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3.7. SR 10-06-2008~j r,~ , City of /'~~rl,%~~~~~ Elk .-~-~ River REQUEST FOR ACTION To Item Number Ci Council 3.7. Agenda Section Meeting Date Prepared by Consent October 6, 2008 Lori Johnson, City Administrator Item Description Reviewed by Receive Asphalt Toxicity Report Reviewed by Action Requested Receive the asphalt toxicity report. Background/Discussion At the July 7, 2008, overlay improvement project special assessment public hearing, the City Council, in response to concerns by a couple of residents, requested that staff investigate and report back on the toxicity of asphalt. The study has been completed by staff and is attached for your review. No additional action is necessary unless the Council wants to discuss the report in more detail. Financial Impact N/A Attachments Memo from Terry Maurer, Public Works Director, including asphalt toxicity report submitted by Nicola Blake-Bradley, Environmental Technician __ ACtIOn Motion by Second by Vote FOllow Up S:\Council\Lori\2008\Asphalt'1'oxicity Report 10 06 08.doc fiver MEMORANDUM TO: Lori Johnson, City Administrator FROM: Terry Maurer, Public Works Director DATE: September 15, 20089 SUBJECT: Asphalt Toxicity Report At the public hearing fox the 2008 Bituminous Overlay, the City Council asked staff to provide afollow-up report on the toxicity of asphalt pavement, based on comments received from the public at the hearing. In response to this Council request, Nicki Blake-Bradley, Environmental Technician, prepared the attached Asphalt Toxicity Report. In this report you will see that Nicki researched the production of asphalt pavement, the placement of the pavement, and the long-term environmental affects of having the pavement in place. Generally, the report finds that there axe very limited environmental concerns of the long term use of asphalt as a driving surface. In fact, she states that findings of studies have indicated that the runoff from asphalt have found most chemicals in the runoff come from vehicles using the roads or chemicals placed on the roads, rather than from the bituminous surfaces themselves. As you might imagine, Nicki's findings are that there are more environmental concerns in the production of asphalt materials. This is why this tends to be a highly regulated industry. She also talks about some of the environmental concerns with the placement of hot asphalt materials. Hopefully, this report will provide enough information to answer any questions that the Council may have about environmental concerns with bituminous pavements. If you need additional information or have other questions, please contact me. cc: Nicki Blake-Bradley S:\PUBLIC WORKS\2007 CC memos\09 15 08 asphalt toxicity.doc r . Asphalt Toxicity Report Compiled for the Elk River City Council By Nicola Blake-Bradley, Environmental Technician July 31, 2008 Asphalt can be a naturally occurring substance (think of the LaBrea Tarpits), but it is generally created by people in a number of ways. Asphalt production includes numerous ingredients which, when combined, result in a particular performance specification. Ninety-five percent of asphalt is aggregate material from gravel mines and five percent is petroleum distillate products. Within Elk River, Hot Mix Asphalt Plants create different "recipes" of bituminous asphalt for clients who use the asphalt for a variety of operations (not least of which is road paving). Gravel and sand are main constituents of asphalt, so the hot mix plants are located as close to the source of these raw materials as possible. The other main ingredient in asphalt is crude oil derivatives which act as a glue or binder of the other materials. The ingredients are mixed and heated to facilitate application on roofs or paved surfaces. Heating also maintains fluidity during transportation and storage (see storage silos above). Hoppers for hot mix ingredients Unfortunately, it is the crude oil derivatives which contribute to poor air quality by releasing harmful chemicals into the air when heated. Some of the chemicals are cancer causing, including arsenic, benzene, formaldehyde, and cadmium, while others have been labeled as "probable carcinogens" (such as volatile organic compounds [VOCs] and polycyclic aromatic hydrocarbons [PAHs or PACs]). The amount and proportion of individual chemicals released increases as the temperature increases. Fumes generated at high temperatures are more likely to have cancer causing chemicals in them. For example, 80 times more 2 ~, .+ .T1 ~ ~y~ ' ~ fume is generated at 482 degrees Fahrenheit than at 320 degrees Fahrenheit. An estimate from besafenet.com is that "a small asphalt plant producing 100,000 tons of asphalt a year may release up to 50 tons of toxic fugitive emissions into the air" and "stagnant air and local weather patterns often increase the level of exposure to local communities". It is important to note that hot mix asphalt plants must be licensed by the Minnesota Pollution Control Agency (MPCA) for air and water quality issues. Each hot mix plant has a "baghouse" where the majority of chemicals are removed from the air prior to being released to the atmosphere. Hot mix asphalt plants must also submit reports to the MPCA annually, regarding the amount of materials used and total amounts of emissions. Approximately 350,000 asphalt application workers reside in the United States (with approximately 46,000 workers being in the roofing industry). In researching asphalt fume information, it was difficult to find any data regarding "safe exposure limits" for asphalt fumes since complete studies have not been done or levels have not been adopted. For example, fume studies have been conducted at temperatures well below those used in the field (226 degrees vs. 320 or 482 degrees used in field operations). OSHA currently has no permissible exposure limit for asphalt fumes. The original proposed level of exposure was 5 mg/cubic meter in an eight hour work period. Several studies have been done regarding possible effects on human health by NIOSH (National Institute for Occupational Safety and Health). PAHs have been found to "interact with DNA", meaning that mutations may occur due to DNA damage. Airway irritation and airway hyper-reactivity have also been associated with asphalt fumes. Studies have also been conducted on runoff from asphalt pavements to determine environmental toxicity. The main finding with regard to these studies has been that the majority of chemicals in runoff have come from vehicles using the roads or chemicals placed on the roads or roadsides (i.e. de-icers, pesticide/herbicide, crankcase oil, emissions, etc.) rather than the bituminous surfaces themselves. In fact, asphalt has been used to line fish rearing (aquaculture) ponds with good results. Fume, the microscopic chemicals that have evaporated from the hot mix material, is the portion of asphalt most likely to cause health issues for people working with and exposed to asphalt. Fume is obviously inhaled but can also be absorbed through the skin. The main areas of concern for high levels of fume generation and exposure appear to be at the gauging and loading/unloading areas. This would make the most dangerous situation for those workers who are perpetually exposed to the asphalt fumes. Asphalt workers in the roofing industry have the highest risk of forming cancer. Epidemiological information has shown death from cancer of the stomach, respiratory system, and urinary system. Other health effects from asphalt fume exposure include irritation of the eyes, respiratory tract, asthma, bronchitis, and emphysema. Of course, asphalt also poses a threat of severe burning if it comes in contact with bare skin (due to both high heat temperatures and flammability). A Harvard study regarding work risks of asphalt recommended that "to prevent exposure to asphalt" one should work upwind as much as possible, heat the asphalt to the minimum temperature necessary to maintain the quality in order to reduce fume generation, prevent skin contact by wearing protective clothing (long sleeves and gloves), and use ventilation on paving machines. A "State Compensation Insurance Fund" document recommended isolating asphalt operations to minimize worker exposure and to transfer the asphalt automatically by pump whenever possible as well as enclosing the mixing and stirring operations. Ultimately, it appears that there remains a controversy amongst scientists concerning the potential for asphalt to cause serious health issues such as cancer, mainly due to length of exposure (in number of years as opposed to hours or minutes) and other circumstances (such as whether the workers smoke and whether P they were exposed to other substances like coal tar). The respiratory system affects have been well documented though, therefore people with compromised health (COPD, asthma, immune system deficiency, or even strong allergies) are encouraged to avoid exposure to areas where asphalt is being spread as much as possible. Once the asphalt has hardened and cooled, it is considered very safe to use or be nearby. Waste asphalt does not pose a health risk upon removal. It is also 100% recyclable! More than 80 million tons of asphalt has been recycled nationally. Members of the public may dispose of waste asphalt, free of charge, through any of the gravel mine companies creating hot mix, and some of which that are not actively running hot mix plants in Elk River. Please plan to call ahead to determine whether the company is currently accepting waste asphalt as well as to schedule an appointment for delivery. 4