Even rural areas face hazardous materials problems. In addition to the ever-present possibility of a hazardous materials transportation accident, or storage problems associated with small businesses such as agricultural chemical dealers, threats exist which are unique to the rural environment.

Since wells are a primary water supply in most rural areas, a major concern is the introduction of contaminants into groundwater. A serious, and fortunately infrequent, hazard is that of flammable gas in wells. Small volumes of naturally occurring methane gas can enter wells that are drilled into carbonate or shale rock, causing explosions and fire. Venting the wellhead and other areas of the house where gas can be trapped may lessen this hazard. Another source of concern is the common farming practice of applying fertilizers and pesticides to crops next to a barnyard or farmyard, where many can be drawn into a well—a problem that can be reduced by decreasing the use of pesticides in that general area.

Groundwater contamination is a major concern in rural areas, which must deal with pollutants such as livestock waste and pesticide runoff in addition to the problems found in more heavily populated environments.

Farmers sometimes use sewage sludge as a source of plant nutrients. However, some industrial sludge contains heavy metals that may be toxic to crops, humans, and other animals. Because tolerance levels for heavy metals depend on the soil’s physical and chemical characteristics, farmers should work with a professional to determine their soil’s tolerance and stay within its limits.

Phosphate fertilizer can also cause problems. If you notice that fish are dying in an area where phosphates can reach the water from farm runoff, it is possible that phosphates are promoting the growth of algae and other aquatic plants that deplete oxygen. Reduced use of phosphates and runoff control can reduce this problem. Similarly, excessive use of nitrogen can contaminate groundwater and surface water, particularly when fertilizer is applied far in advance of the crop or to improve poor soils.

Accidents involving excessive use of pesticides have resulted in fish kills, human illness, and even death. Pesticides have been known to contaminate groundwater, particularly in very permeable soils or at sinkholes in limestone; once these substances are introduced into the groundwater supply, they can also be carried to surface waters. Developing other pest control procedures to reduce pesticide use and avoiding applications to permeable soils can reduce contamination. Protective clothing is also important whenever pesticides are applied.

Agricultural runoff can carry soil particles, pesticides, bacteria, and other pollutants directly into estuaries and coastal waters, or into rivers that flow into these waters. Control of runoff by each farmer is extremely important in limiting the spread of harmful products.