At a former popular Jazz club in the historic section of downtown Renton, Washington, indoor air quality was impacted with volatile organic compounds associated with dry cleaning solvents that had spread from a nearby dry cleaning operation. Working with Land Science, the environmental consulting firm, Maul Foster & Alongi used Retro-Coat to successfully mitigate vapor intrusion in the building, and the owner is now pleased that the sale of his property can commence.
Narrator: Renton, Washington, founded in 1901 and named after Captain William Renton, a wealthy businessman who made his fortune in coal and timber. Renton is a bedroom community outside of downtown Seattle. Now home to the Seattle Seahawks practice facility, the second largest facility of its kind in the NFL. Many know the greater Seattle area as the epicenter for the start of grunge rock in the ’90s, and the home to the original Starbucks coffee. As a suburb to downtown Seattle, Renton has seen tremendous growth over the last two decades, as technology giants like Microsoft, Amazon, and Nintendo choose the area for their global headquarters. With commercial properties and home values ever increasing, developers are looking for new ways to restore brownfield sites quickly and effectively, to allow them to move forward with future development. In the case of a former popular jazz club in the historic section of downtown Renton, indoor air quality was impacted with volatile organic compounds associated with dry cleaning solvents that had spread from a nearby dry cleaning operation.
Denny: The site is located right downtown in Renton. It’s got parking and all kinds of things, a lot of open space. It has a total of about 7,300 square feet of space. The foot print’s about 5,300. It’s a real good quality building that’s been contaminated by the neighbor’s dry cleaner.
Narrator: Concentrations of PCE and carbon tetrachloride, primary contaminants of concern exceeded the Washington State Department of Ecology risk screening regulatory level of indoor air quality.
Denny: I wanted to make it safe to inhabit the space because there was major vapor intrusion, so I could only not sell it, but I couldn’t lease it.
Yen: We need to turn around, we need to find a solution that is active but also a long-term solution. In terms of remediation approach, we could either put in…install a sub-slab depressurization system, or else use the Retro-Coat, you know, Vapor Intrusion System. And in talking to Land Science, that was one of our options. And so we did a cost analysis for, the Retro-Coat Vapor Intrusion System’s about a third less of the cost.
Thomas: Their goal was how do we protect the public from this. So meeting and talking with and meeting with and talking with over conference calls with a developer, you know, we’re looking at the options of having this Retro-Coat be a be-all-end-all solution for Vapor Intrusion.
Narrator: Land science recommended it’s proprietary Retro-Coat Solution, a patented, odorless, fast-curing epoxy surface proven to effectively mitigate vapor intrusion. Retro-Coat has been tested and proven resistant to chlorinated compounds such as TCE, PCE, and petroleum hydrocarbons. Retro-Coat eliminates the need to remove existing slab or concrete foundations.
Yen: I like a lotta things, working with Tom and the Land Science team, the REGENESIS team in general. They’re experts in their field, very responsive, and very patient in terms of us asking, what do we take to get this work done in three weeks? Was that really viable? And I’m happy to say that all of that materialized just like what Tom and the team…Tom’s team has stated that would be. And ultimately, we have a happy client.
Denny: I have been very pleased that Yen has worked closely with me and oh, we decided on this, it happened very quick. And so I’ve been very pleased with everyone that’s…I’ve been involved with. There’s no more vapor intrusion, and so it’s just a matter of marketing the place and selling it. And I can do that with a clear conscience, which is what I like.
The Retro-Coat™ Vapor Intrusion Coating System is a complete product line that consists of chemically resistant materials to properly protect existing structures from the threat of contaminant vapor intrusion. This animation shows the install steps. Retro-Coat Gel and fillers are used to repair concrete cracks and other imperfections. Retro-Coat PRIMER is then applied to the concrete surface as final preparation. This increases adhesion between the concrete slab and the Retro-Coat and addresses moisture vapor transmission. Finally, Retro-Coat is applied to a nominal thickness of 20 dry mils.
At a residential site in Virginia, vapor intrusion affected the interior living space of a private building due to release of heating oil from an Above Ground Storage Tank (AST) to the sub slab environment beneath the structure. Indoor air quality sampling after the release revealed several petroleum compound contaminants at concentrations above EPA Residential Screening Levels.
- VOCs reduced within one month of operation
- Achieved site goals of meeting VDEQ and DEH IAQ standards, rendering home safe for habitation
At a residential site in Virginia, vapor intrusion affected the interior living space of a private building due to release of heating oil from an Above Ground Storage Tank (AST) to the sub-slab environment beneath the structure. Indoor air quality sampling after the release revealed several petroleum compound contaminants at concentrations above EPA Residential Screening Levels. To minimize the displacement of the homeowners for an extended period of time, the vapor intrusion mitigation system had to produce good indoor air quality results as quickly as possible.
Leading environmental firm, Duncklee & Dunham, designed and installed an active, sub-slab vapor mitigation system and sealed the surface of the slab in the interior of the building with 1000 sq. ft. of Retro-Coat™ applied. The active system consisted of vertical vent wells installed in the building slab to a depth just below the bottom of the slab and connected to a manifold. Soil vapors were extracted from the sub-slab environment with an electric radon fan and exhausted to the exterior atmosphere. Retro-Coat primer and sealant were then applied to the entire surface area of the interior building slab to provide supplemental vapor intrusion prevention.
The Retro-Coat Vapor Intrusion Coating System is a complete product line that consists of chemically resistant materials to properly protect existing structures from the threat of contaminant vapor intrusion.
The vapor mitigation system reduced VOCs in the exhaust gas within one month of operation, and reduced levels of petroleum compounds in indoor air to the extent that the building was suitable for occupancy six weeks after the system startup.
About the Consultant
Duncklee & Dunham is an environmental consulting firm based in North Carolina specializing in environmental geology, hydrogeology, site investigation and remediation, industrial hygiene, civil engineering and brownfields. For questions regarding this project, please contact Andrew Rodak, P.E. at (919) 858-9898.
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