Significant Environmental Quick Summary* Threshold Values for Exposure Notification Initial Response Sample Location Notification Exceptions to Notification Pathway Timing/Method Requirements (see Tables A, B, and C) • Retest well Detected is not associated < GWPC 30 day written • 30 day report with Water from with site investigated recommendations supply well Drinking 1 day verbal • Well survey to 500 > GWPC or NAPL present none Water 5 day written feet > GWPC within 200 foot • Test abutters Groundwater radius or 500 feet none 30 day written • 30 day report with near the well upgradient recommendations • Prior to 90 days Hazard abated by: o removal > threshold Residential inaccessible per RSRs > 15 x Res. DEC o 90 day written parcel o remediated to RSRs • Site in LHD paint abatement program • TPH Industrial/ > 30 x I/C DEC • As above for 90 day abatement • Determine extent Commercial Or > 30 X Res.DEC if • TPH 90 day written Surface soil • Prevent exposure parcel (I/C) PCBs** • Specified organic chemicals list (top 2 feet) • 90 day report with Area of hazard Organic Chemicals As above 90 day written recommendations on I/C parcel > 30 x I/C DEC within 300 feet of parcel boundary of • As above • < 30 x I/C DEC or <30 x Res. DEC residence, Metals > 15 x I/C DEC for PCBs only, as applicable, and 90 day written school, PCBs > 15 x Res. DEC** playground, park already has well-maintained or daycare fencing/pavement facility

SEH Quick Summary Page 1 of 2 9/18/17 Threshold Values for Exposure Notification Initial Response Sample Location Notification Exceptions to Notification Pathway Timing/Method Requirements (see Tables A, B, and C) • Soil vapor not > 10 x VCSV under building • < 10 x DEEP-approved site- Groundwater specific value • 30 day plan to > 10 x Groundwater within 15 feet of • Specified organics 30 day written mitigate or abate Volatilization Criteria a structure • Indoor air monitoring exposure Volatilization implemented to indoor air • Structure vacant • Chemical in industrial use • Immediate • Immediate response Explosive vapors Explosivity meter shows If not confirmed with second verbal to as directed by OCSRD entering a any detection reading OCSRD • Contact local fire structure • 7 day written department • Immediate response • 1 day verbal as directed by OCSRD Entering surface to OSCRD NAPL No verbal notice If OCSRD notified • 30 day plan to water • 30 day monitor, mitigate or Surface written abate Water Groundwater NAPL None • 30 day plan to near and likely 30 day written monitor, mitigate or entering surface > 10 x Acute WQS None abate water *This table is for informational “at-a-glance” purposes. Consult the statute [CGS 22a-6u] for specific wording and requirements of the law. Other available resources with further technical detail include the SEH Form Guidance and Instructions, the SEH Fact Sheet, and the SEH FAQs. ** Use of I/C DEC cannot apply to areas that do not meet, the definition of “other restricted-access” in 40 CFR 761.123, including any location within 300 feet of residential use.

DEC = Direct Exposure Criteria GWPC = Groundwater Protection Criteria LHD = local department NAPL = non-aqueous phase liquid (including “free product”) OCSRD = Oil and Chemical Spill Response Division call 24 hour: 860-424-3338 / 8:30 to 4:30: 860-424-3377 RSRs = Remediation Standard Regulations TPH = total petroleum hydrocarbons VCSV = Volatilization Criteria for Soil Vapor WQS = Water Quality Standards SEH Quick Summary Page 2 of 2 9/18/17