U.S. Environmental Protection Agency, Region 3 Delaware, Maryland, Pennsylvania, Virginia, West Virginia and rag District of Columbia HIDDEN LANE LANDFILL SUPERFUND SITE COMMUNITY UPDATE Sterling, ya EPA Tests Treatment Option to Address Groundwater Contamination In an effort to more efficiently clean up the trichlo- roethene (TCE) contamination in the groundwater at the Hidden Lane Landfill site, EPA is conducting what's called a "treatability study." The results of the study will tell us if we can effectively treat the TCE contamination in place. As part of the study, EPA plans to drill four new monitoring wells near the western boundary of the Hidden Lane Landfill. EPA will then inject treat- ment compounds into the contaminated groundwa- ter. These compounds are designed to degrade the TCE. We will be able to measure the success of the degradation by sampling the monitoring wells. The study is expected to take one year to complete. EPA will share the results of the study with the community including any additional steps that may be needed in order to treat the TCE contamination. EPA to Test Indoor Air Beginning this fall, EPA plans to sample indoor air at several residential and business properties to en- sure that they are not being impacted by "vapor in- trusion." TCE is classified as a "volatile organic compound" which means it has the ability to vaporize, or "off- gas," into the air inside buildings and homes. EPA calls this vapor intrusion. EPA will contact a certain number of property own- ers individually to obtain permission to sample their indoor air. The process is entirely voluntary, easy, and done at no cost to the owner. November 2014 To evaluate whether indoor air is being impacted by vapor intrusion, two types of air samples are taken: 1. Soil Vapor Samples: These samples are called sub-slab samples because they are taken from under a building's foundation. Soil vapors will be collected from beneath the building slab or basement floor through a small hole, using a sam- pling probe about size of a quarter. Once installed the sampling probe is flush with the floor, water- proof, and can be walked-on, covered over, or completely ignored until a sample needs to be tak- en. Drilling through slab to install probe Finishing probe installation Finished product is the size of a quarter ------- 2. Indoor Air Samples: These samples are taken from the lowest point in the building and possibly the next level up. Air is collected slowly over a 24- hour period using a Summa Canister (pictured below), which is about the size of a basketball. Summa Canister What Is vapor Intrusion? Vapor intrusion refers to chemical vapors that can move up through soil and seep into buildings. It can occur when chemicals are spilled on the ground, poured down drains or disposed of improperly. These chemicals, usually volatile organic compounds (VOCs), can 'off gas' from contaminated groundwa- ter or soil. These vapors can enter buildings through cracks in concrete slabs, basement floors and walls, and through openings around sump pumps or where pipes and electrical wires go through the foundation. This pathway is similar to how radon gas seeps into buildings. It is important to note that there are many other sources of VOCs that can impact the air inside build- ings. Many common products contain chemicals that may add to VOCs in the air you breathe. These prod- ucts include paints, glues, cleaning products, cigarette smoke, gasoline stored in garages, thinners, etc. When testing for specific VOCs, like TCE at Hidden Lane, steps are taken to make sure these other sources are considered. For additional information about vapor intrusion, go to: http://www.epa.gov/oswer/vaporintrusion/ Contact us Fred MacMillan EPA Remedial Project Manager 215-814-3201 macmillaii.fred@epa.gov Larry Johnson EPA Community Involvement Coordinator 215-814-3239 iolinson.larrv-C@epa. gov For more information about EPA's work at the Hidden Lane site, visit: http://www.epa.gov/reg3hwmd/super/sites/ VAD980829030/index.htm ------- |