Vapor Mitigation Pilot Test Report

Project location:

St. Paul Senior Living 1207 Addison Road

Capitol Heights, MD

Prepared by: Christopher Ferguson

Protect Environmental

Report Date: October 27, 2017

Vapor Intrusion: Pilot Test Report

Addison Road – 1207 (St. Paul Senior Living) PR1.0

Prepared by: Christopher Ferguson Protect Environmental 9822 Bluegrass Parkway Louisville, KY 40299 Phone: 502-410-5000 Email: Christopher@ProtectEnv.com Preparation Date: October 27, 2017 This report was developed specifically for the vapor mitigation pilot test and building characterization conducted at St. Paul Senior Living Center in Capitol Heights, MD. The pilot test was conducted in accordance with generally accepted industry practices under the supervision of Kyle Hoylman, a mitigation professional credentialed by the National Radon Proficiency Program (NRPP). The vapor mitigation system was designed in accordance with the American National Standards Institute (ANSI) document Radon Mitigation Standards for Multifamily Buildings (ANSI/AARST RMS-MF 2014).

Christopher Ferguson, CHMM Kyle Hoylman Project Manager Mitigation Professional CHMM #19682 NRPP Credential #104372RMT

Vapor Intrusion: Pilot Test Report

Addison Road – 1207 (St. Paul Senior Living) PR1.0

Contents 1.0 Introduction and Summary 2.0 Scope of Work 3.0 Pilot Test Design

3.1 Pilot Test Specifications and Procedures 4.0 Pilot Test Results

4.1 Pilot Test Results Summary – EP-01 4.2 Pilot Test Results Summary – EP-02 4.3 Pilot Test Results Summary – EP-03 4.4 Pilot Test Results Summary – EP-04

5.0 Recommended System Design 6.0 Conclusions Tables Table 1: EP-01 Pilot Test Results Summary Table 2: EP-02 Pilot Test Results Summary Table 3: EP-03 Pilot Test Results Summary Table 4: EP-04 Pilot Test Results Summary Appendices Appendix A: Pilot Test Results Appendix B: Pilot Test Field Log Appendix C: Credential Documentation

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1.0 Introduction and Summary Protect Environmental was engaged to conduct a vapor mitigation pilot test at the subject property located at St. Paul Senior Living, 1207 Addison Road, Capitol Heights, MD. The purpose of the pilot test was to evaluate the sub-slab conditions as they pertain to vapor mobility to develop a vapor mitigation system design for implementation at the property. The pilot test was completed between September 13 and September 14, 2017. The pilot test was conducted in accordance with generally accepted industry practices and the procedures outlined herein. The scope of work included: (1) installation of 4 sub-slab extraction points and 20 temporary monitoring points; (2) performance of sub-slab resistance, environmental influence and pressure field extension (PFE) testing; and, (3) preparation and submission of the pilot test report to the client. Based on the pilot test results, active soil depressurization (ASD) has been determined to be a viable mitigation option for this project. A vapor mitigation system design has been developed for implementation within the target mitigation area capable of maintaining the PFE benchmark of > -.004-inches water column induced pressure differential throughout the sub-slab area of impact with reference to the indoor air environment.

2.0 Scope of Work

The pilot test included the following scope of work components: 1. Installing 4 sub-slab extraction points and 20 temporary monitoring points;

2. Conducting sub-slab resistance, environmental influence and PFE testing. The sub-slab

extraction and monitoring points were temporarily installed and were sealed after the pilot test;

3. Evaluating the building envelope and mechanical systems for purposes of development of a

vapor mitigation system design; and

4. Preparing and submission of a written report to the client. 3.0 Pilot Test Design

Protect mobilized to the site on September 13, 2017 to conduct the pilot test. A total of 4 extraction points and 20 temporary monitoring points were installed to evaluate the sub-slab conditions with reference to maintaining the PFE benchmark of > -.004-inches water column

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induced pressure differential throughout the sub-slab area of impact with reference to the indoor air environment. 3.1 Pilot Test Specifications and Procedures A PFE benchmark of > -.004-inches water column induced pressure differential throughout the sub-slab area of impact with reference to the indoor air environment was established for this project. The procedure for conducting the sub-slab PFE testing for each monitoring point is as follows: 1. Core a 5-inch sub-slab extraction point into the concrete foundation slab using a rotary

hammer drill and masonry carbon drill bit;

2. Excavate each sub-slab extraction point by removing approximately 5 gallons of sub-slab material using a hand auger and bucket vacuum system;

3. Utilizing a Rigid vacuum system connected to the extraction point by a SCH 40 PVC test rig

system sealed with bentonite clay, measure sub-slab resistance by recording the reading of the 0-inch to 50-inch water column pressure differential gauge connected to the rig system;

4. With the vacuum system in operation, measure the induced pressure differential at each of

the sub-slab monitoring points using a calibrated Infiltec digital manometer;

5. Record the static pressure for each extraction point and induced pressure differential for each sub-slab monitoring point in the field log book;

PFE was measured using temporary monitoring points installed in the target mitigation area around the extraction point(s). All sub-slab extraction and temporary monitoring points were refilled and sealed after completion of the Pilot test. 4.0 Pilot Test Results Protect mobilized to the site on September 13, 2017 to conduct the vapor mitigation pilot test. A summary of the pilot test findings is included below. 4.1 Pilot Test Results Summary – EP-01 (Phase I – Right Wing) Sub-slab extraction point EP-01 was installed in the mechanical room of Phase I – Right Wing adjacent to the elevator. A total of 5 sub-slab monitoring points were used to measure induced pressure differential across the slab. Based on the results of the pilot test, PFE of approximately 20-feet was estimated in this area of the building.

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Table 1: EP-01 Pilot Test Results Summary Extraction

Point Soil

Resistance Monitoring Point Distance (feet) PFE (inches H20)

EP-01 5.0"

TP-01 15 -0.008 TP-02 12 -0.010 TP-03 25 -0.009 TP-04 32 -0.002 TP-05 20 -0.007

4.2 Pilot Test Results Summary – EP-02 (Phase I – Left Wing) Sub-slab extraction point EP-02 was installed in the mechanical room of Phase I – Right Wing adjacent to the elevator. A total of 4 sub-slab monitoring points were used to measure induced pressure differential across the slab. Based on the pilot test, PFE of approximately 25-feet was estimated in this area of the building. Table 2: EP-02 Pilot Test Results Summary

Extraction Point

Soil Resistance Monitoring Point Distance (feet) PFE (inches H20)

EP-02 10"

TP-06 21 -0.012 TP-07 30 -0.009 TP-08 20 -0.008 TP-09 24 -0.005

4.3 Pilot Test Results Summary – EP-03 (Phase II) Sub-slab extraction point EP-03 was installed in the mechanical room of Phase II adjacent to the elevator. A total of 5 sub-slab monitoring points were used to measure induced pressure differential across the slab. Based on the pilot test, PFE of approximately 20-feet was estimated in this area of the building. Table 3: EP-03 Pilot Test Results Summary

Extraction Point

Soil Resistance Monitoring Point Distance (feet) PFE (inches H20)

EP-03 37"

TP-10 30 -0.012 TP-11 15 -0.009 TP-12 18 -0.008 TP-13 15 -0.005 TP-14 20 -0.007

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4.4 Pilot Test Results Summary – EP-04 (Phase II) Sub-slab extraction point EP-04 was installed in the mechanical closet of Phase II in a residential unit. A total of 6 sub-slab monitoring points were used to measure induced pressure differential across the slab. Based on the pilot test, PFE of approximately 40-feet was estimated in this area of the building. Table 4: EP-04 Pilot Test Results Summary

Extraction Point

Soil Resistance Monitoring Point Distance (feet) PFE (inches H20)

EP-04 2.0"

TP-15 12 -0.507 TP-16 18 -0.013 TP-17 18 -0.055 TP-18 35 -0.011 TP-19 40 -0.007 TP-20 35 -0.021

5.0 Recommended System Design Based on the results of the pilot test, the following ASD vapor mitigation system design has been developed for implementation within the target mitigation areas of the building. Active soil depressurization involves applying pressure at specific extraction points to maintain negative sub-slab pressure differential with reference to the indoor air environment, thus mitigating potential occupant exposure to the contaminant(s) of concern. A total of 12 mitigation systems will be installed. Each mitigation system will contain the following components: 1 5-inch sub-slab extraction point powered by 1 blower capable of operating at up to 4.2-inches w.g.; up to 50-feet of 3-inch SCH 40 PVC vapor conveyance piping, routing from the interior mechanical closet of each residential unit on the mitigation plan through the building interior to a discharge point a minimum of 12-inches above the roof; 1 3-inch inlet guard; 2 3-inch rubber couplings; 1 fan cord kit; 1 pressure monitoring device; 1 3-inch roof boot; miscellaneous fasteners and system labeling. The mitigation contractor will be responsible for verifying the final system configuration and installation of the electric outlets in the attic to power the blowers. A mitigation system will be installed in the following locations:

Phase I – Unit 101 Phase I – Unit 109 Phase I – Unit 113 Phase I – Unit 120 Phase I – Unit 135 Phase I – Unit 136

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Phase II – Unit 148 Phase II – Unit 150 (mech room adjacent to elevator) Phase II – Unit 154

Phase II – Unit 158 Phase II – Unit 163 Community Center Closet Residential Units = 10, Non-Residential Areas = 2, Buildings = 1

6.0 Conclusions The sole purpose of this report is to provide the client with information regarding the conditions that existed at the property at the time of the pilot test. An uncertainty with any result due to statistical variations and other factors such as daily and seasonal variations in contaminant of concern concentrations does exist. Variations may be due to changes in weather conditions, environmental influence or building conditions and usage. The conclusions contained within this report are derived from information obtained from the client and the on-site activities conducted under the scope of work performed. This report was prepared solely for the use of the client. Use of this report by any party other than the client is prohibited without prior written consent from Protect Environmental. Based on the pilot test results, active soil depressurization (ASD) has been determined to be a viable mitigation option for this project. A vapor mitigation system design has been developed for implementation within the target mitigation area capable of maintaining the PFE benchmark of > -.004-inches water column induced pressure differential throughout the sub-slab area of impact with reference to the indoor air environment.

Vapor Intrusion: Pilot Test Report

Addison Road – 1207 (St. Paul Senior Living) PR1.0

Appendix A Pilot Test Results

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Phase I - Right Wing

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Phase I - Left Wing

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Phase II

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Phase II

Vapor Intrusion: Pilot Test Report

Addison Road – 1207 (St. Paul Senior Living) PR1.0

Appendix B Pilot Test Field Log

Vapor Intrusion: Pilot Test Report

Addison Road – 1207 (St. Paul Senior Living) PR1.0

Appendix C Credential Documentation

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Speaker Bureauer

T RadonDesignation

AARST ARP Mitigation Professional NRPP Measurement ID: RT-104371 valid thru 2019-08-31

NRPP Mitigation ID: RMT-104372 valid thru 2019-08-31

Kyle Hoylman

Protect Environmental LLC Louisville, KY 40299-1906

kyle@protectenvironmental.com

(502) 410-5000 Fax: (502) 410-4990

http://www.protectenvironmental.com

This individual is AARST-NRPP certified to provide Analytical Servicesusing the following device(s):

Sun Nuclear 1023/1026/1027 At Ease Digital Data Logger