN
CONTACT WITH LAND
TREATMENT
SYSTEMS?
Direct contact would expose humans to
contamination but proper design and
management keeps this from becoming a
problem. Restricting public access to the
facility and having plant personnel follow the
usual safeguards of immunization and
hygiene can provide a full measure of health
protection. Disinfectants are an important
aid when the water is applied to public areas
such as parks and golf courses. Pathogens
can be carried by wind from both land
treatment and conventional systems but
there is no evidence that disease has ever
resulted from this. In any case, the transmis-
sion of pathogens as aerosols can be
controlled by using low pressure sprinklers,
buffer zones, tree barriers and site isolation
along with a variety of operational techni-
ques.

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