Pollution Prevention

The U.S. EPA has identified 31 Priority Chemicals and Metals that are potentially harmful to human health and/or the environment. Thirteen of these chemicals, including mercury and Polychlorinated Biphenyls (PCBs) are present in our region. DC Water promotes the reduction of these chemicals in the wastestream through source reduction and product substitution.

In addition to these Priority Chemicals, there are many other contaminants of emerging concern that the U.S. EPA and other agencies are evaluating for environmental impacts, including pharmaceuticals and personal care products, flame retardants, nanomaterials, perfluorinated compounds (PFCs), and others.

Mercury

Mercury is a naturally occurring element that is found in air, water, and soil. It exists in several forms:

  • elemental or metallic mercury,
  • inorganic mercury compounds,
  • and organic mercury compounds.
Although mercury can change its form in the environment, it is persistent and not biodegradable. It bioaccumulates as it moves up the food chain and is very toxic in the organic form (methylmercury).

Mercury in the air can settle into the water or onto the land, where it can be washed into the waterway or sewer system. Because mercury is persistent, historical contamination from past industrial discharges of mercury is of concern. Mercury can accumulate in sewer pipes, leading to long-term releases of mercury to the wastewater treatment plant, even after the original source has been eliminated.

Mercury is present in many consumer products. Products that contain mercury should be replaced with products that do not contain mercury, whenever possible. Some examples of products that may contain mercury include the following:

  • Thermometers
  • Thermostats
  • Fluorescent and other lamps
  • Manometers and barometers
  • Switches and relays
  • Button-cell batteries
  • Dental amalgam
  • Chemicals and formulated products, including laboratory chemicals such as Zenker's solution, B5 solution, and products using thimerosal as a preservative

To dispose of these products, contact a reputable recycler or hazardous waste contractor. Residents in the District of Columbia may dispose of mercury and mercury-containing items during scheduled household hazardous waste collection days. To prevent mercury from entering waterways, never dispose of these products in the regular solid waste trash or the sewer system.

Many states, organizations, and communities have initiated assistance programs (detailed on their website) aimed at reducing mercury pollution from commercial, industrial, and consumer sources and in products.

Dental facilities are encouraged to adopt the Best Management Practices detailed on the ADA's website to reduce the amount of mercury entering the sewer system.

DC Water developed a guidance document for the health care industry discussing wastewater management and pollutant minimization for mercury, unused pharmaceuticals, and other chemicals (PDF 254 kb) .

Polychorinated Biphenyls (PCBs)

PCBs are a class of man-made compounds that were manufactured from 1929 until their ban in 1979. They were used in hundreds of industrial and commercial applications due to their non-flammability, chemical stability, high boiling point, and electrical insulating properties. PCBs do not readily break down and therefore may remain for long periods of time cycling between air, water, and soil. In addition to being persistent, PCBs also bioaccumulate in organisms as itmoves up the food chain and has been demonstrated to cause cancer, as well as other adverse human health effects. Portions of the tidal Potomac River are listed by the District of Columbia, Maryland, and Virginia as impaired waterways due to PCB contamination in fish.

Products containing PCBs should be replaced with new products. PCBs may be present in products and materials produced before the 1979 ban. Examples of these products include the following:

  • Transformers and capacitors
  • Other electrical equipment including voltage regulators, switches, reclosers, bushings, and electromagnets
  • Oil used in motors and hydraulic systems
  • Old electrical devices or appliances containing PCB capacitors
  • Fluorescent light ballasts
  • Cable insulation
  • Thermal insulation material including fiberglass, felt, foam, and cork
  • Adhesives and tapes
  • Oil-based paint
  • Caulking
  • Plastics

PCBs were manufactured and sold under a variety of trade names, the most common being Aroclor. For a complete list of trade names, see the EPA PCB web site.

To dispose of these products, contact a reputable hazardous waste contractor. Residents in the District of Columbia may dispose of PCB-containing items during scheduled household hazardous waste collection days. To prevent PCBs from entering waterways, never dispose of these products in the regular solid waste trash or the sewer system.

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