The Claymont community is working together to establish an independent neighborhood air monitoring program in the area. The program will be funded by a grant to the Claymont Community Coalition from Claymont Steel. The funding will be used to train a volunteer group, the Claymont Community Monitoring Team, on ambient air quality standards and how to use monitoring devices to document air quality. Claymont residents will independently monitor the effectiveness of emissions dust controls from “hot spots.” These "hot spots" are locations that the community has identified as the most impacted by fugitive dust fallout. Sometimes called a "bucket brigade," this monitoring method has been successful in equipping communities with data generated by sampling methods and equipment that meets USEPA sampling protocols. By doing so, community residents are able to make use of sound technical data to find solutions to environmental problems in their neighborhood.
What are mercury and methylmercury?
Mercury is a persistent, bioaccumulative neurotoxin. Mercury can be found in the environment in a variety of forms depending on use, environment and microbial activity. Metallic mercury can be present in switches (particularly certain automobile switches), thermostats and a variety of medical and industrial applications.
Metallic mercury is a volatile compound that can result in high air concentrations in industrial and occupational settings. Health effects attributed to exposure to high concentrations of metallic mercury and associated vapors include permanent damage to the brain and kidneys, as well as tremors, changes in vision and hearing and memory problems.
Methylmercury is an organic compound formed when elemental mercury makes its way into water and soils where microbes convert the mercury to methylmercury through an anaerobic biochemical reaction. Methylmercury can then bioaccumulate in fish through food chain biomagnification, leading to exposure to significantly higher concentrations of methylmercury through consumption of affected fish.
Health effects associated with adult exposure to high concentrations of methylmercury include damage to the kidneys, stomach and large intestine. As with other toxic substances, children and pregnant women are more sensitive to lower dose exposures of methylmercury during fetal and early childhood development. The effects can range from minor decreases in intelligence to more serious developmental delays to severe brain damage.
Reducing mercury emissions in Delaware
In 2006, DNREC decided to take more stringent measures to reduce mercury releases. DNREC’s Pollution Prevention (P2) program initiated an educational program for medical and allied health professionals on preventing releases of mercury from thermometers and devices like blood pressure cuffs. The education program was followed by a focus on mercury air emissions.
Prior to 2006, DNREC believed that the Occidental Chemical (Oxychem) Company facility in Delaware City was the largest emitter of mercury to Delaware’s air, followed by Delaware’s power plants (Edgemoor and Indian River). DNREC adopted new air quality regulations in November 2006 that require power plants to reduce mercury emissions by more than 80 percent. Under these regulations, initial reductions are required by May 2009 and full compliance is required by January 2012.
When Oxychem decided to close down its production line that used mercury, the Division’s Air Quality Management Section took a closer look at other sources of mercury in the state. Since regulations were being implemented to control mercury emissions from the power plants, Air Quality Management moved to the next source on the list of mercury emitters. According to emission estimates submitted to the Division through the Toxic Release Inventory (TRI), Claymont Steel was the next largest emitter of mercury. Because Claymont Steel submitted estimates of mercury emissions based on mathematical calculations, rather than actual emission testing (a standard and acceptable practice under TRI), the Division requested that the company undertake stack sampling for mercury.
The results were staggering. Claymont Steel previously reported mercury emissions ranging from 28 to 39 pounds per year over the past five years. The stack testing of air emissions conducted in 2006 indicated that mercury emissions from the facility’s electric arc furnace (EAF, the device used to melt scrap metal), were actually 360 pounds per year with a potential to reach or exceed 500 pounds per year with the plant operating at full capacity.
Upon learning the results of the Claymont Steel stack test, DNREC ordered Claymont Steel to reduction mercury emissions from its EAF, either by reducing the mercury entering the furnace or by using end-of-pipe controls. The facility immediately discontinued the use of municipal scrap metal as a first step in reducing mercury emissions, as some household appliances, such as washers and dryers, can also contain mercury switches.
The results of a stack test done in December 2006 indicated a 40 percent reduction in mercury emissions compared to the test done earlier in the year. Claymont Steel is continuing to look at additional ways to reduce its mercury emissions in accordance with DNREC’s Order.
Mercury switches and ELVS
Claymont Steel uses scrap vehicles to make steel slag at its facility. Another potential source of mercury in Claymont Steel’s emissions is the mercury switches found in some automobile makes and models. DNREC is working with the auto salvage yard industry to remove these switches prior to scrapping vehicles.
To assist Claymont Steel in reducing its mercury emissions, and to prevent other releases of mercury into Delaware’s environment, DNREC asked the non-profit corporation ELVS to come to Delaware. ELVS, which stands for End of Life Vehicle Solutions, was created by the auto industry to promote recyclability, education, outreach and proper management of substances of concern.
In 2006, ELVS formed the National Vehicle Mercury Switch Recycling Program (NVMSRP). The goal of the NVMSRP is to remove mercury switches from automobiles before the steel in the vehicle is recycled. Mercury switches can be found in convenience lights in trunk and hood compartments and in anti-lock braking system (ABS) modules of some vehicles built before model year 2003.
In December 2006, 63 Delaware scrap and salvage dealers were invited to participate in NVMSRP to remove and recycle mercury switches from pre-2003 vehicles before they are crushed, shredded and melted down as part of the steel recycling process. Mercury can be released to the environment during any of these three steps.
By participating in the NVMSRP, scrap and salvage dealers are eligible to receive, on a first-come, first-served basis, $1 for each mercury switch lighting assembly and $3 for each anti-lock braking system (ABS) module removed and submitted. Switches do not need to be removed from assemblies. Payments out of a $4 million fund began in January 2007, with switches sent in before January 1 eligible for compensation. ELVS will send participants, free of charge, a mercury switch collection bucket, updated educational materials, a list of vehicles with the potential to contain mercury switches, and a detailed instruction sheet on shipping full collection buckets. The buckets are returned with postage paid and additional buckets are available on request, also at no cost.
DNREC continues to encourage scrap and salvage dealers to participate through additional mailings. To join the program or for more information, please contact ELVS at 877-225-ELVS (3587) or visit: End of Life Vehicle Solutions. For more information on recycling mercury switches, please contact Karen G. J’Anthony of the Division’s Solid & Hazardous Waste Management Branch at 302-739-9403 or firstname.lastname@example.org.