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Mercury PMP

Appleton Wastewater Treatment Plant (AWWTP) effluent mercury levels are greater than the recently adopted Wisconsin Administrative Code NR 106.145 Water Quality Based Effluent Limit (WQBEL) of 1.3 nanograms per liter (ng/l). The AWWTP is now required by the DNR to implement a Mercury Pollutant Minimization Program (Mercury PMP). The program intent is to reduce mercury influent contributions from several community sectors.

Wastewater treatment plants are capable of removing in excess of 90% of the mercury entering the plant. However, even this high removal rate is generally not sufficient for the plant effluent to consistently meet the very low limit of 1.3 ng/l. The only cost-effective way to do this is to reduce mercury discharges into the treatment plant from users of the sanitary sewer system. The goal of a Mercury PMP is to achieve and maintain municipal wastewater treatment plant mercury discharges below 1.3 ng/l by reducing or eliminating mercury discharges from the sanitary sewer users. The AWWTP Mercury PMP adheres to the DNR “Mercury Pollutant Minimization Program Guidance Manual for Municipalities” to accomplish mercury reduction goals.

What is Mercury

Mercury or quicksilver is a chemical element recognized on the periodic table as the chemical symbol Hg and an atomic number of 80. It is a heavy, silvery metal that is found as a liquid at room temperature or as a solid crystal salt (Hg+2). Mercury can also be found in organic (with carbon) compounds. The liquid metal form gives off invisible, odorless, toxic vapors.

Where It Can Be Found

There has been a growing effort to eliminate non-essential uses of mercury today due to its toxic and bioaccumulative properties. However, a large number of mercury containing items can still be found in the marketplace even though some manufacturers have taken steps to reduce or eliminate the use of mercury in their products or develop non-mercury or low mercury containing alternatives. Some products that contain metallic mercury include electrical tilt switches, thermostats, certain batteries, dental amalgam, laboratory and medical equipment including measuring instruments such as thermometers, manometers, and barometers. Fluorescent lamps and compact fluorescent lights (CFLs) manufactured today also contain a small amount of mercury sealed within glass tubing. Because of the health risks associated with mercury exposure, manufacturers continue to find ways to reduce the amount of mercury used in fluorescent lighting products.

Organic mercury or mercury that has formed compounds with carbon, is recognized as the form of most concern because it is very soluble, mobile, and capable of bioaccumulation. The most common example of organic mercury includes methylmercury and ethylmercury. Historically, these forms of mercury have been used as fungicide, herbicide, and/or preservative or anti-fouling agent for seed, latex paint, paper products, medicines, vaccines, and cosmetics. Today, most of these uses have been since banned in the U.S. or are less common than observed in the past since mercury’s toxic effects have been recognized.

Mercury Collection and Recycling

Items or compounds containing mercury should not be put in the garbage or poured down the drain. All mercury and mercury-containing items should be recycled. Recycling mercury into new usable products prevents its introduction into the environment. It is also important to remember that many alternatives to mercury containing devices and products are manufactured today. The Outagamie County Solid Waste Department holds Household Hazardous Waste and/or Clean Sweep Programs that provide a venue for mercury disposal to residents during the year at various locations within Outagamie County. The Brown County Solid Waste Department offers similar services for its residents. Households or residents can bring in their mercury containing items at no charge. Businesses are charged a small fee. For more information contact the Outagamie County Department of Solid Waste office at (920) 832-5277 or visit their website referenced below.

Fluorescent lamps and CFLs also can be taken to the Outagamie County Landfill to be recycled year round for a small fee. Some area hardware stores will also accept small CFLs at no charge. For CFL recycling drop off locations in the Appleton area you may also visit Outagamie County Department of Solid Waste website.