Vapor Study Informational Meeting General Mills/Henkel Corp. Superfund Site Van Cleve Recreation Center November 12, 2013 Minnesota Department of Health Minnesota Pollution Control Agency

What we will cover  The issue  Health information  The solution  Your involvement

Our Missions MDH  To protect, maintain and improve the health of all Minnesotans MPCA  Working to protect and improve our environment and enhance human health.

MPCA vs. MDH Roles Outside: MPCA or EPA Inside: MDH

Site Information  Located at 2010 East Hennepin Ave. in Minneapolis  Former General Mills research facility  Used and disposed of chemicals on the site from  1981: discovered contamination  1985: site remediation began  Groundwater extraction and treatment continued until 2010  MPCA continues to monitor groundwater and vapor data

What we know Main contaminant of concern: trichloroethylene (TCE) from on-site disposal ( ) Current contamination status:  Groundwater: Contamination is above drinking water standards but poses no risk to drinking water supplies.  Vapors: Potential risk to residents in part of area above groundwater plume. More data needed.

What are Volatile Organic Compounds (VOCs)?  Chemical solvents used for cleaning and degreasing  Common in consumer products and frequently found at waste sites  Easily evaporate from products, or soil and water if spilled or disposed  The major VOC of concern at the General Mills site is trichloroethylene (TCE)

Why is Vapor Intrusion a Possible Public Health Concern?  Studies show people spend about % of their time indoors (even children).  There has been a growing interest in indoor air quality.  The science of indoor air assessment has grown tremendously in recent years.  Radon gas awareness: Effective January 1, 2014, the Minnesota Radon Awareness Act requires additional disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota. Before signing a purchase agreement to sell or transfer residential real property, the seller shall disclose in writing to the buyer any knowledge the seller has of radon concentrations in the dwelling.

Inhalation Exposure Uncertainties  Difficult to estimate how much is absorbed  Behavior driven  Large differences between individuals  Thus, exposures vary between people MDH health based criteria protect vulnerable people

Inhalation health based value for Trichloroethylene: 2  g/m 3 in air  U.S. EPA and MDH recently completed a TCE toxicological review  An increased risk of heart defects in newborns and immune effects were found in recent studies  We now calculate short term values based on exposures that occur in utero, infancy, or early childhood, to ensure values protect everyone’s health

U.S. EPA TCE Review Non-cancer effects are driving the risk studies 3 critical studies and 2 supporting studies 20 studies Immunosuppression, autoimmune disease, hypersensitivity; decrease in thymus weight; heart defects in the developing fetus Neurologic, kidney, liver, immune, reproductive, and developmental effects kidney effects

Groundwater → Soil Vapor → Sub-slab Vapor → Indoor Air Exposure Pathway

Sub-Slab Vapor Sampling  Critical first step to understand potential for vapor intrusion into indoor air  Simple, quick and easy to do  Results will be generated quickly  Can be used for decision-making

What if TCE Vapor is Found?  Screening values are very protective – even if exceeded the risk is still very low.  Mitigation systems are effective and easy to install.  Mitigation also prevents infiltration of naturally occurring radon gas, which is second leading cause of lung cancer in the U.S.

What’s next?  Sign an access agreement  Sampling begins the week of November 18

Questions Minnesota Department of Health  Rita Messing, Ph.D.:  Emily Hansen, M.S.:  Site Assessment and Consultation Unit: (651)  Minnesota Pollution Control Agency  Hans Neve (651)  Fred Campbell (651) 

Thank You

Indoor Air Sampling (not needed)  Typically use stainless steel (Summa) canisters that are under a vacuum  Long-term (up to 24 hour) sample time  Do’s and don’ts: no smoking, don’t use fireplace or candles, do keep windows closed  Home chemicals need to be removed prior to testing to minimize interferences: e.g. TCE in cleaners  Need very low detection limits