Mercury Minimization

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. Mercury is an element in the Earth’s crust. Humans cannot create or destroy mercury. Pure mercury is a liquid metal, sometimes referred to as quicksilver that volatizes readily. It has traditionally been used to make products like thermometers, switches, and some light bulbs.

The North Carolina Department of Environmental Quality (DEQ) has issued a statewide total maximum daily load (TMDL) for mercury. The ultimate goal of the TMDL is to ensure safe levels of mercury in fish throughout North Carolina for human consumption.

Mercury Disposal Prohibitions

The state of North Carolina prohibits the disposal of hazardous waste into municipal solid waste landfills. Dental facilities that prepare amalgam may produce amalgam waste containing mercury. Waste amalgam caught in the traps and screens of plumbing as well as other scraps of amalgam from dental offices must be shipped to a properly permitted facility. 

Amalgam in wastewater is regulated either by the Sewer Use Ordinance of the local wastewater authority for dischargers to the sewer systems or by the local health department for dischargers to a septic tank. The sewer discharge limit for all users for mercury recommended in the N.C. Sewer Use Ordinance template is 0.0003 mg/l. Local limits may differ. Dischargers to a septic tank are prohibited from discharging hazardous waste and form contaminating groundwater at the compliance boundary.

Mercury in Household Products

  • Thermometers (looks like a silvery liquid)
  • Thermostats
  • Blood-pressure cuffs
  • Barometers
  • Fluorescent and high-intensity discharge (HID) lamps
  • Mercurochrome
  • Auto switches
  • Float switches
  • Button-cell batteries
  • Old latex paint (pre-1990)
  • Some oil-based paints
  • Old alkaline batteries (pre-1996)
  • Old light-up tennis shoes (pre-1997)
  • Chemistry sets
  • Old fungicides for seeds and turf
  • Dental amalgam
  • Some imported jewelry (glass ampules with silver liquid)
  • Weight/counterweight in grandfather clocks