The Environmental Protection Agency estimates that 25% of this nation's fuel tanks may be leaking fuel into the ground. That number is probably higher in rural areas, since many farmers buy fuel tanks second hand. Petroleum fuels contain highly toxic compounds - including benzene, xylene, toluene, and lead - which have been found to cause cancer and other adverse health effects.
All underground and surface fuel tanks should be closely
monitered for leaks and spills. Aged or corroded tanks should
be replaced. It does not pay to ignore a problem with a
storage tank, as most insurance companies no longer protect
storage tank owner's from liability for gasoline cleanup
costs if the owner's tank pollutes ground water.
Failed septic systems are a common source of nitrate,
bacteria, viruses, and household cleaning agents in ground water.
While septic systems are generally built to last 20 years,
researches at the University of Missouri have found that 75% of
the home septic systems in that state fail within 2 to 3 years.
Pesticide mixing areas are very vulnerable spots.
Spilling just 4 oz. of a chemical in a 100 square foot area is
equivalent to applying 100 pounds per acre.
Careless disposal practices also pose a serious threat to
surface and ground waters. Even empty containers need to be
disposed of properly.
Most states now regulate hazardous waste disposal of
business waste - such as left over pesticide - making it illegal
to dispose on-farm. Improper disposal of wastes can lead to ground
pollution by concentrating the pollutants at one site. The most
common on-farm, risky disposal practices include disposal of
paint cans (lead and mercury source), solvents, batteries (acid
and lead source), and used motor oil.
Besides polluting water with nitrates and phosphates, manure
can be a source of bacteria and other pathogens that pose a serious
health risk. Many of the 150 diseases that animals can transmit to
humans can be found in manure.
Manure storage over bedrock and overflows from liquid facilities
can pose risks to ground- and nearby surface water. Manure in earthen
pits generally forms a ground seal of organic matter that limits
leaching potential, but seasonal emptying and filling can cause the
seal to break down. In addition, abandoned storage facilities present
high risks to water sources.
Barnyards can be a major source of water pollution,
especially when heavy rains flush animal wastes into nearby streams,
lakes, or drainageways. Ground water is also vulnerable in areas
having a high water table, shallow depth to bedrock, or very
permeable soil.
Reducing the amount of water flowing over the barnyard will
help control pollutionrisks. For example, placing gutters on
rooftops near the barnyard to collect and divert rainfall would
help. This clean water, and runoff from upslope lands should then
be diverted.
Also, water that falls on the barnyard should be collected
in concrete settling basins and the solids allowed to settle.
Liquids can then be allowed to flow over a grassed area where the
remaining pollutants can be filtered out.
Manure should be applied to fields according to a well-timed
nutrient plan.
Pit or trench silos, or those with earthen floors pose
pollution risks to ground water. High-moisture silage (65% and up)
tends to produce an effluent. Grass silage at 75% moisture produces
only a trickle, but at 85% moisture this increases to 79 gallons
per ton silage.