Vapor Study Informational Meeting

General Mills/Henkel Corp. Superfund SiteVan Cleve Recreation Center

November 12, 2013

Minnesota Department of HealthMinnesota Pollution Control Agency

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

Our MissionsMDH 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 1947-1962 1981: discovered contamination 1985: site remediation began Groundwater extraction and treatment continued until

2010 MPCA continues to monitor groundwater and vapor data

What we knowMain contaminant of concern: trichloroethylene (TCE) from on-site disposal (1947-62)

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 85 - 90% 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 mg/m3 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

12

72 studies

3 critical studies and

2 supporting

studies20 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

QuestionsMinnesota Department of Health Rita Messing, Ph.D.: rita.messing@state.mn.us Emily Hansen, M.S.: emily.hansen@state.mn.us Site Assessment and Consultation Unit: (651) 201-4897 www.health.state.mn.us/divs/eh/hazardous/index.html

Minnesota Pollution Control Agency Hans Neve

hans.neve@state.mn.us, (651) 757-2608 Fred Campbell fred.campbell@state.mn.us, (651) 757-2260 www.pca.state.mn.us

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