This section gives an overview of agriculture-related teaching areas, the activities occurring within them and the resulting wastes. Both hazardous and non-hazardous wastes should be considered for reduction. Planning ahead to reduce waste can save money and time. If waste cannot be avoided, proper collection and disposal can be determined by consulting with state and local officials.

(For information about determining whether a waste is hazardous or not, see the Environmental Protection Agency (EPA) brochure What Makes Your Waste Hazardous.)

Agricultural and Power Mechanics

Activities include working on and overhauling small internal combustion engines, electrical motors and circuits, and other forms of industrial/farm machinery as well as hydraulic system repair and maintenance. These processes involve many fluids, components, and products that may be hazardous if not properly handled and disposed of. These items include:

• Used oil and filters - Should not be poured on the ground; recycling services exist in most communities
• Antifreeze - Can often be recycled if kept separate from other wastes
• Transmission fluid - Can sometimes be included with used oil for recycling
• Brake fluid - Can often be recycled if kept separate from other fluid wastes
• Gasoline - Highly flammable; small amounts of clean gas can be added to vehicles to avoid other safety and disposal issues
• Solvents - Are particularly hazardous to inhale and should be conserved as much as possible
• Tires - Waste tires are difficult to dispose of and often their disposal is expensive
• Batteries - Can usually be recycled
• Absorbents - Can become a hazardous waste; use drip trays and pans to prevent spills; use squeegees for clean up rather than absorbents.

Construction and Carpentry

Activities in this teaching lab encompass layout and construction of wood-based projects such as parts of a building or wall; rafter layout and construction; and other small woodworking projects. Potential wastes produced in this lab setting include:

• Paints and stains - Buy only what is needed and choose less hazardous products
• Strippers and solvents - Filter and reuse
• Wood wastes - Use wood efficiently to reduce waste; use non-chemically treated wood whenever possible; compost sawdust

Greenhouse/Farm Plots

Greenhouses and outdoor growing areas are becoming more common in the agricultural curriculum. Activities in these areas include propagating and growing plants (watering, fertilizing and pest control) and conducting plant growth experiments. Many of the chemicals used are potentially hazardous. Fertilizers include phosphorus and nitrogen that can cause water pollution if runoff is improperly managed. Common wastes found in a greenhouse area include:

• Plant wastes - Dead plants and thinnings should be incinerated or otherwise properly disposed if they have been sprayed with chemicals. Clippings and trimmings should be composted rather than allowed to wash into storm drains.
• Ag chemicals - Fertilizers, herbicides, and insecticides can pose serious health risks to humans and pollute surface waters when improperly used. Pesticide containers should be rinsed and disposed of properly. Follow all directions on product labels, callibrate application equipment and consider integrated pest management and non-chemical alternatives.
• Potting soil/plant growth media - Generally has been sterilized and is not chemically treated. Care must be given to control loss due to wind or watering. Soil in outdoor plots should be planted or covered to prevent erosion.
• Runoff - Runoff from watering plants in the greenhouse may contain fertilizers and pesticides that can contaminate surface and groundwater if allowed to flow along hard surfaces to storm drains. Reduce water consumption and prevent pollution by collecting runoff and reusing for the next watering.
• Irrigation water - Irrigation water can be wasted by over-watering or ineffective watering. (Watering on windy days or during the heat of the day causes water to be wasted due to evaporation.) Understanding and monitoring soil structure and moisture is key to effective irrigation.

Metals and Welding

Arc welding, and layout and fabrication of sheet metal projects, use a number of compounds and materials that can produce potentially hazardous wastes. Most lab facilities use protective equipment to minimize human exposure to such materials and compounds. The common wastes produced in metals laboratories include:

• Welding exhaust fumes - When torches or arc welders are used, fumes are produced. Using flux and inert gasses for shielding produces additional gasses. Management of emissions is an important health and safety consideration. EPA and insurance company guidelines generally state that these fumes must be collected and filtered before being vented to the outside.
• Material wastes - Metals, welding rods, and other excess raw material can often be minimized with good resource management, reused in smaller projects, or recycled at local facilities.
• Fluxes and cleaners - These compounds are used to clean metal prior to the metal being worked. Use carefully and sparingly to prevent spills and contamination of water (either sub-surface or sewage). Do not wash spills down the drain.
• Welding dust - Metal dust is produced when metals are ground or processed. Metal dust is harmful to breathe, and can be highly volatile. Some metals contain particularly hazardous compounds.
• Metal marking dyes - Metal marking dyes are commonly used in project layout; spills should be cleaned up instead of washed down a drain.

Animal Confinement and Aquaculture

Many schools integrate livestock operations into their curricula. These programs utilize barns, corrals, and other livestock related facilities and equipment. Livestock production waste can severely impact the local environment and drinking water. Local, state and federal rules and regulations may apply. Aquaculture is an emerging technology. Commonly used materials and the wastes produced include:

• Manure - Prevent surface and groundwater pollution by properly locating confinement facilities away from water sources and runoff areas. Also avoid livestock overcrowding.
• Carcasses - Improper disposal can spread disease, attract rodents and pollute groundwater
• Feed - Avoid overfeeding so that excess feeds are not lost to soil or groundwater. Testing has shown that runoff water and streams contain many of the components in animal feed. Such components include growth additives and antibiotics. Detectable levels have also been found in fish.
• Salt and mineral supplements - Prevent loss to the soil or water by feeding these nutrients in block form versus loose granules.
• Medical products (including medicine, medicine containers, syringes, needles, gloves, artificial insemination products, etc.) - As wastes, these become more hazardous if they have been exposed to infectious matter. Check local and state agency regulations. Buy in appropriate amounts so products are used before the expiration date.