Pollution Prevention & Control


Keeping Mercury out of our Waterways

Mercury is a metallic element that is liquid and free flowing at room temperature. It is a persistent, bioaccumulative toxin that poses a risk to human health, wildlife and the environment. Although naturally occurring in the environment, mercury can be released into the air, water and soil by human activity.

Mercury that is released into the sanitary sewer system will eventually make its way to a municipal water resource recovery facility (WRRF) or to a septic system. Municipal WRRFs, including WSSC Water's WRRFs, are not designed to treat or reduce mercury in the wastewater. Therefore, mercury that enters the influent of a wastewater treatment plant settles out in the plant treatment process, concentrates in the biosolids, volatilizes into the air or passes through the treatment plant into the receiving waters. When mercury enters water, bacterial processes can transform it into a toxic, organic form (methyl mercury) that can accumulate in fish, other animals that eat fish, and humans.

Some Mercury Uses (List compiled by the Maryland Department of the Environment (MDE))

  • Fluorescent lamps
  • Mercury switches
  • Electrical Relays
  • Mercury vapor lamps
  • Thermostat probes
  • Metal halide lamps
  • Gauges
  • Laboratory solutions
  • High pressure sodium lamps
  • Thermometers
  • Dental amalgams
  • Manometers
  • Button batteries
  • Contact lens solutions containing thimerosal
  • Barometers
  • Alkaline-type batteries prior to 1996
  • Old latex paints prior to 1990

Mercury or mercury-containing products disposed of to solid waste might end up in the landfill. Over time, the mercury could leach out into the landfill leachate. If the leachate is discharged at a WWTP, the mercury may end up in the sludge or pass through into the receiving waterway.

To prevent mercury from entering waterways, never discharge mercury to the sanitary sewer system or to solid waste. Contact a reputable recycler to remove the waste from your facility or for small businesses contact the local County Health Department for disposal options, and remember, whenever possible, substitute non-mercury-containing products for mercury-containing products.

Montgomery County 

Residents located in Montgomery County may dispose of mercury and mercury-containing items during scheduled County household hazardous waste collection events. For more information call the Montgomery County Division of Solid Waste Services (301) 840-2370 or visit their website at www.montgomerycountymd.gov/sws/ or email them at recycle@montgomerycountymd.gov.

Businesses who are Small Quantity Generators (less than 220 lbs. of hazardous waste per calendar month) of mercury and other hazardous material in Montgomery County may register for Montgomery County's Ecowise collection program. A fee is assessed on a per pound basis at the point of collection. To register for this program contact (301) 840-2371.

Prince George's County 

Residents of Prince George's County may dispose of mercury and mercury-containing items at the Household Hazardous Waste Collection Facility located within the Brown Station Road Landfill. For more information call the Prince George's County Waste Reduction Section (301) 883-5045.

Businesses who are Small Quantity Generators of mercury and other hazardous material in Prince George's County will be referred to contractor. To obtain a referral, contact (301) 883-5045.

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