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40 vapor abatement systems were installed. Of the 40 systems installed, 39 already underwent 30-day performance sampling, and 32 also had the 90-day performance sample collected. All showed dramatic reductions on the VOC levels.
The last system installed is due for the 30-day sample next week, and the rest will be schedule that week as well. A fan was replaced at one of the properties due to noise problems. Any necessary adjustment to the systems will be completed after the 90-day performance sampling.
U.S. EPA collected 269 sub slab samples, 220 from residential properties, and 49 from commercial/industrial properties. Fourty-one residential properties had sub slab results over MDH's screening level for PCE and/or TCE. Also, 12 commercial/industrial properties exceeded the MDH's screening levels.
EPA collected indoor air samples at 52 properties; 40 residential, 12 commercial. One residential property owner denied access for the indoor air sampling.
Indoor air sampling results showed exceedances to the MDH's indoor screening level for TCE and/or PCE at 8 residential properties. An additional 3 residential properties exceeded MDH's combined hazard index. Five commercial properties exceeded the MDH's indoor commercial screening levels.
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