Tom Glanville
Iowa State University Extension
Every
so often abandoned wells capture widespread attention when
a child falls into an open shaft and disappears. However,
abandoned wells pose numerous safety concerns every day that
don't receive as much attention as a dramatic rescue or fatal
accident.
Wells
can be found almost anywhere, especially in Iowa where rural
communities and farms depend on them for drinking water. As
small farms merge into larger ones, however, farmsteads are
abandoned, leaving thousands of unused wells throughout the
state. Communities also have developed extensive public water
systems, making individual wells obsolete.
It's
difficult to determine the number of abandoned wells in Iowa.
County assessors' records show there may be at least 35,000
unused wells, and census data suggest many, many more than
that. In 1900, there were about 250,000 active farms in Iowa,
compared to only 102,000 in 1992. More than 145,000 farmsteads
have been abandoned in Iowa since the turn of the century,
and most had at least one well.
Old
windmills or pump houses make some abandoned wells easy to
spot. Others are hidden beneath grass, brush, or collapsed
buildings. These hidden holes can lead to personal injury
or equipment damage. Worse yet, many hand-dug or bored wells
are large enough to trap an unsuspecting child, wild animal,
or pet.
Abandoned
wells also threaten groundwater quality. Layers of soil and
rock that cap groundwater supplies naturally filter out silt,
bacteria, and some chemicals. This protection is destroyed
when open holes drilled through the protective layers allow
contaminants to directly enter groundwater. Contaminants also
enter nearby private water supplies through missing or defective
well caps and leaky casings on abandoned wells.
The
only way to reduce safety hazards and groundwater contamination
caused by abandoned wells is to plug them. However, there's
more to plugging a well than simply dumping something down an
open hole.
Plugging
materials must be strong, durable, and free from contaminants.
To prevent migration of contaminants through the well bore
and into valuable underground water sources, the well should
be plugged with water-tight "sealing materials." When this
is not economical, Iowa law allows "fill materials," such
as clean sand, gravel, agricultural lime, or crushed stone,
to be used with the sealing materials.
Effective
well plugging calls for experience with well construction
materials and methods, and a working knowledge of the geology
of the well site. Inappropriate materials and methods can
lead to settling, sudden collapse, and continued groundwater
contamination. Once materials are in place, they're almost
impossible to remove in correcting a defective job. Furthermore,
most plugging operations require special tools to remove old
pumps and piping, pumps to properly install sealing materials
inside the well, and excavating equipment to remove the top
four feet of casing, which is required by state law. Compacted
soil also must be mounded over the well site to prevent water
from collecting above the abandoned well.
Because
of the difficulties, it is recommended that most wells be
plugged by a certified well contractor. Check resources at
the bottom of this page for more details.
Recognizing
the safety hazards caused by abandoned wells, the Iowa Legislature
included well plugging in the 1987 Groundwater Protection Act.
The Iowa Department of Natural Resources established a priority
for plugging wells with highest priority given to wells that
pose the greatest threat to personal safety and groundwater
quality.
In general,
the law requires wells abandoned since April 25, 1990, to
be plugged within 90 days of abandonment. Exceptions can be
granted for wells designated as "standby wells," as long as
they are in good repair and do not permit entry of contaminants.
The
responsibility for plugging an abandoned well falls on the
landowner, although cost-sharing grants are available. More
details are available in the publications listed at the bottom
of this page.
It's
difficult to convince every landowner to plug abandoned wells.
Proper well plugging requires time and money, and costs vary
considerably with well depth, diameter, and local geology.
Some
people may say that well plugging is like "pouring money down
the drain." However, open wells threaten safety and precious
water resources. A few hundred dollars to plug an abandoned
well could prevent contamination of drinking water or avoid
a serious accident involving family or friends.
How
much do you know?
- Open,
abandoned wells are dangerous because
- bacteria
and pesticides can enter them and contaminate groundwater
- people
or animals can become trapped in them
- people
could stumble on wells hidden beneath grass or brush.
- farm
equipment operators could mistakenly drive over them.
- all
of the above.
- Wells
abandoned since April 1990 must be plugged within 90 days.
True or false?
- According
to Iowa law, landowners are responsible for plugging unused
wells on their property. True or false?
- County
assessors' records show there may be how many abandoned
wells in Iowa?
- more
than 35,000
- about
20,000
- about
10,000
- less
than 2,000
See
answers at the end of the next section.
What
can you do?
Open, abandoned
wells are a safety hazard. Consider these tips to reduce your
risks:
- Locate
all abandoned wells in your operation. Look closely around
old homesteads or buildings used for livestock.
- When
you rent new property, contact landowners about well locations.
- Discuss
location and dangers of abandoned wells with all family
members and workers.
- Make
sure all active and "standby" wells are in good repair and
do not permit entry of contaminants.
- Get
bids from certified well contractors to plug wells that
are in bad repair or will not be used again.
Answers
to quiz:
1-e;
2-True; 3-True; 4-a.
- There's
more to plugging a well than simply dumping something inside
the casing. For more information and a description of the
Iowa law, get a copy of the publication, Successfully Plugging
Your Abandoned Well, Pm-1328, at your local extension office.
- Service
clubs and other groups wanting to learn more about abandoned
wells may borrow an 18-minute slide/tape presentation, "Plugging
Abandoned Wells," available at any extension office.
- For
more details about well plugging practices, obtain Guidelines
for Plugging Abandoned Wells, Technical Information Series
#15, from the Geological Survey Bureau of the Iowa Department
of Natural Resources, (319) 335-1575.
- To
see if grants are available for plugging wells, contact
the county board of supervisors or the county environmental
health officer.
Disclaimer
and Reproduction Information: Information in NASD does not represent
NIOSH policy. Information included in NASD appears by permission
of the author and/or copyright holder. More
NASD Review: 04/2002
This document
is Fact Sheet
Pm-1563f
,
a series of the Safe Farm Program, Iowa State University Extension,
Ames, Iowa. Safe Farm promotes health and safety in agriculture.
It is funded by the National Institute for Occupational Safety
and Health (NIOSH #U05/CCU706051-03), Iowa State University,
and a network of groups that serve Iowa farm workers and their
families. Publication date: November 1994.
Prepared
by Tom Glanville, extension agricultural engineer; edited
by Laura Miller, extension communications, Iowa State University
Extension, Ames, Iowa.
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